Home

Eclipse-Based Front-End for OMSjp - ETH E

1. get setDBName getName getStructuredValue getSourcelnstance get setDBDirectoryPath getChildren getDBObjects EN AK setConnected getFolderType DBCollMember DBMacro DBMethod DBCollection DBType getAttributelDString getName itgetName getMembertype getName getMembershipCollections getInputs getSignature get setDisplayAttribute getMembers getSub SuperCollections DatabaseManager DBBinaryCollection DBObjectType omsWorkspace l omsDriver interface findMembers addAttribute getManager DatabaseManager IDAEA NEEmENt getMethods getWorkspace addChild getSub SuperTypes getConnectedDB Be getVisibleAttributes getDBObjectCache leleteChild Figure 5 1 Model Classes The DBElement class comprises all objects that can be displayed in the database explorer tree offering methods to set and get the parent element Using the setKind method tree ob jects are classified into system and user data objects The DBElement class is abstract and does not have a physical manifestation in the tree However it has five subclasses repre senting different tree objects Instances of the Database class build the top level elements in the tree standing for OMS databases stored in the local file system The Database class has a reference to the DBCache class The cache enables the database to save and retrieve created tre
2. Figure 4 1 Schematic Perspective Layout using a View for Objects objects selected in another view As a consequence of this a view can always display one object that is selected somewhere else in the workbench If the user wants to open an object he either has to select the object in the database explorer or he has to open the collection where the object is member This means that switching between two objects belonging to two different collections also involves switching between these collections This is rather circumstantial and we can assume that the user would like to have more than one object open atatime Another disadvantage is the focus An Eclipse convention says that the editor area should be the focal point of the workbench Therefore views are typically placed marginally Browsing and editing objects is a very frequent task while modeling and administrating a database Having a view displaying these objects would force the user to focus on the margin instead of the centered editor area to a rather large extent of the working time View to Display Collections Another proposed solution was to invert the arrangement Since collections are less often edited than objects the idea was to display collections in a view while objects are opened in the main editor area Figure 4 2 shows the possible layout Using this solution the perspective would still profit from the fact that both collections and objects are visible at the sam
3. Coll1 JObject DB Explorer p Object person 0218 Coll1 name Peter Smith person 0216 age 28 person 0218 Console Other views Figure 4 3 Schematic Perspective Layout using the Editor Area for Objects and Collections The advantage of this solution is that the user can open as many objects and collections as he wants The editor area becomes quite large if only a small console view is placed at the bottom of the window If a collection is displayed it is useful to have enough space available since the user can access more collection members without scrolling If an object is opened in the editor area the space is not completely filled since only some attribute values are presented But the object can be augmented by displaying context information in the remaining space CHAPTER 4 OMS FRONT END DESIGN 27 The aim of context information is that the user can gain access to associated objects and collections directly by following links in the object editor Displaying all objects in the editor area implicates that the user is not able to see more than one object at a time but we assume that 1t is not so important since associated objects are directly accessible using the provided links After having discussed the advantages and disadvantages of these three approaches we de cided to take the third one since it seemed to be the most promising and also the most flexible approach concerning the layout of the
4. VVorkbenchPart dispose getConfigurationElement getSite IWorkbenchPartSite setTitle ViewPart getViewSite IViewSite init saveState DBExplorerView createPartControl Figure 5 2 View Part Integration into the Eclipse Workbench Views are part of a view site IViewSite which is part of a workbench page IVorkbenchPage In order to enable lazy instantiation the IVVorkbenchPart holds on to instances of IViewReferences rather than to the IViewPart itself This permits that views can be referenced without actually loading the plug in defining the view The database explorer uses the JFace UI toolkit see section 3 2 The object tree in the database explorer is a JFace Tree Viewer which wraps an instance of the SWT Tree widget A tree viewer displays a hierarchical list of objects in a parent child relationship TreeViewer CHAPTER 5 OMS FRONT END IMPLEMENTATION 45 is a subclass of StructuredViewer which represents an abstract base implementation for structure oriented viewers like tree list and table viewers In general viewers are model based adapters on a SWT widget which accesses its model by means of a content provider and a label provider The classes used to implement the database explorer view are presented in figure 5 3 DBExplorerView viewer TreeViewer createPartControl 5 interface StructuredViewer IDBElementListener content
5. D private 0845 Moira Norrie 6D private 0846 Beat Signer Co private 0848 Alexios Palinginis Figure B 6 Collection Editor database explorer is used and launched by clicking on the location type object the collection type is already initialised accordingly as shown in figure B 7 amp New OMS collection OMS collection Create a new OMS collection Collection name Collection type location 0576 Browse Figure B 7 Collection Wizard The newly created collection is added to the database explorer and opened in the editor area Creating a Sub Supercollection In order to create a new sub or supercollection either the sub and supercollection section in the collection editor or open the context menu on a collection in the database explorer can be used Creating a Binary Collection Association Since no graphical schema editor is available binary collections which are based on an asso ciation have to be created using a wizard as well The fastest way to create an association is to mark the source and the target collection in the database explorer and call the Association wizard as presented in figure B 8 APPENDIX B USER MANUAL 73 contacts2 1 Collections l BA Test 01261 E Contacts 0592 A ETH_Persons 0593 Ll Locations 0596 E OMS Database Lc JOrganisations 0597 E Persons 0
6. l Lives at 0595 gt AL SS Figure B 12 Adding Objects to a Collection using Drag amp Drop and the target collection are identical a dialog appears to let the user decide which object to take as source object Figure B 13 visualises the process 7B YLlives_at 0595 23 Be contacts2 1 Lives at 0595 amp Collections S Locations 0596 B Privates 0600 private 0574 E Locations 0596 location 0576 location 0860 Frohburgstrasse 35 location 0861 Benedikt Fontana We 2 location P Raemistrasse 101 j Eollection Entent location 0863 inneggstrasse 3 Object Attribute Object Attribute location 0864 Haldeneggsteig 4 private 0853 Claudia Ignat location 0878 Nordstr 18 gt ton 0855 lt Claudsstrassa 59 private 0687 Alain Wrgler location 0869 Trichtenhausenstr location 0866 Haldeneggsteig location 0867 Raemistrasse 101 88 Organisations 0597 e Hl Persons 0599 Ed Privates 0600 private 0645 Immo Noack private 0850 Michael Grossniklaus private 0852 Beat Signer Figure B 13 Adding Objects to a Binary Collection using Drag amp Drop Removing Collection Members Collection members can be removed from a collection either using the corresponding action in the context menu of the collection editor or in the database explorer It is
7. Enter your query Query Result domain o Defeng Ma c Works_for range_restriction all Org in c Organisations person 0660 Gustavo Alonso Andreas Steiner having Org name Institute for Information Systems person 0662 Armin Fessler person 0663 Claus Hagen person 0666 Uwe Roehm person 0661 Markus Tresch Figure 4 10 AQL View On the left hand side of the window the user can enter the query After the execution of the query the result is displayed in the table on the right side If the result comprises objects double clicking them will open the object in the editor area A history functionality enables the user to revert to previous executed queries 4 2 6 Console Window The Eclipse workbench provides a console view which can display several consoles The OMS front end uses its own OMS console which is added to the Eclipse console view when the OMS perspective is activated The OMS console displays error messages in red and information messages in blue as it is presented in figure 4 11 El console gt AQL Z iml 215 m OMS Console ttt OMS Message Console 09 41 23 Could not open database 09 42 02 Macro execution of test2 02150 finished successfully Figure 4 11 OMS Console CHAPTER 4 OMS FRONT END DESIGN 35 4 2 7 Match Window The OMS front end offers a fourth view the Match view The view can be compared to the Search view in the Java persp
8. FormPage getToolkit FormPage tgetEditorinput IEditorSite getEditorSite init CollectionEditor close a N editor FormEditor B getEditor FormEditor addPages getManagedForm initialize ObjectEditor isActive getPartControl editorinput addPages Figure 5 4 Editor Part Integration into the Eclipse Workbench 48 5 7 PACKAGE EDITORS collection editor can be found in section 5 9 To construct these editors the OMS plug in provides some kind of framework offering different components that can be reused in the collection and object editors as well as in dialog windows to add new values Figure 5 5 provides an overview of the graphical components that are used to construct an editor page Peter Smith 0677 n private 0575 Attributes Collections Peter Smith i Text Entry Text Entry Link Label Button i m f Works for G organisation 0664 ETH description number i Table Entrv 41 1 362 8845 Button Section ir Table Section lage 0613 gt years integer uni private Awork_places 0572 gt results location set person LAA er Ze en Figure 5 5 Building Blocks of an OMS Editor Page An editor page can have various sections whereas each section groups information that be longs together The Eclipse pla
9. 0 infos o OMSBrowserPlugin I Description Resource In Folder O getResourceBundle The field ISharedimages IMG OBJS TASK TSKisd DBExplorerview ch ethz globis omsjp omsbrowserfsrc line 65 a start BundleContext a stop BundleContext E Problems 52 Javadoc Declaration Search Console Tasks Properties ch ethz globis omsjp omsbrowser OMSBrowserPlugin ch ethz globis omsjp omsbrowser src Figure 3 4 Eclipse Workbench Java Perspective Perspective A workbench window can have several perspectives but only one of them is visible at a time The user chooses which perspective to display and he can quickly switch 22 3 4 ECLIPSE USER INTERFACE AND ITS PARADIGMS between different perspectives if needed A perspective is an arrangement of editors and views and every perspective contributes special actions to the menu and tool bar Each perspective is designed to perform a specific task such as writing or debugging a Java program and each of the views in the perspective is chosen to allow the user to deal with different aspects of that task A perspective always contains a single editor area which can be hidden or not Additionally the perspective controls the initial view visibility the layout how the editor area and the views are arranged and which actions are visible The concept of perspectives helps to filter information and as a result of this the Eclipse system scales to a large number of installed to
10. 56 2 A ME 45 5 6 3 MatchViewW 0 46 5 6 4 Console VieW o ee 46 5 7 Package EDITORS iii Ea a AE 0 re 46 58 Package EDITORS OBJECT 2 2 49 5 9 Package EDITORS COLLEGTION 50 5 10 Package ACTIONS 6 Liria Ta E O al oe A wk 51 5 11 Package WIZARDS Ir ass e a A ds alas ME 51 5 12 Package PREFERENCES e 52 5 13 Package UTIL lt 2 valan ee a dh h ee es 53 6 Conclusions 55 6 1 Achievement ana o e 55 6 1 1 Intended Goals iaa an sede A A A hk 55 6 1 27 DISCUSSION ws ee a DES tar a ta ent L dee aa a 56 6 2 Future Works octal ate aoe ee kd A 6 58 A Plugin XML Manifest 61 B User Manual 67 B 1 System Requirements 67 B 2 Installation 2 2 22 mann 67 B 3 Getting Started eae ak a ea ck an cB ke 68 B 4 Browsing and Updating the Database 70 B 5 Querying the Database 79 Introduction During the last couple of years the Global Information Systems Group of the ETH Zurich has developed an object oriented database management tool suite called OMS 8 OMS consists of a series of tools and technologies designed to support database development At the moment most of the tools that belong to the OMS suite offer their own graphical user interface GUI or so called front end With the introduction of OMSIP 9 a Java library providing access to OMS
11. btype o41 lt string gt Ed ba test 03011 btype o41 lt string gt EZ string type 03238 btype 041 lt string gt El testtype 03731 btypeto53 lt uri gt Sub Types El testtype2 03733 wm btvpe o53 lt uri gt tE Macros btype o41 lt string gt Ed private 0575 F G System btype 053 lt uri gt Ed eth_person 0578 test 02190 test input 0 string uni test input 1 lacation set gt number integer uni person ia work_places 0572 gt results location set person Awork_places 0608 gt results location set person Hi work_placesO 0614 gt results location set person El work_placesO2 0615 gt results location set person E console 53 AQL OMS Console tr OMS Message Console tir Figure 4 5 Eclipse Workbench OMS Perspective Springgay 11 advises to only add a perspective to Eclipse if it is really necessary He fears that if every Eclipse plug in uses its own perspective the user would soon be overwhelmed by perspective choices However he considers that it is justified to add a perspective if there is a certain group of related tasks which would benefit from a predefined configuration of actions and views For the OMS front end this is the case The process of modeling and administrating a database is completely unrelated to developing Java projects or Eclipse plug
12. caused by the OMS plug in or by the underlying library and what kind of problem it was Apart from the missing schema editor the OMS front end meets all requirements and it allows to reason that we achieve the intended results In our opinion the OMS front end is a valuable alternative to the existing OMS Pro GUI making the modelling process of OMS databases easier and more intuitive The benefits will become even more noticeable if OMSIP offers drivers for other OMS platforms than OMS Pro since it will enable the users to manage different OMS databases without having to get acquainted with a new graphical user interface Furthermore the OMS front end integrates well into the Eclipse workbench since the editor windows use the same graphical components as the plug in manifest editor and most of the conventions were respected 58 6 2 FUTURE WORK 6 2 Future Work The OMS front end already provides a lot of basic functionality and useful features to support the OMS modelling process However there is still an ample scope to apply improvements The following list presents the possible enhancements Schema Editor The OMS front end improves the process of adding relations between objects But the most intuitive way to add an association between two collections for instance is still the way of drawing the association in a graphical schema editor Therefore the introduction of such an editor is a useful extension Since Eclipse offers an elabora
13. the state of the database explorer is saved to a file called oms xmi The file is placed in the Eclipse run time workspace located in the local file system Listing 5 3 shows a sample oms xml file which represents two database instances in the workspace The Contacts database was con nected when Eclipse was closed and therefore the connection will be reopened when Eclipse is started again lt xml version 1 0 encoding UTF 8 22 lt oms gt lt database connected false name Phonebook path C Program Files omspro2 1 demo phonebook oms gt lt database connected true name Contacts path C Program Files omspro2 1 demo contacts oms gt lt collection attr friends id 01261 gt lt collection attr name id 01389 gt lt collection attr name id 0592 gt lt collection attr street id 0596 gt lt collection attr phone id 0600 gt lt collection attr characteristics id 0242 gt lt database gt lt oms gt Listing 5 3 Sample OMS XML File Another functionality of the OMSBrowserPlugin class is the initialisation of the OMS pref erence page to configure the OMSIP driver The implementation of the preference page is described in section 5 12 Furthermore the OMSBrowserPlugin class maintains an instance of the class java util HashMap as image cache and it offers a public method to retrieve images used in the user interface of the OMS front end CHAPTER 5
14. 8 New OMS Database Wizard Classes The actual wizard pages displaying the entries to fill in the requested data extend the Wiz ardPage class which implements the IVVizardPage interface The task of a wizard page is to present a page of information to the user validate any information filled in by the user and provide accessors for the wizard class to gather the entered information 5 12 Package PREFERENCES The Eclipse platform offers a preference framework which provides a mechanism for dis playing options to the user and saving changed options across multiple Eclipse sessions The OMS front end uses this mechanism to add a specific OMS preference page to the Eclipse Preferences dialog allowing the user to indicate the storage location of the OMS database system and an appropriate driver value The OMS preference page is hooked into the system by contributing an XML declaration to the org eclipse ui preferencePages extension point The actual logic to set up the page can be found in the DBPreferencePage class in the preferences package The preference page is initialised with default values which are stored in the main plug in class of the OMS front end namely the OMSBrowserPlugin class If values are changed they are added to the preference store interface IPreferenceStore associated with the OMSBrowserPlugin class as well CHAPTER 5 OMS FRONT END IMPLEMENTATION 53 5 13 Package UTIL The util package contains a conglome
15. Database Explorer View Extension Similar extension declarations exist for all views and editors the perspective as well as for wizards and the preference page 5 2 Package OMSBROWSER The omsbrowser package contains a single class called OMSBrowserPlugin which is the plug in class specified in the plugin xml declaration section The class offers methods for the startup and the shutdown of the plug in which are called by the Eclipse runtime environment 40 5 2 PACKAGE OMSBROWSER Once plug ins are loaded into the memory they are never unloaded until the Eclipse work bench is closed Therefore the shutdown method is only called when the user choose to leave Eclipse To preserve the state of the OMS perspective across multiple platform sessions the plug in class contains methods to save and restore objects displayed in the database explorer based on a memento mechanism Mementos are designed to save and restore objects in a form that they can be stored persistently in the file system They are able to skip objects in the restoring process if an appropriate class is not available anymore or to restore objects from the provided data even though the class for the object is different from the one that was originally saved Mementos map arbitrary string keys to primitive values and they allow to have other mementos as children The OMSBrowserPlugin class uses a memento based on XML as external storage format If the user closes the Eclipse workbench
16. E org eclipse ui org eclipse ui Extension Point actionSets editors Eclipse Workbench Plug In Figure 3 3 Eclipse Extension Mechanism Any plug in may allow any number of other plug ins to extend it by adding processing ele ments which causes the plug in to modify its behavior In order to control these extensions made by other plug ins every plug in defines precisely specified extension points Extension points are specified using an XML configuration element and they are some kind of slots that extensions can plug into For example the Eclipse workbench offers an extension point which allows other plug ins to add menus to the main menu bar at a specific location CHAPTER 3 ECLIPSE PLATFORM 21 Every plug in can define multiple extension points and every plug in can extend multiple extension points offered by other plug ins 3 4 Eclipse User Interface and its Paradigms The workbench plug in supplies structures in which tools interact with the user and it is therefore synonymous with the Eclipse Platform graphical user interface and with the main window the user sees when the platform is running The Eclipse user interface has its own paradigm and follows certain conventions Developers that contribute to the Eclipse work bench are asked to stick to the available guidelines 3 The Eclipse platform user interface paradigm is centred around editors views and perspec tives The user can choose which p
17. Lee print_locations 0594 gt System OMS Method e Collections OMS Macro A E Types 5 Macros Figure B 4 Database Explorer APPENDIX B USER MANUAL 71 Browsing Collections The Collections folder contains first the unary collections followed by the binary collec tions Expanding the collection nodes makes the collection extent visible Choosing a Display Value for a Collection All collection members that belong to the collection extent of a unary collection are displayed by providing the type the object id and one of their attribute values Initially the first attribute value is taken for every collections But the user can choose a different attribute if he likes To do this access the context menu in the database explorer by right clicking on the appropriate collection and select the Choose Attribute action A dialog is opened where the user can choose the name of the attribute value that should be displayed for this collection As a consequence of this all members of this collection show the new attribute value throughout the whole Eclipse user interface Choosing the Sort Criteria in the Database Explorer In the database explorer collections provide access to their members by displaying the object 1d and a single attribute value The database explorer allows to determine the sort criteria using the local pull down menu of the database explorer as shown in figure B 5 The collection members can either be
18. OMS FRONT END IMPLEMENTATION 41 5 3 Package MODEL The database explorer see section 4 2 2 is designed to display a hierarchical list of OMS database objects in a parent child relationship From a conceptual point of view it is quite similar to the Navigator in the Resource perspective or the Package Explorer in the Java Perspective Both the navigator and the package explorer use the Eclipse IResource class and its subtypes as internal model The IResource class is the generic class for files and folders which form per se a hierarchical structure In order to map the OMS database objects into the database explorer tree structure it was necessary to build a custom internal model based on a parent child relationship The final model is shown in figure 5 1 presenting classes and the most important public methods interface interface IDBObject IEditorinput getObjectID exists getSourceObject getlmageDescriptor getType getName DBElement getAttributes getPersistable getAttribute Value getToo TipText dbManager setAttributeValue get setParent deleteDatabaseObject get setKind DBObject sourceObj OMSObject Database DBElementFolder DBBulkObject DBinstance dbObjects DBCollMember sourcelnst OMSInstance dbCache DBCache
19. Otherwise there were no further constraints what technique to use A stand alone Java Swing application would have been possible but it was decided to integrate the front end into the Eclipse 2 environment 1 2 Motivation for Using Eclipse Eclipse is an Integrated Development Environment IDE that can be used for developing applications in various programming languages Most commonly it is used for developing Java applications and during the last few years the number of developers that are using Eclipse increased considerably One of the reasons for this trend might be that the user is able to CHAPTER 1 INTRODUCTION 3 customise his development environment suitable to his needs Eclipse is an open source project offering an extensible architecture This fact enables de velopers to integrate their own specialised tools seamlessly into the Eclipse environment In addition to the extensibility Eclipse offers a lot of functionality and powerful tools that simplify the implementation of graphical user interfaces This is very convenient from a de veloper s point of view and a valuable basis for the integrating of an OMS front end into Eclipse The mechanism of integrating one s own tools into Eclipse gives the users the possibility of composing a development environment from a set of highly specialised tools Users are able to choose which tools they would like to use and can therefore only install the tools they need to perform their tas
20. PLATFORM 17 Eclipse Platform Workbench UI JFace Team Help Debug SVVT Core Workspace Figure 3 2 Eclipse Platform standard programs and tools of the underlying operating system Tools integrated in the plat form are provided with an API for dealing with workspace resources The workspace is also responsible for notifying other interested plug ins about resource changes such as files that are created deleted or changed In earlier versions of Eclipse tools were based on files and folders and therefore tightly cou pled with workspace resources Recently the Eclipse developers got rid of this coupling and made the workspace and resources an optional part of the platform It is now possible to have configurations of the platform that will not have a workspace This allows tools to work with other data sources such as database objects or data streams Workbench The workbench provides Eclipse with an extensible user interface The work bench API and its implementation are built form two tool kits SWT Standard Widget Toolkit The Standard Widget Toolkit is a graphical user interface toolkit for the Java program ming language It was created by the developers of the Eclipse project to provide access to the native user interface facilities of the operating systems that host Eclipse The SWT graphics library offers a common OS independent API for w
21. The first possibility is to open the collection to which the object should be added in the collection editor and then click the Add button A list dialog presents all objects that have the same type as the target collection and that are not yet member of the collection The dialog is shown in figure B 11 The objects that are selected are subsequently added to the collection fe JEx_ETH 0594 x Ex_ETH 0594 kaj person 0572 Collection Extent Super Collections Object attribute Add Contacts 0592 Add 6D person 0644 Andreas Steiner B Persons 0599 6D person 0659 Hans Joerg Schek New New 6D person 0661 Markus Tresch person 0664 Defasa hi 6D person 0670 e 6D person 0671 1 person 0687 4 Select all objects you want to add 6D person 0800 6D person 0801 6D person 0802 E BC J Adrian Kobler person o851 6D person 0818 d person 0651 person 0830 a BC J Albert Weiss person 0845 6D person 0853 4 Alex Scherer person 0713 person 0854 6D person 01331 Cancel lt amp Add Object Figure B 11 Adding Objects to a Collection The second possibility is to use drag and drop by dragging objects from the database explorer into the collection extent table in the collection editor In this case it is also possible to add members of a sub or supertype of the collection membertype The drag
22. a multi page editor using Eclipse Forms The object editor is used to represent all kind of database objects apart from collections The screenshot provided in figure 4 9 shows the representation of a collection member The title of the page as well as the tab label display an attribute value of the represented object in addition to the object id This helps the user to easily get back to an already open editor without having to remember the object id Peter Smith 0677 X o Peter Smith 0677 Ed private 0575 Attributes lt Collections name Peter Smith phone 41 1 632 7379 Fax 41 1 632 1172 Links email mailto smith inf ethz ch Browse Lives at WWW http www inF ethz chipersonal smith Browse Situated_at i title Dr Works for D organisation 0664 ETH photo file simages ETH smith gif Browse birthdate 10 28 1970 12 00 AM phones description number Add home 41 1 362 8845 Favourite music file f fimages MUSIC Fugees2 mov Browse transport null Browse Methods lage 0577 gt years integertuni private jage 0613 gt years integer uni private test 02190 test input 0 string uni test input 1 location set gt number integer uni person Edwork_places 0572 gt resul
23. and drop process is shown in figure B 12 Adding a Link between Two Objects The easiest way to establish a link between two objects is to open one of these objects in the object editor and to make use of the Links section Every link table in the Links section offers a context menu which allows to add a new link A list dialog provides all objects of the target collection to choose from Another possibility is to use drag and drop If a binary collection is open in the collection editor one object that is member of the source collection and one object that is member of the target collection can be selected in the database explorer Dropping these objects on the collection extent of the binary collection adds a new binary collection member If the source 76 B 4 BROWSING AND UPDATING THE DATABASE amp contacts2 1 gt Collections H BA Test 01261 Hl Contacts 0592 E ETH_Persons 0593 N Ex_ETH 0594 GB Ex_ETH 0594 2 Ex_ETH 0594 person 0572 Collection Extent Ai Lorain 9596 Object attribute Add i a ey person 0644 Andreas Steiner l Privates 0600 GD person 0659 Hans Joerg Schek New private 0645 Immo Noack person 0661 Markus Tresch 5D person 0663 Claus Hagen private 0850 Michael Grossnikla p Beat Signer ls Alexios Palinginis Moira Norrie B testColl 01389
24. applies a commit rollback paradigm as storing paradigm which is very convenient for the user All changes on open database objects affect the state of the database immediately This allows the user to work efficiently without having to perform Save operations every time a change has been made Between two Commit operations the database can be in an inconsistent state without getting any error messages The Rollback operation allows to discard all changes since the database was last committed 8 2 3 EVALUATION RESULTS 22 Classification Editor BEE Schema Edit Zoom Display fk O REM S 35 Q Q 2H j i harcan Persons ni ni nriya Era pron Ex ETH Privates Browse d New Collection New Subcoll of gt Reload Figure 2 3 OMS Pro Classification Editor Context Information In OMS Pro every object that is displayed in the object area pro vides a menu bar Depending on the kind of object the menu bar offers different menu items that deliver information about the object to the user The menu item Links shows all objects that are associated to this object This is a very useful concept since the user can immediately understand the context of an object The Collections menu shows to which collections the object belongs and to which collections it could be added All possible types that an object can have are listed in the Evolve menu Collection and Macro Panel The coll
25. can be used it is necessary to set the general OMS properties comprising the OMS home directory and the OMSIP driver In order to set these properties open the OMS preference page menu Window Preferences shown in figure B 1 Preferences Workbench OMS Ant Build Order General OMS Settings Help 4 Install Update OMS home C Program Files omspro2 1 Browse Java Bons OMS driver omsjp omspro user null localhost Plug in Development Quantum DB Readme Example Run Debug Team Template Editor Restore Defaults Apply Import Export Cancel Figure B 1 OMS Preference Page The form contains two fields to fill in The first one is the home or installation directory of OMS Pro The second entry contains the currently used OMS P driver The default value is omsjp omspro user null localhost which represents the OMS Pro driver if OMS Pro is locally installed on the machine If these values do not correspond to the user s environment the appropriate ones should be entered Opening the OMS Perspective Having set the OMS properties the OMS front end is ready to use To model OMS databases 1t is recommended to switch to the OMS perspective To open the OMS perspective choose APPENDIX B USER MANUAL 69 the OMS perspective from the menu Window Open Perspective Initially the OMS perspective shows the database explorer view at the left and th
26. conventions are introduced The next step was to work out some design proposals which were then discussed to decide on a final design for the OMS front end The difficulties were to find suitable solutions that improve the weaknesses of the existing OMS Pro GUI and respect the conventions of Eclipse at the same time The results of this design phase are covered in chapter 4 The design phase was followed by the actual implementation phase Chapter 5 presents technical details about the implementation whereas chapter 6 summarises the main conclusions 1 3 DOCUMENT STRUCTURE Evaluation of the OMS Pro Graphical User Interface An evaluation of the existing OMS Pro graphical user interface GUI served as a starting point for the design of the OMS Eclipse plug in The goal of the evaluation was to explore the strengths and the weaknesses of the existing OMS Pro GUI Concepts that were considered as especially useful should be adopted for the new Eclipse plug in whereas weaknesses should be enhanced in order to improve the usability of the application considerably This chapter provides the main findings of the evaluation and it summarises the requirements for the eclipse based front end that were derived from the findings 2 1 Methodology The evaluation of the OMS Pro GUI as it was carried out for this diploma thesis was not a scientific study in the sense that a lot of different persons were interviewed according to predefined questionnaires wh
27. fast accessible in the New menu of the OMS perspective The import wizard class Import Database Wizard is added to the Import menu of the Eclipse workbench and is therefore forced to implement the IImportWizard interface and the org eclipse ui importWizards extension point Figure 5 8 shows how the OMS front end wizards integrate into the Eclipse wizard framework using the wizard to create a new OMS database as an example 52 5 12 PACKAGE PREFERENCES interface interface interface IDialogPage IRunnableContext IWizardContainer createControl run getCurrentPage IVVizardPage setTitle getShell setDescription showPage setVisible updateButtons interface updateTitleBar IWizard interface addPages IWizardPage getNextPage getNextPage getPreviousPage interface getPreviousPage performFinish IWorkbenchWizard getWizard getStartingPage isPageComplete getContainer IVVizardContainer N WizardPage Wizard interface interface INewWizard limportVVizard isCurrentPage setWindowTitle setErrorMessage setDefaultPagelmageDescriptor setMessage setNeedsProgressMonitor A getContainer ZN NewDatabaseWizardPage createControl getDBName getLocationPath NewDatabaseWizard page NewDatabaseWizardPage Figure 5
28. it might be helpful if the system could remember which objects were open Furthermore the collection and macro panel do not have a state memory If the user expands the system collections in the collection panel and then adds a new collection to the system the system collections collapse and have to be expanded again Window Switches Editing a database in OMS Pro requires many window switches be tween the main application window and the graphical schema editor windows since some tasks are easier to accomplish in one or the other window An example is the task of adding a new association between two collections The process of adding the association is easy to do in the schema editor by connecting the two corresponding collections with a line But if the user wants to edit the cardinalities of the association he has to switch back to the main window and edit the cardinalities in the association object These switches make it difficult to keep an overview especially since the graphical schema editor windows are independent windows which are not integrated in the main application window Data Separation The user and system data are not clearly enough separated It might be the case that the user would like to have a list with all methods he added to the database Methods are not listed in the associated type but a possibility to get a list is to user the Match functionality in the Objects menu The result of this is a list with user and syst
29. page associated with it namely the CollectionListPage which consists of three sections The main section is the CollectionListSection presenting the collection extent in a JFace table viewer The SubCollectionListSection and the SuperCollectionList Section offer sub and supercollections respectively The sections implement the IDBEle mentListener interface to manage refresh operations due to events CHAPTER 5 OMS FRONT END IMPLEMENTATION 51 5 10 Package ACTIONS The actions package contains a couple of action classes Each of these classes represents an action that is placed in one of the various context menus or associated with a button in the user interface All action classes subclass the JFace Action class which in turn implements the IAction interface The IAction interface offers methods to set the action label the image associated with the action if it is used in a context menu and most importantly the run method which actually executes the action The JFace Action class is a base implementation of the IA ction interface Subclasses usually override the run method 5 11 Package WIZARDS Wizards are special dialogs used when a modal operation requires a particular sequence for its information collection Wizards have a title area along the top a content area in the middle showing the various wizard pages and a button container at the bottom providing Next Back Finish and Cancel buttons In the OMS front end w
30. plug in that offers a set of custom widgets and other supporting classes that were before used as internal Eclipse classes These classes form a toolkit to create Web like user interfaces by extending SWT in order to get the desired behavior SWT controls can typically appear either in traditional dialogs message boxes dialogs wizards preference pages or in content areas used for views and editors If the controls are added to dialogs they use colors and fonts as provided by the operation system and the goal is to fill a rather small dialog area Controls in views and editors are supposed to fill the entire content area they should scroll their content and the colors and fonts should be those provided by the system for use in the content area Eclipse Forms are designed to meet these requirements by offering a toolkit that manages among other things colors and a factory which creates basic SWT controls in order to fit into the form context The result looks very much like forms in HTML browsers Therefore the form toolkit comprises some additional custom controls used to add hyperlinks image hyperlinks and expandable sections to the form More information about CHAPTER 4 OMS FRONT END DESIGN 33 Eclipse Forms can found in 13 a draft of a programming guide that will eventually move to the official Eclipse help 4 2 4 Object Editor Concerning the means of design the object editor is very similar to the collection editor It is also
31. process is completed and the plug in can be activated and used The activation of a plug in involves loading the plug in resources into memory instantiating the plug in runtime class and initialising its instance Since an Eclipse environment can have an unlimited number of installed plug ins the available memory and a reasonable start up time make it impossible to activate all plug ins at system startup Therefore Eclipse follows the principle of lazy loading which means that a plug in is only loaded into memory if Eclipse is required to perform some function of the plug in To be able to load required plug ins the Eclipse runtime must know all plug ins that are currently installed Eclipse gathers this knowledge using a discovery mechanism at system startup This mechanism involves the parsing of all plug in XML manifest files and these parsed plug in specifications are then cached in an in memory repository called the plug in registry If a plug in is activated the Eclipse runtime queries the plug in registry to obtain the plug in runtime class to instantiate and to know what resources to load into memory Each plug in gets its own Java class loader Most of the plug ins provide buttons or additional menu entries to the Eclipse workbench The graphical appearance of these workbench components is also specified in the plug in 20 3 3 ECLIPSE PLUG IN ARCHITECTURE XML manifest which allows the workbench to display these buttons and menu entries
32. the execution of the query failed If the result consists of database objects they can be opened with a double click 80 B 5 QUERYING THE DATABASE Setting the History Preference The AQL view provides a history functionality which means that executed queries are stored These query statements can be retrieved using the arrow buttons to go back and forth in the query list The AQL view has its own preference page Window Preferences gt OMS AQL which allows indicating how many queries should be available in the history list Acknowledgements First of all I would like to thank my supervisor Michael Grossniklaus for his valuable feed back for reviewing my report and for the great effort he put into OMSIP to make my front end work Furthermore I want to thank Prof Moira C Norrie for giving me the opportunity to accomplish my diploma thesis in her group I also would like to thank Ljiljana Vukelja for her constructive comments on the user interface design and Olivier Jeger for helping me vvith the design of the icons Thanks to Rolf Bruderer Olivier Jeger and especially Jean Daniel Merkli for kindly supporting me during this thesis Finally I am grateful to my parents for their support in every respect 81 1 2 3 4 5 6 7 8 9 10 11 12 Bibliography E Clayberg and D Rubel Eclipse Building Commercial Quality Plug ins Addison Wesley 2004
33. to lose beneficial functionality the new front end should adopt from the OMS Pro GUI Section 4 1 describes issues that had to be solved in the design process and some proposals that were not realised in the final version because of the time available The final design is presented in section 4 2 4 1 Design Issues and Proposals At first view the main window of the OMS Pro user interface and the Eclipse workbench look quite alike The Eclipse workbench window though can have several perspectives and the user is allowed to change the layout of these perspectives The main Eclipse window can therefore adopt many different appearances However by comparing a predefined perspective 23 24 4 1 DESIGN ISSUES AND PROPOSALS layout as presented in figure 3 4 to the main application window of OMS Pro see figure 2 1 1t is apparent that their structure is very similar in design Both windows have a menu bar and a tool bar at the top The right side of the window is used to display the project structure or the database structure respectively At the bottom a console window can be found in both cases and the main area is used to open objects displayed in the right window component Considering these facts it was obvious to reason that a new Eclipse based front end could easily be fitted into an own perspective of the Eclipse workbench However at closer inspection not everything was as clear as it seemed and we had to take some major decisions conce
34. using the rollback functionality Context information is important to keep track of data in a system Therefore the OMS front end offers context information as required The information is displayed directly in the corresponding editor windows which makes the information fast accessible and manageable Any information section that the user does not want to see can be collapsed in order to con centrate on the essential parts of the editor window For collection members a section with links to related objects is displayed This section helps to simplify the process of adding links between two objects If the user has one object open in the editor area he just has to choose an appropriate object from a list dialog which can then be linked The list does not only display object identifiers but it offers an attribute value in addition to the type and the id of the object This fact enables the user to find the intended object without having to open it beforehand This is a major improvement compared to the present OMS Pro GUI Another enhancement is the introduction of the database explorer which replaces the collec tion and macro panel of the OMS Pro user interface These panels are a good approach to start with but they offer only a limited portion of information However the database ex plorer displays the most frequently used database objects in a clear tree structure The user is able to expand only those tree nodes he requires in order to focus on th
35. with out actually loading the plug in Only when the user performs these actions the plug in is activated and the corresponding action class is called Plug ins may be dependent on functions of other plug ins A dependency of another plug in can be indicated in the XML manifest using the requires tag If a plug in which depends on other non active plug ins is activated these plug ins are loaded transitively in order to guarantee an error free execution of the requested plug in 3 3 3 Extension Mechanism As described in section 3 3 2 plug ins can depend on other plug ins if they use the function ality offered by the plug in A second kind of relationship between plug ins are extensions The extension mechanism is the essential mechanism used to allow plug ins to extend the functionality of other plug ins For example if a plug in which implements an HTLM editor is added to the workbench the plug in has to extend the general Eclipse editor plug in in order to allow an integration of the HTML editor into the Eclipse user interface Figure 3 3 shows schematically how the extension mechanism works HTML Editor Plug in Extension add Extension add Editor Extension HTML menu to HTML editor to workbench vvorkben XML l Class X declaration contributes implements creates calls Y Extension Points XML Interface definition
36. 2 fle fmages MUSIC fugees2 mov Browse m Browse Methods Blase 0577 0 gt yes lage 0613 Q 1 lacation set gt number integer uni person test 02190 f E 0572 0 0608 Ework places0 0614 0 gt 1 Ework places02 0615 0 gt Figure B 10 Object Editor chosen for the parent collection Below a hyperlink to the type of the object is provided The Attributes section shows all attribute values of the object whereas all collections where this object is member are listed in the Collections section The Links section shows how this object is related to other database objects and the Methods section presents all methods that can be executed on this object Creating a Collection Member In order to create a new collection member either the New button in the collection extent section of the collection editor can be pushed or the New OMS Collection Member on a collection in the database explorer can be selected This action does not need a wizard The object is directly created and added to the collection where it was created The newly created object is opened in the editor area Editing Attribute Values The Attributes section in the object editor allows editing of all attribute values of an object Dep
37. 599 E Privates 0600 Ed Lives at 0595 Gy Part of 0598 Gy Situated_at 0601 Gy Works For 0602 s Import Database OMS Object Type i OMS Collection gt Types G OMS Collection Member Macros H System OMS Method contacts2 3 OMS Macro Figure B 8 Create a New Association As a result the association wizard shown in figure B 9 is opened The source and the target collection are initialised according to the selection in the database explorer The Inverse button can be used to swap the source and the target collection The newly created association is added to the database explorer and opened in the editor area New OMS association OMS assocation Create a new OMS association Name Employed_At Source Collection Ex_ETH 0594 Cardinality Jo pe Target Collection Organisations 0597 Browse Cardinality Jo pe Inverse Figure B 9 Association Wizard Browsing a Collection Member Collection members are shown in the database explorer if the collection node is expanded Members of unary collection can be opened in the editor area with a double click The members are presented in object editor windows as shown in figure B 10 The object editor has different areas and sections The title area displays the attribute value 74 B 4 BROWSING AND UPDATING THE DATABASE Peter Smith 0677 E private 0575 Peter Smith m 4411 632 7379 4411 632 117
38. Eclipse http www eclipse org N Edgar K Haaland J Li and K Peter Eclipse User Interface Guidelines February 2004 http www eclipse org articles Article Ul Guidelines Contents html M Grossniklaus OMS A Uniform Java Interface to Heterogenous OMS Platforms Technical White Paper April 2004 Version 1 0 B Majewski A Shape Diagram Editor December 2004 http www eclipse org articles Article GEF diagram editor shape html M C Norrie An Extended Entity Relationship Approach to Data Management in Object Oriented Systems In Proc 12th Int Conf on Entity Relationship Approach Springer Verlag LNCS 823 1993 M C Norrie A Wiirgler K von Gunten A Palinginis and M Grossniklaus OMS Pro 2 0 Introductory Tutorial Technical Report March 2003 OMS Object Model System http ww oms ethz ch OMS http www oms ethz ch omsjp SICStus Prolog http www sics se sicstus D Springgay Using Perspectives in the Eclipse UI IBM OTI Labs August 2001 http www eclipse org articles using perspectives PerspectiveArticle html TCL Tool Command Language Tk User Interface Toolkit http www tcel tk software tcltk 83 84 BIBLIOGRAPHY 13 S Tilkov Eclipse Forms Programming Guide February 2004 14 P Zoio Building a Database Schema Diagram Editor with GEF September 2004 http www eclipse org articles Article GEF editor gef schema editor html
39. Eclipse Based Front End for OMSIP Diploma Thesis Barbara Aeppli lt barbara computerscience ch gt Prof Moira C Norrie Michael Grossniklaus Global Information Systems Group Department of Computer Science ETH Zurich February 17th 2005 Eidgen ssische Technische Hochschule Z rich 8 e b I S Swiss Federal Institute of Technology Zurich Copyright O 2004 Global Information Systems Group Abstract OMSIP is a Java interface which makes access to heterogenous OMS platforms possible in a uniform manner To enhance software development based on OMSIP the aim of this diploma thesis was to build a graphical user interface on top of OMSIP for modelling and adminis trating OMS databases The resulting front end has the advantage that it is applicable to all OMS platforms supported by OMSIP To facilitate the implementation process the front end has been implemented as a plug in for the widely used Eclipse Platform Eclipse offers an extensible architecture and supporting functionality common to front end applications Furthermore the popularity of Eclipse leads to a reduced learning effort for the new OMS front end since it adopts well known Eclipse paradigms and conventions Introduction dls OMS SUITE dad Fik A 1 2 Motivation for Using Eclipse 1 3 Document Structure Evaluation of the OMS Pro Graphical User Interface 2 1 Methodology cs Sak ey oth Sa a ee 2 2 OMS Pro Concepts and Termino
40. ML MANIFEST OMS Jar File The actual code of the plug in is stored in a JAR file as well Typically the JAR file is named for the last segment in the plug in s identifier but it could basically have any name as long as the name is declared in the plug in manifest file For the OMS plug in the JAR file is called OMSBrowser jar which in fact corresponds to the last segment of the plug in identifier The plug in code is divided into twelve Java packages containing a varying number of Java classes All package names are prefixed by the string ch ethz globis omsjp omsbrowser In the UML diagrams appearing in this chapter classes and interfaces in grey are provided by the Eclipse platform whereas those in red are own classes and interfaces Sections 5 2 until 5 13 explain all packages in more details whereas section 5 1 provides information about the plug in manifest file 5 1 Plug In XML Manifest As stated in chapter 3 every plug in has exactly one plug in manifest file The manifest de fines various high level aspects so that the plug in does not have to load until some function ality is required It contains four major parts which are described in the following paragraphs providing some XML snippets The whole plug in manifest file can be found in the appendix A Plug In Declaration Section The declaration contains the plug in identifier which is designed to uniquely identify the plug in Usually the same naming convention as for Java pac
41. Method id ch ethz globis omsjp omsbrowser wizards NewMethod gt lt extension gt lt extension point org eclipse ui perspectiveExtensions gt lt perspectiveExtension targetID org eclipse ui resourcePerspective gt lt perspectiveShortcut id ch ethz globis omsjp omsbrowser perspectiv OMSPerspective gt lt perspectiveShortcut gt lt perspectiveExtension gt lt perspectiveExtension targetID org eclipse jdt ui JavaPerspective gt lt perspectiveShortcut id ch ethz globis omsjp omsbrowser perspective OMSPerspective gt lt perspectiveExtension gt lt extension gt lt extension point org eclipse ui views gt lt category name 0MS id ch ethz globis omsjp omsbrowser gt lt category gt lt view 64 name Database Explorer icon icons database_explorer gif category ch ethz globis omsjp omsbrowser class ch ethz globis omsjp omsbrowser views DBExplorerView id ch ethz globis omsjp omsbrowser views DBExplorerView gt lt view gt lt view icon icons sample gif class ch ethz globis omsjp omsbrowser views AQLView category ch ethz globis omsjp omsbrowser name AQL id ch ethz globis omsjp omsbrowser views AQLView gt lt view icon icons match_view gif class ch ethz globis omsjp omsbrowser views MatchView category ch ethz globis omsjp omsbrowser name Match id ch ethz globis omsjp omsbrowser views MatchView gt lt
42. Provider ITreeContentProvider DBExplorerViewContentProvider labelProvider ILabelProvider setContentProvider interface ITreeContentProvider AbstractTreeViewer interface ILabelProvider add remove expandToLevel collapsToLevel TreeViewer setLabelProvider getTree Figure 5 3 Database Explorer View Classes The database explorer displays database objects and thus uses the model described in section 5 3 To access the model the tree viewer uses the DBExplorerViewContentProvider which is responsible for extracting the appropriate objects from an input object in our case the DatabaseManager which is the parent object of all databases in the workspace Having the raw objects the DBExplorerViewLabelProvider is called to determine the image and the label that is actually displayed in the tree Optionally the tree viewer in the database explorer makes use of the DBExplorerViewSorter which sorts the tree objects according to defined sort criteria before they are displayed If the content of the database manager or any database object change methods specified in the IDBElementListener interface are called The DBExplorerViewContentProvider implements this interface and is thus responsible for reacting to any changes and updating the tree viewer 5 6 2 AQL View The AQL view integrates into the Eclipse platform in the same way as the database exp
43. abase explorer that are gathered in a context menu The context menu adapts according to the user selection in the tree An important menu entry is the New menu which enables the user to create new databases and new data base objects In most of the cases choosing a New action launches a wizard As an example the wizard to create new OMS databases is shown in figure 4 7 New OMS database OMS database Create a new OMS database Database name Location IM Use default Paisa Figure 4 7 Wizard to Create a New OMS Database The wizards are necessary since the user has to indicate preliminary information in order to enable a precise object creation The entry fields in these wizards are pre filled depending on the selection in the database explorer This helps the user to efficiently create new objects without having to fill in large forms For example to create a new association between two collections it is possible to select two collections in the database explorer and launch the wizard The user only has to indicate which of the collections should be the source collection and the association can be created If the user wants to create database objects which do not need any preliminary information as for example a new macro wizards are omitted to simplify the process of creating new objects 32 4 2 FINAL DESIGN 4 2 3 Collection Editor If the user double clicks on a collection in the database explorer an edito
44. as the DBObjectType class is a specialised class for object types offering additional methods Since the user should be able to open all these OMS objects in the Eclipse editor area the IDBObject interface inherits from the IEditorInput interface enabling these objects to be opened by an editor The last subclass of DBElement is the DBObjectBulk class which stands for binary or multi valued collection members These objects do not correspond to any OMS object and therefore this class does not implement the IDBObject interface but subclasses the DBElement class directly Internally it holds references to the underlying instances of IDBObject Having this class hierarchy allows us to map the OMS database objects into a hierarchical tree structure so that every object knows its parent object and all child objects Apart from the Database class three classes in the model can act as parent objects All other classes are tree leaves The classes that are possible parent objects implement the IDBParentElement interface offering methods to add remove and delete child objects The Database class does not need to provide these methods since its only children are instances of the class DBElementFolder which cannot be deleted or removed Providing a hierarchical class structure for the tree viewer in the database explorer is one thing but all these objects and the whole OMS front end need access to the underlying OMS databases using OMSIP The connection handlin
45. ation was executed success fully or not If it failed there is no possibility to find out why it failed Undoing Updates by Rollback Any modifications since the last commit can be undone by choosing the Rollback Database functionality in the context menu of the database explorer B 5 Querying the Database The OMS front end offers an AQL view which allows to query the database In the OMS perspective the AQL view is by default placed behind the console window It can be activated using the tab in the tab bar or if it is closed by choosing the Window Show View AQL menu entry The AQL window is shown in figure B 17 Console SFE Match im Enter your query Query Result domain person 0664 Defeng Ma person 0644 Andreas Steiner in c Organisations 6D person 0660 Gustavo Alonso c Works_for range restriction having Org name Institute for Information Systems person 0662 Armin Fessler 6D person 0663 Claus Hagen 6D person 0666 Uwe Roehm person 0661 Markus Tresch Figure B 17 AQL View Executing a Query To execute a query the query text has to be entered in the text field on the left side of the window If more information is needed about how to write queries please consult the OMS Introductory Tutorial 7 The Run button executes the query and the result is displayed in the table on the right side or the system informs the user that
46. bject ObjectEditor gt lt extension gt lt extension point org eclipse ui newWizards gt lt category name 0MS id ch ethz globis omsjp omsbrowser gt lt wizard finalPerspective ch ethz globis omsjp omsbrowser perspective OMSPerspective class ch ethz globis omsjp omsbrowser wizards NewDatabaseWizard icon icons database_connected_new gif category ch ethz globis omsjp omsbrowser name 0MS Database id ch ethz globis omsjp omsbrowser wizards NewDatabase gt lt wizard icon icons object_type_new gif class ch ethz globis omsjp omsbrowser wizards NewTypeWizard category ch ethz globis omsjp omsbrowser name 0MS Object Type id ch ethz globis omsjp omsbrowser wizards APPENDIX A PLUGIN XML MANIFEST 63 NewType gt lt wizard icon icons unary_collection_new gif class ch ethz globis omsjp omsbrowser wizards NewCollectionWizard category ch ethz globis omsjp omsbrowser name OMS Collection id ch ethz globis omsjp omsbrowser wizards NewCollection gt lt wizard icon icons binary_collection_new gif class ch ethz globis omsjp omsbrowser wizards NewAssociationWizard category ch ethz globis omsjp omsbrowser name OMS Association id ch ethz globis omsjp omsbrowser wizards NewAssociation gt lt wizard icon icons method_new gif class ch ethz globis omsjp omsbrowser wizards NewMethodWizard category ch ethz globis omsjp omsbrowser name 0MS
47. cation window despite the fact that they were still active The user either thinks that the window was closed and chooses the corresponding menu entry again to reopen the window or he has to minimise the main application window to be able to reset the focus manually Object Window Size Database objects are opened in the main panel of the main appli cation window They are displayed as small object windows The size of these windows is in many cases unadapted Buttons that are at the bottom of the window to cancel or execute an action are not visible at once The user first has to resize the object window in order to make these buttons accessible If the object window contains child components as for example a scrollable list these components do not resize if the window is resized If such a list contains more entries than it can display the user still has to scroll in the list even though the window may be big enough to show all list entries Furthermore the maximisation function of objects windows in not useful at all The maximised object windows become so big that the user is forced to scroll in order to make the close button visible again Arrangement of Object Windows The arrangement of the object windows in not sat isfactory Depending on the number and positioning of already open object windows in the main panel it can happen that a new object is opened in a way that only a part of the object is actually visible The user first of all ha
48. ch is shut down the application checks if a database was still connected and the next time the user chooses to restart Eclipse the connection is restored Moreover the display attributes that the user can choose for every collection in order to determine how the collection members are presented are preserved across multiple sessions File system dialogs memorise which directory was last accessed and the dialog directly selects this directory the next time it is launched The one requirement that was not satisfied is the introduction of a schema editor as described in section 4 1 3 Only the basic updating and browsing functionality was implemented The main reason for this was that the process of really getting to know the whole Eclipse frame work took longer than expected Most of the books and material that are available treat quite simple plug in examples which are all file based The OMS plug in moves away from this file based paradigm and it uses newly introduced Eclipse features which needed a lot of effort to get things working Fortunately Eclipse has a large open source community which is very useful to exchange experiences and programming solutions and which advances the whole Eclipse project Another reason that the schema editor implementation had to be skipped was due to the fact that the underlying OMSIP library was still incomplete and erroneous This slowed the implementation process down It was time consuming to find out if a problem was
49. d in the local file system and click Finish The database is added to the database explorer Opening or Closing a Database To open a database choose the Open Database entry from the context menu in the database explorer Please note that if another database is connected the connection is closed since only 70 B 4 BROWSING AND UPDATING THE DATABASE Import OMS database OMS Database Import an existing OMS database Location C Program Files omspro2 11demolcontacts oms ew Figure B 3 Import Database Wizard one active connection can be open at a time To close an open database choose the Close Database entry from the context menu B 4 Browsing and Updating the Database The database explorer provides access to frequently used OMS database objects such as col lections types and macros The system data is listed separately in the System folder Figure B 4 shows the database explorer and its context menu e contacts2 1 contacts2 2 Collections Hl Contacts 0582 GW contact 0583 Paul Smith Fl Locations 0586 Situated At 0588 contact 0583 location 05905 5 Types Ef oms Database Ed contact 0571 Ed age 0584 Delete OMS Object Type Ed last_salary 0592 E E location 0585 u Import Database BI OMS Collection E Macros E OMS Association e count contacts 0591 z print_contacts 0593 o
50. d with the entries to react to certain kinds of events The EditorFormEn tryAdapter class serves as a base implementation of the IEditorFormEntryListener inter face CHAPTER 5 OMS FRONT END IMPLEMENTATION 49 interface IFormPart setForminput initialize commit interface IDoubleClickListener inkEnteredi Bere AZ linkExited setFormEntryListener createControl createMainLabel setForminput initialize interface createButtons eau ae IEditorFormEntrvListener HaddListeners getManagedForm focusGained buttonSelected i textValueChanged SectionPart A getSection DBTableEntry DBTextEntry expansionStateChanged tableViewer textField createTableColumns setValue getValue DBEditorSection page FormPage EditorFormEntryAdapter setMinimumTableSize cancelEdit DBEditorTableSection dbTableEntry createDBTableEntry textValueChanged Figure 5 6 Reusable Form Editor Components 5 8 Package EDITORS OBJECT The OMS plug in offers two different editors The collection editor is used to display collec tion objects all other database objects are shown in the object editor The object editor class ObjectEditor is a form editor and therefore extends the Eclipse FormEditor class It is a multi page editor containing a single page namely the ObjectA t
51. databases it becomes possible to develop a single front end that can be used uniformly for all OMS platforms 1 1 OMS Suite The OMS suite is based on its own object model OM 6 OM is a generic object data model which specifies constructs and operations for the management of interrelated collections of data objects It is designed to support database development from conceptual design through to implementation independent of a particular programming language environment Up to the present the OMS suite comprises a number of platforms which implement the OM model using different programming environments such as Prolog Java Oberon or Python The platform implemented in SICStus Prolog 10 is called OMS Pro 7 OMS Pro supports rapid prototyping but it can be used for the implementation phase as well OMS Pro provides a TCL Tk 12 graphical user interface for browsing querying and manipulating database objects The user interface is rather advanced but it still has some deficits Another platform that belongs to the OMS family is eOMS eOMS is based on PostgreSQL and implemented in Python It offers a concurrency control mechanism to allow multi user access These different OMS platforms are very heterogenous and do not provide a common Ap plication Programming Interface APD OMS Pro offers a collection of Prolog predicates as API and hence no interface that can be accessed directly from Java This is not very conve nient for application devel
52. ders build tool plug ins The Eclipse Platform is divided up into the core part and the user interface UD part Anything classified as user interface needs a window system whereas components that belong to the core can run without window system The user interface part of the Eclipse Platform is known as the Workbench The core part is simply called the Platform Core Figure 3 2 shows the major components of the Eclipse Platform Platform Runtime The platform runtime is a micro kernel that is responsible for discov ering integrating and running plug ins At start up the runtime environment discovers what plug ins are installed and creates a registry of information about them To reduce start up time and resource usage it does not load and activate any plug in until the plug in is actually needed This mechanism is called lazy loading and it is used consistently throughout Eclipse Except for this runtime kernel all functionality in Eclipse is implemented as a plug in Workspace The workspace is the plug in that is responsible for managing the user s re sources Resource is the collective term for projects folders and files The workspace consists of one or more top level projects whereas each project maps to a corresponding user specified directory in the file system Each project contains folders and files that are created and ma nipulated by the user All folders and files in the workspace are directly accessible to the CHAPTER 3 ECLIPSE
53. dragging editor windows with the mouse to a new location Unfortunately this mechanism cannot be accessed programmatically using an API The only way to use it would involve manipulations of internal Eclipse classes which 1s rather unreliable and which the Eclipse developers strongly advise against it Thus we had to accept that the editor area normally displays only one object at a time We discussed several approaches to get around this problem by incorporating the views that can be arranged around the editor area The following paragraphs describe the main choices that were discussed View to Display Objects An early idea was to use a view to display database objects such as collection members type objects methods and macros Only collection objects should be opened in the editor area A schematic perspective layout is provided in figure 4 1 The advantage of this approach is that collections and objects are visible at the same time The user can open several collections in the editor area Each of the collections is represented as an editor and is accessible through a tab in the tab bar As described in section 3 4 views usually reflect aspects of the currently active editor or of CHAPTER 4 OMS FRONT END DESIGN 25 Menu bar Tool bar Coll1 Database Explorer Collection Extent person o215 Joe Black person 0218 Peter Smith Console Object person 0218 name Peter Smith age 28
54. e B 16 By double clicking the objects listed in the match view table they are opened in the editor area and it is possible to edit their attributes Depending on the kind of object attribute editing operations need to be executed carefully since the database might not be consistent anymore after the editing process For example if the user changes the source collection of an association the members of the associated binary collection might have the wrong format and in this case it is no longer possible to open these objects Console AQL match x A Console AQL een x type def stype o61 6D cover check trigger o81 jparam list stype o62 6D coll_check trigger o82 lives_at_struct stype 0631 intersect_check trigger 083 situated_at_struct stype 0632 6D equal check trigger 084 phone struct stype 0633 D total check trigger 085 part_of_struct stype o634 strict_check trigger 086 ul works_For_struct stype 0635 6D macro check trigger 087 timeTriggerEvent_struct stype o68 check publish mimes trigger o88 Figure B 16 Two Match Result Windows Deleting Objects Any kind of database objects can be deleted using the context menu in the database explorer or in some of the editor windows If the user executes the Delete action the selected object is deleted in the OMS database and it is removed everywhere in the OMS perspect
55. e access and throw an exception Since the OMS front end should be extensible to add future components all libraries are exported to allow another plug in to access them Dependencies Section The requires section of the plug in manifest indicates all plug ins that the OMS plug in is dependent on This information is needed since the plug in class loader must know which plug ins will be visible to the OMS plug in during execution It is also possible to require a designated version of a plug in If the OMS front end is activated all required plug ins are activated transitively 1f they have not been loaded before Extensions Section The OMS front end declares various extensions offered by the Eclipse workbench to contribute own components to the user interface Listing 5 2 shows the view extension that is used to define the database explorer view The extension specifies among other things the name and the icon of the view the category the view belongs to and the main class which implements the view lt extension point org eclipse ui views gt lt category name 0MS id ch ethz globis omsjp omsbrowser gt lt category gt lt view name Database Explorer icon icons database_explorer gif category ch ethz globis omsjp omsbrowser class ch ethz globis omsjp omsbrowser views DBExplorerView id ch ethz globis omsjp omsbrowser views DBExplorerView gt lt view gt lt extension gt Listing 5 2 OMS Plug In
56. e console view at the bottom of the workbench window The AQL view is hidden behind the console view Creating a New OMS Database If the user wants to create a new OMS database he can open the New Database wizard shown in figure B 2 The wizard can be opened either by selecting the menu File New OMS Database or by right clicking in the database explorer and choosing New OMS Database New OMS database OMS database Create a new OMS database Database name Location IM Use default E Figure B 2 New Database Wizard To create a new database enter a name and a storage location if the database should not be stored in the default directory By clicking Finish the database is created and added to the database explorer Since a database connection must be established for the creation process the newly created database is already open in the database explorer and ready for browsing Importing an Existing OMS Database The OMS front end allows importing an already existing OMS database which is stored in the local file system In order to import a database open the Import Database wizard This can be done either by selecting the menu File Import and then choosing OMS database or by right clicking in the database explorer and choosing Import Database The wizard presented in figure B 3 is shown To import a database fill in the location where the database is store
57. e current task The database explorer moreover offers a context menu with common actions to choose from It is possible to create any kind of object displayed in the tree using the context menu In most of the cases the new objects are created with the help of wizards Wizards may be considered as circumstantial but the wizards used in the OMS front end initialise the entry fields according to the user s selection when the wizard is called and accelerate thus the creation process For example if the user wants to create a new association he can select two collections in the tree call the wizard and he is able to finish the process only by typing the name of the association A further requirement was to reduce to use of object ids and to make working with objects easier The OMS front end uses different approaches to fulfil this task One approach is to display collection members always together with an attribute value regardless if the object is shown as tree object or as tab bar label Initially the first attribute value is taken but if this value does not help to identify objects quickly the user can choose a different display attribute for every collection If the user chooses a different attribute value for a collection affected members of this collection are notified throughout the whole Eclipse user interface to change their display attribute value correspondingly This gives the user a powerful tool CHAPTER 6 CONCLUSIONS 57 to identify obj
58. e explorer extends this point to register itself as an Eclipse view Views must implement the org eclipse ui IViewPart interface Typically views subclass the org eclipse ui part ViewPart class and are thus indirectly sub classes of org eclipse ui part WorkbenchPart inheriting much of the behavior needed to implement the IViewPart interface The DBExplorerView class is the main class of the database explorer and subclasses ViewPart The createPartControl method overrides the method specified in the superclass It is a callback method creating all controls comprised in the view Figure 5 2 shows how the database explorer view integrates into the existing Eclipse framework Classes and interfaces in grey are provided by the Eclipse platform interface IWorkbenchPage tactivate in IWorkbenchPart findView interface IWorkbenchSite getPage IWorkbenchPage getViewReferences IViewReference getShell getWorkbenchWindow interface interface interface IWorkbenchPartSite IWorkbenchPart IWorkbenchPartReference registerContextMenu createPartControl dispose getSite IWorkbenchPartSite getld getPage IWorkbenchPage getPart IWorkbenchPart interface interface interface IViewSite IViewPart IViewReference getActionBars getViewSite IViewSite getView IViewPart init tsaveState
59. e objects in a rather efficient way since the DBCache uses instances of the class java util Hashtable class to manage the tree objects 42 5 3 PACKAGE MODEL On the next hierarchy level the tree displays folder objects to reasonably structure the database contents These folders are represented by the class DBElementFolder which internally stores its child objects The DBInstance and the DBObject class comprise all database object that corresponds one to one to an OMS object in the OMS database system Therefore these two abstract classes implement the IDBObject interface offering methods common to all OMS objects The classes wrap OMSIP objects namely instances of OMSInstance and OMSObject respec tively The DBObject class provides three concrete subclasses for collection members macros and methods DBCollMember DBMacro and DBMethod These classes offer in addition to the common database object methods specific methods applicable only for this kind of object The DBInstance class comprises types and collections objects In OMSIP collections types and associations are subtypes of the OMSInstance class which represents an instance of the underlying OMSObject The DBInstance class holds therefore a reference to the OMSIn stance class Collections are classified into unary and binary collections which are mapped to the class DBCollection and its subclass DBBinaryCollection The DBType class com prises all possible types available in OMS where
60. e time Moreover the user can open several objects in the editor area and easily switch between them But there is again the disadvantage that a view can only display one object and therefore only one collection This is neither what we had in mind since we did not want to restrict the browsing functionality by only allowing to view one collection at a time A further disadvantage is that the presentation of a collection uses more space than a view normally does since some collections are binary or even ternary The consequence is that the console window or for example an AQL window to query the database need to share the space with the collection view This does not make much sense since the console should always be visible to display information and error messages 26 4 1 DESIGN ISSUES AND PROPOSALS Menu bar Tool bar Database Object Explorer Object person 0218 name Peter Smith age 28 Coll1 Console Collection Extent person o215 Joe Black person 0218 Peter Smith Figure 4 2 Schematic Perspective Layout using a View for Collections Editor Area for all Objects A third discussed approach was to abandon the idea of using views and to display all objects in the editor area instead regardless if it is a collection or another object The space at the bottom of the window can be used for the console as shown in figure 4 3 Menu bar Tool bar
61. ection and the macro panels are convenient for the user since they allow the user to gain an overview of the database and fast access to frequently used objects Graphical Schema Editors The graphical schema editors are helpful tools since they visualise relations between collection and type objects In the base and object type editor super and subtype relations are shown whereas in the classification editor super and subcol lection relations constraints and associations between collections are represented graphically Having such a graphical representation gives the user a valuable overview over the database Further it facilitates schema changes and the browsing of these objects since they can be opened directly from the schema editor by double clicking CHAPTER 2 EVALUATION OF THE OMS PRO GRAPHICAL USER INTERFACE 9 2 3 2 Weaknesses of the OMS Pro GUI The weaknesses that were found are categorised into three major categories graphical model and usability problems Graphical Problems This category comprises problems that arise due to a poor graphical representation of com ponents or due to an inaccurate implementation A more careful implementation or an imple mentation using a different graphic library might solve these problems Window Focus Dialog windows as for example the preference window or the graphical schema editor windows tend to loose their focus unprovoked They often disappear in the background behind the main appli
62. ective of Eclipse The view is not initially shown in the OMS perspective but the perspective contains a placeholder which defines where to open the view if it is needed The match view is opened every time the user wants to retrieve database objects that match a certain object type using the Match operation in the context menu of the database explorer The retrieved objects are listed in the result table of the match view Figure 4 12 shows two match view windows The window on the left hand side displays all structured types that are part of the database whereas the right match window shows all existing triggers All objects can be opened and edited with a double click Console AQL IS E console aqu R RE type def stype o61 cover check trigger o81 param _list stype o62 6D coll check trigger 082 Ed lives_at_struct stype o631 6D intersect_check trigger 083 Ed situated_at_struct stype 0632 ED equal_check trigger 084 phone struct stype o633 6D total check trigger 085 part of struct stype 0634 69 strict_check trigger 086 Ed works_for_struct stype 0635 6D macro_check trigger o87 Ed timeTriggerEvent_struct stype o68 ED check publish mimes trigger 088 Figure 4 12 Two Match Windows 36 4 2 FINAL DESIGN OMS Front End Implementation The OMS front end is implemented as an Eclipse plug in using the Eclipse plug in mecha nism as described
63. ects without having to open them Another approach to make working with objects less challenging is the introduction of icons Every type of database objects has its own icon which is consistently used in the workbench The user is able to visually recognise different object types This helps to distinguish different kinds of objects and the user benefits if he wants to get back to an object which is already open in the editor area The possibilities for redesigning the object arrangement and the layout of the object area were rather limited by the Eclipse platform and its conventions Having overlapping windows would have been possible but it was neither what we aimed for nor would the concept have fitted into the workbench Therefore the object area was designed to display complete object windows and only one at a time More detailed thoughts about the available options are presented in section 4 1 1 The result is satisfying since the user is able to focus on the currently active object without being disturbed by other object windows in his field of vision Furthermore the editor windows present important context information which reduces the need to have multiple objects open at the same time The problem of the inefficient tab bar ordering was solved implicitly since the Eclipse framework already offers a mechanism for managing the tab bar As required the OMS front end offers an application state memory in different application parts If the workben
64. em internal methods This makes it rather difficult to find all user defined methods Having access to the system data is an advantage but in the user interface a clear distinction of user and system data is preferred 12 2 4 REQUIREMENTS Hidden Functionality The creation of a new object assumes an already defined object type The functionality to create an object is visible at first sight in the menu bar whereas the functionality to create a type is hidden and not obvious The creation of types can be done in the graphical object type editor or using DDL The same is true for adding associations collections or methods Object IDs Most of the time the user has to work with object ids which is not very natural for humans Object ids are excellent for the system to manage objects but they are quite abstract for the user For the user it is a lot easier to remember a name than an object id OMS Pro makes some attempts to use attribute values together with object ids to facilitate working with objects Examples are the tab bar or when opening a collection through the collection panel This technique should be introduced consistently throughout the whole application 2 4 Requirements The aim of the evaluation was to establish requirements for the OMS Eclipse plug in The evaluation resulted in a number of positive and negative aspects described in section 2 3 which form a valuable basis to derive requirements The idea was to adopt the strengths o
65. ending on the type of the attribute the section offers a different form entry for displaying and editing the attribute value If it is not clear what kind of type an attribute has the user can move the mouse over the attribute label and a tool tip appears indicating the attribute type Simple text values such as for example string integer or real values are displayed in a com mon text field which can be directly edited Attributes of type date offer an additional calendar to pick a date If no time is indicated the time value is set to 12 00 AM by default Attributes of type uri offer a button to browse the local file system If the attribute represents a database object the user can choose an appropriate object from a list dialog Structured attributes and bulk attribute values provide a context menu for the editing process by clicking the right mouse button on the attribute field An additional dialog is opened to change or add new attribute values APPENDIX B USER MANUAL 75 Accessing URIs Attributes of type uri can be accessed by clicking on the attribute label which is in this case a link For http entries the system s standard browser is opened whereas for mailto entries the standard mail program is activated Image files are shown in an appropriate application if the file path is absolute Adding an Object to another Collection There are two possibilities to add an object to another collection
66. ently active editor input or they augment other views by displaying information of an object selected in another view Views have a simpler life cycle than editors any action performed in a view should immediately be saved and affect the state of the workspace and underlying resources OMS Front End Design The process of finding a reasonable design for the new OMS front end was influenced by two main goals One goal was to include the evaluation results presented in chapter 2 The OMS front end that was developed during this diploma thesis provides a graphical user interface that can be uniformly applied to all OMS platforms supported by OMSIP OMS Pro which is one of these platforms already offers its own user interface implemented in TCL Tk This interface was evaluated to identify strengths and weaknesses that led to a set of requirements listed in section 2 4 The new front end was designed in order to maximise the number of satisfied requirements The second goal was to find a design that integrates as seamless as possible into the existing Eclipse framework As covered in section 3 4 Eclipse has its own user interface paradigms The aim was to respect these paradigms as far as possible in order to finally get a front end that fits well into the Eclipse platform This second goal was not always compatible with the first one Therefore the Eclipse conventions were broken in some cases in order to meet the established requirements or in order not
67. er opens a file in a certain directory the chances are high that the next file that is accessed is located in the same directory or nearby Keeping track of user preferences and choices is convenient for the user Another case where it makes sense to store the state is when closing and reopening the system Often the user resumes his work where he finished and it is helpful for the user if the system has exactly the same state as before the application was closed The introduction of an application state memory is therefore a requirement for the OMS Eclipse plug in 14 2 4 REQUIREMENTS Eclipse Platform 3 1 Introduction Eclipse is a universal platform for integrating development tools into the Eclipse workbench The Eclipse Platform is implemented in Java and it is simply a framework and a set of services for building a development environment from plug in components Eclipse has no specific knowledge about any domain and is not limited to Java language applications However the Eclipse SDK includes the Eclipse Platform and a set of plug ins including the Java Develop ment Tools JDT and the Plug in Development Environment PDE The Eclipse Platform the JDT and PDE plug in form together the Eclipse project as 1t is shown in figure 3 1 Eclipse is an open source project and together with its extensible architecture it allows soft ware developers to extend Eclipse and to build tools that integrate seamlessly with the Eclipse environmen
68. erspective to display and the chosen perspective then determines the actual appearance of the workbench Figure 3 4 exhibits the most important workbench concepts and terminology Menu bar Tool bar amp Java OMSBrowserPlugin java Eclipse Platform File Edit Source Refactor Navigate Search Project Run Window Help Cr 0 Q a G 1807 i g o Perspective HE Package Explorer 53 GJ omsBrowserPlugin java 3 O ye Editors 12 ch ethz globis omsip omsbrowser A Be MOD ate src E ch ethz globis omsjp omsbrowser i Zurich All Rights Reserved J OMSBrowserPlugin java hi 8 ch ethz globis omsjp omsbrowser actions are is the proprietary information of ETH Zurich Use is subject E ch ethz globis omsjp omsbrowser editors H E ch ethz globis omsjp omsbrowser editors coll H E ch ethz globis omsjp omsbrowser editors obj H BB ch ethz globis omsjp omsbrowser model package ch ethz globis omsjp omsbrowser E ch ethz globis omsjp omsbrowser perspectivi El ch ethz globis omsjp omsbrowser popup acti gt import java util MissingResourceException lt E ch ethz globis omsip omsbrowser views E ch ethz globis omsjp omsbrowser wizards Bs Plug in Dependencies The main plugin class to be used in the desktop author Barbara Aeppli lt aepplibalstudent ethz ch gt version 1 0 since OMSjp 1 0 OMSBrowserPlugin 9 5 getdefauit o 5 getResourceString String a resourceBundle ResourceBundle O errors 1 warning
69. est file contains information about the plug in and it tells the Eclipse runtime how the plug in can be activated Listing 3 1 shows a minimal plug in manifest file CHAPTER 3 ECLIPSE PLATFORM 19 lt xml version 1 0 encoding UTF 8 gt lt plugin gt name HTML Editor id ch ethz globis test htmleditor version 1 0 2 provider ETH Zurich lt runtime gt lt library name htmleditor jar gt lt export name x gt lt library gt lt runtime gt lt plugin gt lt xml gt Listing 3 1 Minimal Plug In Manifest File Every plug in has a unique identifier XML attribute id which is used to refer to the plug in within the manifest files of other related plug ins Other attributes like name version or provider just contain information about the plug in itself The library name attribute specifies the name of the jar library that is generated when the plug in is deployed 3 3 2 Plug In Deployment and Activation To deploy a plug in all resources that belong to this plug in are copied into an individual folder residing in the plugins directory of the Eclipse installation directory These resources comprise first of all the plug in manifest file which is essential for the activation process then all jar files containing the compiled class files and other resources such as for example an icons folder with icons used in the plug in After restarting the Eclipse workbench the installation and deployment
70. extension gt lt extension point org eclipse ui perspectives gt lt perspective icon icons oms_logo gif class ch ethz globis omsjp omsbrowser perspectiv OMSPerspectiveFactory name 0MS id ch ethz globis omsjp omsbrowser perspectiv OMSPerspective gt lt extension gt lt extension point org eclipse ui importWizards gt lt wizard icon icons database_connected_new gif class ch ethz globis omsjp omsbrowser wizards ImportDatabaseWizard name 0MS Database id ch ethz globis omsjp omsbrowser wizards ImportDatabase gt lt extension gt lt extension point org eclipse ui preferencePages gt lt page class ch ethz globis omsjp omsbrowser preferences DBPreferencePage name 0MS APPENDIX A PLUGIN XML MANIFEST 65 id ch ethz globis omsjp omsbrowser preferences DBPreferencePage gt lt page class ch ethz globis omsjp omsbrowser preferences AQLViewPreferencePage category ch ethz globis omsjp omsbrowser preferences DBPreferencePage name AQL View id ch ethz globis omsjp omsbrowser preferences AQLPreferencePage gt lt extension gt lt plugin gt 66 User Manual B 1 System Requirements In order to use the OMS front end the following system components need to be installed on the computer Windows operating system OMS Pro 3 0 Eclipse 3 0 B 2 Installation The OMS front end can either be installed manuall
71. f DBElement objects use an own event object class called DBElementEvent DBElementEvent inherits from the java util EventObject class and takes a DBElement as source event object in the constructor 5 5 Package PERSPECTIVE The Eclipse user interface defines the extension point org eclipse ui perspectives to add a new perspective to the Eclipse workbench The OMS perspective contributes to this exten sion point by providing an XML declaration in the plug in manifest The declaration con tains the identifier of the perspective its name and icon and the perspective class which has to implement the IPerspectiveFactory interface The factory class is called OMSPerspec tiveFactory and implements the single method defined in the IPerspectiveFactory interface createlnitialLayout This method specifies the initial page layout for the perspective namely where to put which view how to place the editor area and what shortcuts to add in the various menus and tool bars The factory class is only used to define the initial layout of the perspec tive when the perspective is opened After that the class is discarded and the perspective is restored exactly the way as it was when Eclipse was closed OMSPerspectiveListener is the second class in this package implementing the IPerspec tiveListener interface Its method perspectiveActivated is called whenever the user opens a new perspective or switches to an already open perspective The OMSPerspectiveListener cla
72. f OMS Pro as far as possible and to improve the weaknesses at the same time The following list summarises the main requirements for the OMS Eclipse plug in e Keep Storing Paradigm The commit rollback paradigm that OMS Pro uses is very convenient for the user since the user does not have to care about numerous save operations and no changes are lost due to a forgotten save operation Therefore the OMS Eclipse plug in should adopt the storing paradigm if possible Offer Context Information One of the strengths of OMS Pro is the context information that is provided for a database object The user is able to understand quite quickly how an object is related to other objects and how it is integrated in the database A requirement for the OMS Eclipse plug in is thus to make context information easily accessible Offer Graphical Schema Editors The graphical schema editors are an essential element of the OMS Pro graphical user interface since they help the user to obtain an overview of the database really fast Such graphical schema editors should also be part of the OMS Eclipse plug in But it is also important that all tasks can also be executed without graphical schema editors to reduce the window switching on the one hand On the other hand functionality that is only available in the graphical schema editors is not obvious to find and should therefore also be accessible directly in the main window Extend Object Panels OMS Pro offers collectio
73. face but in the end they were not implemented due to time constraints and therefore not part of the final design Nevertheless the follow ing paragraph describes some design ideas how to integrate the schema editors into the OMS front end since they are an important component to round out the user interface All modeling functionality is provided in the OMS front end version without the schema editors but they would support the modeling process by visualising the relationships between collections The three different schemas as described in section 2 2 could be integrated in a multi page editor that opens in the editor area Figure 4 4 shows how such an editor could look like The advantage of a multi page editor is that the user does not have worry about choosing the right schema editor but he can open the multi page schema editor and easily switch between the pages until the appropriate schema editor is found Further it is often the case that the user needs more than one schema editor to perform a task For example the process of adding a new collection in the classification editor often involves the creation of a new object type in the type editor Therefore it is convenient for the user to have all three schema editors bundled in one editor window 28 4 2 FINAL DESIGN Schema Palette Collection J Subcollection gaSupercolection Y Association A Constraint Collections Types Base Types Figure 4 4 Proposal f
74. g is done by the DatabaseManager class which is one of the central classes in the OMS plug in The DatabaseManager class uses a Singleton pattern which means that only one instance of the class is available throughout the running time of the OMS plug in The database manager holds instances of all databases in the workspace and is therefore the parent object of the Database class Further it initialises the OMS driver and the OMS workspace when the user starts working with database objects and it is responsible for presenting the OMS console when the OMS perspective is activated The database manager class offers methods to import create open close delete commit and rollback OMS databases and it verifies that at most one database connection is open at a time Moreover the class is responsible for managing listener classes implementing the IDBElementListener interface and notifies them if a DBElement object changes CHAPTER 5 OMS FRONT END IMPLEMENTATION 43 5 4 Package MODEL EVENT The model event package offers a listener interface called IDBElementListener It contains methods which are called if an object of type DBElement is added removed or changed or if the user chooses a different display attribute for a collection Classes implementing the interface should register itself using the addDBElementListener method offered in the DatabaseManager class to make sure that it receives all notifications Event notifications concerning changes o
75. hausting navigation the hierarchy levels are not strictly separated If the file browser shows drive letters the selection of a drive results in a list of drive letters followed by the directories of the chosen drive For the user it is not obvious to which drive the listed directories belong The file browsers do not provide a state memory They are not able to store the location in the file system the user accessed last Tab Bar Every object that is opened in the object area of the main application window is represented by a tab in the tab bar The tab bar is displayed at the top of the object area The problem with the tab bar is that the ordering of the tabs does not correspond to the opening order of the objects This is rather irritating for the user and makes it difficult to retrieve already open objects The user expects to find the tab of the last opened object at the very right of all open tabs Furthermore humans rely on a visual orientation and learn which object corresponds to which tab without actually reading the tab label OMS Pro does not follow these principles It does first of all a grouping of tabs according to the object type and within objects of the same type the tabs are ordered alphabetically One consequence is that every time an object is opened the tab ordering changes and the user has to repeat reading tab labels carefully to retrieve an object Adding Associations The process of adding an association between two objects i
76. he WorkbenchPage class holds on to instances of the IEditorReference class rather that the editor itself to allow lazy initialisation The methods presented in the workbench classes are those used in connection with editors As apparent from figure 5 4 the OMS front end uses two editors which are multi page form editors The object editor is described in more details in section 5 8 whereas more to the CHAPTER 5 OMS FRONT END IMPLEMENTATION 47 interface IWorkbenchPage activate in IWorkbenchPart interface IWorkbenchSite findView getPage IWorkbenchPage getViewReferences IEditorReference getShell hideView showView getWorkbenchWindow interface interface l IWorkbenchPart IWorkbenchPartReference IWorkbenchPartSite dispose getPage IWorkbenchPage registerContextMenu getSite IWorkbenchPartSite getPart IWorkbenchPart IN IN A interface interface IEditorReference interface IEditorPart Edi TEditorP 2 E E IEditorSite getEditorinput IEditorSite De A Va getActionBars getEditorSite y getActionBarContributor init WorkbenchPart dispose getConfigurationElement getSite IVVorkbenchPartSite setTitle interface IFormPage getEditor FormEditor getManagedForm pages FormPage setActivePage getPartControl getActiveEditor findPage
77. ich were then analysed and interpreted But the evaluation is based on personal experiences we made while working with OMS Pro during the last couple of years and on discussions we had with other people that are using the system as well 2 2 OMS Pro Concepts and Terminology The OMS Pro GUI is implemented using TCL Tk and consists of a main application win dow and a few additional windows that can be opened from the main window through user interaction The main application window is shown initially It can be seen in figure 2 1 The following list describes the most important elements of the main application window 2 2 OMS PRO CONCEPTS AND TERMINOLOGY db c program files omspro2 1 demo contacts2 1 Database Schema Collections Objects Macros WebElements Queries Windows GRU B RI vor DML OPL AQL Devin Pret 4 80 contact Lukas Relly eth_person Privates _ Situated_at Stefano Spaccapietra eth_person Uwe Roehm eth_person Works_for check_all macro print_staff macro pris T ES Object Browse Evolve Collections Triggers Display Jese S private 0845 iojxi nami Object Browse Evolve Collections Triggers Links Display phor name Moira Norrie 41 1 632 7242 41 1 632 1659 mailto norrie inf ethz ch http www globis ethz ch staff 1098804574199 Prof Object Browse AQL Display Pr photo file ima contact 0637 birthdate 4 7 1924 contact 0642 p
78. idgets and graph ics but it is more closely mapped to the native graphics capabilities of the underlying operating system than Swing or AWT This fact not only makes SWT faster but also allows Java programs to have a look and feel more like native applications The Eclipse Platform and most of the tools that plug in to it use SWT for presenting information to the user 18 3 3 ECLIPSE PLUG IN ARCHITECTURE e JFace a UI toolkit built on top of SWT JFace is a higher level user interface construction toolkit that is designed to be used in conjunction with SWT JFace provides classes for handling and simplifying com mon GUI programming tasks and its API as well as the implementation are window system independent It includes standard GUI toolkit components such as dialogs wizard frameworks and progress reporting for long running operations Two additional features that are useful are actions and viewers Team The team component is responsible for providing support for version control and configuration management It adds views to allow the user to interact with whatever version control system Help In the same way that plug ins add functionality to Eclipse the help component of the Eclipse platform offers a navigation structure that allows tools to define and contribute its own documentation Raw content is added as HTML files whereas the arranging of the raw content into online guides with a suitable navigation structure is expressed separa
79. in section 3 3 The front end plug in contributes to the Eclipse workbench which is the user interface of Eclipse by extending various extension points offered by the workbench If the OMS front end is installed Eclipse adds a plug in directory to the Eclipse installation directory The directory name is ch ethz globis omsjp omsbrowser which is the global iden tifier of the OMS plug in The structure of the plug in directory is similar to those of all other plug ins and contains the following files and folders Plug In XML File The plugin xmi file is a file in XML format that describes the OMS plug in and how it integrates into Eclipse Icons Folder The plug in directory contains typically an icons or images subdirectory to place image files that ship as part of the plug in In the OMS plug in the subdirectory is called icons and it contains various image files that are used for the graphical design of the plug in The icons folder is referenced by the plugin xml file and by various plug in classes Library Folder The OMS plug in accesses OMS databases by means of the OMSIP library The OMS library consists of a JAR file called omsjp jar To work with OMS Pro OMSIP needs an appropriate driver which is stored in a JAR file called omspro jar and a Prolog library called jasper jar The plug in directory contains therefore a library folder called lib where these three JAR files are placed 37 38 5 1 PLUG IN X
80. ins and it therefore makes sense to integrate the numerous database tasks into one perspective Furthermore working with OMS databases needs its own views such as the database explorer or the AQL window and by creating an own perspective these views can initially be added to the perspective layout in order to make all necessary tools available The user can open the OMS perspective using the Window menu in the Eclipse menu bar or using the provided shortcuts in the Resource and in the Java perspective When switching between perspectives the currently open editor windows stay open Thus if the user has several Java classes open and switches from the Java to the OMS perspective and vice versa these editors are not closed It may appear confusing to have Java files among database 30 4 2 FINAL DESIGN objects but it conforms to the Eclipse conventions and it allows to work with different sources without actually having to switch between perspectives For a developer it might be useful to have a Java source file next to a database object if the Java application accesses an OMS database 4 2 2 Database Explorer The most important view of the OMS perspective is the Database Explorer It is the ana logue of the Navigator in the Resource perspective or of the Package Explorer in the Java perspective Considering OMS Pro the database explorer combines the Collection and the Macro panel and e
81. ive To delete a database a dialog is displayed which allows the user to choose if he just wants to remove the database from the Eclipse environment or if the database should be deleted entirely from the file system For members of unary collections the user can choose between the Delete and the Remove From Collection action Choosing Delete provokes the dele tion of the database object and additionally the database object is removed from all unary collections it has been member References to the object in binary collections or attribute APPENDIX B USER MANUAL 79 values need to be removed manually The Remove From Collection action only removes the selected object from the corresponding collection without deleting it Members of binary collections cannot be deleted but only removed from the collection If the user executes a Match operation all matching objects are listed in the Match view The table in the match view offers a Delete action as well to allow the user to delete any kind of database objects If this delete action is used the database object is deleted but there are no further delete operations to restore the database consistency and the OMS perspective is not notified Refresh operations have to be done manually Committing a Database The context menu of the database explorer offers a menu entry to commit the currently open database The OMS console informs the user if the commit oper
82. ive contains a placeholder for the match view behind the AQL view which defines the location of the view when it is opened 5 6 4 Console View The console view differs from the other views since the view itself is implemented and of fered by the Eclipse framework The OMS console is thus an extension of the existing console view The implementation of the OMS console view comprises a single class OMSConsole Manager which is responsible for adding an OMS console page to the existing console using the addConsole method of the Eclipse ConsolePlugin The OMS console is based on an in stance of type MessageConsole and offers methods to write information and error messages to the screen 5 7 Package EDITORS The Eclipse platform offers some basic editors such as a standard text editor as well as highly specialised multi page editors such as the plug in manifest editor The OMS front end cannot profit from the available editors since a text editor is not sufficient to represent database objects and the plug in manifest editor is too specialised Therefore the OMS plug in provides 1ts own editors to view database objects Editors integrate into the Eclipse workbench in a similar way as views Figure 5 4 is thus analogical structured as the view part classes presented in figure 5 2 The difference is that an editor class has to implement the IEditorPart interface instead of the IViewPart interface as views do and editors are contained in an IEditorSite T
83. izards are introduced to create the following OMS objects e Database using the NewDatabaseWizard class e Object Type using the NewTypeWizard class e Collection using the NewCollectionWizard class Association using the NewAssociation Wizard class Method using the NewMethod Wizard class An additional wizard is used to import already existing OMS databases into the Eclipse workspace All wizard classes subclass the Wizard class which implements the Wizard interface and provides much of the Wizard behaviour The Wizard interface contains methods to add the wizard pages and to get the current the previous and the next page in the wizard The task of the wizard classes in the OMS front end is to create and initialise the pages it contains and execute the operation when the Finish button is pressed In addition to subclassing the Wizard class all wizards in the OMS front end that create new objects and that are intended to be placed in the New menu of the Eclipse workbench menu are forced to implement the INewWizard interface Moreover they are required to contribute to the org eclipse ui newWizards extension point in the plug in manifest Implementing this extension point provokes Eclipse to automatically provide an action delegate for the wizard class and display it in the New menu in the tool bar of the Eclipse workbench window Fur ther the OMS perspective adds shortcuts for these wizards in order to make them easily and
84. kages is applied Therefore the identifier of the OMS front end corresponds to the package prefix Further the declaration specifies the name the plug in provider and the version These values are human readable text and are not required to be unique The last attribute in the declaration indicates the plug in class which is described in section 5 2 Listing 5 1 shows the plug in declaration of the OMS plug in lt plugin id ch ethz globis omsjp omsbrowser name OMSBrowser Plug in version 1 0 0 provider name ETH Zurich Global Information Systems Group class ch ethz globis omsjp omsbrowser OMSBrowserPlugin gt Listing 5 1 OMS Plug In Declaration Runtime Section The runtime section of the plug in enumerates the libraries that con tain the plug in code For each library the export attribute specifies which classes are acces sible to other plug ins This is necessary since Eclipse imposes more restrictions on plug in CHAPTER 5 OMS FRONT END IMPLEMENTATION 39 interaction than in a typical Java application Each plug in has its own class loader restrict ing the visibility to code specified in the plug in manifest This means that a class X in one plug in which is in the same package a another class Y in a required plug in cannot access the public method in class Y The compilation process finishes without errors but if the code is executed in the Eclipse framework the class loader will restrict th
85. ks This fact helps to keep Eclipse manageable and reduces the risk of having a completely overloaded user interface When it comes to developing Java applications that are built on top of an OMS database a further advantage of having an OMS front end tool directly available within Eclipse emerges The developer can use one single tool for the implementation process of the Java application as well as for the modeling and administration of the underlying OMS database This elim inates the switching between applications and makes working more comfortable Beginners that implement a Java project coupled to an OMS database for the first time only need to get acquainted with one development environment Or even better 1f they already know how to work with the Java development tools provided by Eclipse it is only a small step to learn how to work with OMS databases since the OMS front end integrates into the Eclipse user interface and adopts its paradigms and conventions 1 3 Document Structure After getting acquainted with the Eclipse environment the first task of the diploma thesis was to evaluate the existing OMS Pro graphical user interface The goal of the evaluation was to find requirements for the new front end The findings of this evaluation and the derived requirements are presented in chapter 2 Chapter 3 gives a short overview of Eclipse The main concepts concerning the extensible architecture of Eclipse and its user interface para digms and
86. location 0852 location 0864 contact 0645 location 0862 phones mobile contact 0648 location 0868 mobile contact 0649 location 0868 mobile contact 0665 location 0863 mobile contact 0666 llocation 0865 mobile contact 0667 location 0866 home contact nee Incatian MET mobile favourite music file images MUSIC Ugachaka avi transport file sr fimaqesiCARSimovie z3 mpg w y w work placeso gt Method work_places 0 conflict due to multiple inheritence on ptype 0578 the one linked to ptype 0570 chosen Method work places 0 conflict due to multiple inheritence on ptype o578 the one linked to ptype 0570 chosen PR Figure 2 1 OMS Pro Main Application Window Menu Bar The main functionality can be found in the menu bar Context menus using the right mouse button are not available in the OMS Pro main window Tool Bar Some important actions as for example commit and rollback actions are represented by a short cut button in the tool bar Collection Panel User as well as system collections are placed in a panel that is visible all the time It is also possible to open collections using the Collection menu in the menu bar but the panel allows to have these objects clearly arranged and accessible with fewer mouse clicks Macro Panel The same concept as for collections exists for macros The panel displays all user and system
87. logy 2 3 Evaluation Results 2 3 1 Strengths of the OMS Pro GUI 2 3 2 Weaknesses of the OMS Pro GUI 24 Requirements Eclipse Platform 3 1 Introduction 3 2 Platform Overview 3 3 Eclipse Plug In Architecture 3 3 1 Plug In Description 3 3 2 Plug In Deployment and Activation 3 3 3 Extension Mechanism 3 4 Eclipse User Interface and its Paradigms OMS Front End Design 4 1 Design Issues and Proposals 4 1 1 Layout and Object Arrangement 4 1 2 Adding Links between Objects 41 3 Sehema Editors 4 2 gt Final D SHMI ya hoe Se ap E E 4 2 1 OMS Perspective 4 2 2 Database Explorer 4 2 3 Collection Editor 4 2 4 Object Editor 4 2 5 AQL Window 4 2 6 ConsoleWindow 4 2 7 Match Window Contents vi CONTENTS 5 OMS Front End Implementation 37 51 Plug In XML Manifest 0 ia os i E n s na SE 38 5 2 Package OMSBROWSER 2 2 2 39 5 3 Package MODEL 3 23 c geni es Sa 812 am e A ee 41 5 4 Package MODEL EVENT 2 22 43 55 Package PERSPECTIVE ta t jt 43 5 67 Package VIEWS 2 2 tetra sto he amp s a er S e x 43 5 6 1 DatabaseExplorerVieWN 44
88. lorer Its implementation comprises one class called AQLView which subclasses the ViewPart class in the Eclipse framework Calling the createPartControl method creates the main panel for the AQL view consisting of a SWT Text entry some instances of the SWT Button class 46 5 7 PACKAGE EDITORS and a JFace TableViewer which is a subclass of the StructuredViewer The table viewer is used to display query results by means of a content and a label provider The AQLView class has an inner class called ResultContentProvider which implements the IStructuredCon tentProvider interface This interface consists of a single method getElements to extract the table elements from an input object In the AQLView the input object is an instance of the class OMSValue representing the query result As label provider a base implementation of the ILabelProvider interface provided by the Eclipse framework is used The AQLView class holds a private instance of the ArrayList class to store query strings that were executed in the past 5 6 3 Match View The match view is a third view that is implemented analogue to the other views Its main class MatchView subclasses ViewPart and contains an inner class as content provider for the table that displays the found database objects If the match action is executed and the view is currently closed then the MatchAction class located in the action package makes sure that an instance of the match view is opened The OMS perspect
89. macros the latter as an optionally expandable tree node Main Panel Object Area All objects that the user opens are displayed somewhere within the main panel or object area of the application Each object is represented as a rectangular object window and additionally with a tab in the tab bar The tab bar is at the top of the main panel CHAPTER 2 EVALUATION OF THE OMS PRO GRAPHICAL USER INTERFACE 7 Console The console window provides system and error messages to the user Graphical schema editors can be opened via the menu or tool bar in the main window but they are displayed in separate windows The system offers a base type and an object type editor see figure 2 2 to add edit and remove new types and a classification editor see figure 2 3 to add edit and remove collections associations and constraints These schema editors offer context menus in addition to the tool and menu bar S Type Editor IE Schema Edit Zoom Display KJOREASGSIAQ contact location 5 attributes 8 attributes person jorganisatio 2 attributes 1 attribute Browse Edit New Type New Subtype of gt Reload private eth_persor 4 attributes 2 atfributes 4 Figure 2 2 OMS Pro Object Type Editor 2 3 Evaluation Results The following two sections provide an enumeration of the most important strengths and weak nesses of the OMS Pro GUI 2 3 1 Strengths of the OMS Pro GUI Storing Paradigm OMS Pro
90. n and macro panels They are extremely helpful to gain an overview over the existing database objects and to access them quickly Therefore the CHAPTER 2 EVALUATION OF THE OMS PRO GRAPHICAL USER INTERFACE 13 OMS Eclipse plug in should offer such panels as well and in addition to collection and macro panels similar panels for other database objects such as types or methods should be considered Redesign Object Arrangement The object arrangement in the object area is not optimal If a number of objects are open it gets quite hard to work with these objects since the object area tends to become very crowded and objects can only be found through the tab bar Attempts should be made to propose a different approach for the object area Provide Intuitive Tab Ordering Having an intuitive tab bar is important since tab bars are commonly used The OMS Eclipse plug in should thus introduce a tab bar that allows to retrieve objects efficiently Reduce Use of Object IDs Since object ids are not a natural way of working with objects for humans they should be extended or replaced through meaningful attribute values Enhance Process of Adding Associations The process of adding associations between two objects is rather circumstantial This process should be simplified by offering more intuitive ways of introducing links Introduce Application State Memory An application state memory is useful since it saves time while working with a system If a us
91. n editor showing all collection members as thumbnails providing more attribute values at first sight It is even conceivable to display an image file as thumbnail 1f the object contains one DDL Pages DDL the Data Definition Language is a language especially defined for OMS to spec ify an OMS schema definition The DDL language can be used to refine a graphically developed data model or to define a data model from scratch Expert users often know these definition languages very well and they would be much faster without the graphi cal support Therefore an idea would be to add a page to all editor windows displaying the DDL sources of the according object The user could then choose to modify an object directly by modifying the DDL source or using the graphical support CHAPTER 6 CONCLUSIONS 59 Complete Functionality The OMS front end does not offer the whole range of functionality that OMS Pro does For example it is not possible to check databases for consistency If a database is in consistent there is no way to find out which constraints are violated The missing functionality should be added to the front end in order to support the complete mod elling process 60 6 2 FUTURE WORK Plugin XML Manifest lt xml version 1 0 encoding UTF 8 gt lt eclipse version 3 0 gt lt plugin id ch ethz globis omsjp omsbrowser name OMSBrowser Plug in version 1 0 0 provider name ETH Zurich Global Information Sys
92. nhances them by adding object types collection members and methods Figure 4 6 shows the database explorer B contacts2 1 amp contacts2 2 1 G gt Collections N Contacts 0582 GD contact 0583 Paul Smith Locations 0586 y Situated At 0588 contact 0583 location 05922 gt Types E oms Database E contact 0571 age 0584 Delete OMS Object Type last_salary 0592 9 E location 0585 Lis Import Database Gl OMS Collection gt Macros e OMS Association F lt count_contacts 0591 ed print_contacts 0593 o Ll print locations 0594 System OMS Method e Collections Fi OMS Macro gt Types gt Macros Figure 4 6 Database Explorer View The database explorer shows all database instances that were either imported from the local file system or created directly within Eclipse If a connection to one of the database instances is established the content of this database can be browsed Due to SICStus Prolog the implementation language of OMS Pro only one database connection can be open at a time The explorer strictly separates user and system data which helps the user to keep track of the data User as well as system data are categorised analogue into collections types and macros Types list their associated methods and collections provide access to their members At the beginning of the design phase we were not quite sure if the database expl
93. nu entry called New which has nothing to do with replacing or removing links CHAPTER 2 EVALUATION OF THE OMS PRO GRAPHICAL USER INTERFACE 11 Another approach to add an association is to open the binary collection that is based on this association and to add a new entry to this collection using the same dialog window as in the previous approach Usability Problems Usability problems reduce the usability of the system and make it rather tedious to work with the system Solving these problems should lead to a more user friendly system Overlapping Windows in Object Area OMS Pro allows to open numerous object win dows in the object area of the application window These object windows overlap and with an increasing number of open objects the object area tends to become more and more crowded It gets difficult to work with these objects since there exists no clear arrangement and the growing number of open objects produces a rather disturbing impression on the screen Application State Memory OMS Pro does not provide an application state memory Such a memory mechanism is responsible for saving and restoring the state of a dialog an object or of the application If the OMS Pro application is closed all open objects are closed as well If the user restarts the application he has to reopen all objects on his own If some objects are used quite frequently or if the user was in the process of modifying an object for example writing a macro
94. ols without having an overcrowded user interface Once a perspective is open the user is free to customize it to suit his needs The user can close views add views from other perspectives or change the layout As long as a perspective stays open the customization is preserved also across multiple sessions More information about perspectives can be found in 1 chapter 10 or 11 Editors Editors are opened in the single editor area of a perspective If more than one editor is open at a given moment then these editors are stacked using tabs Editors allow the user to open edit and save objects Usually these objects are files but editors can also be opened on other data sources such as for example a database object or some kind of input stream Editors follow the classic open modify save paradigm much like file system based tools When an editor is active it can add actions to the menu and the tool bar The editor area is designed to be the focal point of the workbench where the actual tasks are executed The editor area is the same in every perspective This means that if the user switches between different perspectives the currently open editors stay open and are visible in every perspective Views A perspective can have many views arranged around the outside of the editor area A view provides information about an object the user is currently working with in the work bench Views usually augment editors by reflecting some aspects of the curr
95. opers who want to access OMS databases from a Java application 1 2 1 2 MOTIVATION FOR USING ECLIPSE Therefore OMSIP was developed and became the latest member of the OMS suite OMS is a uniform Java library that allows transparent access to heterogenous OMS plat forms as back ends OMSIP maps the OM model of the database into concepts that can be used in a Java application An application built using OMSIP can run with various OMS platforms such as OMS Pro and eOMS if an adequate driver for the underlying platform is available see 4 At the moment this is only the case for OMS Pro but support for e OMS is planned Figure 1 1 shows an overview of the OMSIP architecture Java Application SA i OMSjp Uniform Java Interface l OMS Pro eOMS OMS Pro GUI A Ci Figure 1 1 Architecture Overview The fact that database supported applications using OMSIP are flexible to freely exchange their underlying OMS platform inspired the idea of implementing a single OMS front end based on OMSIP Such a front end is applicable to all OMS platforms supported by OMSIP This implies that only one graphical user interface has to be implemented and maintained for several platforms which leads to a reduced development effort Since OMSIP is a Java interface it was not under consideration that a front end on top of OMS should be implemented using a different programming language than Java
96. or a possible Schema Editor To simplify the actual editing process the schema editor could offer a design palette con taining the graphical elements that can be added to the schema The schema editor would be linked with other views as for example the database explorer The Eclipse Graphical Editing Framework GEF which is a powerful framework for visually creating and editing models could be a helpful tool to implement such a graphical schema editor Basic information can be found in 5 and 14 4 2 Final Design Discussions of the design issues mentioned in section 4 1 1 led to a final design which is described and visualised in this section The OMS front end consists of an own perspective that is added to the Eclipse workbench The perspective initially comprises three views a database explorer presented in section 4 2 2 an AQL window described in section 4 2 5 and a console window see section 4 2 6 A fourth view is opened every time a match operation is executed A description of this view can be found in section 4 2 7 The editor area forms the focal point of the workbench and as stated earlier all objects that are opened are shown in this area using a corresponding editor see section 4 2 3 and 4 2 4 Since the editor area is quite large the empty space is used to present context information The user can view associated information at first sight and navigate by following the provided links Browsing the database becomes similar to
97. orer tree should make the collection members available or not Collections can have a large number of members and by expanding such collections in the tree it can be rather difficult to overview CHAPTER 4 OMS FRONT END DESIGN 31 the database workspace and it uses quite a lot of scrolling activity Nevertheless we decided to list the collection members since the editor area only shows one object at a time Collection members and collections cannot be visible side by side in the editor area and therefore it makes sense to display the collection members in the database explorer tree to allow drag and drop operations and to complete the information in the database explorer Collection members are represented as strings comprising the type the object id and an at tribute value By default the first attribute value of an object is taken but the user has the possibility to choose a different attribute value for every collection Displaying an attribute value for every collection member contributes to an improved usability by reducing the use of object ids The user is able to choose a key attribute in order to find objects without having to know objects ids by heart or opening all objects until the desired one is found Every type of object introduces its own icon in the database tree which is used throughout the whole OMS perspective Consistently used icons support the user to identify objects visually The user can execute various actions in the dat
98. perspective If all objects are opened in the editor area the user is free to add whatever views around it and there are no constraints on the arrange ment of the views 4 1 2 Adding Links between Objects The process of adding links between objects is one of the weaknesses of OMS Pro as de scribed in section 2 3 2 Hence the aim was to improve the way of introducing links One idea was to display source and target collections select an object from both collections and drag these objects into a binary collection Since the editor area can only display one collection at a time we had to abandon this idea However another PhD student of the group provided us with results from one of her former studies She found that if a user intends to link two objects it is more natural to establish a link starting from one object instead of taking two objects and connect them Therefore we decided that the OMS front end should adopt this technique The idea is that the user can add a link starting either from the source or the target object To establish the link the user only has to choose the second object and the object pair is automatically added to the binary collection This technique avoids that the user has to open both objects and the binary collection as it is necessary using object fishing of OMS Pro 4 1 3 Schema Editors One of the established requirements was to offer graphical schema editors They were planned to be part of the final user inter
99. plorer The newly created macro is directly opened in the editor area Browsing and Creating Methods Methods are associated with object types therefore they are listed in the database explorer as child objects of the type object they belong to New methods are created with the method wizard presented in figure B 15 Creating Objects For the most frequently used database objects special wizards are provided to create new instances of these objects All other kinds of objects can be created by using the New OMS Object action which is provided in the context menu of the database explorer The action is enabled if it is called on an object type in the resource tree As a result an object based on the selected object type is created and opened in the editor area Retrieving Objects Objects which are not listed in the database explorer tree can be retrieved by using the match functionality possibly known from OMS Pro On every object type a Match operation can 78 B 4 BROWSING AND UPDATING THE DATABASE New OMS Method OMS method Create a new OMS method k Method name Belongs to type organisation 0573 Browse Figure B 15 Method Wizard be executed All objects that are based on this object type are displayed in a view especially opened for such a request The view can be compared to the Search view in the Java perspective of Eclipse Two different match result windows are presented in figur
100. possible to remove more than one object at the same time using the collection editor Browsing Types The database explorer provides access to user and system types To open a type object it can be double clicked and an object editor window shows up in the editor area The editor window provides the common Attributes section a Supertvpe and a Subtype section to view add or remove sub and supertypes and a Method section to add and remove new methods Creating Types New object types are created using a the Type Wizard shown in figure B 14 APPENDIX B USER MANUAL 77 New OMS object type OMS object type Create a new OMS object type Type name test_typel cr Figure B 14 Object Type Wizard To create instances of base types or structured types no special wizard is available The user has to use the New OMS Object action in the database explorer on the btvpe and stvpe object respectively Browsing and Creating Macros All user and system macros are listed in the database explorer They can be opened in an object editor window providing the Attributes section In order to execute macros the Attributes section offers a Run button Unfortunately the OMS front end is not able to show any side effects of the macro It only indicates if the execution was successful or not To create a new macro the user can choose the New OMS Macro action in the database ex
101. r window as shown in figure 4 8 is opened in the editor area The collection editor is a multi page editor which means that it can contain various pages accessible by means of a tab bar at the bottom of the window EJPrivates 0589 X Privates 0589 Ika private 0575 Collection Extent Super Collections Object attribute E Contacts 0581 amp private 0637 Immo Noack E Persons 0588 private 0670 Epaminondas Kapetanios private 0677 Antonia Erni private 0679 Alain Wrgler 6D private 0843 Michael Grossniklaus amp private 0845 Moira Norrie private 0846 Beat Signer private 0848 Alexios Palinginis Sub Collections Remove From Collection J Delete Figure 4 8 Collection Editor The final version of the collection editor only contains a single page but we still chose to use a multi page editor to make the editor easily extensible Additional pages could contain more context information or associated DDL Data Definition Language of OMS statements In the final version the single page displays the collection extent as a table where the user can add and remove members The right hand side of the editor page shows all super and subcollections Below the title a link to the member type of the collection is provided The style of the collection editor is based on a new Eclipse 3 0 feature called Eclipse Forms Eclipse Forms is a
102. ration of classes which are used in the OMS plug in The DBObjectTransfer and the DBObjectDropTargetAdapter are required in con nection with drag and drop actions The DBObjectTransfer class inherits from the java io ByteArrayTransferClass and is responsible for transferring database objects A database object is identified by its object id and the parent object Therefore the DBOb jectTransfer class writes these two values into a java io DataOutputStream and reads it again to restore the transferred object The DBObjectDropTargetA dapter is a base imple mentation of the Eclipse DropTargetListener interface and is used to perform the actual drop operation Another group of Java classes in the util package are base implementations of content and la bel providers The DefaultContentProvider implements the IStructuredContentProvider interface which can be used for all JFace table viewers The ListLabelProvider and the TableLabelProvider are implemented to serve as basic label providers for JFace list viewers and table viewers respectively The CollectionListDialog the ObjectListDialog and the TypeListDialog class are dialog classes allowing the user to choose from a list of possible collections types or other objects They all subclass the SelectionDialog class offered in the org eclipse ui dialogs package 54 5 13 PACKAGE UTIL Conclusions 6 1 Achievement The goal of this diploma thesis was to design and implement a graphical user inte
103. rface for OMS which is built on top of OMSIP OMSIP is a Java interface that allows to access different OMS platforms in a uniform manner The resulting OMS front end is implemented as an Eclipse plug in and enables the user to access OMS databases directly through the Eclipse environment 6 1 1 Intended Goals In the early stages of this diploma thesis the existing OMS Pro graphical user interface was evaluated The aim was to derive requirements for the OMS front end for Eclipse The following list summarises briefly the requirements that were established in section 2 4 e Keep the commit rollback storing paradigm e Offer context information e Offer graphical schema editors Extend the object panels used by OMS Pro e Redesign the object arrangement in the object area Provide an intuitive tab ordering 55 56 6 1 ACHIEVEMENT Reduce the use of objects ids to make the working with objects easier Enhance the process of adding associations Introduce an application state memory 6 1 2 Discussion The first requirement was to keep the storing paradigm of OMS Pro The OMS front end adopts the commit 7 rollback paradigm suggested by the existing OMS Pro GUI This is against the Eclipse conventions but in the case of editing database objects instead of text files it makes sense to immediately take over any changes made The user does not have to perform a lot of save operations and unintentional modifications can be discarded
104. rning the object arrangement and the layout of the OMS front end These decisions also influenced the process of adding links between objects as described in section 4 1 2 4 1 1 Layout and Object Arrangement One component that we were sure about right from the start was a database explorer view that displays the contents of the databases present in the workspace similar to the Eclipse resource navigator Besides this database explorer component it needed some consideration until we got to the final design One of the main difficulties was to find a solution how to map the main application area of OMS Pro to the editor view paradigm in Eclipse OMS Pro offers an area where the user can open multiple objects which can be viewed side by side or as overlapping windows On the one hand this can be an advantage since the user can for example view a collection and a member of this collection at the same time On the other hand the problem of this object area is that it tends to become overcrowded and quite complex with an increasing number of open objects Therefore we intended not to adopt the concept of overlapping windows Eclipse offers an editor area which is designed to display a single editor at a time representing a file or in our case a database object For every new editor window that is opened a new tab is added to the tab bar If the user wants to have more than one editor window displayed on the screen he can tile the editor area arbitrarily by
105. s rather circumstantial The user has different possibilities to establish a link between objects The most natural approach is to add a link starting from the source object and then indicating the target object OMS Pro does support this approach offering the Links menu that can be found in the menu bar of every object window The Links menu provides a list of all possible associations the object could be part of and all existing links to other objects The user can then add a new link using the menu entry New in the Links menu The source object of the new link is already clear but OMS Pro displays a dialog window where the user has to specify the source as well as the target object The value fields are preselected but the preselection does not correspond to the object that should be linked To set the value fields the user can directly enter the object id which he has to look up or to know by heart An auto complete function is available but it does only work when the preselection is cleared Another way to set the value field is to use object fishing which means that the user has to click on the object to fill in This requires that the object to click on is opened in the object area If the user finally sets the two objects that should be linked the user can choose between the operations Insert Replace or Remove This is not consistent with the fact that the dialog window appeared after clicking on a me
106. s to scroll the main panel or to displace the object in order to centre the object in the main panel and actually look at the whole object content Model Problems Model problems are problems where the result of a function or action does not correspond to the mental model of the user A mental model is a set of beliefs that a user holds about how things or in this case software features work Such a mental model is often established based on former experiences with tasks that are similar to the one that should be currently solved If a user is solving a task and the result of an action is different from his expectations the user is confused and the learning process is slowed down The user cannot revert to something known and even worse he has to react differently than in another known case 10 2 3 EVALUATION RESULTS File Browsers The file browsers offered in OMS Pro are not intuitive to use They do not correspond to the expectations users have from working with Windows or Linux The file structure is not displayed as a tree but as a list To navigate between hierarchy levels the user can either go up or down one hierarchy level at a time or he can type the target directory manually in the selection field If the nesting of directories is very deep the navigation in the file system is rather tedious Typing the target directory manually assumes that the user knows the exact path by heart and is able to spell it correctly In addition to the ex
107. s type has to be displayed Some dialog classes as for example the AddValueDialog class reuse the DBValueEntry class to offer appropriate forms to allow the user to add attribute values DBValueEntry Objector i formPages JEctterin put createEntry obj IEditorinput exists createProcedureEntry getimageDescriptor createDateEntry createTextFieldEntry createStructuredEntry createBulkEntry createUriEntry ObjectAttributeSection createObjectEntry AddValueDialog createSectionContent createAttributeEntries ObjectAttributePage refresh a dispose createFormContent updateFormTitle ObjectLinksSection Ina GEBEN createSectionContent createLinkAreas DBEditorSection ObjectCollectionSection ObjectMethodSection SubTypeSection SuperTypeSection FereateSectionContent ereateSectionContent createSectionContent createSectionContent createTable createMethodTable makeActions makeActions interface IDBElementListener dbElementAdded V DBEditorTableSection dbElementRemoved dbElementChanged dbCollectionAttributeChanged Figure 5 7 Object Editor Classes 5 9 Package EDITORS COLLECTION The collection editor is used to display collection objects Its structure is analogue to the object editor The CollectionEditor class is the main editor class extending the FormEditor class It has a single
108. sorted by the object id or alphabetically according to the attribute value Database Explorer X contacts2 1 v by ObjectID 1 contacts2 3 by Name amp Collections Contacts 0592 LE ETH_Persons 0593 L Ex_ETH 0594 Locations 0596 Figure B 5 Change Sort Criteria Opening a Collection in the Editor Area To open a collection in the editor area double click on the corresponding collection in the database explorer A collection editor window as shown in figure B 6 is opened in the editor area The editor window shows the collection extent as a table The collection members in the table can be opened with a double click If it is a binary collection either the source or the target object of a collection member can be opened depending on the table cell that is doubleclicked Creating a Unary Collection A new unary collection can be created using the Collection wizard If the wizard is called using the File New menu then the wizard page is blank If the context menu of the 72 B 4 BROWSING AND UPDATING THE DATABASE Ed private 0575 Collection Extent Super Collections Object attribute Gi Contacts 0581 private 0637 Immo Noack E Persons 0588 private 0670 Epaminondas Kapetanios private 0677 Antonia Erni private 0679 Alain Wrgler GD private 0843 Michael Grossniklaus Sub Collections
109. ss checks if the OMS perspective was activated and if so 1t reactivates the OMS console in the console view 5 6 Package VIEWS Views are part of the Eclipse workbench From a developer s point of view it is necessary to specify the workbench more precisely and clarify some Eclipse terminology The term used to represent the entire Eclipse user interface is workbench The workbench itself has no physical manifestation but it is displayed in one or more workbench windows These basic top level windows make up an Eclipse application having a menu and tool bar on the top and the status line at the bottom of the window The main body of a workbench window between the tool bar and the status line is represented by the workbench page which in turn is made up of workbench parts Workbench parts come in two varieties namely views and editors The initial size and orientation of the parts in the page are determined by the perspective Parts interact with the rest of the window via their site The site is not a visible entity but simply an API mechanism to separate the methods that operate on the view from the methods that operate on controls and services outside the view 44 5 6 PACKAGE VIEWS 5 6 1 Database Explorer View The database explorer view is one of the three views that belongs to the OMS perspective Similarly as the perspective extension point a view extension point org eclipse ui views is offered by the Eclipse workbench The databas
110. surfing the internet since links to objects that might be relevant for the user are directly shown in the editor Every time a link is opened a new editor window is added to the editor area including a new tab in the tab bar This induced us to name this browsing technique Tabbed Browsing The aim of this technique is that the user can work mainly task driven This means that the user can perform his work having in mind a high level task that he wishes to accomplish Since the system offers context information and links to associated objects the user does not have to interrupt the task in order to find a certain object CHAPTER 4 OMS FRONT END DESIGN 29 but he is able to use the guidance of the system and follow straightforward links to associated objects 4 2 1 OMS Perspective The core piece of the OMS front end is an own perspective that is added to the Eclipse workbench A screenshot of the OMS perspective is provided in figure 4 5 OMS person 0570 Eclipse Platform File Edit Navigate Search Project Run Window Help mi BBA e Database Explorer X B contacts2 1 amp Collections 5 Types suse fos El contact 0569 a 70 O D TestJavaclass java El person 0570 5 person 0570 GJ 70 ia organisation 0573 Attributes Super Types Ed private 0575 name person Ed contact 0569 Ed eth_person 0578 Sk attrst name type object 022 E location 0580 ba test 5301
111. t Since Eclipse 3 0 the developer can also choose to build stand alone rich client applications that are simply using the platform runtime and its plug in mechanism With this Rich Client Platform RCP approach the spectrum of possible applications grows enor mously since the user interface and the underlying model of the application do not have to integrate into the Eclipse workbench and workspace anymore This fact enables the developer to implement almost freely designed applications Section 3 2 explains the components of the Eclipse Platform In section 3 3 a survey of the Eclipse plug in architecture can be found and finally section 3 4 provides information about the Eclipse graphical user interface and its conventions 3 2 Platform Overview Eclipse Platform is the name for the core framework and services upon which plug in exten sions are created It provides the runtime in which plug ins are loaded and run The Eclipse 15 16 3 2 PLATFORM OVERVIEW Eclipse Platform Java Workbench Development Tools JFace Workspace Environment PDE Platform Runtime Eclipse Project AS Figure 3 1 Eclipse Project Overview Platform itself is not really a true product that would ship by itself Its direct consumers are tool builders since they add the value to the Eclipse Platform that makes it useful to end users The Eclipse Platform is basically just the nucleus around which tool buil
112. te plug in architecture it is even possible to design an independent plug in for the schema editor which extends the OMS plug in Drag and Drop Drag and drop is a useful tool to easily make connections between objects The OMS front end offers a basic drag and drop mechanism allowing the user to add collections members to a collection by dragging objects from the database explorer tree into the collection editor The OMS front end could be enhanced by offering more drag and drop operations that simplify other modelling tasks For example to establish links between objects it would be helpful if the user could drop an appropriate object directly on the link table in the Links section Another idea is to allow the user to drop an object on any other object to link these two objects if possible If it is clear which association suits the link would be added automatically otherwise the system could show a dialog window to let the user choose from possible associations between these two objects Icon View In the final front end version the collection editor shows a list of collection members with one of their attribute values At the beginning of this thesis one idea was to let the user choose how he would like to have the collection members displayed The choices would be analogue to the Windows explorer where files can be viewed as detailed list or as large icons for example Therefore the OMS plug in could offer a second page in the collectio
113. tely in XML files Debug The debug component offers a generic debug mechanism that cannot only be used for the Java language It includes launch configurations to specify how to run a program a generic debug model offering breakpoints standard debug events and actions and a generic debug user interface with its own perspective 3 3 Eclipse Plug In Architecture As described in section 3 2 the Eclipse platform consists of the platform runtime which is a small kernel and a varying set of plug ins 3 3 1 Plug In Description A plug in is the smallest unit of an Eclipse function that can be developed and delivered separately Small tools as for example an action to create zip files are usually written as a single plug in whereas complex tools such as an HTML editor may span several plug ins These plug ins are then grouped into installable pieces so called features Eclipse plug ins are actually components that provide a certain type of service within the Eclipse environment A plug in is represented by an instance of a plug in run time class or plug in class for short The plug in class provides methods that are called for the activation or deactivation process of the plug in All plug in classes extend the org eclipse core runtime Plugin class which is an abstract class providing generic function ality for managing and configuring plug ins In addition to the plug in class every plug in is described by an XML plug in manifest file This manif
114. tems Group class ch ethz globis omsjp omsbrowser OMSBrowserPlugin gt lt runtime gt lt library name lib jasper jar gt lt export name x gt lt library gt lt library name lib omspro jar gt lt export name x gt lt library gt lt library name lib omsjp jar gt lt export name x gt lt library gt slibrary name OMSBrowser Jjar gt lt export name x gt lt library gt lt runtime gt lt requires gt lt import plugin org eclipse ui gt lt import plugin org eclipse core runtime gt lt import plugin org eclipse jface text gt 61 62 lt import plugin org eclipse core resources gt lt import plugin org eclipse ui editors gt lt import plugin org eclipse ui ide gt lt import plugin org eclipse jdt core gt lt import plugin org eclipse ui forms gt lt import plugin org eclipse ui console gt lt requires gt lt extension point org eclipse ui editors gt lt editor class ch ethz globis omsjp omsbrowser editors collection CollectionEditor icon icons unary_collection gif default false name Collection Editor id ch ethz globis omsjp omsbrowser editors collection CollectionEditor gt lt editor class ch ethz globis omsjp omsbrowser editors object ObjectEditor icon icons single_object gif default false name Object Editor id ch ethz globis omsjp omsbrowser editors o
115. tform offers a base implementation of a section called Sec tionPart The SectionPart class as vvell as the IFormPart interface it implements are lo cated in the org eclipse ui forms package A section has a title and can be in an expanded or collapse state The OMS plug in offers a DBEditorSection and an even more specialised DBEditorTableSection The DBEditor TableSection is preset having a JFace table viewer as main component of the section with the possibility to add buttons to the right side of the table The classes that belong to the framevvork are presented in figure 5 6 If a section is more complex than just displaying a table vievver vvith buttons to the left the DBEditorSection can be used by adding the desired form entries manually Form entries are reusable components of the OMS plug in editor framework that can be added to form editors An entry can either be a text entry class DBTextEntry or a table entry class DBTableEntry both subclassing the abstract DBFormEntry class An instance of the DB TextEntry class consists horizontally from left to right of an optional label a SWT text field and an optional button The DBTableEntry is similar offering a JFace table viewer instead of a text field and more than one button to the right In order to add actions to the buttons or a hyperlink instead of a label the framework pro vides the IEditorFormEntryListener interface Classes implementing this listener interface can be associate
116. tributePage As described in section 5 7 the OMS plug in offers generic section components that can be added to the editor pages The object editor is constructed of different sections depending on the kind of database object it represents Figure 5 7 provides an overview of all object editor classes The ObjectAttributeSection displaying the attributes of a database object is common to all database objects shown in the object editor Type objects offer additionally the ObjectMeth odSection and the SubTypeSection and SuperTypeSection to present sub or supertypes respectively Collection members offer the ObjectCollectionSection presenting all member ship collections the ObjectMethodsSection and the ObjectLinksSection to show related objects All sections implement the IDBElementListener interface to be able to react to any events The ObjectMethodSection the Super TypeSection the SubTypeSection as well as the Ob jectCollectionSection display simple tables and extend therefore the DBEditorTableSection class The ObjectLinksSection uses several DBTableEntry instances to display several link tables whereas the ObjectA ttributeSection is the most complex one It displays the different attribute values and depending on the attribute type For each attribute type the form entry has to adopt a different shape Therefore the DBValueEntry class exists which is a helper class 50 5 9 PACKAGE EDITORS COLLECTION knowing how each attribute depending on it
117. ts location set person Ea work_places 0608 gt results location set person Eilwork_placesO 0614 gt results location set person Ed work _placesO2 0615 gt results location set person Figure 4 9 Object Editor Depending on the kind of object the editor offers different information sections The At tributes section is common to all kinds of objects whereas the Links section is special for this type of object For collection members the Links section offers valuable context information that helps the user to immediately understand the context of an object By convention editors in Eclipse usually follow a classical open modify save paradigm In chapter 2 we stated that the commit rollback paradigm is one of the strengths of OMS Pro and should thus be adopted in the OMS front end We therefore decided to break the conventions The collection editor as well as the object editor do not need any save operations Any changes made to database objects are immediately reflected in the database 34 4 2 FINAL DESIGN 4 25 AQL Window In addition to the database explorer view the OMS front end offers an AQL view which can be used to query databases using the own query language of OMS called AQL In the initial perspective layout the AQL view is placed in the console area behind the console window Figure 4 10 shows how the AQL window looks like Console ESE match
118. y or with the help of the Update Manager provided by Eclipse To install the OMS front end manually please follow the instructions below 1 Download the OMSBrowser zip file 2 Unzip the contents of the OMSBrowser zip file into the ECLIPSE_HOME directory which is the main directory of the Eclipse installation for exam ple C Program Files eclipse The ECLIPSE HOME plugins directory should now contain two directories called ch ethz globis omsjp omsbrowser_1 0 0 and ch ethz globis omsjp omsbrowser help 1 0 0 3 If Eclipse was running during the unzip process restart the Eclipse workbench For an installation with the help of the Update Manager the following steps need to be ac complished 67 68 B 3 GETTING STARTED 1 Select the Help Software Updates Find and Install menu entry to open the Install Update dialog 2 Choose the option Search for new features to install and advance to the next dialog window 3 In order to download the OMS front end a new Remote Site has to be added with the URL of the OMS front end update site Mark the check box of the added update site to include it in the search process 4 The search result presents the OMS Browser Feature which can be selected If the terms in the license agreement are accepted the OMS plug in is installed Eclipse has to be restarted B 3 Getting Started Setting OMS Properties Before the OMS front end

Eclipse-Based Front-End for OMSjp - ETH E

Contents

Download Pdf Manuals

Related Search

Related Contents