Using e3x property view with e4 Selection service from EMF Model - eclipse-rcp

I built a small e4 RCP application containing both an "e4 xmi" tree view populated by emf generated model code (using ComposedAdapterFactory) and an "e3 properties view".
Tried following "dirksmetric tutorial" to display property view in application.e4xmi (shared elements) with an empty property view.
To get a tree's selected element displayed in my property sheet (IItemPropertySource), I did the following things :
On my e4 treeviewer side, I use the e4 selection service in #createComposite:
// Register the viewer as a selection provider (to be consumed by the property view...)
viewer.addSelectionChangedListener(new ISelectionChangedListener() {
#Override
public void selectionChanged(SelectionChangedEvent event) {
IStructuredSelection selection = (IStructuredSelection) event.getSelection();
// set the selection to the service
selectionService.setSelection(
selection.size() == 1? selection.getFirstElement(): selection.toArray());
}
});
On the e3 "classical" property sheet side, I defined a couple of things :
I called IDE.registerAdapters in my ApplicationWorkbenchAdvisor#initialize.
I declared my property source adapter as follow in my plugin.xml :
extension point="org.eclipse.core.runtime.adapters">
factory adaptableType="org.eclipse.emf.ecore.EObject"
class="myappmodeler.properties.ModelPropertiesAdapter">
adapter type="org.eclipse.ui.views.properties.IPropertySource">
My ModelPropertiesAdapter#getAdapter returns a property source :
public Object getAdapter(Object adaptableObject, Class adapterType) {
if (adapterType== IPropertySource.class && adaptableObject instanceof EObject){
emfGlobalFactory = new ComposedAdapterFactory();
emfGlobalFactory.addAdapterFactory(new RepositorystructureItemProviderAdapterFactory());
emfGlobalFactory.addAdapterFactory(new ApplicationItemProviderAdapterFactory());
emfGlobalFactory.addAdapterFactory(new ServiceItemProviderAdapterFactory());
return new AdapterFactoryContentProvider(emfGlobalFactory).getPropertySource(adaptableObject);
}
return null;
}
My problem is this adapter is not even executed.
Currently using Eclipse neon (it was recently updated to synchronise E3 and E4 selection service)
https://bugs.eclipse.org/bugs/show_bug.cgi?id=403930

There are different ways to fix this problem, but for my case, these are the steps
I took to these steps to solve mine
Take control of the base model - create an interface which extends EObject
Create custom property provider, source and descriptor - extends org.eclipse.emf.edit.ui.provider.*
at runtime we need IItemPropertySource
Create a content provider class (extends AdapterFactoryContentProvider) and override createPropertySource with custom property source
Note; I also developed a table layout which means implementing custom ItemProvider (implement ITableItemLabelProvider) for individual elements in the model
Worked perfectly with ESelectionService
Hope these notes helps somebody

Related

How to capture the value of a cell of a TableViewer where a contextual menu has been activated in eclipse e4?

In one of my eclipse e4 application JMSToolBox, some data is displayed in aTableViewer
A contextual menu is defined in the e4 model file (e4xmi) and linked to theTableViewer like this
menuService.registerContextMenu(tableViwere.getTable(), <name of the e4 part menu>);
Attached to the contextual menu in the e4 model, a "menu item" is linked to a"Dynamic Menu Contribution" class that dynamically add the menu items to the menu:
public class VisualizerShowPayloadAsMenu {
#Inject private EModelService modelService;
#AboutToShow
public void aboutToShow(EModelService modelService, List<MMenuElement> items) {
// Not the real code..., illustrate adding a dynamic menu item to the contextual menu
MDirectMenuItem dynamicItem = modelService.createModelElement(MDirectMenuItem.class);
dynamicItem.setLabel(<name..>);
dynamicItem.setContributorURI(Constants.BASE_CORE_PLUGIN);// "platform:/plugin/org.titou10.jtb.core");
dynamicItem.setContributionURI(Constants.VISUALIZER_MENU_URI);// "bundleclass://org.titou10.jtb.core/org.titou10.jtb.visualizer.ui.VisualizerShowPayloadAsHandler");
items.add(dynamicItem);
}
Now, what I want to do is to capture the data in the underlying cell where the contextual menu has been activated, and get that value back in the method annotated by"#AboutToShow" in order
to addMDirectMenuItementries to the contextual menu with a label containing that value
Q: how to do that with eclipse rcp e4?
In the attached picture, the right click happened in the cell with content="ID:414d5120514d41414544202020202020ee4bb25612666920". I would like to get this value back in the #AboutToShowmethod and add menu items to the"Open Payload as..."menu based on that value
Thanks
I found a way to do it!
I'm not sure it is the best way, but at least it works and it is quite simple
The following code is here to illustrate the idea, it is not valid Java.
In the part that manage theTableViewer:
TableViewer tableViewer = new TableViewer(composite, SWT.BORDER | SWT.FULL_SELECTION | SWT.MULTI);
{...}
new TableViewerFocusCellManager(tableViewer, new JTBFocusCellHighlighter(tableViewer, windowContext));
JTBFocusCellHighlighterclass:
public class JTBFocusCellHighlighter extends FocusCellHighlighter {
private IEclipseContext windowContext;
private Table table;
public JTBFocusCellHighlighter(ColumnViewer viewer, IEclipseContext windowContext) {
super(viewer);
this.windowContext = windowContext;
this.table = ((TableViewer) viewer).getTable();
}
#Override
protected void focusCellChanged(ViewerCell newCell, ViewerCell oldCell) {
super.focusCellChanged(newCell, oldCell);
// Capture the content of the cell (or other info..) and store it in Eclipse Context
windowContext.set("key", newCell.getText());
TableColumn tableColumn = table.getColumn(newCell.getColumnIndex());
}
}
Real code implementation: JTBSessionContentViewPart , JTBFocusCellHighlighter and FilterMenu

How to retain the state of a treeviewer in Java RCP application?

I have a simple RCP application having couple of wizards out of which one is having a tree viewer. I want to retain the state of the selected item in the tree viewer next time I open that particular view. As of now I have implemented using static variables and its working fine.I want to know how it can be done in a better way?
//Sample Code
private static RepositoryLocationItem lastRepoItemSelected;
Composite parent=new Composite(SWT.NONE)
treeViewer = new TreeViewer(parent);
treeViewer.setContentProvider(new MovingBoxContentProvider());
treeViewer.setLabelProvider(new MovingBoxLabelProvider());
treeViewer.setInput(getInitalInput());
treeViewer.addSelectionChangedListener(new ISelectionChangedListener() {
/* Setting the value of lastRepoItemSelected */
});
if(lastRepoItemSelected !=null)
{
treeViewer.setSelection(new StructuredSelection(lastRepoItemSelected),true);
}
Assuming this is a 3.x style RCP (your view extends ViewPart) you can use the saveState method to save your view state:
#Override
public void saveState(final IMemento memento)
{
// TODO set values in the 'memento'
}
You can then use the init method to restore values from the memento when the view is shown again:
#Override
public void init(final IViewSite site, final IMemento memento)
throws PartInitException
{
super.init(site, memento);
// TODO restore from 'memento'
}
Note: Mementos are persisted across restarts of your RCP so you need to store values in them which are valid in a new instance of the RCP.
Also look at the Eclipse wiki entry for more information.
For a WizardPage you can use the IDialogSettings. You must set this up in your Wizard using something like:
IDialogSettings pluginSettings = Activator.getDefault().getDialogSettings();
IDialogSettings wizardSettings = pluginSettings.getSection("id of your wizard");
if (wizardSettings == null) {
wizardSettings= new DialogSettings("id of your wizard");
pluginSettings.addSection(wizardSettings);
}
setDialogSettings(wizardSettings);
where Activator is your plugin activator class and "name of your wizard" is a id for your wizard (which can be anything as long as it is unique in your plugin).
In your wizard page you can then get the settings with:
IDialogSettings settings = getDialogSettings();
IDialogSettings has lots of methods for saving and restore various sorts of values, such as:
settings.put("key", "string value");
String value = settings.get("key");

How to pass an object from one part to another part in Eclispe e4 RCP?

I am building an application with eclipse e4 RCP. I have a navigator (similar to Navigator in eclipse IDE) and I would like to link it to an editor (similar to how a file in Navigator in eclipse IDE is linked to an editor). Currently I am using EPartService to open up my editor Part (by creating a new instance) when the user double clicks on a file in the Navigator tree. But I would like to pass it a parameter (a String or an Object) to let it know which file to open in the editor. I want to be able to open multiple editors for different nodes of the Navigator tree. I have done a lot of research on internet but could not find a solution. I think its a common problem and the e4 framework should provide an mechanism to pass such parameters from one Part to another Part. Current code is as below:
viewer.addDoubleClickListener(event -> {
final IStructuredSelection selection = (IStructuredSelection) event.getSelection();
FileNode file = null;
boolean partExists = false;
if (selection.getFirstElement() instanceof FileNode ) {
file = (FileNode ) selection.getFirstElement();
for (MPart part1 : partService.getParts()) {
if (part1.getLabel().equals(file.getName())) {
partService.showPart(part1, PartState.ACTIVATE);
partExists = true;
break;
}
}
if (!partExists) {
MPart part2 = partService
.createPart("com.parts.partdescriptor.fileeditor");
part2.setLabel(file.getName());
partService.showPart(part2, PartState.ACTIVATE);
}
}
});
Is it possible to say something like part2.setParameter("PARAM_NAME", "FILE_NAME"); ?
When you have an MPart you can call:
MPart mpart = ...
MyClass myClass = (MyClass)mpart.getObject();
to get your class for the part (the class defined in the 'Class URI' for the part in the Application.e4xmi). You can then call any methods you have defined on your part class.
You can also set data in the 'transient data' area of a part:
mpart.getTransientData().put("key", "data");
Object data = mpart.getTransientData().get("key");

How to bind view model to a UserControl in MVVMCROSS?

I am using the excellent Mvvmcross and Ninja Coder for Mvvmcross for building a cross platform app. For my windows store app I have created a view and a view model using Ninja coder. I have also created a UserControl which will be referenced in the view. Hence I need to bind the same viewmodel to the User control also. I have been trying to set the Data context of the user control to the singleton instance of viewmodel. I have set the data context of the user control like below.
public sealed partial class SearchResultsGridViewControl : UserControl
{
private SearchresultsViewModel _viewModel;
public SearchResultsGridViewControl()
{
this.InitializeComponent();
_viewModel = Mvx.IocConstruct<SearchresultsViewModel>();
this.DataContext = _viewModel;
}
}
But when I refer this User Control in my main view, it throws an error in XAML saying "Object Reference not set to an instance of an object. Cannot create an instance of SearchResultsGridViewControl".
This is my viewmodel:
public class SearchresultsViewModel : BaseViewModel
{
private ISearchResultsService _searchResultsService;
public SearchresultsViewModel(ISearchResultsService searchResultsService)
{
_searchResultsService = searchResultsService;
var items = _searchResultsService.DisplaySearchResults();
SchoolDetails = new ObservableCollection<School>(items);
}
private ObservableCollection<School> _schoolDetails;
public ObservableCollection<School> SchoolDetails
{
get { return _schoolDetails; }
set
{
_schoolDetails = value;
RaisePropertyChanged(() => SchoolDetails);
}
}
public ICommand RefineCommand
{
get
{
refineCommand = refineCommand ?? new MvxCommand(FilterSearchResultsBasedOnRefine);
return refineCommand;
}
}
public void FilterSearchResultsBasedOnRefine()
{
SchoolDetails = new ObservableCollection<School>(_searchResultsService.FilterSchoolsBasedOnRefine(MidDayMeals, PlayGround, DigitalClassroom, DayBoarding, TransportationFacility));
}
}
The grid view in my usercontrol is getting populated when it loads for the first time. But when RefineCommand is called to update the collection from the main view, the grid view in usercontrol is not getting updated. And I am guessing its because of that error earlier in setting the data context of the user control to view model. Please let me know what could be going wrong. I have been banging my head about it for days.
I've been using MVVMCross with Windows Store fairly recently. Without looking back at my code, I'm pretty sure that the Datacontext will inherit from it's parent unless overridden.
So as long as the MvxPage that you have presented has a viewmodel, any user control that you add to it, either in XAML or in code-behind, should share the same data context. If you are looking at doing some MVVMCross data-binding from the User Control, you should probably make sure your User Control implements IMvxStoreView, and ensure that the ViewModel property is set to the value of DataContext.
Hope that help.
Cheers,
Tristan
I think your first problem "Object Reference not set to an instance of an object" is a design time only issue - because you are trying to set the viewmodel using Mvx. at design time. You can workaround this issue if you want to by using design time viewmodels and possibly also by using one of the design time helpers (see https://github.com/MvvmCross/MvvmCross/blob/v3.1/CrossCore/Cirrious.CrossCore.Wpf/Platform/MvxDesignTimeHelper.cs).
I've no idea what your second problem is "The grid view in my usercontrol is getting populated when it loads for the first time. But when RefineCommand is called to update the collection from the main view, the grid view in usercontrol is not getting updated" - this sounds like an issue either in your xaml or in the results returned from FilterSearchResultsBasedOnRefine. From the current level of detail, I can't see what it is. My "gut feeling" is that the problem won't be MvvmCross specific - it'll just be a general Mvvm/data-binding issue.

How to handle property sheet from customized editor in eclipse plugin development?

I have to bind my editor widget objects in property sheet.So that i can the property of my widget from property view.
Please help me on this, if possible provide me some code snippets.
You have a good example in the Getting started with Properties
Using the Properties view is simple enough.
Since it shows properties for the selected object, the first step to using it is to make sure that the workbench selection service knows about the object selected in your view. There’s an entire Eclipse Corner article written on the subject of the selection service
public void createPartControl(Composite parent) {
viewer = new TableViewer(parent, SWT.MULTI | SWT.H_SCROLL | SWT.V_SCROLL);
viewer.setContentProvider(new ViewContentProvider());
viewer.setLabelProvider(new ViewLabelProvider());
getSite().setSelectionProvider(viewer);
viewer.setInput(getViewSite());
}
Once you have your view contributing to the workbench selection, you need to make sure that the objects that your view is selecting contribute properties
(extract)
public class Person implements IPropertySource {
private String name;
private Object street;
private Object city;
public Person(String name) {
this.name = name;
this.street = "";
this.city = "";
}
public Object getEditableValue() {
return this;
}
public IPropertyDescriptor[] getPropertyDescriptors() {
return new IPropertyDescriptor[] {
new TextPropertyDescriptor("name", "Name"),
new TextPropertyDescriptor("street", "Street"),
new TextPropertyDescriptor("city", "City")
};
}
I indicated earlier that this solution is “not necessarily [the] most correct”. This is because, for this to work, my domain object needs to know about the very view-centric (and Eclipse-centric) notion of being a property source; in short, there is a tight-coupling between the model and view and this not a good thing™.
Using adapter is a better approach, as described in this article:
Person should implement IAdaptable.
See also this recent article on how to create a custom property view
how to hack the Properties View to listen only to a specific view.
The isImportant() method is the one which decides whether to create an IPage for the specific IWorkbenchPart or not.
The idea is to override that method and return false for all the workbenchPart that we are not interested in. Lets create the view first:
<view
class="com.eclipse_tips.views.CustomPropertiesView"
icon="icons/sample.gif"
id="com.eclipse-tips.views.customePropertiesView"
name="My Properties View">
</view>
The CustomPropertiesView should extend PropertySheet and override the isImportant():
public class CustomPropertiesView extends PropertySheet {
#Override
protected boolean isImportant(IWorkbenchPart part) {
if (part.getSite().getId().equals(IPageLayout.ID_PROJECT_EXPLORER))
return true;
return false;
}
}
In this case, I'm making the view only to respond to Project Explorer and ignore other views
According to this thread, the same principle should be valid for an Editor instead of a View.
The property sheet listens to the workbench page selection provider.
The selection provider depends on what viewer/editor is active.
Each editor/viewer provides their own selection provider to use when that editor/viewer is active.
This way the property sheet doesn't care who is active, it just listens to the selection provider.
That way depending upon the view, a different set of properties are displayed.
For example, the Navigator view provides IResource selections, so the property sheet then displays IResource properties when the Navigator is active.
The Workbench Selection mechanism is illustrated in this article
The ISelectionListener is a simple interface with just one method.
A typical implementation looks like this:
private ISelectionListener mylistener = new ISelectionListener() {
public void selectionChanged(IWorkbenchPart sourcepart, ISelection selection) {
if (sourcepart != MyView.this && // 1
selection instanceof IStructuredSelection) { // 2
doSomething(((IStructuredSelection) selection).toList()); // 3
}
}
};
Depending on your requirements your listener implementation probably needs to deal with the following issues as shown in the code snippet above:
In case we also provide selections (e.g. a view or editor) we should exclude our own selection events from processing. This avoids unexpected results when the user selects elements within our part (1).
Check whether we can handle this kind of selection (2).
Get the selected content from the selection and process it (3).