How to set initial state of an Eclipse action contribution

Question

What I'm trying to achieve is to contribute an action to the IProject pop up menu. The action is defined like this in my plugin.xml:

   <extension
         point="org.eclipse.ui.popupMenus">
      <objectContribution
            adaptable="true"
            objectClass="org.eclipse.core.resources.IProject"
            nameFilter="*"
            id="RemoteSync.contribution1">
         <action
               label="Enable RemoteSync"
               class="remotesync.builder.ToggleNatureAction"
               menubarPath="additions"
               enablesFor="1"
               id="RemoteSync.addRemoveNatureAction"
               style="toggle">
         </action>
      </objectContribution>
   </extension>

On run() I do setPersistentProperty() in order to save the menu toggle state and I want to restore that later when the plug in starts or whenever the pop up menu is displayed on setActivePart().

Here are the relevant pieces of code:

public void run(IAction action) {
    if (selection instanceof IStructuredSelection) {
        for (Iterator it = ((IStructuredSelection) selection).iterator(); it
                .hasNext();) {
            Object element = it.next();
            IProject project = null;
            if (element instanceof IProject) {
                project = (IProject) element;
            } else if (element instanceof IAdaptable) {
                project = (IProject) ((IAdaptable) element)
                        .getAdapter(IProject.class);
            }
            if (project != null) {
                toggleNature(project);
                try {
                    ((IResource) project).setPersistentProperty(
                            new QualifiedName("", ENABLED_PROPERTY), new Boolean(action.isChecked()).toString());
                } catch (CoreException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    }
}


public void setActivePart(IAction action, IWorkbenchPart targetPart) {
    if (selection instanceof IStructuredSelection) {
        for (Iterator it = ((IStructuredSelection) selection).iterator(); it
                .hasNext();) {
            Object element = it.next();
            IProject project = null;
            if (element instanceof IProject) {
                project = (IProject) element;
            } else if (element instanceof IAdaptable) {
                project = (IProject) ((IAdaptable) element)
                        .getAdapter(IProject.class);
            }
            if (project != null) {
                toggleNature(project);
                try {
                    String status = ((IResource) project).getPersistentProperty(
                            new QualifiedName("", ENABLED_PROPERTY));
                    action.setChecked(new Boolean(status));
                } catch (CoreException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    }
}

Everything works as expected but one thing - when the IProject context menu is first activated it does not reflect the saved state, but if I bring the menu up again it shows the saved state as expected. Then if I bring the menu up for another project it once again shows with incorrect state, but the second time works fine.

Answer 1

well, take a look at these lines

            String status = ((IResource) project).getPersistentProperty(
                        new QualifiedName("", ENABLED_PROPERTY));

      ((IResource) project).setPersistentProperty(
                        new QualifiedName("", ENABLED_PROPERTY), new Boolean(action.isChecked()).toString());

The variable 'project' points to the selected project and therefore the state is only stored in its meta data. if you want to store the state independant of the project, a solution might be storing them in the workspace metadata.

Answer 2

Well, it seems there is either a problem with my code or bug/feature in Eclipse 3.6 I20100608-0911 which prevents selectionChanged() from firing properly the first time you click on resource (IProject in my case):

public void selectionChanged(IAction action, ISelection selection) {
    this.selection = selection;
}

As I found out events are fired in this order when bringing up the context menu for the first time:

1. selectionChanged()
2. setActivePart()
3. selectionChanged()

The ISelection passed to selectionChanged() the first time is always "empty selection".

After the first time, bringing the context menu yields the following order in which events are fired:

1. setActivePart()
2. selectionChanged()

That's why we should fire selectionChanged() every time inside setActivePart() in order to make sure we get the most recent selection:

public void setActivePart(IAction action, IWorkbenchPart targetPart) {
    selectionChanged(action, targetPart.getSite().getPage().getSelection());
    ...
}

I hope that helps someone ;)

Answer 3

Yes.It has surely helped me.Was wondering how i ll be getting my solution all this while :)