Description Mik Kersten 2007-12-19 20:21:32 EST

Mylyn has had a problematic bug where its Focus action would not get enabled on the Project Explorer or Navigator views if those views were visible on startup.  This bug does not manifest itself with the Package Explorer, or if the view is not visible on startup (e.g. start with a perspective that doesn't have it, toggle a perspective that does, or simply open the view).  The cause of this bug was that IViewActionDelegate.init(IViewPart) does not always get called when the view is created.  I'm not sure if this additional laziness is intentional or not, but the result is some inconsistency.

The problem appears to be in the following code in PartPluginAction, since the selection provider might not be around on start.  It seems to be around for the Package Explorer but not for the Project Explorer, so the action initialization that is triggered by the selectionChanged(..), which in turn calls PluginAction.createDelegate(), ends up never being called.

    protected void registerSelectionListener(IWorkbenchPart aPart) {
        ISelectionProvider selectionProvider = aPart.getSite()
                .getSelectionProvider();
        if (selectionProvider != null) {
            selectionProvider.addSelectionChangedListener(this);
            selectionChanged(selectionProvider.getSelection());
        }
    }
    
We don't currently have a better work-around than to do the following on the lazy start of the Context UI, which happens on first task activation, not on bundle activation.  Forcing the selection in this way will trigger the desired initialization of the view actions.  But it's a pretty weird thing for us to be doing, and will be invoked on views that do not have the Focus action added to them.  Others could also run into this problem if they expect init(IViewPart) to be called.

			for (IWorkbenchWindow window : PlatformUI.getWorkbench().getWorkbenchWindows()) {
				if (window.getActivePage() != null) {
					IViewReference[] views = window.getActivePage().getViewReferences();
					for (IViewReference viewReference : views) {
						IViewPart viewPart = viewReference.getView(false);
						if (viewPart != null) {
							ISelectionProvider selectionProvider = viewPart.getSite().getSelectionProvider();
							if (selectionProvider != null) {
								selectionProvider.setSelection(selectionProvider.getSelection());
							}
						}
					}
				}
			}