Perspective lifecycle

Some actions need to appear in every view, like a help button that will open a page on an online help system like a Wiki.
You can add that action programmatically by intercepting perspective lifecyle events using a PerspectiveAdapter.

Set up a help listener in ApplicationWorkbenchWindowAdvisor.postWindowOpen():

public void postWindowOpen() {
    // setup perspective change listener
    HelpManager.setUpHelpListener();
}

In the HelpManager class you add the listener:

public static void setUpHelpListener() {
  Display display = Display.getDefault();
  if (null != display) {
    display.asyncExec(new Runnable() {
      public void run() {
         scanAllViews();
         final IWorkbench workbench = PlatformUI.getWorkbench();
        // listen for changes that may occur
        workbench.getActiveWorkbenchWindow().
            addPerspectiveListener(new PerspectiveAdapter() {

          @Override
          public void perspectiveChanged(IWorkbenchPage page,
               IPerspectiveDescriptor perspective,
            IWorkbenchPartReference partRef, String changeId) {

            if ((partRef instanceof IViewReference) 
                && (changeId == IWorkbenchPage.CHANGE_VIEW_SHOW)) {
              IViewReference viewRef = (IViewReference) partRef;
              String id = viewRef.getId();
              addhelpAction(workbench, id);
            }

            if (changeId == IWorkbenchPage.CHANGE_RESET_COMPLETE) {
              scanAllViews();
            }
          }

          @Override
          public void perspectiveOpened(IWorkbenchPage page, 
              IPerspectiveDescriptor perspective) {
             scanAllViews();
          }
          
          @Override
          public void perspectiveActivated(IWorkbenchPage page, 
              IPerspectiveDescriptor perspective) {
            scanAllViews();
          }
        });
//  System.out.println("PerspectiveChangeListener installed");
      }


    });
  } else {
// TODO error handling            
//  System.out.println("PerspectiveChangeListener installation failed");
  }
}

And in scanAllViews you scan the registered views:

private void IWorkbench scanAllViews() {
  final IWorkbench workbench = PlatformUI.getWorkbench();
  // add to all existing views
  IViewDescriptor[] views = workbench.getViewRegistry().getViews();
  for (IViewDescriptor view : views) {
    String id = view.getId();
    addhelpAction(workbench, id);
  }
}

Setting up the help actions can be done like this:

private static void addhelpAction(final IWorkbench workbench, String id) {
  IWorkbenchWindow activeWorkbenchWindow = workbench.getActiveWorkbenchWindow();
  if(null == activeWorkbenchWindow)
    return;
  IWorkbenchPage activePage = activeWorkbenchWindow.getActivePage();
  if(null == activePage)
    return;
  IViewPart viewPart = activePage.findView(id);
  if (null == viewPart)
    return;
  IToolBarManager toolBarManager = viewPart.getViewSite().
   getActionBars().getToolBarManager();
  IAction action = ViewHelpUrlAction.createInstance(viewPart);
  if (null == toolBarManager.find(ViewHelpUrlAction.ID)) {
//            System.out.println("ADDING TB: " + id);
    if (null == toolBarManager.find(IWorkbenchActionConstants.MB_ADDITIONS)) {
      toolBarManager.add(new Separator(IWorkbenchActionConstants.MB_ADDITIONS));
    }
    toolBarManager.appendToGroup(IWorkbenchActionConstants.MB_ADDITIONS, action);
    toolBarManager.update(true);
  }
  IMenuManager menuManager = viewPart.getViewSite().getActionBars().getMenuManager();
  if (null == menuManager.find(ViewHelpUrlAction.ID)) {
//            System.out.println("ADDING MB: " + id);
    if (null == menuManager.find(IWorkbenchActionConstants.MB_ADDITIONS)) {
      menuManager.add(new Separator(IWorkbenchActionConstants.MB_ADDITIONS));
    }
    menuManager.appendToGroup(IWorkbenchActionConstants.MB_ADDITIONS, action);
    menuManager.update(true);
  }
}

That's it! Your action can then take the desired action, like opening a page on a Wiki with the view name as key.