public MenuKey(MMenuContribution mc) {
   super(
       mc.getParentId(),
       mc.getPositionInParent(),
       mc.getTags(),
       (MCoreExpression) mc.getVisibleWhen(),
       mc.getTransientData().get(FACTORY));
   this.contribution = mc;
   mc.setWidget(this);
 }
 public static boolean isVisible(MMenuContribution menuContribution, ExpressionContext eContext) {
   if (menuContribution.getVisibleWhen() == null) {
     return true;
   }
   return isVisible((MCoreExpression) menuContribution.getVisibleWhen(), eContext);
 }
  // this is similar in nature to:
  // org.eclipse.e4.ui.internal.workbench.ContributionsAnalyzer.addMenuContributions(MMenu,
  // ArrayList<MMenuContribution>, ArrayList<MMenuElement>)
  // the difference is it needs to add all the contributions and manage their
  // visiblility through a RAT
  private void addMenuBarContributions(
      final MMenu menuModel,
      ArrayList<MMenuContribution> toContribute,
      final IEclipseContext ctx,
      final ExpressionContext eContext) {
    HashSet<String> existingMenuIds = new HashSet<String>();
    HashSet<String> existingSeparatorNames = new HashSet<String>();
    for (MMenuElement child : menuModel.getChildren()) {
      String elementId = child.getElementId();
      if (child instanceof MMenu && elementId != null) {
        existingMenuIds.add(elementId);
      } else if (child instanceof MMenuSeparator && elementId != null) {
        existingSeparatorNames.add(elementId);
      }
    }

    boolean done = toContribute.size() == 0;
    while (!done) {
      ArrayList<MMenuContribution> curList = new ArrayList<MMenuContribution>(toContribute);
      int retryCount = toContribute.size();
      toContribute.clear();

      for (final MMenuContribution menuContribution : curList) {
        final ArrayList<MMenuElement> menuContributionsToRemove = new ArrayList<MMenuElement>();
        if (!ContributionsAnalyzer.processAddition(
            menuModel,
            menuContributionsToRemove,
            menuContribution,
            existingMenuIds,
            existingSeparatorNames)) {
          toContribute.add(menuContribution);
        } else {
          if (menuContribution.getVisibleWhen() != null) {
            ctx.runAndTrack(
                new RunAndTrack() {
                  @Override
                  public boolean changed(IEclipseContext context) {
                    if (!menuModel.isToBeRendered()
                        || !menuModel.isVisible()
                        || menuModel.getWidget() == null) {
                      return false;
                    }
                    boolean rc = ContributionsAnalyzer.isVisible(menuContribution, eContext);
                    for (MMenuElement element : menuContributionsToRemove) {
                      element.setToBeRendered(rc);
                    }
                    return true;
                  }
                });
          }
          ArrayList<ArrayList<MMenuElement>> lists = pendingCleanup.get(menuModel);
          if (lists == null) {
            lists = new ArrayList<ArrayList<MMenuElement>>();
            pendingCleanup.put(menuModel, lists);
          }
          lists.add(menuContributionsToRemove);
        }
      }
      // We're done if the retryList is now empty (everything done) or
      // if the list hasn't changed at all (no hope)
      done = (toContribute.size() == 0) || (toContribute.size() == retryCount);
    }
  }