Bug 157072 [ActionSets][Contributions] QuickMenuAction funtionality should be made public
The QuickMenuAction class should be made public and usable by IWorkbenchWindowPulldownDelegate{2}. As it is you need to roll this functionality yourself in the run method of your delegate (and it is by no means straightforward).
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/actions/QuickMenuAction.java
*  <code>null</code> if now position inside the widget can
     *  be computed
     */
    protected Point computeMenuLocation(Table table) {
        TableItem[] items = table.getSelection();
        Rectangle clientArea = table.getClientArea();
        switch (items.length) {
        case 0: {
            return null;
        }
        case 1: {
            Rectangle bounds = items[0].getBounds(0);
            Rectangle iBounds = items[0].getImageBounds(0);
            Rectangle intersect = clientArea.intersection(bounds);
            if (intersect != null && intersect.height == bounds.height) {
                return new Point(Math.max(0, bounds.x + iBounds.width
                        + getAvarageCharWith(table) * CHAR_INDENT), bounds.y
                        + bounds.height);
            } else {
                return null;
            }
        }
        default: {
            Rectangle[] rectangles = new Rectangle[items.length];
            for (int i = 0; i < rectangles.length; i++) {
                rectangles[i] = items[i].getBounds(0);
            }
            Rectangle iBounds = items[0].getImageBounds(0);
            Point cursorLocation = table.getDisplay().getCursorLocation();
            Point result = findBestLocation(getIncludedPositions(rectangles,