scope componentPopupMenu.

// TODO: get rid of map (just look for adapter in listeners)

static Map<JComponent, L> componentPopupMenu_map;
static ThreadLocal<MouseEvent> #mouseEvent;

svoid componentPopupMenu_init {
  swing {
    if (componentPopupMenu_map == null)
      componentPopupMenu_map = (Map) vm_generalMap_get('componentPopupMenu_map);
    if (componentPopupMenu_map == null)
      vm_generalMap_put(componentPopupMenu_map := componentPopupMenu_map = newWeakHashMap());
      //componentPopupMenu_map = or((Map<JComponent, L>) getOpt(creator(), 'componentPopupMenu_map), (Map<JComponent, L>) (Map) newWeakHashMap());
    if (mouseEvent == null)
      //mouseEvent = or((ThreadLocal<MouseEvent>) getOpt(creator(), 'componentPopupMenu_mouseEvent), new ThreadLocal);
      mouseEvent = (ThreadLocal<MouseEvent>) vm_generalMap_get('mouseEvent);
    if (mouseEvent == null)
      vm_generalMap_put(componentPopupMenu_mouseEvent := mouseEvent = new ThreadLocal);
  }
}

// menuMaker = voidfunc(JPopupMenu)
static void componentPopupMenu(final JComponent component, fO menuMaker) {
  componentPopupMenu_init();
  if (component != null && menuMaker != null) swing {
    L maker = componentPopupMenu_map.get(component);
    if (maker == null) {
      componentPopupMenu_map.put(component, maker = new L);
      if (!component instanceof JInternalFrame) // lil' hack
        component.addMouseListener(new componentPopupMenu_Adapter(maker));
    }
    maker.add(menuMaker);
  }
}

sclass componentPopupMenu_Adapter extends MouseAdapter {
  L maker;
  
  *(L *maker) {}
  
  public void mousePressed(MouseEvent e) { displayMenu(e); }
  public void mouseReleased(MouseEvent e) { displayMenu(e); }

  void displayMenu(MouseEvent e) {
    if (e.isPopupTrigger()) displayMenu2(e);
  }
    
  void displayMenu2(MouseEvent e) {
    new JPopupMenu menu;
    int emptyCount = menu.getComponentCount();
    
    temp tempSetTL(mouseEvent, e);
    for (O menuMaker : maker)
      pcallF(menuMaker, menu);
      
    vmBus_send('showingPopupMenu, e.getComponent(), menu);
    
    // show menu if any items in it
    if (menu.getComponentCount() != emptyCount)
      menu.show(e.getComponent(), e.getX(), e.getY());
  }
}

end scope

Began life as a copy of #1005719