canvas = new Canvas(mapContainer, SWT.DOUBLE_BUFFERED);
hoverShell = new HoverShell(canvas);
MenuManager menuMgr= new MenuManager();
menuMgr.setRemoveAllWhenShown(true);
menuMgr.addMenuListener(menuListener);
Menu menu = menuMgr.createContextMenu(canvas);
canvas.setMenu(menu);
getSite().registerContextMenu(menuMgr, theController.getSelectionProvider());
canvasListener = new CanvasListener(canvas);