// init mutex
this.theMutexObject = new Object();
// init components
this.zoomIn = new ZoomIn();
this.zoomOut = new ZoomOut();
this.zoomBox = new ZoomBox();
//this.toolBar = new JPanel(new GridBagLayout());
this.toolBar = new JToolBar();
this.toolBar.setFloatable(false);
this.toolBar.add(this.zoomBox.getView());