Java Tutorial/SWT/Tracker

Create a tracker: drag when torn off

   <source lang="java">

/*******************************************************************************

* Copyright (c) 2000, 2004 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
*     IBM Corporation - initial API and implementation
*******************************************************************************/

//package org.eclipse.swt.snippets; /*

* Tracker example snippet: create a tracker (drag when "torn off")
*
* For a list of all SWT example snippets see
* http://www.eclipse.org/swt/snippets/
*/

import org.eclipse.swt.SWT; import org.eclipse.swt.graphics.Point; import org.eclipse.swt.graphics.Rectangle; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Event; import org.eclipse.swt.widgets.Listener; import org.eclipse.swt.widgets.Shell; import org.eclipse.swt.widgets.Tracker; public class TrackerTornOff {

 public static void main(String[] args) {
   final Display display = new Display();
   final Shell shell = new Shell(display);
   shell.setSize(200, 200);
   shell.open();
   Listener listener = new Listener() {
     Point point = null;
     static final int JITTER = 8;
     public void handleEvent(Event event) {
       switch (event.type) {
       case SWT.MouseDown:
         point = new Point(event.x, event.y);
         break;
       case SWT.MouseMove:
         if (point == null)
           return;
         int deltaX = point.x - event.x,
         deltaY = point.y - event.y;
         if (Math.abs(deltaX) < JITTER && Math.abs(deltaY) < JITTER) {
           return;
         }
         Tracker tracker = new Tracker(display, SWT.NONE);
         Rectangle rect = display.map(shell, null, shell.getClientArea());
         rect.x -= deltaX;
         rect.y -= deltaY;
         tracker.setRectangles(new Rectangle[] { rect });
         tracker.open();
       // FALL THROUGH
       case SWT.MouseUp:
         point = null;
         break;
       }
     }
   };
   shell.addListener(SWT.MouseDown, listener);
   shell.addListener(SWT.MouseMove, listener);
   shell.addListener(SWT.MouseUp, listener);
   while (!shell.isDisposed()) {
     if (!display.readAndDispatch())
       display.sleep();
   }
   display.dispose();
 }

}</source>

Create a tracker on mouse down

   <source lang="java">

import org.eclipse.swt.SWT; import org.eclipse.swt.graphics.Rectangle; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Event; import org.eclipse.swt.widgets.Listener; import org.eclipse.swt.widgets.Shell; import org.eclipse.swt.widgets.Tracker; public class TrackerMouseDown {

 public static void main(String[] args) {
   Display display = new Display();
   final Shell shell = new Shell(display);
   shell.open();
   shell.addListener(SWT.MouseDown, new Listener() {
     public void handleEvent(Event e) {
       Tracker tracker = new Tracker(shell, SWT.NONE);
       tracker.setRectangles(new Rectangle[] { new Rectangle(e.x, e.y, 100, 100), });
       tracker.open();
     }
   });
   while (!shell.isDisposed()) {
     if (!display.readAndDispatch())
       display.sleep();
   }
   display.dispose();
 }

}</source>