1 /*
   2  * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package sun.lwawt;
  27 
  28 import java.awt.Component;
  29 import java.awt.Container;
  30 import java.awt.Cursor;
  31 import java.awt.Point;
  32 
  33 import java.util.concurrent.atomic.AtomicBoolean;
  34 
  35 import sun.awt.SunToolkit;
  36 
  37 public abstract class LWCursorManager {
  38 
  39     // A flag to indicate if the update is scheduled, so we don't
  40     // process it twice
  41     private AtomicBoolean updatePending = new AtomicBoolean(false);


  42 
  43     protected LWCursorManager() {
  44     }
  45 
  46     /*
  47      * Sets the cursor to correspond the component currently under mouse.
  48      *
  49      * This method should not be executed on the toolkit thread as it
  50      * calls to user code (e.g. Container.findComponentAt).
  51      */
  52     public void updateCursor() {
  53         updatePending.set(false);
  54         updateCursorImpl();
  55     }
  56 
  57     /*
  58      * Schedules updating the cursor on the corresponding event dispatch
  59      * thread for the given window.
  60      *
  61      * This method is called on the toolkit thread as a result of a
  62      * native update cursor request (e.g. WM_SETCURSOR on Windows).
  63      */
  64     public void updateCursorLater(LWWindowPeer window) {
  65         if (updatePending.compareAndSet(false, true)) {
  66             Runnable r = new Runnable() {
  67                 @Override
  68                 public void run() {
  69                     updateCursor();
  70                 }
  71             };
  72             SunToolkit.executeOnEventHandlerThread(window.getTarget(), r);
  73         }
  74     }
  75 
  76     private void updateCursorImpl() {
  77         LWWindowPeer windowUnderCursor = LWWindowPeer.getWindowUnderCursor();
  78         Point cursorPos = getCursorPosition();
  79         LWComponentPeer<?, ?> componentUnderCursor = null;
  80         // TODO: it's possible to get the component under cursor directly as
  81         // it's stored in LWWindowPee anyway (lastMouseEventPeer)
  82         if (windowUnderCursor != null) {
  83             componentUnderCursor = windowUnderCursor.findPeerAt(cursorPos.x, cursorPos.y);
  84         }
  85         Cursor cursor = null;
  86         if (componentUnderCursor != null) {
  87             Component c = componentUnderCursor.getTarget();
















  88             if (c instanceof Container) {
  89                 Point p = componentUnderCursor.getLocationOnScreen();
  90                 c = ((Container)c).findComponentAt(cursorPos.x - p.x, cursorPos.y - p.y);

  91             }
  92             // Traverse up to the first visible, enabled and showing component
  93             while (c != null) {
  94                 if (c.isVisible() && c.isEnabled() && (c.getPeer() != null)) {
  95                     break;
  96                 }
  97                 c = c.getParent();
  98             }
  99             if (c != null) {
 100                 cursor = c.getCursor();
 101             }
 102         }
 103         // TODO: default cursor for modal blocked windows
 104         setCursor(windowUnderCursor, cursor);
 105     }
 106 
 107     /*
 108      * Returns the current cursor position.
 109      */
 110     // TODO: make it public to reuse for MouseInfo
 111     protected abstract Point getCursorPosition();
 112 
 113     /*
 114      * Sets a cursor. The cursor can be null if the mouse is not over a Java window.


 115      */
 116     protected abstract void setCursor(LWWindowPeer windowUnderCursor, Cursor cursor);
 117 
 118 }
--- EOF ---