1 /* 2 * Copyright (c) 2011, 2013, 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.AWTAccessor; 36 import sun.awt.SunToolkit; 37 38 public abstract class LWCursorManager { 39 40 /** 41 * A flag to indicate if the update is scheduled, so we don't process it 42 * twice. 43 */ 44 private final AtomicBoolean updatePending = new AtomicBoolean(false); 45 46 protected LWCursorManager() { 47 } 48 49 /** 50 * Sets the cursor to correspond the component currently under mouse. 51 * 52 * This method should not be executed on the toolkit thread as it 53 * calls to user code (e.g. Container.findComponentAt). 54 */ 55 public final void updateCursor() { 56 updatePending.set(false); 57 updateCursorImpl(); 58 } 59 60 /** 61 * Schedules updating the cursor on the corresponding event dispatch 62 * thread for the given window. 63 * 64 * This method is called on the toolkit thread as a result of a 65 * native update cursor request (e.g. WM_SETCURSOR on Windows). 66 */ 67 public final void updateCursorLater(final LWWindowPeer window) { 68 if (updatePending.compareAndSet(false, true)) { 69 Runnable r = new Runnable() { 70 @Override 71 public void run() { 72 updateCursor(); 73 } 74 }; 75 SunToolkit.executeOnEventHandlerThread(window.getTarget(), r); 76 } 77 } 78 79 private void updateCursorImpl() { 80 final Point cursorPos = getCursorPosition(); 81 final Component c = findComponent(cursorPos); 82 final Cursor cursor; 83 final Object peer = LWToolkit.targetToPeer(c); 84 if (peer instanceof LWComponentPeer) { 85 final LWComponentPeer<?, ?> lwpeer = (LWComponentPeer<?, ?>) peer; 86 final Point p = lwpeer.getLocationOnScreen(); 87 cursor = lwpeer.getCursor(new Point(cursorPos.x - p.x, 88 cursorPos.y - p.y)); 89 } else { 90 cursor = (c != null) ? c.getCursor() : null; 91 } 92 setCursor(cursor); 93 } 94 95 /** 96 * Returns the first visible, enabled and showing component under cursor. 97 * Returns null for modal blocked windows. 98 * 99 * @param cursorPos Current cursor position. 100 * @return Component or null. 101 */ 102 private static final Component findComponent(final Point cursorPos) { 103 final LWComponentPeer<?, ?> peer = LWWindowPeer.getPeerUnderCursor(); 104 Component c = null; 105 if (peer != null && peer.getWindowPeerOrSelf().getBlocker() == null) { 106 c = peer.getTarget(); 107 if (c instanceof Container) { 108 final Point p = peer.getLocationOnScreen(); 109 c = ((Container) c).findComponentAt(cursorPos.x - p.x, 110 cursorPos.y - p.y); 111 } 112 while (c != null) { 113 final Object p = AWTAccessor.getComponentAccessor().getPeer(c); 114 if (c.isVisible() && c.isEnabled() && p != null) { 115 break; 116 } 117 c = c.getParent(); 118 } 119 } 120 return c; 121 } 122 123 /** 124 * Returns the current cursor position. 125 */ 126 // TODO: make it public to reuse for MouseInfo 127 protected abstract Point getCursorPosition(); 128 129 /** 130 * Sets a cursor. The cursor can be null if the mouse is not over a Java 131 * window. 132 * @param cursor the new {@code Cursor}. 133 */ 134 protected abstract void setCursor(Cursor cursor); 135 }