/*
* Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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*/
package sun.lwawt;
import java.awt.Component;
import java.awt.Container;
import java.awt.Cursor;
import java.awt.Point;
import java.util.concurrent.atomic.AtomicBoolean;
import sun.awt.SunToolkit;
public abstract class LWCursorManager {
/**
* A flag to indicate if the update is scheduled, so we don't process it
* twice.
*/
private final AtomicBoolean updatePending = new AtomicBoolean(false);
protected LWCursorManager() {
}
/**
* Sets the cursor to correspond the component currently under mouse.
*
* This method should not be executed on the toolkit thread as it
* calls to user code (e.g. Container.findComponentAt).
*/
public final void updateCursor() {
updatePending.set(false);
updateCursorImpl();
}
/**
* Schedules updating the cursor on the corresponding event dispatch
* thread for the given window.
*
* This method is called on the toolkit thread as a result of a
* native update cursor request (e.g. WM_SETCURSOR on Windows).
*/
public final void updateCursorLater(final LWWindowPeer window) {
if (updatePending.compareAndSet(false, true)) {
Runnable r = new Runnable() {
@Override
public void run() {
updateCursor();
}
};
SunToolkit.executeOnEventHandlerThread(window.getTarget(), r);
}
}
private void updateCursorImpl() {
final Point cursorPos = getCursorPosition();
final Component c = findComponent(cursorPos);
final Cursor cursor;
final Object peer = LWToolkit.targetToPeer(c);
if (peer instanceof LWComponentPeer) {
final LWComponentPeer<?, ?> lwpeer = (LWComponentPeer<?, ?>) peer;
final Point p = lwpeer.getLocationOnScreen();
cursor = lwpeer.getCursor(new Point(cursorPos.x - p.x,
cursorPos.y - p.y));
} else {
cursor = (c != null) ? c.getCursor() : null;
}
setCursor(cursor);
}
/**
* Returns the first visible, enabled and showing component under cursor.
* Returns null for modal blocked windows.
*
* @param cursorPos Current cursor position.
* @return Component or null.
*/
private static final Component findComponent(final Point cursorPos) {
final LWComponentPeer<?, ?> peer = LWWindowPeer.getPeerUnderCursor();
Component c = null;
if (peer != null && peer.getWindowPeerOrSelf().getBlocker() == null) {
c = peer.getTarget();
if (c instanceof Container) {
final Point p = peer.getLocationOnScreen();
c = ((Container) c).findComponentAt(cursorPos.x - p.x,
cursorPos.y - p.y);
}
while (c != null) {
if (c.isVisible() && c.isEnabled() && (c.getPeer() != null)) {
break;
}
c = c.getParent();
}
}
return c;
}
/**
* Returns the current cursor position.
*/
// TODO: make it public to reuse for MouseInfo
protected abstract Point getCursorPosition();
/**
* Sets a cursor. The cursor can be null if the mouse is not over a Java
* window.
* @param cursor the new {@code Cursor}.
*/
protected abstract void setCursor(Cursor cursor);
}