/*
* 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.
*
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package com.apple.eawt.event;
import java.awt.*;
import java.util.*;
import java.util.List;
import javax.swing.*;
final class GestureHandler {
private static final String CLIENT_PROPERTY = "com.apple.eawt.event.internalGestureHandler";
// native constants for the supported types of high-level gestures
static final int PHASE = 1;
static final int ROTATE = 2;
static final int MAGNIFY = 3;
static final int SWIPE = 4;
// installs a private instance of GestureHandler, if necessary
static void addGestureListenerTo(final JComponent component, final GestureListener listener) {
final Object value = component.getClientProperty(CLIENT_PROPERTY);
if (value instanceof GestureHandler) {
((GestureHandler)value).addListener(listener);
return;
}
if (value != null) return; // some other garbage is in our client property
final GestureHandler newHandler = new GestureHandler();
newHandler.addListener(listener);
component.putClientProperty(CLIENT_PROPERTY, newHandler);
}
// asks the installed GestureHandler to remove it's listener (does not uninstall the GestureHandler)
static void removeGestureListenerFrom(final JComponent component, final GestureListener listener) {
final Object value = component.getClientProperty(CLIENT_PROPERTY);
if (!(value instanceof GestureHandler)) return;
((GestureHandler)value).removeListener(listener);
}
// called from native - finds the deepest component with an installed GestureHandler,
// creates a single event, and dispatches it to a recursive notifier
static void handleGestureFromNative(final Window window, final int type, final double x, final double y, final double a, final double b) {
if (window == null) return; // should never happen...
EventQueue.invokeLater(new Runnable() {
public void run() {
final Component component = SwingUtilities.getDeepestComponentAt(window, (int)x, (int)y);
final PerComponentNotifier firstNotifier;
if (component instanceof RootPaneContainer) {
firstNotifier = getNextNotifierForComponent(((RootPaneContainer)component).getRootPane());
} else {
firstNotifier = getNextNotifierForComponent(component);
}
if (firstNotifier == null) return;
switch (type) {
case PHASE:
firstNotifier.recursivelyHandlePhaseChange(a, new GesturePhaseEvent());
return;
case ROTATE:
firstNotifier.recursivelyHandleRotate(new RotationEvent(a));
return;
case MAGNIFY:
firstNotifier.recursivelyHandleMagnify(new MagnificationEvent(a));
return;
case SWIPE:
firstNotifier.recursivelyHandleSwipe(a, b, new SwipeEvent());
return;
}
}
});
}
final List<GesturePhaseListener> phasers = new LinkedList<GesturePhaseListener>();
final List<RotationListener> rotaters = new LinkedList<RotationListener>();
final List<MagnificationListener> magnifiers = new LinkedList<MagnificationListener>();
final List<SwipeListener> swipers = new LinkedList<SwipeListener>();
GestureHandler() { }
void addListener(final GestureListener listener) {
if (listener instanceof GesturePhaseListener) phasers.add((GesturePhaseListener)listener);
if (listener instanceof RotationListener) rotaters.add((RotationListener)listener);
if (listener instanceof MagnificationListener) magnifiers.add((MagnificationListener)listener);
if (listener instanceof SwipeListener) swipers.add((SwipeListener)listener);
}
void removeListener(final GestureListener listener) {
phasers.remove(listener);
rotaters.remove(listener);
magnifiers.remove(listener);
swipers.remove(listener);
}
// notifies all listeners in a particular component/handler pair
// and recursively notifies up the component hierarchy
static class PerComponentNotifier {
final Component component;
final GestureHandler handler;
public PerComponentNotifier(final Component component, final GestureHandler handler) {
this.component = component;
this.handler = handler;
}
void recursivelyHandlePhaseChange(final double phase, final GesturePhaseEvent e) {
for (final GesturePhaseListener listener : handler.phasers) {
if (phase < 0) {
listener.gestureBegan(e);
} else {
listener.gestureEnded(e);
}
if (e.isConsumed()) return;
}
final PerComponentNotifier next = getNextNotifierForComponent(component.getParent());
if (next != null) next.recursivelyHandlePhaseChange(phase, e);
}
void recursivelyHandleRotate(final RotationEvent e) {
for (final RotationListener listener : handler.rotaters) {
listener.rotate(e);
if (e.isConsumed()) return;
}
final PerComponentNotifier next = getNextNotifierForComponent(component.getParent());
if (next != null) next.recursivelyHandleRotate(e);
}
void recursivelyHandleMagnify(final MagnificationEvent e) {
for (final MagnificationListener listener : handler.magnifiers) {
listener.magnify(e);
if (e.isConsumed()) return;
}
final PerComponentNotifier next = getNextNotifierForComponent(component.getParent());
if (next != null) next.recursivelyHandleMagnify(e);
}
void recursivelyHandleSwipe(final double x, final double y, final SwipeEvent e) {
for (final SwipeListener listener : handler.swipers) {
if (x < 0) listener.swipedLeft(e);
if (x > 0) listener.swipedRight(e);
if (y < 0) listener.swipedDown(e);
if (y > 0) listener.swipedUp(e);
if (e.isConsumed()) return;
}
final PerComponentNotifier next = getNextNotifierForComponent(component.getParent());
if (next != null) next.recursivelyHandleSwipe(x, y, e);
}
}
// helper function to get a handler from a Component
static GestureHandler getHandlerForComponent(final Component c) {
if (!(c instanceof JComponent)) return null;
final Object value = ((JComponent)c).getClientProperty(CLIENT_PROPERTY);
if (!(value instanceof GestureHandler)) return null;
return (GestureHandler)value;
}
// recursive helper to find the next component/handler pair
static PerComponentNotifier getNextNotifierForComponent(final Component c) {
if (c == null) return null;
final GestureHandler handler = getHandlerForComponent(c);
if (handler != null) {
return new PerComponentNotifier(c, handler);
}
return getNextNotifierForComponent(c.getParent());
}
}