/*
* Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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* 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
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*/
package com.sun.lwuit.util;
import com.sun.lwuit.*;
import com.sun.lwuit.events.*;
import com.sun.lwuit.plaf.Style;
import java.util.Vector;
/**
* Handles event dispatching while guaranteeing that all events would
* be fired properly on the EDT regardless of their source. This class handles listener
* registration/removal in a safe and uniform way.
*
* @author Shai Almog
*/
public class EventDispatcher {
private boolean blocking = false;
private Vector listeners;
private Object[] pending;
private Object pendingEvent;
private static boolean fireStyleEventsOnNonEDT = false;
/**
* When set to true, style events will be dispatched even from non-EDT threads.
* When set to false, when in non-EDT threads, style events will not be dispatched at all (And developer has to make sure changes will be reflected by calling revalidate after all the changes)
*
* Default is false. Setting this to true results in a performance penalty, and it is better instead to simply aggregate events performed on non-EDT threads and when all are over - call revalidate on the relevant container.
*
* @param fire true to fire on non-EDT, false otherwise
*/
public static void setFireStyleEventsOnNonEDT(boolean fire) {
fireStyleEventsOnNonEDT = fire;
}
class CallbackClass implements Runnable {
private Object[] iPending;
private Object iPendingEvent;
public CallbackClass() {
if(!blocking) {
iPendingEvent = pendingEvent;
iPending = pending;
}
}
/**
* Do not invoke this method it handles the dispatching internally and serves
* as an implementation detail
*/
public final void run() {
if(!Display.getInstance().isEdt()) {
throw new IllegalStateException("This method should not be invoked by external code!");
}
if(blocking) {
iPendingEvent = pendingEvent;
iPending = pending;
}
if(iPending instanceof ActionListener[]) {
fireActionSync((ActionListener[])iPending, (ActionEvent)iPendingEvent);
return;
}
if(iPending instanceof FocusListener[]) {
fireFocusSync((FocusListener[])iPending, (Component)iPendingEvent);
return;
}
if(iPending instanceof DataChangedListener[]) {
fireDataChangeSync((DataChangedListener[])iPending, ((int[])iPendingEvent)[0], ((int[])iPendingEvent)[1]);
return;
}
if(iPending instanceof SelectionListener[]) {
fireSelectionSync((SelectionListener[])iPending, ((int[])iPendingEvent)[0], ((int[])iPendingEvent)[1]);
return;
}
if(iPending instanceof StyleListener[]) {
Object[] p = (Object[])iPendingEvent;
fireStyleChangeSync((StyleListener[])iPending, (String)p[0], (Style)p[1]);
pendingEvent = null;
pending = null;
return;
}
}
};
private final Runnable callback = new CallbackClass();
/**
* Add a listener to the dispatcher that would receive the events when they occurs
*
* @param listener a dispatcher listener to add
*/
public synchronized void addListener(Object listener) {
if(listeners == null) {
listeners = new Vector();
}
if(!listeners.contains(listener)){
listeners.addElement(listener);
}
}
/**
* Returns the vector of the listeners
*
* @return the vector of listeners attached to the event dispatcher
*/
public Vector getListenerVector() {
return listeners;
}
/**
* Remove the listener from the dispatcher
*
* @param listener a dispatcher listener to remove
*/
public synchronized void removeListener(Object listener) {
if(listeners != null) {
listeners.removeElement(listener);
}
}
/**
* Fires the event safely on the EDT without risk of concurrency errors
*
* @param index the index of the event
* @param type the type of the event
*/
public void fireDataChangeEvent(int index, int type) {
if(listeners == null || listeners.size() == 0) {
return;
}
DataChangedListener[] array;
synchronized(this) {
array = new DataChangedListener[listeners.size()];
for(int iter = 0 ; iter < array.length ; iter++) {
array[iter] = (DataChangedListener)listeners.elementAt(iter);
}
}
// if we already are on the EDT just fire the event
if(Display.getInstance().isEdt()) {
fireDataChangeSync(array, type, index);
} else {
pending = array;
pendingEvent = new int[] {type, index};
if(blocking) {
Display.getInstance().callSeriallyAndWait(callback);
} else {
Display.getInstance().callSerially(new CallbackClass());
}
pending = null;
pendingEvent = null;
}
}
/**
* Fires the style change even to the listeners
*
* @param property the property name for the event
* @param source the style firing the event
*/
public void fireStyleChangeEvent(String property, Style source) {
if(listeners == null || listeners.size() == 0) {
return;
}
StyleListener[] array;
synchronized(this) {
array = new StyleListener[listeners.size()];
for(int iter = 0 ; iter < array.length ; iter++) {
array[iter] = (StyleListener)listeners.elementAt(iter);
}
}
// if we already are on the EDT just fire the event
if(Display.getInstance().isEdt()) {
fireStyleChangeSync(array, property, source);
} else if (fireStyleEventsOnNonEDT) {
pending = array;
pendingEvent = new Object[] {property, source};
Display.getInstance().callSerially(new CallbackClass());
pending = null;
pendingEvent = null;
}
}
/**
* Synchronious internal call for common code
*/
private void fireDataChangeSync(DataChangedListener[] array, int type, int index) {
for(int iter = 0 ; iter < array.length ; iter++) {
array[iter].dataChanged(type, index);
}
}
/**
* Synchronious internal call for common code
*/
private void fireStyleChangeSync(StyleListener[] array, String property, Style source) {
for(int iter = 0 ; iter < array.length ; iter++) {
array[iter].styleChanged(property, source);
}
}
/**
* Synchronious internal call for common code
*/
private void fireSelectionSync(SelectionListener[] array, int oldSelection, int newSelection) {
for(int iter = 0 ; iter < array.length ; iter++) {
array[iter].selectionChanged(oldSelection, newSelection);
}
}
/**
* Fires the event safely on the EDT without risk of concurrency errors
*
* @param ev the ActionEvent to fire to the listeners
*/
public void fireActionEvent(ActionEvent ev) {
if(listeners == null || listeners.size() == 0) {
return;
}
ActionListener[] array;
synchronized(this) {
array = new ActionListener[listeners.size()];
for(int iter = 0 ; iter < array.length ; iter++) {
array[iter] = (ActionListener)listeners.elementAt(iter);
}
}
// if we already are on the EDT just fire the event
if(Display.getInstance().isEdt()) {
fireActionSync(array, ev);
} else {
pending = array;
pendingEvent = ev;
if(blocking) {
Display.getInstance().callSeriallyAndWait(callback);
} else {
Display.getInstance().callSerially(new CallbackClass());
}
pending = null;
pendingEvent = null;
}
}
/**
* Fires the event safely on the EDT without risk of concurrency errors
*
* @param oldSelection old selection
* @param newSelection new selection
*/
public void fireSelectionEvent(int oldSelection, int newSelection) {
if(listeners == null || listeners.size() == 0) {
return;
}
SelectionListener[] array;
synchronized(this) {
array = new SelectionListener[listeners.size()];
for(int iter = 0 ; iter < array.length ; iter++) {
array[iter] = (SelectionListener)listeners.elementAt(iter);
}
}
// if we already are on the EDT just fire the event
if(Display.getInstance().isEdt()) {
fireSelectionSync(array, oldSelection, newSelection);
} else {
pending = array;
pendingEvent = new int[] {oldSelection, newSelection};
if(blocking) {
Display.getInstance().callSeriallyAndWait(callback);
} else {
Display.getInstance().callSerially(new CallbackClass());
}
pending = null;
pendingEvent = null;
}
}
/**
* Synchronious internal call for common code
*/
private void fireActionSync(ActionListener[] array, ActionEvent ev) {
for(int iter = 0 ; iter < array.length ; iter++) {
if(!ev.isConsumed()) {
array[iter].actionPerformed(ev);
}
}
}
/**
* Fires the event safely on the EDT without risk of concurrency errors
*
* @param c the Component that gets the focus event
*/
public void fireFocus(Component c) {
if(listeners == null || listeners.size() == 0) {
return;
}
FocusListener[] array;
synchronized(this) {
array = new FocusListener[listeners.size()];
for(int iter = 0 ; iter < array.length ; iter++) {
array[iter] = (FocusListener)listeners.elementAt(iter);
}
}
// if we already are on the EDT just fire the event
if(Display.getInstance().isEdt()) {
fireFocusSync(array, c);
} else {
pending = array;
pendingEvent = c;
if(blocking) {
Display.getInstance().callSeriallyAndWait(callback);
} else {
Display.getInstance().callSerially(new CallbackClass());
}
pending = null;
pendingEvent = null;
}
}
/**
* Synchronious internal call for common code
*/
private void fireFocusSync(FocusListener[] array, Component c) {
if(c.hasFocus()) {
for(int iter = 0 ; iter < array.length ; iter++) {
array[iter].focusGained(c);
}
} else {
for(int iter = 0 ; iter < array.length ; iter++) {
array[iter].focusLost(c);
}
}
}
/**
* Returns true if the event dispatcher has registered listeners
*
* @return true if the event dispatcher has registered listeners
*/
public boolean hasListeners() {
return listeners != null && listeners.size() > 0;
}
/**
* Indicates whether this dispatcher blocks when firing events or not, normally
* a dispatcher uses callSeriallyAndWait() to be 100% synchronos with event delivery
* however this method is very slow. By setting blocking to false the callSerially
* method is used which allows much faster execution for IO heavy operations.
*
* @return the blocking state
*/
public boolean isBlocking() {
return blocking;
}
/**
* Indicates whether this dispatcher blocks when firing events or not, normally
* a dispatcher uses callSeriallyAndWait() to be 100% synchronos with event delivery
* however this method is very slow. By setting blocking to false the callSerially
* method is used which allows much faster execution for IO heavy operations.
*
* @param blocking the blocking value
*/
public void setBlocking(boolean blocking) {
this.blocking = blocking;
}
}