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Diffstat (limited to 'libjava/java/awt/EventQueue.java')
| -rw-r--r-- | libjava/java/awt/EventQueue.java | 551 |
1 files changed, 0 insertions, 551 deletions
diff --git a/libjava/java/awt/EventQueue.java b/libjava/java/awt/EventQueue.java deleted file mode 100644 index f5b67f3..0000000 --- a/libjava/java/awt/EventQueue.java +++ /dev/null @@ -1,551 +0,0 @@ -/* EventQueue.java -- - Copyright (C) 1999, 2000, 2001, 2002, 2003, 2005 Free Software Foundation - -This file is part of GNU Classpath. - -GNU Classpath is free software; you can redistribute it and/or modify -it under the terms of the GNU General Public License as published by -the Free Software Foundation; either version 2, or (at your option) -any later version. - -GNU Classpath 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 for more details. - -You should have received a copy of the GNU General Public License -along with GNU Classpath; see the file COPYING. If not, write to the -Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA -02110-1301 USA. - -Linking this library statically or dynamically with other modules is -making a combined work based on this library. Thus, the terms and -conditions of the GNU General Public License cover the whole -combination. - -As a special exception, the copyright holders of this library give you -permission to link this library with independent modules to produce an -executable, regardless of the license terms of these independent -modules, and to copy and distribute the resulting executable under -terms of your choice, provided that you also meet, for each linked -independent module, the terms and conditions of the license of that -module. An independent module is a module which is not derived from -or based on this library. If you modify this library, you may extend -this exception to your version of the library, but you are not -obligated to do so. If you do not wish to do so, delete this -exception statement from your version. */ - - -package java.awt; - -import gnu.java.awt.ClasspathToolkit; - -import java.awt.event.ActionEvent; -import java.awt.event.InputEvent; -import java.awt.event.InvocationEvent; -import java.awt.event.WindowEvent; -import java.lang.reflect.InvocationTargetException; -import java.util.EmptyStackException; - -/* Written using on-line Java 2 Platform Standard Edition v1.3 API - * Specification, as well as "The Java Class Libraries", 2nd edition - * (Addison-Wesley, 1998). - * Status: Believed complete, but untested. - */ - -/** - * This class manages a queue of <code>AWTEvent</code> objects that - * are posted to it. The AWT system uses only one event queue for all - * events. - * - * @author Bryce McKinlay - * @author Aaron M. Renn (arenn@urbanophile.com) - */ -public class EventQueue -{ - private static final int INITIAL_QUEUE_DEPTH = 8; - private AWTEvent[] queue = new AWTEvent[INITIAL_QUEUE_DEPTH]; - - private int next_in = 0; // Index where next event will be added to queue - private int next_out = 0; // Index of next event to be removed from queue - - private EventQueue next; - private EventQueue prev; - private AWTEvent currentEvent; - private long lastWhen = System.currentTimeMillis(); - - private EventDispatchThread dispatchThread = new EventDispatchThread(this); - private boolean shutdown = false; - - private long lastNativeQueueAccess = 0; - private long humanLatencyThreshold = 100; - - synchronized void setShutdown (boolean b) - { - shutdown = b; - } - - synchronized boolean isShutdown () - { - if (shutdown) - return true; - - // This is the exact self-shutdown condition specified in J2SE: - // http://java.sun.com/j2se/1.4.2/docs/api/java/awt/doc-files/AWTThreadIssues.html - - if (peekEvent() == null - && ((ClasspathToolkit) Toolkit.getDefaultToolkit()).nativeQueueEmpty()) - { - Frame[] frames = Frame.getFrames(); - for (int i = 0; i < frames.length; ++i) - if (frames[i].isDisplayable()) - return false; - return true; - } - return false; - } - - /** - * Initializes a new instance of <code>EventQueue</code>. - */ - public EventQueue() - { - } - - /** - * Returns the next event in the queue. This method will block until - * an event is available or until the thread is interrupted. - * - * @return The next event in the queue. - * - * @exception InterruptedException If this thread is interrupted while - * waiting for an event to be posted to the queue. - */ - public synchronized AWTEvent getNextEvent() - throws InterruptedException - { - if (next != null) - return next.getNextEvent(); - - ClasspathToolkit tk = ((ClasspathToolkit) Toolkit.getDefaultToolkit()); - long curr = System.currentTimeMillis(); - - if (! tk.nativeQueueEmpty() && - (curr - lastNativeQueueAccess > humanLatencyThreshold)) - { - tk.iterateNativeQueue(this, false); - lastNativeQueueAccess = curr; - } - - while (next_in == next_out) - { - // Only the EventDispatchThread associated with the top of the stack is - // allowed to get events from the native source; everyone else just - // waits on the head of the queue. - - if (isDispatchThread()) - { - // We are not allowed to return null from this method, yet it - // is possible that we actually have run out of native events - // in the enclosing while() loop, and none of the native events - // happened to cause AWT events. We therefore ought to check - // the isShutdown() condition here, before risking a "native - // wait". If we check it before entering this function we may - // wait forever for events after the shutdown condition has - // arisen. - - if (isShutdown()) - throw new InterruptedException(); - - tk.iterateNativeQueue(this, true); - lastNativeQueueAccess = System.currentTimeMillis(); - } - else - { - try - { - wait(); - } - catch (InterruptedException ie) - { - } - } - } - - AWTEvent res = queue[next_out]; - - if (++next_out == queue.length) - next_out = 0; - return res; - } - - /** - * Returns the next event in the queue without removing it from the queue. - * This method will block until an event is available or until the thread - * is interrupted. - * - * @return The next event in the queue. - * @specnote Does not block. Returns null if there are no events on the - * queue. - */ - public synchronized AWTEvent peekEvent() - { - if (next != null) - return next.peekEvent(); - - if (next_in != next_out) - return queue[next_out]; - else - return null; - } - - /** - * Returns the next event in the queue that has the specified id - * without removing it from the queue. - * This method will block until an event is available or until the thread - * is interrupted. - * - * @param id The event id to return. - * - * @return The next event in the queue. - * - * @specnote Does not block. Returns null if there are no matching events - * on the queue. - */ - public synchronized AWTEvent peekEvent(int id) - { - if (next != null) - return next.peekEvent(id); - - int i = next_out; - while (i != next_in) - { - AWTEvent qevt = queue[i]; - if (qevt.id == id) - return qevt; - } - return null; - } - - /** - * Posts a new event to the queue. - * - * @param evt The event to post to the queue. - * - * @exception NullPointerException If event is null. - */ - public synchronized void postEvent(AWTEvent evt) - { - if (evt == null) - throw new NullPointerException(); - - if (next != null) - { - next.postEvent(evt); - return; - } - - /* Check for any events already on the queue with the same source - and ID. */ - int i = next_out; - while (i != next_in) - { - AWTEvent qevt = queue[i]; - Object src; - if (qevt.id == evt.id - && (src = qevt.getSource()) == evt.getSource() - && src instanceof Component) - { - /* If there are, call coalesceEvents on the source component - to see if they can be combined. */ - Component srccmp = (Component) src; - AWTEvent coalesced_evt = srccmp.coalesceEvents(qevt, evt); - if (coalesced_evt != null) - { - /* Yes. Replace the existing event with the combined event. */ - queue[i] = coalesced_evt; - return; - } - break; - } - if (++i == queue.length) - i = 0; - } - - queue[next_in] = evt; - if (++next_in == queue.length) - next_in = 0; - - if (next_in == next_out) - { - /* Queue is full. Extend it. */ - AWTEvent[] oldQueue = queue; - queue = new AWTEvent[queue.length * 2]; - - int len = oldQueue.length - next_out; - System.arraycopy(oldQueue, next_out, queue, 0, len); - if (next_out != 0) - System.arraycopy(oldQueue, 0, queue, len, next_out); - - next_out = 0; - next_in = oldQueue.length; - } - - if (dispatchThread == null || !dispatchThread.isAlive()) - { - dispatchThread = new EventDispatchThread(this); - dispatchThread.start(); - } - - // Window events might represent the closing of a window, which - // might cause the end of the dispatch thread's life, so we'll wake - // it up here to give it a chance to check for shutdown. - - if (!isDispatchThread() - || (evt.getID() == WindowEvent.WINDOW_CLOSED) - || (evt.getID() == WindowEvent.WINDOW_CLOSING)) - ((ClasspathToolkit) Toolkit.getDefaultToolkit()).wakeNativeQueue(); - - notify(); - } - - /** - * Causes runnable to have its run method called in the dispatch thread of the - * EventQueue. This will happen after all pending events are processed. The - * call blocks until this has happened. This method will throw an Error if - * called from the event dispatcher thread. - * - * @exception InterruptedException If another thread has interrupted - * this thread. - * @exception InvocationTargetException If an exception is thrown when running - * runnable. - * - * @since 1.2 - */ - public static void invokeAndWait(Runnable runnable) - throws InterruptedException, InvocationTargetException - { - if (isDispatchThread ()) - throw new Error("Can't call invokeAndWait from event dispatch thread"); - - EventQueue eq = Toolkit.getDefaultToolkit().getSystemEventQueue(); - Thread current = Thread.currentThread(); - - InvocationEvent ie = - new InvocationEvent(eq, runnable, current, true); - - synchronized (current) - { - eq.postEvent(ie); - current.wait(); - } - - Exception exception; - - if ((exception = ie.getException()) != null) - throw new InvocationTargetException(exception); - } - - /** - * This arranges for runnable to have its run method called in the - * dispatch thread of the EventQueue. This will happen after all - * pending events are processed. - * - * @since 1.2 - */ - public static void invokeLater(Runnable runnable) - { - EventQueue eq = Toolkit.getDefaultToolkit().getSystemEventQueue(); - - InvocationEvent ie = - new InvocationEvent(eq, runnable, null, false); - - eq.postEvent(ie); - } - - /** - * Return true if the current thread is the current AWT event dispatch - * thread. - */ - public static boolean isDispatchThread() - { - EventQueue eq = Toolkit.getDefaultToolkit().getSystemEventQueue(); - - /* Find last EventQueue in chain */ - while (eq.next != null) - eq = eq.next; - - return (Thread.currentThread() == eq.dispatchThread); - } - - /** - * Return the event currently being dispatched by the event - * dispatch thread. If the current thread is not the event - * dispatch thread, this method returns null. - * - * @since 1.4 - */ - public static AWTEvent getCurrentEvent() - { - EventQueue eq = Toolkit.getDefaultToolkit().getSystemEventQueue(); - Thread ct = Thread.currentThread(); - - /* Find out if this thread is the dispatch thread for any of the - EventQueues in the chain */ - while (ct != eq.dispatchThread) - { - // Try next EventQueue, if any - if (eq.next == null) - return null; // Not an event dispatch thread - eq = eq.next; - } - - return eq.currentEvent; - } - - /** - * Allows a custom EventQueue implementation to replace this one. - * All pending events are transferred to the new queue. Calls to postEvent, - * getNextEvent, and peekEvent and others are forwarded to the pushed queue - * until it is removed with a pop(). - * - * @exception NullPointerException if newEventQueue is null. - */ - public synchronized void push(EventQueue newEventQueue) - { - if (newEventQueue == null) - throw new NullPointerException (); - - /* Make sure we are at the top of the stack because callers can - only get a reference to the one at the bottom using - Toolkit.getDefaultToolkit().getSystemEventQueue() */ - if (next != null) - { - next.push (newEventQueue); - return; - } - - /* Make sure we have a live dispatch thread to drive the queue */ - if (dispatchThread == null) - dispatchThread = new EventDispatchThread(this); - - int i = next_out; - while (i != next_in) - { - newEventQueue.postEvent(queue[i]); - next_out = i; - if (++i == queue.length) - i = 0; - } - - next = newEventQueue; - newEventQueue.prev = this; - } - - /** Transfer any pending events from this queue back to the parent queue that - * was previously push()ed. Event dispatch from this queue is suspended. - * - * @exception EmptyStackException If no previous push was made on this - * EventQueue. - */ - protected void pop() throws EmptyStackException - { - if (prev == null) - throw new EmptyStackException(); - - /* The order is important here, we must get the prev lock first, - or deadlock could occur as callers usually get here following - prev's next pointer, and thus obtain prev's lock before trying - to get this lock. */ - synchronized (prev) - { - prev.next = next; - if (next != null) - next.prev = prev; - - synchronized (this) - { - int i = next_out; - while (i != next_in) - { - prev.postEvent(queue[i]); - next_out = i; - if (++i == queue.length) - i = 0; - } - // Empty the queue so it can be reused - next_in = 0; - next_out = 0; - - ((ClasspathToolkit) Toolkit.getDefaultToolkit()).wakeNativeQueue(); - setShutdown(true); - dispatchThread = null; - this.notifyAll(); - } - } - } - - /** - * Dispatches an event. The manner in which the event is dispatched depends - * upon the type of the event and the type of the event's source object. - * - * @exception NullPointerException If event is null. - */ - protected void dispatchEvent(AWTEvent evt) - { - currentEvent = evt; - - if (evt instanceof InputEvent) - lastWhen = ((InputEvent) evt).getWhen(); - else if (evt instanceof ActionEvent) - lastWhen = ((ActionEvent) evt).getWhen(); - else if (evt instanceof InvocationEvent) - lastWhen = ((InvocationEvent) evt).getWhen(); - - if (evt instanceof ActiveEvent) - { - ActiveEvent active_evt = (ActiveEvent) evt; - active_evt.dispatch(); - } - else - { - Object source = evt.getSource(); - - if (source instanceof Component) - { - Component srccmp = (Component) source; - srccmp.dispatchEvent(evt); - } - else if (source instanceof MenuComponent) - { - MenuComponent srccmp = (MenuComponent) source; - srccmp.dispatchEvent(evt); - } - } - } - - /** - * Returns the timestamp of the most recent event that had a timestamp, or - * the initialization time of the event queue if no events have been fired. - * At present, only <code>InputEvent</code>s, <code>ActionEvent</code>s, - * <code>InputMethodEvent</code>s, and <code>InvocationEvent</code>s have - * timestamps, but this may be added to other events in future versions. - * If this is called by the event dispatching thread, it can be any - * (sequential) value, but to other threads, the safest bet is to return - * System.currentTimeMillis(). - * - * @return the most recent timestamp - * @see InputEvent#getWhen() - * @see ActionEvent#getWhen() - * @see InvocationEvent#getWhen() - * @see InputMethodEvent#getWhen() - * @since 1.4 - */ - public static long getMostRecentEventTime() - { - EventQueue eq = Toolkit.getDefaultToolkit().getSystemEventQueue(); - if (Thread.currentThread() != eq.dispatchThread) - return System.currentTimeMillis(); - return eq.lastWhen; - } -} |