JDK14/Java14源码在线阅读
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* published by the Free Software Foundation. Oracle designates this
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*
* This code is distributed in the hope that it will be useful, but WITHOUT
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* 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).
*
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*
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package java.awt;
import java.awt.event.*;
import java.awt.peer.ComponentPeer;
import java.lang.ref.WeakReference;
import java.lang.reflect.InvocationTargetException;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.EmptyStackException;
import sun.awt.*;
import sun.awt.dnd.SunDropTargetEvent;
import sun.util.logging.PlatformLogger;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.atomic.AtomicInteger;
import java.security.AccessControlContext;
import jdk.internal.access.SharedSecrets;
import jdk.internal.access.JavaSecurityAccess;
/**
* {@code EventQueue} is a platform-independent class
* that queues events, both from the underlying peer classes
* and from trusted application classes.
* <p>
* It encapsulates asynchronous event dispatch machinery which
* extracts events from the queue and dispatches them by calling
* {@link #dispatchEvent(AWTEvent) dispatchEvent(AWTEvent)} method
* on this {@code EventQueue} with the event to be dispatched
* as an argument. The particular behavior of this machinery is
* implementation-dependent. The only requirements are that events
* which were actually enqueued to this queue (note that events
* being posted to the {@code EventQueue} can be coalesced)
* are dispatched:
* <dl>
* <dt> Sequentially.
* <dd> That is, it is not permitted that several events from
* this queue are dispatched simultaneously.
* <dt> In the same order as they are enqueued.
* <dd> That is, if {@code AWTEvent} A is enqueued
* to the {@code EventQueue} before
* {@code AWTEvent} B then event B will not be
* dispatched before event A.
* </dl>
* <p>
* Some browsers partition applets in different code bases into
* separate contexts, and establish walls between these contexts.
* In such a scenario, there will be one {@code EventQueue}
* per context. Other browsers place all applets into the same
* context, implying that there will be only a single, global
* {@code EventQueue} for all applets. This behavior is
* implementation-dependent. Consult your browser's documentation
* for more information.
* <p>
* For information on the threading issues of the event dispatch
* machinery, see <a href="doc-files/AWTThreadIssues.html#Autoshutdown"
* >AWT Threading Issues</a>.
*
* @author Thomas Ball
* @author Fred Ecks
* @author David Mendenhall
*
* @since 1.1
*/
public class EventQueue {
private static final AtomicInteger threadInitNumber = new AtomicInteger(0);
private static final int LOW_PRIORITY = 0;
private static final int NORM_PRIORITY = 1;
private static final int HIGH_PRIORITY = 2;
private static final int ULTIMATE_PRIORITY = 3;
private static final int NUM_PRIORITIES = ULTIMATE_PRIORITY + 1;
/*
* We maintain one Queue for each priority that the EventQueue supports.
* That is, the EventQueue object is actually implemented as
* NUM_PRIORITIES queues and all Events on a particular internal Queue
* have identical priority. Events are pulled off the EventQueue starting
* with the Queue of highest priority. We progress in decreasing order
* across all Queues.
*/
private Queue[] queues = new Queue[NUM_PRIORITIES];
/*
* The next EventQueue on the stack, or null if this EventQueue is
* on the top of the stack. If nextQueue is non-null, requests to post
* an event are forwarded to nextQueue.
*/
private EventQueue nextQueue;
/*
* The previous EventQueue on the stack, or null if this is the
* "base" EventQueue.
*/
private EventQueue previousQueue;
/*
* A single lock to synchronize the push()/pop() and related operations with
* all the EventQueues from the AppContext. Synchronization on any particular
* event queue(s) is not enough: we should lock the whole stack.
*/
private final Lock pushPopLock;
private final Condition pushPopCond;
/*
* Dummy runnable to wake up EDT from getNextEvent() after
push/pop is performed
*/
private static final Runnable dummyRunnable = new Runnable() {
public void run() {
}
};
private EventDispatchThread dispatchThread;
private final ThreadGroup threadGroup =
Thread.currentThread().getThreadGroup();
private final ClassLoader classLoader =
Thread.currentThread().getContextClassLoader();
/*
* The time stamp of the last dispatched InputEvent or ActionEvent.
*/
private long mostRecentEventTime = System.currentTimeMillis();
/*
* The time stamp of the last KeyEvent .
*/
private long mostRecentKeyEventTime = System.currentTimeMillis();
/**
* The modifiers field of the current event, if the current event is an
* InputEvent or ActionEvent.
*/
private WeakReference<AWTEvent> currentEvent;
/*
* Non-zero if a thread is waiting in getNextEvent(int) for an event of
* a particular ID to be posted to the queue.
*/
private volatile int waitForID;
/*
* AppContext corresponding to the queue.
*/
private final AppContext appContext;
private final String name = "AWT-EventQueue-" + threadInitNumber.getAndIncrement();
private FwDispatcher fwDispatcher;
private static volatile PlatformLogger eventLog;
private static final PlatformLogger getEventLog() {
if(eventLog == null) {
eventLog = PlatformLogger.getLogger("java.awt.event.EventQueue");
}
return eventLog;
}
private static boolean fxAppThreadIsDispatchThread;
static {
AWTAccessor.setEventQueueAccessor(
new AWTAccessor.EventQueueAccessor() {
public Thread getDispatchThread(EventQueue eventQueue) {
return eventQueue.getDispatchThread();
}
public boolean isDispatchThreadImpl(EventQueue eventQueue) {
return eventQueue.isDispatchThreadImpl();
}
public void removeSourceEvents(EventQueue eventQueue,
Object source,
boolean removeAllEvents)
{
eventQueue.removeSourceEvents(source, removeAllEvents);
}
public boolean noEvents(EventQueue eventQueue) {
return eventQueue.noEvents();
}
public void wakeup(EventQueue eventQueue, boolean isShutdown) {
eventQueue.wakeup(isShutdown);
}
public void invokeAndWait(Object source, Runnable r)
throws InterruptedException, InvocationTargetException
{
EventQueue.invokeAndWait(source, r);
}
public void setFwDispatcher(EventQueue eventQueue,
FwDispatcher dispatcher) {
eventQueue.setFwDispatcher(dispatcher);
}
@Override
public long getMostRecentEventTime(EventQueue eventQueue) {
return eventQueue.getMostRecentEventTimeImpl();
}
});
AccessController.doPrivileged(new PrivilegedAction<Object>() {
public Object run() {
fxAppThreadIsDispatchThread =
"true".equals(System.getProperty("javafx.embed.singleThread"));
return null;
}
});
}
/**
* Initializes a new instance of {@code EventQueue}.
*/
public EventQueue() {
for (int i = 0; i < NUM_PRIORITIES; i++) {
queues[i] = new Queue();
}
/*
* NOTE: if you ever have to start the associated event dispatch
* thread at this point, be aware of the following problem:
* If this EventQueue instance is created in
* SunToolkit.createNewAppContext() the started dispatch thread
* may call AppContext.getAppContext() before createNewAppContext()
* completes thus causing mess in thread group to appcontext mapping.
*/
appContext = AppContext.getAppContext();
pushPopLock = (Lock)appContext.get(AppContext.EVENT_QUEUE_LOCK_KEY);
pushPopCond = (Condition)appContext.get(AppContext.EVENT_QUEUE_COND_KEY);
}
/**
* Posts a 1.1-style event to the {@code EventQueue}.
* If there is an existing event on the queue with the same ID
* and event source, the source {@code Component}'s
* {@code coalesceEvents} method will be called.
*
* @param theEvent an instance of {@code java.awt.AWTEvent},
* or a subclass of it
* @throws NullPointerException if {@code theEvent} is {@code null}
*/
public void postEvent(AWTEvent theEvent) {
SunToolkit.flushPendingEvents(appContext);
postEventPrivate(theEvent);
}
/**
* Posts a 1.1-style event to the {@code EventQueue}.
* If there is an existing event on the queue with the same ID
* and event source, the source {@code Component}'s
* {@code coalesceEvents} method will be called.
*
* @param theEvent an instance of {@code java.awt.AWTEvent},
* or a subclass of it
*/
private void postEventPrivate(AWTEvent theEvent) {
theEvent.isPosted = true;
pushPopLock.lock();
try {
if (nextQueue != null) {
// Forward the event to the top of EventQueue stack
nextQueue.postEventPrivate(theEvent);
return;
}
if (dispatchThread == null) {
if (theEvent.getSource() == AWTAutoShutdown.getInstance()) {
return;
} else {
initDispatchThread();
}
}
postEvent(theEvent, getPriority(theEvent));
} finally {
pushPopLock.unlock();
}
}
private static int getPriority(AWTEvent theEvent) {
if (theEvent instanceof PeerEvent) {
PeerEvent peerEvent = (PeerEvent)theEvent;
if ((peerEvent.getFlags() & PeerEvent.ULTIMATE_PRIORITY_EVENT) != 0) {
return ULTIMATE_PRIORITY;
}
if ((peerEvent.getFlags() & PeerEvent.PRIORITY_EVENT) != 0) {
return HIGH_PRIORITY;
}
if ((peerEvent.getFlags() & PeerEvent.LOW_PRIORITY_EVENT) != 0) {
return LOW_PRIORITY;
}
}
int id = theEvent.getID();
if ((id >= PaintEvent.PAINT_FIRST) && (id <= PaintEvent.PAINT_LAST)) {
return LOW_PRIORITY;
}
return NORM_PRIORITY;
}
/**
* Posts the event to the internal Queue of specified priority,
* coalescing as appropriate.
*
* @param theEvent an instance of {@code java.awt.AWTEvent},
* or a subclass of it
* @param priority the desired priority of the event
*/
private void postEvent(AWTEvent theEvent, int priority) {
if (coalesceEvent(theEvent, priority)) {
return;
}
EventQueueItem newItem = new EventQueueItem(theEvent);
cacheEQItem(newItem);
boolean notifyID = (theEvent.getID() == this.waitForID);
if (queues[priority].head == null) {
boolean shouldNotify = noEvents();
queues[priority].head = queues[priority].tail = newItem;
if (shouldNotify) {
if (theEvent.getSource() != AWTAutoShutdown.getInstance()) {
AWTAutoShutdown.getInstance().notifyThreadBusy(dispatchThread);
}
pushPopCond.signalAll();
} else if (notifyID) {
pushPopCond.signalAll();
}
} else {
// The event was not coalesced or has non-Component source.
// Insert it at the end of the appropriate Queue.
queues[priority].tail.next = newItem;
queues[priority].tail = newItem;
if (notifyID) {
pushPopCond.signalAll();
}
}
}
private boolean coalescePaintEvent(PaintEvent e) {
ComponentPeer sourcePeer = ((Component)e.getSource()).peer;
if (sourcePeer != null) {
sourcePeer.coalescePaintEvent(e);
}
EventQueueItem[] cache = ((Component)e.getSource()).eventCache;
if (cache == null) {
return false;
}
int index = eventToCacheIndex(e);
if (index != -1 && cache[index] != null) {
PaintEvent merged = mergePaintEvents(e, (PaintEvent)cache[index].event);
if (merged != null) {
cache[index].event = merged;
return true;
}
}
return false;
}
private PaintEvent mergePaintEvents(PaintEvent a, PaintEvent b) {
Rectangle aRect = a.getUpdateRect();
Rectangle bRect = b.getUpdateRect();
if (bRect.contains(aRect)) {
return b;
}
if (aRect.contains(bRect)) {
return a;
}
return null;
}
private boolean coalesceMouseEvent(MouseEvent e) {
EventQueueItem[] cache = ((Component)e.getSource()).eventCache;
if (cache == null) {
return false;
}
int index = eventToCacheIndex(e);
if (index != -1 && cache[index] != null) {
cache[index].event = e;
return true;
}
return false;
}
private boolean coalescePeerEvent(PeerEvent e) {
EventQueueItem[] cache = ((Component)e.getSource()).eventCache;
if (cache == null) {
return false;
}
int index = eventToCacheIndex(e);
if (index != -1 && cache[index] != null) {
e = e.coalesceEvents((PeerEvent)cache[index].event);
if (e != null) {
cache[index].event = e;
return true;
} else {
cache[index] = null;
}
}
return false;
}
/*
* Should avoid of calling this method by any means
* as it's working time is dependent on EQ length.
* In the worst case this method alone can slow down the entire application
* 10 times by stalling the Event processing.
* Only here by backward compatibility reasons.
*/
private boolean coalesceOtherEvent(AWTEvent e, int priority) {
int id = e.getID();
Component source = (Component)e.getSource();
for (EventQueueItem entry = queues[priority].head;
entry != null; entry = entry.next)
{
// Give Component.coalesceEvents a chance
if (entry.event.getSource() == source && entry.event.getID() == id) {
AWTEvent coalescedEvent = source.coalesceEvents(
entry.event, e);
if (coalescedEvent != null) {
entry.event = coalescedEvent;
return true;
}
}
}
return false;
}
private boolean coalesceEvent(AWTEvent e, int priority) {
if (!(e.getSource() instanceof Component)) {
return false;
}
if (e instanceof PeerEvent) {
return coalescePeerEvent((PeerEvent)e);
}
// The worst case
if (((Component)e.getSource()).isCoalescingEnabled()
&& coalesceOtherEvent(e, priority))
{
return true;
}
if (e instanceof PaintEvent) {
return coalescePaintEvent((PaintEvent)e);
}
if (e instanceof MouseEvent) {
return coalesceMouseEvent((MouseEvent)e);
}
return false;
}
private void cacheEQItem(EventQueueItem entry) {
int index = eventToCacheIndex(entry.event);
if (index != -1 && entry.event.getSource() instanceof Component) {
Component source = (Component)entry.event.getSource();
if (source.eventCache == null) {
source.eventCache = new EventQueueItem[CACHE_LENGTH];
}
source.eventCache[index] = entry;
}
}
private void uncacheEQItem(EventQueueItem entry) {
int index = eventToCacheIndex(entry.event);
if (index != -1 && entry.event.getSource() instanceof Component) {
Component source = (Component)entry.event.getSource();
if (source.eventCache == null) {
return;
}
source.eventCache[index] = null;
}
}
private static final int PAINT = 0;
private static final int UPDATE = 1;
private static final int MOVE = 2;
private static final int DRAG = 3;
private static final int PEER = 4;
private static final int CACHE_LENGTH = 5;
private static int eventToCacheIndex(AWTEvent e) {
switch(e.getID()) {
case PaintEvent.PAINT:
return PAINT;
case PaintEvent.UPDATE:
return UPDATE;
case MouseEvent.MOUSE_MOVED:
return MOVE;
case MouseEvent.MOUSE_DRAGGED:
// Return -1 for SunDropTargetEvent since they are usually synchronous
// and we don't want to skip them by coalescing with MouseEvent or other drag events
return e instanceof SunDropTargetEvent ? -1 : DRAG;
default:
return e instanceof PeerEvent ? PEER : -1;
}
}
/**
* Returns whether an event is pending on any of the separate
* Queues.
* @return whether an event is pending on any of the separate Queues
*/
private boolean noEvents() {
for (int i = 0; i < NUM_PRIORITIES; i++) {
if (queues[i].head != null) {
return false;
}
}
return true;
}
/**
* Removes an event from the {@code EventQueue} and
* returns it. This method will block until an event has
* been posted by another thread.
* @return the next {@code AWTEvent}
* @exception InterruptedException
* if any thread has interrupted this thread
*/
public AWTEvent getNextEvent() throws InterruptedException {
do {
/*
* SunToolkit.flushPendingEvents must be called outside
* of the synchronized block to avoid deadlock when
* event queues are nested with push()/pop().
*/
SunToolkit.flushPendingEvents(appContext);
pushPopLock.lock();
try {
AWTEvent event = getNextEventPrivate();
if (event != null) {
return event;
}
AWTAutoShutdown.getInstance().notifyThreadFree(dispatchThread);
pushPopCond.await();
} finally {
pushPopLock.unlock();
}
} while(true);
}
/*
* Must be called under the lock. Doesn't call flushPendingEvents()
*/
AWTEvent getNextEventPrivate() throws InterruptedException {
for (int i = NUM_PRIORITIES - 1; i >= 0; i--) {
if (queues[i].head != null) {
EventQueueItem entry = queues[i].head;
queues[i].head = entry.next;
if (entry.next == null) {
queues[i].tail = null;
}
uncacheEQItem(entry);
return entry.event;
}
}
return null;
}
AWTEvent getNextEvent(int id) throws InterruptedException {
do {
/*
* SunToolkit.flushPendingEvents must be called outside
* of the synchronized block to avoid deadlock when
* event queues are nested with push()/pop().
*/
SunToolkit.flushPendingEvents(appContext);
pushPopLock.lock();
try {
for (int i = 0; i < NUM_PRIORITIES; i++) {
for (EventQueueItem entry = queues[i].head, prev = null;
entry != null; prev = entry, entry = entry.next)
{
if (entry.event.getID() == id) {
if (prev == null) {
queues[i].head = entry.next;
} else {
prev.next = entry.next;
}
if (queues[i].tail == entry) {
queues[i].tail = prev;
}
uncacheEQItem(entry);
return entry.event;
}
}
}
waitForID = id;
pushPopCond.await();
waitForID = 0;
} finally {
pushPopLock.unlock();
}
} while(true);
}
/**
* Returns the first event on the {@code EventQueue}
* without removing it.
* @return the first event
*/
public AWTEvent peekEvent() {
pushPopLock.lock();
try {
for (int i = NUM_PRIORITIES - 1; i >= 0; i--) {
if (queues[i].head != null) {
return queues[i].head.event;
}
}
} finally {
pushPopLock.unlock();
}
return null;
}
/**
* Returns the first event with the specified id, if any.
* @param id the id of the type of event desired
* @return the first event of the specified id or {@code null}
* if there is no such event
*/
public AWTEvent peekEvent(int id) {
pushPopLock.lock();
try {
for (int i = NUM_PRIORITIES - 1; i >= 0; i--) {
EventQueueItem q = queues[i].head;
for (; q != null; q = q.next) {
if (q.event.getID() == id) {
return q.event;
}
}
}
} finally {
pushPopLock.unlock();
}
return null;
}
private static final JavaSecurityAccess javaSecurityAccess =
SharedSecrets.getJavaSecurityAccess();
/**
* 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:
*
* <table class="striped">
* <caption>Event types, source types, and dispatch methods</caption>
* <thead>
* <tr>
* <th scope="col">Event Type
* <th scope="col">Source Type
* <th scope="col">Dispatched To
* </thead>
* <tbody>
* <tr>
* <th scope="row">ActiveEvent
* <td>Any
* <td>event.dispatch()
* <tr>
* <th scope="row">Other
* <td>Component
* <td>source.dispatchEvent(AWTEvent)
* <tr>
* <th scope="row">Other
* <td>MenuComponent
* <td>source.dispatchEvent(AWTEvent)
* <tr>
* <th scope="row">Other
* <td>Other
* <td>No action (ignored)
* </tbody>
* </table>
*
* @param event an instance of {@code java.awt.AWTEvent},
* or a subclass of it
* @throws NullPointerException if {@code event} is {@code null}
* @since 1.2
*/
protected void dispatchEvent(final AWTEvent event) {
final Object src = event.getSource();
final PrivilegedAction<Void> action = new PrivilegedAction<Void>() {
public Void run() {
// In case fwDispatcher is installed and we're already on the
// dispatch thread (e.g. performing DefaultKeyboardFocusManager.sendMessage),
// dispatch the event straight away.
if (fwDispatcher == null || isDispatchThreadImpl()) {
dispatchEventImpl(event, src);
} else {
fwDispatcher.scheduleDispatch(new Runnable() {
@Override
public void run() {
if (dispatchThread.filterAndCheckEvent(event)) {
dispatchEventImpl(event, src);
}
}
});
}
return null;
}
};
final AccessControlContext stack = AccessController.getContext();
final AccessControlContext srcAcc = getAccessControlContextFrom(src);
final AccessControlContext eventAcc = event.getAccessControlContext();
if (srcAcc == null) {
javaSecurityAccess.doIntersectionPrivilege(action, stack, eventAcc);
} else {
javaSecurityAccess.doIntersectionPrivilege(
new PrivilegedAction<Void>() {
public Void run() {
javaSecurityAccess.doIntersectionPrivilege(action, eventAcc);
return null;
}
}, stack, srcAcc);
}
}
private static AccessControlContext getAccessControlContextFrom(Object src) {
return src instanceof Component ?
((Component)src).getAccessControlContext() :
src instanceof MenuComponent ?
((MenuComponent)src).getAccessControlContext() :
src instanceof TrayIcon ?
((TrayIcon)src).getAccessControlContext() :
null;
}
/**
* Called from dispatchEvent() under a correct AccessControlContext
*/
private void dispatchEventImpl(final AWTEvent event, final Object src) {
event.isPosted = true;
if (event instanceof ActiveEvent) {
// This could become the sole method of dispatching in time.
setCurrentEventAndMostRecentTimeImpl(event);
((ActiveEvent)event).dispatch();
} else if (src instanceof Component) {
((Component)src).dispatchEvent(event);
event.dispatched();
} else if (src instanceof MenuComponent) {
((MenuComponent)src).dispatchEvent(event);
} else if (src instanceof TrayIcon) {
((TrayIcon)src).dispatchEvent(event);
} else if (src instanceof AWTAutoShutdown) {
if (noEvents()) {
dispatchThread.stopDispatching();
}
} else {
if (getEventLog().isLoggable(PlatformLogger.Level.FINE)) {
getEventLog().fine("Unable to dispatch event: " + event);
}
}
}
/**
* Returns the timestamp of the most recent event that had a timestamp, and
* that was dispatched from the {@code EventQueue} associated with the
* calling thread. If an event with a timestamp is currently being
* dispatched, its timestamp will be returned. If no events have yet
* been dispatched, the EventQueue's initialization time will be
* returned instead.In the current version of
* the JDK, only {@code InputEvent}s,
* {@code ActionEvent}s, and {@code InvocationEvent}s have
* timestamps; however, future versions of the JDK may add timestamps to
* additional event types. Note that this method should only be invoked
* from an application's {@link #isDispatchThread event dispatching thread}.
* If this method is
* invoked from another thread, the current system time (as reported by
* {@code System.currentTimeMillis()}) will be returned instead.
*
* @return the timestamp of the last {@code InputEvent},
* {@code ActionEvent}, or {@code InvocationEvent} to be
* dispatched, or {@code System.currentTimeMillis()} if this
* method is invoked on a thread other than an event dispatching
* thread
* @see java.awt.event.InputEvent#getWhen
* @see java.awt.event.ActionEvent#getWhen
* @see java.awt.event.InvocationEvent#getWhen
* @see #isDispatchThread
*
* @since 1.4
*/
public static long getMostRecentEventTime() {
return Toolkit.getEventQueue().getMostRecentEventTimeImpl();
}
private long getMostRecentEventTimeImpl() {
pushPopLock.lock();
try {
return (Thread.currentThread() == dispatchThread)
? mostRecentEventTime
: System.currentTimeMillis();
} finally {
pushPopLock.unlock();
}
}
/**
* @return most recent event time on all threads.
*/
long getMostRecentEventTimeEx() {
pushPopLock.lock();
try {
return mostRecentEventTime;
} finally {
pushPopLock.unlock();
}
}
/**
* Returns the event currently being dispatched by the
* {@code EventQueue} associated with the calling thread. This is
* useful if a method needs access to the event, but was not designed to
* receive a reference to it as an argument. Note that this method should
* only be invoked from an application's event dispatching thread. If this
* method is invoked from another thread, null will be returned.
*
* @return the event currently being dispatched, or null if this method is
* invoked on a thread other than an event dispatching thread
* @since 1.4
*/
public static AWTEvent getCurrentEvent() {
return Toolkit.getEventQueue().getCurrentEventImpl();
}
private AWTEvent getCurrentEventImpl() {
pushPopLock.lock();
try {
if (Thread.currentThread() == dispatchThread
|| fxAppThreadIsDispatchThread) {
return (currentEvent != null)
? currentEvent.get()
: null;
}
return null;
} finally {
pushPopLock.unlock();
}
}
/**
* Replaces the existing {@code EventQueue} with the specified one.
* Any pending events are transferred to the new {@code EventQueue}
* for processing by it.
*
* @param newEventQueue an {@code EventQueue}
* (or subclass thereof) instance to be use
* @see java.awt.EventQueue#pop
* @throws NullPointerException if {@code newEventQueue} is {@code null}
* @since 1.2
*/
public void push(EventQueue newEventQueue) {
if (getEventLog().isLoggable(PlatformLogger.Level.FINE)) {
getEventLog().fine("EventQueue.push(" + newEventQueue + ")");
}
pushPopLock.lock();
try {
EventQueue topQueue = this;
while (topQueue.nextQueue != null) {
topQueue = topQueue.nextQueue;
}
if (topQueue.fwDispatcher != null) {
throw new RuntimeException("push() to queue with fwDispatcher");
}
if ((topQueue.dispatchThread != null) &&
(topQueue.dispatchThread.getEventQueue() == this))
{
newEventQueue.dispatchThread = topQueue.dispatchThread;
topQueue.dispatchThread.setEventQueue(newEventQueue);
}
// Transfer all events forward to new EventQueue.
while (topQueue.peekEvent() != null) {
try {
// Use getNextEventPrivate() as it doesn't call flushPendingEvents()
newEventQueue.postEventPrivate(topQueue.getNextEventPrivate());
} catch (InterruptedException ie) {
if (getEventLog().isLoggable(PlatformLogger.Level.FINE)) {
getEventLog().fine("Interrupted push", ie);
}
}
}
if (topQueue.dispatchThread != null) {
// Wake up EDT waiting in getNextEvent(), so it can
// pick up a new EventQueue. Post the waking event before
// topQueue.nextQueue is assigned, otherwise the event would
// go newEventQueue
topQueue.postEventPrivate(new InvocationEvent(topQueue, dummyRunnable));
}
newEventQueue.previousQueue = topQueue;
topQueue.nextQueue = newEventQueue;
if (appContext.get(AppContext.EVENT_QUEUE_KEY) == topQueue) {
appContext.put(AppContext.EVENT_QUEUE_KEY, newEventQueue);
}
pushPopCond.signalAll();
} finally {
pushPopLock.unlock();
}
}
/**
* Stops dispatching events using this {@code EventQueue}.
* Any pending events are transferred to the previous
* {@code EventQueue} for processing.
* <p>
* Warning: To avoid deadlock, do not declare this method
* synchronized in a subclass.
*
* @exception EmptyStackException if no previous push was made
* on this {@code EventQueue}
* @see java.awt.EventQueue#push
* @since 1.2
*/
protected void pop() throws EmptyStackException {
if (getEventLog().isLoggable(PlatformLogger.Level.FINE)) {
getEventLog().fine("EventQueue.pop(" + this + ")");
}
pushPopLock.lock();
try {
EventQueue topQueue = this;
while (topQueue.nextQueue != null) {
topQueue = topQueue.nextQueue;
}
EventQueue prevQueue = topQueue.previousQueue;
if (prevQueue == null) {
throw new EmptyStackException();
}
topQueue.previousQueue = null;
prevQueue.nextQueue = null;
// Transfer all events back to previous EventQueue.
while (topQueue.peekEvent() != null) {
try {
prevQueue.postEventPrivate(topQueue.getNextEventPrivate());
} catch (InterruptedException ie) {
if (getEventLog().isLoggable(PlatformLogger.Level.FINE)) {
getEventLog().fine("Interrupted pop", ie);
}
}
}
if ((topQueue.dispatchThread != null) &&
(topQueue.dispatchThread.getEventQueue() == this))
{
prevQueue.dispatchThread = topQueue.dispatchThread;
topQueue.dispatchThread.setEventQueue(prevQueue);
}
if (appContext.get(AppContext.EVENT_QUEUE_KEY) == this) {
appContext.put(AppContext.EVENT_QUEUE_KEY, prevQueue);
}
// Wake up EDT waiting in getNextEvent(), so it can
// pick up a new EventQueue
topQueue.postEventPrivate(new InvocationEvent(topQueue, dummyRunnable));
pushPopCond.signalAll();
} finally {
pushPopLock.unlock();
}
}
/**
* Creates a new {@code secondary loop} associated with this
* event queue. Use the {@link SecondaryLoop#enter} and
* {@link SecondaryLoop#exit} methods to start and stop the
* event loop and dispatch the events from this queue.
*
* @return secondaryLoop A new secondary loop object, which can
* be used to launch a new nested event
* loop and dispatch events from this queue
*
* @see SecondaryLoop#enter
* @see SecondaryLoop#exit
*
* @since 1.7
*/
public SecondaryLoop createSecondaryLoop() {
return createSecondaryLoop(null, null, 0);
}
private class FwSecondaryLoopWrapper implements SecondaryLoop {
final private SecondaryLoop loop;
final private EventFilter filter;
public FwSecondaryLoopWrapper(SecondaryLoop loop, EventFilter filter) {
this.loop = loop;
this.filter = filter;
}
@Override
public boolean enter() {
if (filter != null) {
dispatchThread.addEventFilter(filter);
}
return loop.enter();
}
@Override
public boolean exit() {
if (filter != null) {
dispatchThread.removeEventFilter(filter);
}
return loop.exit();
}
}
SecondaryLoop createSecondaryLoop(Conditional cond, EventFilter filter, long interval) {
pushPopLock.lock();
try {
if (nextQueue != null) {
// Forward the request to the top of EventQueue stack
return nextQueue.createSecondaryLoop(cond, filter, interval);
}
if (fwDispatcher != null) {
return new FwSecondaryLoopWrapper(fwDispatcher.createSecondaryLoop(), filter);
}
if (dispatchThread == null) {
initDispatchThread();
}
return new WaitDispatchSupport(dispatchThread, cond, filter, interval);
} finally {
pushPopLock.unlock();
}
}
/**
* Returns true if the calling thread is
* {@link Toolkit#getSystemEventQueue the current AWT EventQueue}'s
* dispatch thread. Use this method to ensure that a particular
* task is being executed (or not being) there.
* <p>
* Note: use the {@link #invokeLater} or {@link #invokeAndWait}
* methods to execute a task in
* {@link Toolkit#getSystemEventQueue the current AWT EventQueue}'s
* dispatch thread.
*
* @return true if running in
* {@link Toolkit#getSystemEventQueue the current AWT EventQueue}'s
* dispatch thread
* @see #invokeLater
* @see #invokeAndWait
* @see Toolkit#getSystemEventQueue
* @since 1.2
*/
public static boolean isDispatchThread() {
EventQueue eq = Toolkit.getEventQueue();
return eq.isDispatchThreadImpl();
}
final boolean isDispatchThreadImpl() {
EventQueue eq = this;
pushPopLock.lock();
try {
EventQueue next = eq.nextQueue;
while (next != null) {
eq = next;
next = eq.nextQueue;
}
if (eq.fwDispatcher != null) {
return eq.fwDispatcher.isDispatchThread();
}
return (Thread.currentThread() == eq.dispatchThread);
} finally {
pushPopLock.unlock();
}
}
final void initDispatchThread() {
pushPopLock.lock();
try {
if (dispatchThread == null && !threadGroup.isDestroyed() && !appContext.isDisposed()) {
dispatchThread = AccessController.doPrivileged(
new PrivilegedAction<EventDispatchThread>() {
public EventDispatchThread run() {
EventDispatchThread t =
new EventDispatchThread(threadGroup,
name,
EventQueue.this);
t.setContextClassLoader(classLoader);
t.setPriority(Thread.NORM_PRIORITY + 1);
t.setDaemon(false);
AWTAutoShutdown.getInstance().notifyThreadBusy(t);
return t;
}
}
);
dispatchThread.start();
}
} finally {
pushPopLock.unlock();
}
}
final void detachDispatchThread(EventDispatchThread edt) {
/*
* Minimize discard possibility for non-posted events
*/
SunToolkit.flushPendingEvents(appContext);
/*
* This synchronized block is to secure that the event dispatch
* thread won't die in the middle of posting a new event to the
* associated event queue. It is important because we notify
* that the event dispatch thread is busy after posting a new event
* to its queue, so the EventQueue.dispatchThread reference must
* be valid at that point.
*/
pushPopLock.lock();
try {
if (edt == dispatchThread) {
dispatchThread = null;
}
AWTAutoShutdown.getInstance().notifyThreadFree(edt);
/*
* Event was posted after EDT events pumping had stopped, so start
* another EDT to handle this event
*/
if (peekEvent() != null) {
initDispatchThread();
}
} finally {
pushPopLock.unlock();
}
}
/*
* Gets the {@code EventDispatchThread} for this
* {@code EventQueue}.
* @return the event dispatch thread associated with this event queue
* or {@code null} if this event queue doesn't have a
* working thread associated with it
* @see java.awt.EventQueue#initDispatchThread
* @see java.awt.EventQueue#detachDispatchThread
*/
final EventDispatchThread getDispatchThread() {
pushPopLock.lock();
try {
return dispatchThread;
} finally {
pushPopLock.unlock();
}
}
/*
* Removes any pending events for the specified source object.
* If removeAllEvents parameter is {@code true} then all
* events for the specified source object are removed, if it
* is {@code false} then {@code SequencedEvent}, {@code SentEvent},
* {@code FocusEvent}, {@code WindowEvent}, {@code KeyEvent},
* and {@code InputMethodEvent} are kept in the queue, but all other
* events are removed.
*
* This method is normally called by the source's
* {@code removeNotify} method.
*/
final void removeSourceEvents(Object source, boolean removeAllEvents) {
SunToolkit.flushPendingEvents(appContext);
pushPopLock.lock();
try {
for (int i = 0; i < NUM_PRIORITIES; i++) {
EventQueueItem entry = queues[i].head;
EventQueueItem prev = null;
while (entry != null) {
if ((entry.event.getSource() == source)
&& (removeAllEvents
|| ! (entry.event instanceof SequencedEvent
|| entry.event instanceof SentEvent
|| entry.event instanceof FocusEvent
|| entry.event instanceof WindowEvent
|| entry.event instanceof KeyEvent
|| entry.event instanceof InputMethodEvent)))
{
if (entry.event instanceof SequencedEvent) {
((SequencedEvent)entry.event).dispose();
}
if (entry.event instanceof SentEvent) {
((SentEvent)entry.event).dispose();
}
if (entry.event instanceof InvocationEvent) {
AWTAccessor.getInvocationEventAccessor()
.dispose((InvocationEvent)entry.event);
}
if (entry.event instanceof SunDropTargetEvent) {
((SunDropTargetEvent)entry.event).dispose();
}
if (prev == null) {
queues[i].head = entry.next;
} else {
prev.next = entry.next;
}
uncacheEQItem(entry);
} else {
prev = entry;
}
entry = entry.next;
}
queues[i].tail = prev;
}
} finally {
pushPopLock.unlock();
}
}
synchronized long getMostRecentKeyEventTime() {
pushPopLock.lock();
try {
return mostRecentKeyEventTime;
} finally {
pushPopLock.unlock();
}
}
static void setCurrentEventAndMostRecentTime(AWTEvent e) {
Toolkit.getEventQueue().setCurrentEventAndMostRecentTimeImpl(e);
}
private void setCurrentEventAndMostRecentTimeImpl(AWTEvent e) {
pushPopLock.lock();
try {
if (!fxAppThreadIsDispatchThread && Thread.currentThread() != dispatchThread) {
return;
}
currentEvent = new WeakReference<>(e);
// This series of 'instanceof' checks should be replaced with a
// polymorphic type (for example, an interface which declares a
// getWhen() method). However, this would require us to make such
// a type public, or to place it in sun.awt. Both of these approaches
// have been frowned upon. So for now, we hack.
//
// In tiger, we will probably give timestamps to all events, so this
// will no longer be an issue.
long mostRecentEventTime2 = Long.MIN_VALUE;
if (e instanceof InputEvent) {
InputEvent ie = (InputEvent)e;
mostRecentEventTime2 = ie.getWhen();
if (e instanceof KeyEvent) {
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