com.sun.glass.ui.monocle.RunnableProcessor Maven / Gradle / Ivy
/*
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* 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.
*
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package com.sun.glass.ui.monocle;
import com.sun.glass.ui.Application;
import java.util.LinkedList;
import java.util.concurrent.CountDownLatch;
/**
* RunnableProcessor provides control over nested run loops in the JavaFX
* event queue.
*/
class RunnableProcessor implements Runnable {
private RunnableQueue queue = new RunnableQueue();
private static class RunLoopControl {
boolean active; // thread should continue to process events.
Object release; // object to return with on leave nested
}
// our stack of nested run loops
private LinkedList activeRunLoops = new LinkedList();
@Override
public void run() {
runLoop();
}
/**
* Posts a Runnable to the JavaFX event queue using this RunnableProcessor
*
* @param r an action to be performed on the JavaFX application thread.
*/
void invokeLater(Runnable r) {
queue.postRunnable(r);
}
/**
* Posts a Runnable to the JavaFX event queue and waits for the Runnable
* to complete.
*
* @param r an action to be performed on the JavaFX application thread.
*/
void invokeAndWait(final Runnable r) {
final CountDownLatch latch = new CountDownLatch(1);
queue.postRunnable(() -> {
try {
r.run();
} finally {
latch.countDown();
}
});
try {
latch.await();
} catch (InterruptedException e) { }
}
private Object runLoop() {
final RunLoopControl control = new RunLoopControl();
//push this new instance on the stack
activeRunLoops.push(control);
control.active = true;
while (control.active) {
try {
queue.getNextRunnable().run();
} catch (Throwable e) {
Application.reportException(e);
}
}
return control.release;
}
Object enterNestedEventLoop() {
// we are being called on the current active event thread
// via dispatch, so it is stalled until we return.
// start our nested loop, which will block until that exits
Object ret = runLoop();
// and return the value that was passed into leaveNested
return ret;
}
void leaveNestedEventLoop(Object retValue) {
// we are being called from dispatch of the current running
// event thread. We want to cause this thread to exit, and
// restart the nested on.
RunLoopControl current = activeRunLoops.pop();
assert current != null;
// let the current run loop die when we return to dispatch.
current.active = false;
// and give it the ret object so it will return it to the
// blocked nesting call.
current.release = retValue;
// when we return from this dispatched event, we will exit
// because we are no longer active, and then the nested
// call can return the release value we just provided.
}
void shutdown() {
synchronized (queue) {
queue.clear();
while (!activeRunLoops.isEmpty()) {
RunLoopControl control = activeRunLoops.pop();
control.active = false;
}
queue.notifyAll();
}
}
/** Posts a Runnable to the JavaFX event queue using the global
* RunnableProcessor.
*
* @param r an action to be performed on the JavaFX application thread.
*/
static void runLater(Runnable r) {
NativePlatformFactory.getNativePlatform()
.getRunnableProcessor()
.invokeLater(r);
}
}