Mega Code Archive
Detect Event Dispatch Thread rule violations
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/*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
import java.lang.ref.WeakReference;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JEditorPane;
import javax.swing.JFrame;
import javax.swing.RepaintManager;
import javax.swing.SwingUtilities;
/**
* <p>
* This class is used to detect Event Dispatch Thread rule violations<br>
* See <a
* href="http://java.sun.com/docs/books/tutorial/uiswing/misc/threads.html">How
* to Use Threads</a> for more info
* </p>
* <p/>
* <p>
* This is a modification of original idea of Scott Delap<br>
* Initial version of ThreadCheckingRepaintManager can be found here<br>
* <a href="http://www.clientjava.com/blog/2004/08/20/1093059428000.html">Easily
* Find Swing Threading Mistakes</a>
* </p>
*
* @author Scott Delap
* @author Alexander Potochkin
*
* https://swinghelper.dev.java.net/
*/
public class CheckThreadViolationRepaintManager extends RepaintManager {
// it is recommended to pass the complete check
private boolean completeCheck = true;
private WeakReference<JComponent> lastComponent;
public CheckThreadViolationRepaintManager(boolean completeCheck) {
this.completeCheck = completeCheck;
}
public CheckThreadViolationRepaintManager() {
this(true);
}
public boolean isCompleteCheck() {
return completeCheck;
}
public void setCompleteCheck(boolean completeCheck) {
this.completeCheck = completeCheck;
}
public synchronized void addInvalidComponent(JComponent component) {
checkThreadViolations(component);
super.addInvalidComponent(component);
}
public void addDirtyRegion(JComponent component, int x, int y, int w, int h) {
checkThreadViolations(component);
super.addDirtyRegion(component, x, y, w, h);
}
private void checkThreadViolations(JComponent c) {
if (!SwingUtilities.isEventDispatchThread() && (completeCheck || c.isShowing())) {
boolean repaint = false;
boolean fromSwing = false;
boolean imageUpdate = false;
StackTraceElement[] stackTrace = Thread.currentThread().getStackTrace();
for (StackTraceElement st : stackTrace) {
if (repaint && st.getClassName().startsWith("javax.swing.")) {
fromSwing = true;
}
if (repaint && "imageUpdate".equals(st.getMethodName())) {
imageUpdate = true;
}
if ("repaint".equals(st.getMethodName())) {
repaint = true;
fromSwing = false;
}
}
if (imageUpdate) {
// assuming it is java.awt.image.ImageObserver.imageUpdate(...)
// image was asynchronously updated, that's ok
return;
}
if (repaint && !fromSwing) {
// no problems here, since repaint() is thread safe
return;
}
// ignore the last processed component
if (lastComponent != null && c == lastComponent.get()) {
return;
}
lastComponent = new WeakReference<JComponent>(c);
violationFound(c, stackTrace);
}
}
protected void violationFound(JComponent c, StackTraceElement[] stackTrace) {
System.out.println();
System.out.println("EDT violation detected");
System.out.println(c);
for (StackTraceElement st : stackTrace) {
System.out.println("\tat " + st);
}
}
public static void main(String[] args) throws Exception {
// set CheckThreadViolationRepaintManager
RepaintManager.setCurrentManager(new CheckThreadViolationRepaintManager());
// Valid code
SwingUtilities.invokeAndWait(new Runnable() {
public void run() {
test();
}
});
System.out.println("Valid code passed...");
repaintTest();
System.out.println("Repaint test - correct code");
// Invalide code (stack trace expected)
test();
}
static void test() {
JFrame frame = new JFrame("Am I on EDT?");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new JButton("JButton"));
frame.pack();
frame.setVisible(true);
frame.dispose();
}
// this test must pass
static void imageUpdateTest() {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JEditorPane editor = new JEditorPane();
frame.setContentPane(editor);
editor.setContentType("text/html");
// it works with no valid image as well
editor.setText("<html><img src=\"file:\\lala.png\"></html>");
frame.setSize(300, 200);
frame.setVisible(true);
}
private static JButton test;
static void repaintTest() {
try {
SwingUtilities.invokeAndWait(new Runnable() {
public void run() {
test = new JButton();
test.setSize(100, 100);
}
});
} catch (Exception e) {
e.printStackTrace();
}
// repaint(Rectangle) should be ok
test.repaint(test.getBounds());
test.repaint(0, 0, 100, 100);
test.repaint();
}
}
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