content: /*
   * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
   * the License. You may obtain a copy of the License at
   * <p>
   * http://www.apache.org/licenses/LICENSE-2.0
   * <p>
   * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
   * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
   * specific language governing permissions and limitations under the License.
   * <p>
   * Copyright 2012-2015 the original author or authors.
   */
  package exception;
  
  import java.lang.ref.WeakReference;
  import java.util.Objects;
  import javax.swing.JComponent;
  import javax.swing.RepaintManager;
  
  import static javax.swing.SwingUtilities.isEventDispatchThread;
  
  /**
   * <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>
   * This is a modification of original idea of Scott Delap.<br>
   * </p>
   *
   * @author Scott Delap
   * @author Alexander Potochkin
   * <p>
   * <a href="https://swinghelper.dev.java.net/">...</a>
   */
  abstract class CheckThreadViolationRepaintManager extends RepaintManager {
  	private final boolean completeCheck;
  
  	private WeakReference<JComponent> lastComponent;
  
  	CheckThreadViolationRepaintManager() {
  		// it is recommended to pass the complete check
  		this(true);
  	}
  
  	CheckThreadViolationRepaintManager(boolean completeCheck) {
  		this.completeCheck = completeCheck;
  	}
  
  	@Override
  	public synchronized void addInvalidComponent(JComponent component) {
  		checkThreadViolations(Objects.requireNonNull(component));
  		super.addInvalidComponent(component);
  	}
  
  	@Override
  	public void addDirtyRegion(JComponent component, int x, int y, int w, int h) {
  		checkThreadViolations(Objects.requireNonNull(component));
  		super.addDirtyRegion(component, x, y, w, h);
  	}
  
  	private void checkThreadViolations(JComponent c) {
  		if (!isEventDispatchThread() && (completeCheck || c.isShowing())) {
  			boolean imageUpdate = false;
  			boolean repaint = false;
  			boolean fromSwing = 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<>(c);
  			violationFound(c, stackTrace);
  		}
  	}
  
  	abstract void violationFound(JComponent c, StackTraceElement[] stackTrace);
  }