org.eclipse.jdt.debug.ui/ui/org/eclipse/jdt/internal/debug/ui/JavaModelListener.java

package org.eclipse.jdt.internal.debug.ui;

/**********************************************************************
Copyright (c) 2000, 2002 IBM Corp.  All rights reserved.
This file is made available under the terms of the Common Public License v1.0
which accompanies this distribution, and is available at
http://www.eclipse.org/legal/cpl-v10.html
**********************************************************************/

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.eclipse.core.resources.IWorkspaceRunnable;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.debug.core.DebugPlugin;
import org.eclipse.debug.core.model.IBreakpoint;
import org.eclipse.jdt.core.ElementChangedEvent;
import org.eclipse.jdt.core.IElementChangedListener;
import org.eclipse.jdt.core.IJavaElement;
import org.eclipse.jdt.core.IJavaElementDelta;
import org.eclipse.jdt.core.IMethod;
import org.eclipse.jdt.core.IType;
import org.eclipse.jdt.debug.core.IJavaBreakpoint;
import org.eclipse.jdt.debug.core.IJavaMethodBreakpoint;
import org.eclipse.jdt.internal.debug.core.JDIDebugPlugin;

/**
 * Listens to Java model element changes and uninstalls breakpoints when:<ul>
 *  <li>the breakpoint type's corresponding package fragment root is removed, closed, or removed from the classpath.</li>
 *  <li>the breakpoints is a method breakpoint and the method has been removed.</li>
 * </ul>
 */
class JavaModelListener implements IElementChangedListener {
	/**
	 * @see IElementChangedListener#elementChanged(ElementChangedEvent)
	 */
	public void elementChanged(ElementChangedEvent e) {
		if (e.getType() != ElementChangedEvent.POST_CHANGE) {
			return;
		}
		List removedElements= new ArrayList();
		getRemovedElements(e.getDelta(), removedElements);
		if (removedElements.isEmpty()) {
			return;
		}
				
		final List breakpointsToRemove= new ArrayList();
		IBreakpoint[] breakpoints= DebugPlugin.getDefault().getBreakpointManager().getBreakpoints(JDIDebugPlugin.getUniqueIdentifier());
		IJavaBreakpoint breakpoint= null;
		for (int i= 0, numBreakpoints= breakpoints.length; i < numBreakpoints; i++) {
			breakpoint= (IJavaBreakpoint)breakpoints[i];
			if (!(breakpoint instanceof IJavaBreakpoint)) {
				continue;
			}
			if (breakpoint instanceof IJavaMethodBreakpoint) {
				IJavaMethodBreakpoint methodBreakpoint= (IJavaMethodBreakpoint)breakpoint;
				IMethod method= null;
				try {
					method = BreakpointUtils.getMethod(methodBreakpoint);
				} catch (CoreException x) {
					JDIDebugUIPlugin.log(x);
				}
				if (method != null && containedInCollection(method, removedElements)) {
					breakpointsToRemove.add(breakpoint);
				}
				continue;
			}
			
			try {
				IType type= BreakpointUtils.getType(breakpoint);
				if (type != null && containedInCollection(type, removedElements)) {
					breakpointsToRemove.add(breakpoint);
				}
			} catch (CoreException x) {
				JDIDebugUIPlugin.log(x);
			}
		}
		if (!breakpointsToRemove.isEmpty()) {
			IWorkspaceRunnable wr = new IWorkspaceRunnable() {
				public void run(IProgressMonitor monitor) throws CoreException {
					Iterator itr= breakpointsToRemove.iterator();
					while (itr.hasNext()) {
						IBreakpoint breakpoint = (IBreakpoint) itr.next();
						DebugPlugin.getDefault().getBreakpointManager().removeBreakpoint(breakpoint, true);	
					}	
				}
			};
			
			fork(wr);
		} 
	}
	
	/**
	 * Recursively traverses the given Java element delta looking for Java elements
	 * which have been removed, closed, or removed from the classpath
	 */
	protected void getRemovedElements(IJavaElementDelta delta, List removedElements) {
		if ((delta.getKind() & IJavaElementDelta.REMOVED) != 0 || (delta.getFlags() & IJavaElementDelta.F_CLOSED) != 0 ||
			(delta.getFlags() & IJavaElementDelta.F_REMOVED_FROM_CLASSPATH) != 0) {
			removedElements.add(delta.getElement());
		}
			
		IJavaElementDelta[] subdeltas= delta.getAffectedChildren();
		for (int i= 0, numDeltas= subdeltas.length; i < numDeltas; i++) {
			getRemovedElements(subdeltas[i], removedElements);
		}
	}
	
	protected void fork(final IWorkspaceRunnable wRunnable) {
		Runnable runnable= new Runnable() {
			public void run() {
				try {
					ResourcesPlugin.getWorkspace().run(wRunnable, null);
				} catch (CoreException ce) {
					DebugPlugin.log(ce);
				}
			}
		};
		new Thread(runnable).start();
	}	
	
	protected boolean containedInCollection(IJavaElement element, List removedElements) {
		if (removedElements.contains(element)) {
			return true;
		}
		IJavaElement parent= element.getParent();
		while (parent != null) {
			if(removedElements.contains(parent)) {
				return true;
			}
			parent= parent.getParent();
		}
		return false;
	}
}