| /******************************************************************************* |
| * Copyright (c) 2000, 2005 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.jdt.internal.ui.viewsupport; |
| |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| import org.eclipse.core.runtime.IProgressMonitor; |
| import org.eclipse.core.runtime.IStatus; |
| import org.eclipse.core.runtime.NullProgressMonitor; |
| import org.eclipse.core.runtime.OperationCanceledException; |
| import org.eclipse.core.runtime.Status; |
| import org.eclipse.core.runtime.jobs.Job; |
| |
| import org.eclipse.jface.text.ITextSelection; |
| import org.eclipse.jface.util.ListenerList; |
| import org.eclipse.jface.viewers.IPostSelectionProvider; |
| import org.eclipse.jface.viewers.ISelection; |
| import org.eclipse.jface.viewers.ISelectionChangedListener; |
| import org.eclipse.jface.viewers.ISelectionProvider; |
| import org.eclipse.jface.viewers.SelectionChangedEvent; |
| |
| import org.eclipse.ui.IEditorInput; |
| import org.eclipse.ui.texteditor.ITextEditor; |
| |
| import org.eclipse.jdt.core.IJavaElement; |
| |
| import org.eclipse.jdt.core.dom.CompilationUnit; |
| |
| import org.eclipse.jdt.internal.ui.JavaPlugin; |
| import org.eclipse.jdt.internal.ui.JavaUIMessages; |
| import org.eclipse.jdt.internal.ui.javaeditor.ASTProvider; |
| |
| /** |
| * Infrastructure to share an AST for editor post selection listeners. |
| */ |
| public class SelectionListenerWithASTManager { |
| |
| private static SelectionListenerWithASTManager fgDefault; |
| |
| /** |
| * @return Returns the default manager instance. |
| */ |
| public static SelectionListenerWithASTManager getDefault() { |
| if (fgDefault == null) { |
| fgDefault= new SelectionListenerWithASTManager(); |
| } |
| return fgDefault; |
| } |
| |
| |
| private final static class PartListenerGroup { |
| private ITextEditor fPart; |
| private ISelectionChangedListener fSelectionListener, fPostSelectionListener; |
| private Job fCurrentJob; |
| private ListenerList fAstListeners; |
| /** |
| * Lock to avoid having more than one calculateAndInform job in parallel. |
| * Only jobs may synchronize on this as otherwise deadlocks are possible. |
| */ |
| private final Object fJobLock= new Object(); |
| |
| public PartListenerGroup(ITextEditor part) { |
| fPart= part; |
| fCurrentJob= null; |
| fAstListeners= new ListenerList(); |
| |
| fSelectionListener= new ISelectionChangedListener() { |
| public void selectionChanged(SelectionChangedEvent event) { |
| ISelection selection= event.getSelection(); |
| if (selection instanceof ITextSelection) { |
| fireSelectionChanged((ITextSelection) selection); |
| } |
| } |
| }; |
| |
| fPostSelectionListener= new ISelectionChangedListener() { |
| public void selectionChanged(SelectionChangedEvent event) { |
| ISelection selection= event.getSelection(); |
| if (selection instanceof ITextSelection) { |
| firePostSelectionChanged((ITextSelection) selection); |
| } |
| } |
| }; |
| } |
| |
| public boolean isEmpty() { |
| return fAstListeners.isEmpty(); |
| } |
| |
| public void install(ISelectionListenerWithAST listener) { |
| if (isEmpty()) { |
| ISelectionProvider selectionProvider= fPart.getSelectionProvider(); |
| if (selectionProvider instanceof IPostSelectionProvider) { |
| ((IPostSelectionProvider) selectionProvider).addPostSelectionChangedListener(fPostSelectionListener); |
| selectionProvider.addSelectionChangedListener(fSelectionListener); |
| } |
| } |
| fAstListeners.add(listener); |
| } |
| |
| public void uninstall(ISelectionListenerWithAST listener) { |
| fAstListeners.remove(listener); |
| if (isEmpty()) { |
| ISelectionProvider selectionProvider= fPart.getSelectionProvider(); |
| if (selectionProvider instanceof IPostSelectionProvider) { |
| ((IPostSelectionProvider) selectionProvider).removePostSelectionChangedListener(fPostSelectionListener); |
| selectionProvider.removeSelectionChangedListener(fSelectionListener); |
| } |
| } |
| } |
| |
| public void fireSelectionChanged(final ITextSelection selection) { |
| if (fCurrentJob != null) { |
| fCurrentJob.cancel(); |
| } |
| } |
| |
| public void firePostSelectionChanged(final ITextSelection selection) { |
| if (fCurrentJob != null) { |
| fCurrentJob.cancel(); |
| } |
| final IJavaElement input= getJavaElement(); |
| if (input == null) { |
| return; |
| } |
| |
| fCurrentJob= new Job(JavaUIMessages.SelectionListenerWithASTManager_job_title) { |
| public IStatus run(IProgressMonitor monitor) { |
| if (monitor == null) { |
| monitor= new NullProgressMonitor(); |
| } |
| synchronized (fJobLock) { |
| return calculateASTandInform(input, selection, monitor); |
| } |
| } |
| }; |
| fCurrentJob.setPriority(Job.DECORATE); |
| fCurrentJob.setSystem(true); |
| fCurrentJob.schedule(); |
| } |
| |
| private IJavaElement getJavaElement() { |
| IEditorInput editorInput= fPart.getEditorInput(); |
| if (editorInput != null) |
| return (IJavaElement)editorInput.getAdapter(IJavaElement.class); |
| |
| return null; |
| } |
| |
| protected IStatus calculateASTandInform(IJavaElement input, ITextSelection selection, IProgressMonitor monitor) { |
| if (monitor.isCanceled()) { |
| return Status.CANCEL_STATUS; |
| } |
| // create AST |
| try { |
| CompilationUnit astRoot= JavaPlugin.getDefault().getASTProvider().getAST(input, ASTProvider.WAIT_ACTIVE_ONLY, monitor); |
| |
| if (astRoot != null && !monitor.isCanceled()) { |
| Object[] listeners; |
| synchronized (PartListenerGroup.this) { |
| listeners= fAstListeners.getListeners(); |
| } |
| for (int i= 0; i < listeners.length; i++) { |
| ((ISelectionListenerWithAST) listeners[i]).selectionChanged(fPart, selection, astRoot); |
| if (monitor.isCanceled()) { |
| return Status.CANCEL_STATUS; |
| } |
| } |
| return Status.OK_STATUS; |
| } |
| } catch (OperationCanceledException e) { |
| // thrown when cancelling the AST creation |
| } |
| return Status.CANCEL_STATUS; |
| } |
| } |
| |
| |
| private Map fListenerGroups; |
| |
| private SelectionListenerWithASTManager() { |
| fListenerGroups= new HashMap(); |
| } |
| |
| /** |
| * Registers a selection listener for the given editor part. |
| * @param part The editor part to listen to. |
| * @param listener The listener to register. |
| */ |
| public void addListener(ITextEditor part, ISelectionListenerWithAST listener) { |
| synchronized (this) { |
| PartListenerGroup partListener= (PartListenerGroup) fListenerGroups.get(part); |
| if (partListener == null) { |
| partListener= new PartListenerGroup(part); |
| fListenerGroups.put(part, partListener); |
| } |
| partListener.install(listener); |
| } |
| } |
| |
| /** |
| * Unregisters a selection listener. |
| * @param part The editor part the listener was registered. |
| * @param listener The listener to unregister. |
| */ |
| public void removeListener(ITextEditor part, ISelectionListenerWithAST listener) { |
| synchronized (this) { |
| PartListenerGroup partListener= (PartListenerGroup) fListenerGroups.get(part); |
| if (partListener != null) { |
| partListener.uninstall(listener); |
| if (partListener.isEmpty()) { |
| fListenerGroups.remove(part); |
| } |
| } |
| } |
| } |
| |
| /** |
| * Forces a selection changed event that is sent to all listeners registered to the given editor |
| * part. The event is sent from a background thread: this method call can return before the listeners |
| * are informed. |
| * @param part The editor part that has a changed selection |
| * @param selection The new text selection |
| */ |
| public void forceSelectionChange(ITextEditor part, ITextSelection selection) { |
| synchronized (this) { |
| PartListenerGroup partListener= (PartListenerGroup) fListenerGroups.get(part); |
| if (partListener != null) { |
| partListener.firePostSelectionChanged(selection); |
| } |
| } |
| }} |