| /******************************************************************************* |
| * Copyright (c) 2000, 2006 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.ui.actions; |
| |
| import java.util.ArrayList; |
| import java.util.Iterator; |
| import java.util.List; |
| |
| import org.eclipse.core.runtime.Assert; |
| import org.eclipse.core.runtime.IAdaptable; |
| import org.eclipse.core.runtime.ListenerList; |
| |
| import org.eclipse.core.resources.IResource; |
| |
| import org.eclipse.jface.viewers.ISelection; |
| import org.eclipse.jface.viewers.ISelectionChangedListener; |
| import org.eclipse.jface.viewers.ISelectionProvider; |
| import org.eclipse.jface.viewers.IStructuredSelection; |
| import org.eclipse.jface.viewers.SelectionChangedEvent; |
| import org.eclipse.jface.viewers.StructuredSelection; |
| |
| import org.eclipse.jdt.core.IJavaElement; |
| |
| |
| |
| /** |
| * A converting selection provider is a special selection provider which converts |
| * a selection before notifying any listeners. Additional it converts the selection |
| * on <code>getSelection</code> and <code>setSelection</code>. The default strategy |
| * used to adapt the elements of the selection to {@link IJavaElement} or a {@link IResource}, |
| * but implementors can override this behavior. |
| * |
| * @since 3.2 |
| */ |
| public class ConvertingSelectionProvider implements ISelectionProvider { |
| |
| private final ISelectionProvider fProvider; |
| private SelectionChangedListener fListener; |
| |
| private class SelectionChangedListener implements ISelectionChangedListener { |
| |
| ListenerList fListeners= new ListenerList(); |
| |
| public void selectionChanged(SelectionChangedEvent event) { |
| ISelection selection= convertFrom(event.getSelection()); |
| SelectionChangedEvent newEvent= new SelectionChangedEvent(ConvertingSelectionProvider.this, selection); |
| Object[] listeners= fListeners.getListeners(); |
| for (int i= 0; i < listeners.length; i++) { |
| ((ISelectionChangedListener)listeners[i]).selectionChanged(newEvent); |
| } |
| } |
| public void addListener(ISelectionChangedListener listener) { |
| fListeners.add(listener); |
| } |
| public void removeListener(ISelectionChangedListener listener) { |
| fListeners.remove(listener); |
| } |
| public boolean isEmpty() { |
| return fListeners.isEmpty(); |
| } |
| } |
| |
| /** |
| * Creates a {@link ConvertingSelectionProvider} to convert from a given selection provider |
| * using the default mechanism. |
| * |
| * @param provider the provider to covert from and to |
| */ |
| public ConvertingSelectionProvider(ISelectionProvider provider) { |
| Assert.isNotNull(provider); |
| fProvider= provider; |
| } |
| |
| /** |
| * Converts the given original viewer selection into a new |
| * selection. The default behavior adapts the elements in the selection |
| * first to {@link IJavaElement} then to {@link IResource}. |
| * Implementors want to override this method. |
| * |
| * @param viewerSelection the original viewer selection |
| * |
| * @return the new selection to be used |
| */ |
| public ISelection convertFrom(ISelection viewerSelection) { |
| return convertFromUsingDefaultMechanism(viewerSelection); |
| } |
| |
| |
| private ISelection convertFromUsingDefaultMechanism(ISelection viewerSelection) { |
| if (! (viewerSelection instanceof IStructuredSelection)) |
| return viewerSelection; |
| IStructuredSelection selection= (IStructuredSelection)viewerSelection; |
| List result= new ArrayList(selection.size()); |
| for (Iterator iter= selection.iterator(); iter.hasNext();) { |
| Object element= iter.next(); |
| if (element instanceof IResource || element instanceof IJavaElement) { |
| result.add(element); |
| } else if (element instanceof IAdaptable) { |
| IAdaptable adaptable= (IAdaptable)element; |
| IJavaElement jElement= (IJavaElement)adaptable.getAdapter(IJavaElement.class); |
| if (jElement != null) { |
| result.add(jElement); |
| } else { |
| IResource resource= (IResource)adaptable.getAdapter(IResource.class); |
| if (resource != null) { |
| result.add(resource); |
| } else { |
| result.add(element); |
| } |
| } |
| } else { |
| result.add(element); |
| } |
| } |
| return new StructuredSelection(result); |
| } |
| |
| /** |
| * Converts a selection to a viewer selection. The default implementation does not convert |
| * the selection. Implementors want to override this behavior. |
| * |
| * @param selection the selection to convert |
| * |
| * @return a viewer selection |
| */ |
| public ISelection convertTo(ISelection selection) { |
| return selection; |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public final ISelection getSelection() { |
| return convertFrom(fProvider.getSelection()); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public final void setSelection(ISelection selection) { |
| fProvider.setSelection(convertTo(selection)); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public void addSelectionChangedListener(ISelectionChangedListener listener) { |
| if (fListener == null) { |
| fListener= new SelectionChangedListener(); |
| fProvider.addSelectionChangedListener(fListener); |
| } |
| fListener.addListener(listener); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public void removeSelectionChangedListener(ISelectionChangedListener listener) { |
| if (fListener == null) |
| return; |
| fListener.removeListener(listener); |
| if (fListener.isEmpty()) { |
| fProvider.removeSelectionChangedListener(fListener); |
| fListener= null; |
| } |
| } |
| } |