| /******************************************************************************* |
| * Copyright (c) 2005, 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.jface.internal.databinding.internal.viewers; |
| |
| import org.eclipse.jface.internal.databinding.provisional.observable.Diffs; |
| import org.eclipse.jface.internal.databinding.provisional.observable.value.AbstractObservableValue; |
| import org.eclipse.jface.internal.databinding.provisional.viewers.ViewersProperties; |
| import org.eclipse.jface.util.Assert; |
| import org.eclipse.jface.viewers.ISelection; |
| import org.eclipse.jface.viewers.ISelectionChangedListener; |
| import org.eclipse.jface.viewers.IStructuredSelection; |
| import org.eclipse.jface.viewers.SelectionChangedEvent; |
| import org.eclipse.jface.viewers.StructuredSelection; |
| import org.eclipse.jface.viewers.StructuredViewer; |
| |
| /** |
| * @since 3.2 |
| * |
| */ |
| public class StructuredViewerObservableValue extends AbstractObservableValue { |
| |
| private final StructuredViewer viewer; |
| |
| private final String attribute; |
| |
| private boolean updating = false; |
| |
| private Object currentSelection; |
| |
| /** |
| * @param viewer |
| * @param attribute |
| */ |
| public StructuredViewerObservableValue(StructuredViewer viewer, |
| String attribute) { |
| this.viewer = viewer; |
| this.attribute = attribute; |
| this.currentSelection = doGetValue(); |
| if (attribute.equals(ViewersProperties.SINGLE_SELECTION)) { |
| viewer.addSelectionChangedListener(new ISelectionChangedListener() { |
| public void selectionChanged(SelectionChangedEvent event) { |
| if (!updating) { |
| Object oldSelection = currentSelection; |
| currentSelection = doGetValue(); |
| fireValueChange(Diffs.createValueDiff(oldSelection, |
| currentSelection)); |
| } |
| } |
| }); |
| } else { |
| throw new IllegalArgumentException( |
| "Attribute name not valid: " + attribute); //$NON-NLS-1$ |
| } |
| } |
| |
| public void setValue(final Object value) { |
| try { |
| updating = true; |
| if (attribute.equals(ViewersProperties.SINGLE_SELECTION)) { |
| Object oldSelection = currentSelection; |
| viewer.setSelection(value == null ? StructuredSelection.EMPTY |
| : new StructuredSelection(value)); |
| currentSelection = doGetValue(); |
| fireValueChange(Diffs.createValueDiff(oldSelection, |
| currentSelection)); |
| } |
| } finally { |
| updating = false; |
| } |
| } |
| |
| public Object doGetValue() { |
| if (attribute.equals(ViewersProperties.SINGLE_SELECTION)) { |
| ISelection selection = viewer.getSelection(); |
| if (selection instanceof IStructuredSelection) { |
| IStructuredSelection sel = (IStructuredSelection) selection; |
| return sel.getFirstElement(); |
| } |
| } |
| return null; |
| } |
| |
| public Object getValueType() { |
| Assert.isTrue(attribute.equals(ViewersProperties.SINGLE_SELECTION), |
| "unexpected attribute: " + attribute); //$NON-NLS-1$ |
| return Object.class; |
| } |
| |
| } |