| /********************************************************************** |
| * Copyright (c) 2004 QNX Software Systems and others. |
| * All rights reserved. This program and the accompanying materials |
| * are 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 |
| * |
| * Contributors: |
| * QNX Software Systems - Initial API and implementation |
| ***********************************************************************/ |
| package org.eclipse.debug.internal.ui.views; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| import org.eclipse.core.runtime.IPath; |
| import org.eclipse.debug.core.DebugException; |
| import org.eclipse.jface.viewers.StructuredSelection; |
| import org.eclipse.jface.viewers.TreeViewer; |
| import org.eclipse.swt.widgets.TreeItem; |
| |
| /** |
| * The abstract superclass for mementos of the expanded and |
| * selected items in a tree viewer. |
| */ |
| public abstract class AbstractViewerState { |
| |
| // paths to expanded elements |
| private List fExpandedElements = null; |
| // paths to selected elements |
| private IPath[] fSelection = null; |
| |
| /** |
| * Constructs a memento for the given viewer. |
| */ |
| public AbstractViewerState(TreeViewer viewer) { |
| saveState(viewer); |
| } |
| |
| /** |
| * Saves the current state of the given viewer into |
| * this memento. |
| * |
| * @param viewer viewer of which to save the state |
| */ |
| public void saveState(TreeViewer viewer) { |
| List expanded = new ArrayList(); |
| fExpandedElements = null; |
| TreeItem[] items = viewer.getTree().getItems(); |
| try { |
| for (int i = 0; i < items.length; i++) { |
| collectExandedItems(items[i], expanded); |
| } |
| if (expanded.size() > 0) { |
| fExpandedElements = expanded; |
| } |
| } catch (DebugException e) { |
| fExpandedElements = null; |
| } |
| TreeItem[] selection = viewer.getTree().getSelection(); |
| fSelection = new IPath[selection.length]; |
| try { |
| for (int i = 0; i < selection.length; i++) { |
| fSelection[i] = encodeElement(selection[i]); |
| } |
| } catch (DebugException e) { |
| fSelection = null; |
| } |
| } |
| |
| protected void collectExandedItems(TreeItem item, List expanded) |
| throws DebugException { |
| if (item.getExpanded()) { |
| expanded.add(encodeElement(item)); |
| TreeItem[] items = item.getItems(); |
| for (int i = 0; i < items.length; i++) { |
| collectExandedItems(items[i], expanded); |
| } |
| } |
| } |
| |
| /** |
| * Constructs a path representing the given tree item. The segments in the |
| * path denote parent items, and the last segment is the name of |
| * the given item. |
| * |
| * @param item tree item to encode |
| * @return path encoding the given item |
| * @throws DebugException if unable to generate a path |
| */ |
| protected abstract IPath encodeElement(TreeItem item) throws DebugException; |
| |
| /** |
| * Restores the state of the given viewer to this memento's |
| * saved state. |
| * |
| * @param viewer viewer to which state is restored |
| */ |
| public void restoreState(TreeViewer viewer) { |
| if (fExpandedElements != null) { |
| List expansion = new ArrayList(fExpandedElements.size()); |
| for (int i = 0; i < fExpandedElements.size(); i++) { |
| IPath path = (IPath) fExpandedElements.get(i); |
| if (path != null) { |
| Object obj; |
| try { |
| obj = decodePath(path, viewer); |
| if (obj != null) { |
| expansion.add(obj); |
| } |
| } catch (DebugException e) { |
| } |
| } |
| } |
| viewer.setExpandedElements(expansion.toArray()); |
| } |
| if (fSelection != null) { |
| List selection = new ArrayList(fSelection.length); |
| for (int i = 0; i < fSelection.length; i++) { |
| IPath path = fSelection[i]; |
| Object obj; |
| try { |
| obj = decodePath(path, viewer); |
| if (obj != null) { |
| selection.add(obj); |
| } |
| } catch (DebugException e) { |
| } |
| } |
| viewer.setSelection(new StructuredSelection(selection)); |
| } |
| } |
| |
| /** |
| * Returns an element in the given viewer that corresponds to the given |
| * path, or <code>null</code> if none. |
| * |
| * @param path encoded element path |
| * @param viewer viewer to search for the element in |
| * @return element represented by the path, or <code>null</code> if none |
| * @throws DebugException if unable to locate a variable |
| */ |
| protected abstract Object decodePath(IPath path, TreeViewer viewer) throws DebugException; |
| |
| } |