org.eclipse.xtext.ui.editor.outline.impl.OutlineTreeState.java Source code

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Here is the source code for org.eclipse.xtext.ui.editor.outline.impl.OutlineTreeState.java

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/*******************************************************************************
 * Copyright (c) 2010 itemis AG (http://www.itemis.eu) 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
 *******************************************************************************/
package org.eclipse.xtext.ui.editor.outline.impl;

import java.util.Collections;
import java.util.Iterator;
import java.util.Set;

import org.apache.log4j.Logger;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.xtext.ui.editor.outline.IOutlineNode;
import org.eclipse.xtext.ui.util.DisplayRunHelper;

import com.google.common.collect.Sets;

/**
 * Either stores the expansion/selection of a tree viewer or aggregates the new expansion/selection state.
 * 
 * @author Jan Koehnlein - Initial contribution and API
 */
public class OutlineTreeState {

    private static final Logger LOG = Logger.getLogger(OutlineTreeState.class);

    private Set<IOutlineNode> expandedNodes;
    private Set<IOutlineNode> selectedNodes;

    public OutlineTreeState(TreeViewer treeViewer) {
        expandedNodes = Collections.unmodifiableSet(getExpandedNodes(treeViewer));
        selectedNodes = Collections.unmodifiableSet(getSelectedNodes(treeViewer));
    }

    public OutlineTreeState() {
        expandedNodes = Sets.newHashSet();
        selectedNodes = Sets.newHashSet();
    }

    protected Set<IOutlineNode> getExpandedNodes(final TreeViewer treeViewer) {
        final Set<IOutlineNode> expandedNodes = Sets.newHashSet();
        DisplayRunHelper.runSyncInDisplayThread(new Runnable() {
            @Override
            public void run() {
                if (!treeViewer.getTree().isDisposed()) {
                    Object[] expandedElements = treeViewer.getExpandedElements();
                    for (Object expandedElement : expandedElements) {
                        if (!(expandedElement instanceof IOutlineNode))
                            LOG.error("Content outline contains illegal node " + expandedElement);
                        else
                            expandedNodes.add((IOutlineNode) expandedElement);
                    }
                }
            }
        });
        return expandedNodes;
    }

    protected Set<IOutlineNode> getSelectedNodes(final TreeViewer treeViewer) {
        DisplayRunHelper.runSyncInDisplayThread(new Runnable() {
            @Override
            public void run() {
                selectedNodes = Sets.newHashSet();
                ISelection selection = treeViewer.getSelection();
                if (selection instanceof IStructuredSelection) {
                    for (Iterator<?> selectionIter = ((IStructuredSelection) selection).iterator(); selectionIter
                            .hasNext();) {
                        Object selectedElement = selectionIter.next();
                        if (!(selectedElement instanceof IOutlineNode))
                            LOG.error("Content outline contains illegal node " + selectedElement);
                        else
                            selectedNodes.add((IOutlineNode) selectedElement);
                    }
                }
            }
        });
        return selectedNodes;
    }

    public Set<IOutlineNode> getSelectedNodes() {
        return selectedNodes;
    }

    public Set<IOutlineNode> getExpandedNodes() {
        return expandedNodes;
    }

    public boolean addExpandedNode(IOutlineNode node) {
        if (expandedNodes.contains(node))
            return false;
        return expandedNodes.add(node);
    }

    public boolean addSelectedNode(IOutlineNode node) {
        if (selectedNodes.contains(node))
            return false;
        return selectedNodes.add(node);
    }

}