org.eclipse.bpel.common.ui.tray.AdaptingSelectionProvider.java Source code

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Here is the source code for org.eclipse.bpel.common.ui.tray.AdaptingSelectionProvider.java

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/*******************************************************************************
 * Copyright (c) 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.bpel.common.ui.tray;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.eclipse.emf.ecore.EObject;
import org.eclipse.gef.EditPart;
import org.eclipse.gef.EditPartViewer;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.StructuredSelection;

/**
 * The adapting selection provider is used by the BPEL graphical editor
 * so that it can provide its selection in terms of model objects rather
 * than in terms of EditPart objects. This class takes care of converting
 * from model objects to EditParts, and vice versa, when necessary.
 */
public class AdaptingSelectionProvider extends MultiViewerSelectionProvider {

    /**
     * Brand new shiny AdaptingSelectionProvider ...
     * @param viewer
     */
    public AdaptingSelectionProvider(EditPartViewer viewer) {
        super(viewer);
    }

    /**
     * Brand new shiny AdaptingSelectionProvider ...
     */
    public AdaptingSelectionProvider() {
        super();
    }

    @Override
    protected IStructuredSelection calculateSelection(IStructuredSelection selection) {

        if (selection == null || selection.isEmpty()) {
            return StructuredSelection.EMPTY;
        }

        List<EObject> list = new ArrayList<EObject>();
        Set<EObject> newSet = new HashSet<EObject>();

        for (Object model : selection.toArray()) {
            if (model instanceof EditPart) {
                model = ((EditPart) model).getModel();
            }
            if (model instanceof EObject) {
                EObject eObj = (EObject) model;
                if (newSet.add(eObj)) {
                    list.add(eObj);
                }
            }
        }
        if (list.isEmpty()) {
            return StructuredSelection.EMPTY;
        }
        return new StructuredSelection(list);
    }

    /**
     * Set selection to each of the viewers and make sure we ignore callbacks
     * 
     */

    @Override
    protected void internalSetSelection(IStructuredSelection selection) {

        if (selection == null || selection.isEmpty()) {
            return;
        }
        try {
            changingSelection = true;
            for (EditPartViewer viewer : viewers) {
                List<EditPart> newList = new ArrayList<EditPart>();
                Map<Object, EditPart> registry = viewer.getEditPartRegistry();

                for (Object o : selection.toArray()) {
                    EditPart editPart = registry.get(o);
                    if (editPart != null) {
                        newList.add(editPart);
                    }
                }
                viewer.setSelection(new StructuredSelection(newList));
            }
        } finally {
            changingSelection = false;
        }
    }
}