de.ovgu.featureide.fm.ui.editors.featuremodel.actions.DeleteAction.java Source code

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Here is the source code for de.ovgu.featureide.fm.ui.editors.featuremodel.actions.DeleteAction.java

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/* FeatureIDE - An IDE to support feature-oriented software development
 * Copyright (C) 2005-2012  FeatureIDE team, University of Magdeburg
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see http://www.gnu.org/licenses/.
 *
 * See http://www.fosd.de/featureide/ for further information.
 */
package de.ovgu.featureide.fm.ui.editors.featuremodel.actions;

import java.util.Iterator;
import java.util.LinkedList;

import org.eclipse.core.commands.ExecutionException;
import org.eclipse.core.commands.operations.IUndoContext;
import org.eclipse.gef.ui.parts.GraphicalViewerImpl;
import org.eclipse.jface.action.Action;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.jface.viewers.ISelectionChangedListener;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.SelectionChangedEvent;
import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.ui.ISharedImages;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.actions.ActionFactory;

import de.ovgu.featureide.fm.core.Feature;
import de.ovgu.featureide.fm.core.FeatureModel;
import de.ovgu.featureide.fm.ui.FMUIPlugin;
import de.ovgu.featureide.fm.ui.editors.featuremodel.editparts.FeatureEditPart;
import de.ovgu.featureide.fm.ui.editors.featuremodel.editparts.ModelEditPart;
import de.ovgu.featureide.fm.ui.editors.featuremodel.operations.DeleteOperation;

/**
 * Deletes the selected features and moves their unselected children upwards.
 * Also deletes the selected propositional constraint.
 * 
 * @author Thomas Thuem
 * @author Christian Becker
 */
public class DeleteAction extends Action {

    public static final String ID = ActionFactory.DELETE.getId();

    private static ImageDescriptor deleteImage = PlatformUI.getWorkbench().getSharedImages()
            .getImageDescriptor(ISharedImages.IMG_TOOL_DELETE);

    private final Object viewer;

    private final FeatureModel featureModel;

    private ISelectionChangedListener listener = new ISelectionChangedListener() {
        public void selectionChanged(SelectionChangedEvent event) {
            IStructuredSelection selection = (IStructuredSelection) event.getSelection();
            setEnabled(isValidSelection(selection));
        }
    };

    public DeleteAction(Object viewer, FeatureModel featureModel) {
        super("Delete (Del)", deleteImage);
        this.viewer = viewer;
        this.featureModel = featureModel;
        setEnabled(false);
        if (viewer instanceof GraphicalViewerImpl)
            ((GraphicalViewerImpl) viewer).addSelectionChangedListener(listener);
        else
            ((TreeViewer) viewer).addSelectionChangedListener(listener);
    }

    @Override
    public void run() {
        DeleteOperation op = new DeleteOperation(viewer, featureModel);
        op.addContext((IUndoContext) featureModel.getUndoContext());

        try {
            PlatformUI.getWorkbench().getOperationSupport().getOperationHistory().execute(op, null, null);
        } catch (ExecutionException e) {
            FMUIPlugin.getDefault().logError(e);

        }

    }

    private boolean isValidSelection(IStructuredSelection selection) {
        // check empty selection (i.e. ModelEditPart is selected)
        if (selection.size() == 1 && selection.getFirstElement() instanceof ModelEditPart)
            return false;

        // check that a possibly new root can be determined unique
        Feature root = featureModel.getRoot();
        Feature newRoot = root;
        LinkedList<Feature> features = new LinkedList<Feature>(featureModel.getFeatures());
        Iterator<?> iter = selection.iterator();
        while (iter.hasNext()) {
            Object editPart = iter.next();
            if (!(editPart instanceof FeatureEditPart) && !(editPart instanceof Feature))
                continue;
            Feature feature = editPart instanceof FeatureEditPart ? ((FeatureEditPart) editPart).getFeature()
                    : (Feature) editPart;
            if (feature == root) {
                if (root.getChildrenCount() != 1)
                    return false;
                newRoot = root.getFirstChild();
                if (!newRoot.hasChildren())
                    return false;
            }
            features.remove(feature);
        }

        // check that the only child of a deleted root is not deleted too
        if (root != newRoot && !features.contains(newRoot))
            return false;

        return true;
    }
}