era.foss.ui.contrib.EmfObservableMapVaildatingStyledCellLabelProvider.java Source code

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Here is the source code for era.foss.ui.contrib.EmfObservableMapVaildatingStyledCellLabelProvider.java

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/**************************************************************************
 * ERA - Eclipse Requirements Analysis
 * ==============================================
 * Copyright (C) 2009-2013 by Georg Blaschke, Christoph P. Neumann
 * and Bernd Haberstumpf (http://era.origo.ethz.ch)
 **************************************************************************
 * Licensed under the Eclipse Public License - v 1.0 (the "License");
 * you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.eclipse.org/org/documents/epl-v10.html
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 **************************************************************************
*/
package era.foss.ui.contrib;

import java.util.Set;

import org.eclipse.core.databinding.observable.map.IMapChangeListener;
import org.eclipse.core.databinding.observable.map.IObservableMap;
import org.eclipse.core.databinding.observable.map.MapChangeEvent;
import org.eclipse.jface.viewers.LabelProviderChangedEvent;
import org.eclipse.jface.viewers.StyledCellLabelProvider;
import org.eclipse.jface.viewers.ViewerCell;

/**
 * The Class EmfObservableMapVaildatingStyledCellLabelProvider.
 */
public class EmfObservableMapVaildatingStyledCellLabelProvider extends StyledCellLabelProvider {
    /**
     * Observable maps typically mapping from viewer elements to label values. Subclasses may use these maps to provide
     * custom labels.
     */
    protected IObservableMap[] attributeMaps;

    /** The map change listener. */
    private IMapChangeListener mapChangeListener = new IMapChangeListener() {
        public void handleMapChange(MapChangeEvent event) {
            Set<?> affectedElements = event.diff.getChangedKeys();
            LabelProviderChangedEvent newEvent = new LabelProviderChangedEvent(
                    EmfObservableMapVaildatingStyledCellLabelProvider.this, affectedElements.toArray());
            fireLabelProviderChanged(newEvent);
        }
    };

    /**
     * Creates a new label provider that tracks changes to one attribute.
     *
     * @param attributeMap the attribute map
     */
    public EmfObservableMapVaildatingStyledCellLabelProvider(IObservableMap attributeMap) {
        this(new IObservableMap[] { attributeMap });
    }

    /**
     * Creates a new label provider that tracks changes to more than one attribute. This constructor should be used by
     * subclasses that override {@link #update(ViewerCell)} and make use of more than one attribute.
     *
     * @param attributeMaps the attribute maps
     */
    protected EmfObservableMapVaildatingStyledCellLabelProvider(IObservableMap[] attributeMaps) {
        System.arraycopy(attributeMaps, 0, this.attributeMaps = new IObservableMap[attributeMaps.length], 0,
                attributeMaps.length);
        for (int i = 0; i < attributeMaps.length; i++) {
            attributeMaps[i].addMapChangeListener(mapChangeListener);
        }
    }

    public void dispose() {
        for (int i = 0; i < attributeMaps.length; i++) {
            attributeMaps[i].removeMapChangeListener(mapChangeListener);
        }
        super.dispose();
        this.attributeMaps = null;
        this.mapChangeListener = null;
    }

    public void update(ViewerCell cell) {
        Object element = cell.getElement();
        Object value = attributeMaps[0].get(element);
        cell.setText(value == null ? "" : value.toString()); //$NON-NLS-1$
    }

}