org.eclipse.e4.tools.emf.ui.internal.ObservableColumnLabelProvider.java Source code

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Here is the source code for org.eclipse.e4.tools.emf.ui.internal.ObservableColumnLabelProvider.java

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/*******************************************************************************
 * Copyright (c) 2010 BestSolution.at 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:
 *     Tom Schindl <tom.schindl@bestsolution.at> - initial API and implementation
 ******************************************************************************/
package org.eclipse.e4.tools.emf.ui.internal;

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.CellLabelProvider;
import org.eclipse.jface.viewers.LabelProviderChangedEvent;
import org.eclipse.jface.viewers.ViewerCell;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.Image;

public class ObservableColumnLabelProvider<M> extends CellLabelProvider {
    private IObservableMap[] attributeMaps;

    private IMapChangeListener mapChangeListener = new IMapChangeListener() {
        @Override
        public void handleMapChange(MapChangeEvent event) {
            Set<?> affectedElements = event.diff.getChangedKeys();
            LabelProviderChangedEvent newEvent = new LabelProviderChangedEvent(ObservableColumnLabelProvider.this,
                    affectedElements.toArray());
            fireLabelProviderChanged(newEvent);
        }
    };

    /**
     * Creates a new label provider that tracks changes to one attribute.
     * 
     * @param attributeMap
     */
    public ObservableColumnLabelProvider(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
     */
    protected ObservableColumnLabelProvider(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);
        }
    }

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

    @Override
    @SuppressWarnings("unchecked")
    public void update(ViewerCell cell) {
        M element = (M) cell.getElement();
        cell.setText(getText(element));
        cell.setImage(getImage(element));
        cell.setBackground(getBackground(element));
        cell.setForeground(getForeground(element));
        cell.setFont(getFont(element));
    }

    public String getText(M element) {
        Object value = attributeMaps[0].get(element);
        return value == null ? "" : value.toString(); //$NON-NLS-1$
    }

    public Font getFont(M element) {
        return null;
    }

    public Color getBackground(M element) {
        return null;
    }

    public Color getForeground(M element) {
        return null;
    }

    public Image getImage(M element) {
        return null;
    }

}