org.eclipse.contribution.xref.internal.ui.providers.XReferenceLabelProvider.java Source code

Introduction

Here is the source code for org.eclipse.contribution.xref.internal.ui.providers.XReferenceLabelProvider.java

Source

/*******************************************************************************
 * Copyright (c) 2004, 2006 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
 *     Helen Hawkins   - iniital version
 *******************************************************************************/
package org.eclipse.contribution.xref.internal.ui.providers;

import org.eclipse.contribution.xref.core.IXReferenceNode;
import org.eclipse.contribution.xref.ui.IDeferredXReference;
import org.eclipse.contribution.xref.ui.XReferenceUIPlugin;
import org.eclipse.core.runtime.ListenerList;
import org.eclipse.jdt.ui.JavaElementLabelProvider;
import org.eclipse.jface.viewers.DecoratingLabelProvider;
import org.eclipse.jface.viewers.ILabelProvider;
import org.eclipse.jface.viewers.ILabelProviderListener;
import org.eclipse.jface.viewers.LabelProvider;
import org.eclipse.jface.viewers.LabelProviderChangedEvent;
import org.eclipse.swt.graphics.Image;

/**
 * Label provider for the tree of cross references
 */
public class XReferenceLabelProvider extends LabelProvider {

    // any element can be put into the data field of
    // a TreeObject. If it implements IWorkbenchAdapter,
    // it will be displayed correctly in the tree.

    public ILabelProvider labelProvider;

    public XReferenceLabelProvider() {
        labelProvider = new DecoratingLabelProvider(new JavaElementLabelProvider(),
                XReferenceUIPlugin.getDefault().getWorkbench().getDecoratorManager().getLabelDecorator());
    }

    private boolean addedListener = false;

    private ListenerList fListeners;

    public void addListener(ILabelProviderListener listener) {
        super.addListener(listener);
        if (fListeners == null) {
            fListeners = new ListenerList();
        }
        fListeners.add(listener);
        if (!addedListener) {
            addedListener = true;
            // as we are only retrieving images from labelProvider not using it
            // directly, we need to update this label provider whenever that one
            // updates
            labelProvider.addListener(new ILabelProviderListener() {
                public void labelProviderChanged(LabelProviderChangedEvent event) {
                    fireLabelChanged();
                }
            });
        }
    }

    private void fireLabelChanged() {
        if (fListeners != null && !fListeners.isEmpty()) {
            LabelProviderChangedEvent event = new LabelProviderChangedEvent(this);
            Object[] listeners = fListeners.getListeners();
            for (int i = 0; i < listeners.length; i++) {
                ((ILabelProviderListener) listeners[i]).labelProviderChanged(event);
            }
        }
    }

    public String getText(Object obj) {
        String ret = obj.toString();
        Object data = ((TreeObject) obj).getData();
        if ((data != null) && !(data instanceof IDeferredXReference)) {
            ret = labelProvider.getText(data);
        }
        return ret;
    }

    public Image getImage(Object obj) {
        Object data = ((TreeObject) obj).getData();
        if (data != null) {
            if (data instanceof IDeferredXReference) {
                return XReferenceUIPlugin.getDefault().getEvaluateImage();
            } else if (data instanceof IXReferenceNode) {
                return labelProvider.getImage(((IXReferenceNode) data).getJavaElement());
            } else {
                return (labelProvider.getImage(data));
            }
        }
        return XReferenceUIPlugin.getDefault().getXReferenceImage();
    }

    public void dispose() {
        fListeners = null;
        if (labelProvider != null) {
            labelProvider.dispose();
            labelProvider = null;
        }
    }
}