bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/ViewerLabel.java

/*******************************************************************************
 * Copyright (c) 2004 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jface.viewers;

import org.eclipse.swt.graphics.Image;

/**
 * The ViewerLabel is the class that is passed to a viewer to handle updates of
 * labels. It keeps track of both original and updates text.
 * 
 * @see IViewerLabelProvider
 * @since 3.0
 */
public class ViewerLabel {
	
	//New values for the receiver. Null if nothing has been set.
	private String newText = null;
	private Image newImage = null;
	
	//The initial values for the receiver.
	private String startText;
	private Image startImage;
	
	public ViewerLabel(String initialText, Image initialImage){
		startText = initialText;
		startImage = initialImage;
	}
	
	/**
	 * Get the image for the receiver. If the new image has been set 
	 * return it, otherwise return the starting image.
	 * 
	 * @return Returns the image.
	 */
	public final Image getImage() {
		if(newImage == null)
			return startImage;
		else
			return newImage;
	}
	
	/**
	 * Set the image for the receiver.
	 * 
	 * @param image
	 *                   The image to set.
	 */
	public final void setImage(Image image) {
		newImage = image;
	}
	/**
	 * Get the text for the receiver. If the new text has been set 
	 * return it, otherwise return the starting text.
	 * 
	 * @return Returns the text.
	 */
	public final String getText() {
		if(newText == null)
			return startText;
		else
			return newText;
	}
	/**
	 * Set the text for the receiver.
	 * 
	 * @param text
	 *                   The label to set.
	 */
	public final void setText(String text){
		newText = text;
	}
	/**
	 * Return whether or not the image has been set.
	 * @return boolean. true if the image has been set
	 * to something new.
	 */
	public boolean hasNewImage() {
		
		//If we started with null any change is an update
		if(startImage == null)
			return newImage != null;
		
		return !(startImage.equals(newImage));
	}
	/**
	 * Return whether or not the text has been set.
	 * @return boolean. true if the text has been set
	 * to something new.
	 */
	public boolean hasNewText() {
		
		//If we started with null any change is an update
		if(startText == null)
			return newText != null;
		
		return  !(startText.equals(newText)); 
	}
}