SWT开发--自定义图片按钮的实现

最近开发RCP控件，需要页面较为美观，虽然使用SWT/JFace做个很炫的页面有点困难，但还是得硬着头皮上了。

首先遇到的问题就是实现图片按钮，由于SWT自带的Button设置BackgroundImage时效果很一般，于是乎只好使用Label为基础，扩展一个自定义图片按钮控件。

代码如下：

import java.util.ArrayList;
import java.util.List;
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Cursor;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Shell;
/**
 * 自定义图片按钮
 * @author Lifeng-Leven
 *
 */
public class ImageButton {
	private Image normalImage;
	private Image mouseOverImage;
	private Image mouseDownImage;
	private Image disabledImage;
	//默认鼠标样式
	private Cursor normalCursor;
	private Cursor handCursor = new Cursor(null, SWT.CURSOR_HAND);
	
	private Label label;
	/**
	 * 按钮是否可用
	 */
	private boolean isDisabled = false;
	
	private List listeners = new ArrayList();
	/**
	 * 自定义带图片的按钮控件
	 * @param parent
	 * @param normalImage
	 * @param mouseOverImage
	 * @param mouseDownImage
	 */
	public ImageButton(Composite parent,Image normalImage,Image mouseOverImage,Image mouseDownImage) {
		this(parent,normalImage,mouseOverImage,mouseDownImage,null);
	}
	/**
	 * 自定义带图片的按钮控件
	 * @param parent
	 * @param normalImage 普通按钮背景图
	 * @param mouseOverImage 鼠标悬浮按钮背景图
	 * @param mouseDownImage 鼠标点击按钮背景图
	 * @param disabledImage 按钮失效背景图
	 */
	public ImageButton(final Composite parent,Image normalImage,Image mouseOverImage,Image mouseDownImage,Image disabledImage) {
		label = new Label(parent, SWT.NONE);
		this.normalImage = normalImage;
		this.mouseOverImage = mouseOverImage;
		this.mouseDownImage = mouseDownImage;
		this.disabledImage = disabledImage;
		normalCursor = parent.getCursor();
		label.setImage(normalImage);
		label.addListener(SWT.MouseEnter, new Listener() {
			public void handleEvent(Event event) {
				if (!isDisabled && ImageButton.this.mouseOverImage != null) {
					label.setImage(ImageButton.this.mouseOverImage);
					parent.getShell().setCursor(handCursor);
				}
			}
		});
		label.addListener(SWT.MouseExit, new Listener() {
			public void handleEvent(Event event) {
				if (!isDisabled && ImageButton.this.normalImage != null) {
					label.setImage(ImageButton.this.normalImage);
					parent.getShell().setCursor(normalCursor);
				}
			}
		});
		label.addListener(SWT.MouseDown, new Listener() {
			public void handleEvent(Event event) {
				if (!isDisabled && ImageButton.this.mouseDownImage != null) {
					label.setImage(ImageButton.this.mouseDownImage);
				}
			}
		});
		label.addListener(SWT.MouseUp, new Listener() {
			public void handleEvent(Event event) {
				if(!isDisabled){
					if(event.widget.equals(label)){
						if (ImageButton.this.mouseOverImage != null) {
							label.setImage(ImageButton.this.mouseOverImage);
						}
					}
					for(OnClickListener listener : listeners){
						listener.onClick();
					}
				}
			}
		});
	}
	/**
	 * 设置按钮是否可用状态
	 * @param isDisabled
	 */
	public void setDisabled(boolean isDisabled){
		this.isDisabled = isDisabled;
		if(isDisabled){
			if(disabledImage!=null){
				label.setImage(disabledImage);
			}
		}
	}
	/**
	 * 处理无用资源
	 */
	public void dispose(){
		if(normalImage!=null && !normalImage.isDisposed()){
			normalImage.dispose();
		}
		if(mouseOverImage!=null && !mouseOverImage.isDisposed()){
			mouseOverImage.dispose();
		}
		if(mouseDownImage!=null && !mouseDownImage.isDisposed()){
			mouseDownImage.dispose();
		}
		if(disabledImage!=null && !disabledImage.isDisposed()){
			disabledImage.dispose();
		}
	}
	/**
	 * 添加动作事件
	 * @param listener
	 */
	public void addClickListener(OnClickListener listener){
		listeners.add(listener);
	}
	/**
	 * 移除动作事件
	 * @param listener
	 */
	public void removeClickListener(OnClickListener listener){
		listeners.remove(listener);
	}
	/**
	 * 自定义动作接口
	 * @author Lifeng-Leven
	 *
	 */
	public interface OnClickListener{
		public void onClick();
	}

	public void setLayoutData(Object btnData) {
		if(label!=null && !label.isDisposed()){
			label.setLayoutData(btnData);
		}
	}
	public Shell getShell() {
		if(label!=null && !label.isDisposed()){
			return label.getShell();
		}
		return null;
	}
}