探侦学院粤语:闲着没事写了两个可以设置背景图片的面板类，感兴趣的下（2）

package craky;import org.eclipse.swt.events.PaintEvent;import org.eclipse.swt.events.PaintListener;import org.eclipse.swt.graphics.Image;import org.eclipse.swt.graphics.ImageData;import org.eclipse.swt.widgets.Composite;/*** 可设置背景图片的Composite* Composite本身是可以设置背景图片的，但是只提供了平铺的显示方式，该类实现了居中、平铺和拉伸三种显示方式。** @author 003*/public class ImageComposite extends Composite implements PaintListener{/*** 居中*/public static final String CENTRE = "Centre";/*** 平铺*/public static final String TILED = "Tiled";/*** 拉伸*/public static final String SCALED = "Scaled";/*** 背景图片*/private Image backgroundImage;/*** 背景图片显示模式*/private String imageDisplayMode;/*** 背景图片显示模式索引（引入此属性有助于必要时扩展）*/private int modeIndex;/*** 构造一个没有背景图片的ImageComposite* @param parent 父组件* @param style 风格*/public ImageComposite(Composite parent, int style){this(parent, style, null, CENTRE);}/*** 构造一个具有指定背景图片和指定显示模式的ImageComposite* @param parent 父组件* @param style 风格* @param image 背景图片* @param modeName 背景图片显示模式*/public ImageComposite(Composite parent, int style, Image image, String modeName){super(parent, style);addPaintListener(this);setBackgroundImage(image);setImageDisplayMode(modeName);}/*** 获取背景图片* @return 背景图片* @see org.eclipse.swt.widgets.Control#getBackgroundImage(Image)*/@Overridepublic Image getBackgroundImage(){return backgroundImage;}/*** 设置背景图片* @param 背景图片* @see org.eclipse.swt.widgets.Control#setBackgroundImage(Image)*/@Overridepublic void setBackgroundImage(Image backgroundImage){this.backgroundImage = backgroundImage;this.redraw();}/*** 获取背景图片显示模式* @return 显示模式*/public String getImageDisplayMode(){return imageDisplayMode;}/*** 设置背景图片显示模式* @param modeName 模式名称，取值仅限于ImagePane.TILED  ImagePane.SCALED  ImagePane.CENTRE*/public void setImageDisplayMode(String modeName){if(modeName != null){modeName = modeName.trim();//居中            if(modeName.equalsIgnoreCase(CENTRE)){this.imageDisplayMode = CENTRE;modeIndex = 0;}//平铺            else if(modeName.equalsIgnoreCase(TILED)){this.imageDisplayMode = TILED;modeIndex = 1;}//拉伸            else if(modeName.equalsIgnoreCase(SCALED)){this.imageDisplayMode = SCALED;modeIndex = 2;}this.redraw();}}/*** 绘图事件*/public void paintControl(PaintEvent e){//如果设置了背景图片则显示        if(backgroundImage != null){int width = this.getSize().x;int height = this.getSize().y;int imageWidth = backgroundImage.getImageData().width;int imageHeight = backgroundImage.getImageData().height;switch(modeIndex){//居中                case 0:{int x = (width - imageWidth) / 2;int y = (height - imageHeight) / 2;e.gc.drawImage(backgroundImage, x, y);break;}//平铺                case 1:{for(int ix = 0; ix < width; ix += imageWidth){for(int iy = 0; iy < height; iy += imageHeight){e.gc.drawImage(backgroundImage, ix, iy);}}break;}//拉伸                case 2:{ImageData data = backgroundImage.getImageData().scaledTo(width, height);e.gc.drawImage(new Image(e.display, data), 0, 0);break;}}}}}