Draw2d 实现连接 拖动 PolylineConnection Dragger

摘要：使用Draw2d ，画图，连线，可拖动图像，连线跟着移动。

1，代码：

public class Connection {
	public static void main(String args[]) {
		Shell shell = new Shell();
		shell.setSize(350, 350);
		shell.open();
		shell.setText("Connection Demo");
		LightweightSystem lws = new LightweightSystem(shell);
		IFigure panel = new Figure();
		lws.setContents(panel);
		// 创建两个四边形的图形实例
		RectangleFigure node1 = new RectangleFigure(), node2 = new RectangleFigure();
		// 设置node1的背景色
		node1.setBackgroundColor(ColorConstants.red);
		// 设置node1的大小和位置
		node1.setBounds(new Rectangle(30, 30, 64, 36));

		// 设置node2的背景色
		node2.setBackgroundColor(ColorConstants.blue);
		// 设置node2的大小和位置
		node2.setBounds(new Rectangle(100, 100, 64, 36));

		// 创建一个连线的实例
		PolylineConnection conn = new PolylineConnection();
		// 设置连线起点的锚点
		conn.setSourceAnchor(new ChopboxAnchor(node1));
		// 设置连线目标的锚点
		conn.setTargetAnchor(new ChopboxAnchor(node2));
		// 设置连线目标的装饰器
		conn.setTargetDecoration(new PolygonDecoration());

		Label label = new Label("Midpoint");
		label.setOpaque(true);
		label.setBackgroundColor(ColorConstants.buttonLightest);
		label.setBorder(new LineBorder());

		// 添加连线的Locator
		conn.add(label, new MidpointLocator(conn, 0));

		// 在底层Figure中添加子Figure
		panel.add(node1);
		panel.add(node2);
		panel.add(conn);
		// 添加node1拖动的监听器
		new Dragger(node1);
		// 添加node2拖动的监听器
		new Dragger(node2);
		Display display = Display.getDefault();
		while (!shell.isDisposed()) {
			if (!display.readAndDispatch())
				display.sleep();
		}
	}

	static class Dragger extends MouseMotionListener.Stub implements MouseListener{
		private Point last;
		public Dragger(IFigure figure) {
			figure.addMouseMotionListener(this);
			figure.addMouseListener(this);
		}
		public void mouseDoubleClicked(MouseEvent e) {
		}
		public void mousePressed(MouseEvent e) {
			last = e.getLocation();
		}
		public void mouseReleased(MouseEvent e) {
		}
		public void mouseDragged(MouseEvent e) {
			Point p = e.getLocation();
			Dimension delta = p.getDifference(last);
			last = p;
			Figure f = (Figure) e.getSource();
			//设置拖动的Figure的位置
			f.setBounds(f.getBounds().getTranslated(delta.width,delta.height));
		}
	}
}

 

图像：