test.java

《Java2图形设计卷II：Swing》配套光盘源码

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Test extends JApplet {
	JDesktopPane desktopPane = new JDesktopPane();

	public void init() {
		Container contentPane = getContentPane();

		contentPane.add(desktopPane, BorderLayout.CENTER);
		desktopPane.setDesktopManager(new OutlineManager());

		JInternalFrame jif = new JInternalFrame(
				  	"Outline Drag and Resize", // title
				  	true,  // resizable
				  	true,  // closable
				  	true,  // maximizable
				  	true); // iconifiable

			jif.setBounds(10, 10, 250, 100);
			desktopPane.add(jif);
	}
}
class OutlineManager extends DefaultDesktopManager { 
	private Rectangle start, last;
	private boolean first = true;

	// dragging ...

	public void beginDraggingFrame(JComponent frame) {
		initializeOutline(frame);
	}
	public void dragFrame(JComponent frame, int x, int y) {
		updateOutline(frame, x, y, start.width, start.height);
	}
	public void endDraggingFrame(JComponent frame) {
		endOutline(frame);
	}

	// resizing ...

	public void beginResizingFrame(JComponent frame, int dir) {
		initializeOutline(frame);
	}
	public void resizeFrame(JComponent frame, 
									int x, int y, int w, int h) {
		updateOutline(frame, x, y, w, h);
	}
	public void endResizingFrame(JComponent frame) {
		endOutline(frame);
	}

	// outline ...

	private void initializeOutline(final JComponent frame) {
		// the call to setVisible() calls repaint, which
		// places a paint event on the event queue.
		// therefore, the effect of the setVisible() call is
		// not apparent until after this method returns

		frame.setVisible(false);
		start = frame.getBounds();
		last = new Rectangle(start);
		first = true;

		// the Runnable below paints the initial outline 
		// after the repaint event spawned by setVisible() is
		// handled

		SwingUtilities.invokeLater(new Runnable() {
			public void run() {
				updateOutline(frame,start.x,start.y,
										start.width,start.height);
			}
		});
	}
	private void updateOutline(JComponent frame, 
									int x, int y, int w, int h) {
		Container container = frame.getParent();
		Graphics g = container.getGraphics();

		try {
			g.setXORMode(container.getBackground());

			if( ! first) {
				g.drawRect(last.x, last.y, 
									last.width-1, last.height-1);
			}
			g.drawRect(x, y, w-1, h-1);
			first = false;
		}
		finally {
			g.dispose();
			last.setBounds(x,y,w,h);
		}
	}
	private void endOutline(JComponent frame) {
		frame.setVisible(true);
		setBoundsForFrame(
				frame, last.x, last.y, last.width, last.height);
	}
}