problem with moving a JWindow

[kalle svensson]

I wonder how to get a JWindow to move across the screen in location after the user's mouse pointer.
When i use the method setLocation((MouseEvent).getX(), (MouseEvent).getY()) in an mousemotion adapter attched to the JWindow a
lot of flicker occurs on the screen. In the code above a JWindow appears and when the user clicks on the yes button then the text "good luck"
displays before the window is closed after a small delay.

The code below is written just for this post. How can i move the window without generating the flicker, what is the general solution for this problem?
I will be very much greatful for any help on this subject.
// kalle

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

public class MovableJWindow extends JWindow {
	public static void main(String[] args) {
		new MovableJWindow();
	}

	public JLabel jLabel1;
	public JPanel jPanel1,jPanel2;
	public JButton jButton1,jButton2;
	
	public MovableJWindow() {	
		setSize(600,400);		
		windowInit();
		
		jPanel1 = new JPanel(new BorderLayout());
		jPanel1.setBorder(BorderFactory.createEmptyBorder(5,5,5,5));
		setContentPane(jPanel1);
		
		jLabel1 = new JLabel("Do you wish to continue?");
		jLabel1.setHorizontalAlignment(JLabel.CENTER);
		jPanel1.add(BorderLayout.CENTER,jLabel1);
		
		jPanel2 = new JPanel();
		jPanel2.setLayout(new BoxLayout(jPanel2,BoxLayout.X_AXIS));
		jPanel1.add(BorderLayout.SOUTH,jPanel2);
	
		jPanel2.add(Box.createGlue());
	
		jButton1 = new JButton("Yes");
		jPanel2.add(jButton1);
		
		jPanel2.add(Box.createHorizontalStrut(5));
		
		jButton2 = new JButton("No");
		jPanel2.add(jButton2);
		
		jPanel2.add(Box.createGlue());
	
		addWindowListener(new WindowAdapter() {			
			public void windowActivated(WindowEvent e) {
				if (!isFocusableWindow()) {
					MovableJWindow.this.toFront();
				}
			}
		});	
		
		addMouseMotionListener(new MouseAdapter() {
			public void mouseMoved(MouseEvent e) {
				
                                int x = e.getX();
				int y = e.getY();	

                                // This is where i get a lot of flicker on the screen when i mouse 
                                // the mouse over the window. 

                                setLocation(x,y);
			}
		});
		
		jButton1.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				jLabel1.setText("Good luck");
				
				final Thread thread1 = new Thread() {
					public void run() {
						try {
						jButton1.setEnabled(false);
						Thread.sleep(1000);
						dispose();
						} catch (Exception err) { err.printStackTrace(); }
					}
				};
				
				thread1.start();
			}
		});
		
		jButton2.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				dispose();
				System.exit(0);
			}
		});

               setVisible(true);
	}
}

[Rob Camick]

The main problem is that the MouseEvents are relative to the component and so the location never changes by more than a pixel, so you keep set the window location back to where it was even as the mouse is continually moving acros the screen.

Generally, moving a component is handled by dragging the component which mean using the mouseDragged() event. A general solution can be found in Moving Windows. This solution converts the mouse events to make the location relative to the screen.

For an older solution that doesn't convert mouse points to the screen, you need to keep track of the previous mouse event so you can determine the change in location:

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class MoveWindow extends JWindow implements MouseListener, MouseMotionListener
{
	Point location;
	MouseEvent pressed;

	public MoveWindow()
	{
//		JPanel panel = new JPanel();
//		panel.setPreferredSize( new Dimension(200, 100) );
//		panel.setBackground(Color.RED);
//		getContentPane().add(panel, BorderLayout.SOUTH);
//		getContentPane().add(new JTextField("Hello World"), BorderLayout.NORTH);
		addMouseListener( this );
		addMouseMotionListener( this );
	}

	public void mousePressed(MouseEvent me)
	{
		pressed = me;
	}

	public void mouseClicked(MouseEvent e) {}
	public void mouseReleased(MouseEvent e) {}

	public void mouseDragged(MouseEvent me)
	{
//		System.out.println(me.getPoint());
		location = getLocation(location);
		int x = location.x - pressed.getX() + me.getX();
		int y = location.y - pressed.getY() + me.getY();
		setLocation(x, y);
	 }

	public void mouseMoved(MouseEvent e) {}
	public void mouseEntered(MouseEvent e) {}
	public void mouseExited(MouseEvent e) {}

	public static void main(String args[])
	{
		MoveWindow window = new MoveWindow();
		window.setSize(300, 300);
		window.setLocationRelativeTo( null );
		window.setVisible(true);
	}
}