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import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.ArrayList;
/** ScribbleGUI.java
@author Fred Swartz
@version 2003-06 (Pavlov Czecho) */
class ScribbleGUI extends JPanel{
private int last_x, last_y; // last x,y position of the mouse
private ArrayList _points = new ArrayList(1000);
private DrawingPanel _drawing = new DrawingPanel();
public ScribbleGUI() { //================================== constructor
// Create and add a button to the Panel
JButton b = new JButton("Clear");
b.addActionListener(new ClearListener());
//--- Layout components
this.setLayout(new BorderLayout());
this.add(b, BorderLayout.NORTH); // add the button to the applet
this.add(_drawing, BorderLayout.CENTER);
}// end init
////////////////////////////////////////////// inner class ClearListener
private class ClearListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
_points.clear();
_drawing.repaint();
}//end actionPerformed
}//end class ClearListener
//////////////////////////////////////////////// inner class DrawingPanel
private class DrawingPanel extends JPanel implements MouseListener,
MouseMotionListener {
//====================================================== constructor
public DrawingPanel() {
setPreferredSize(new Dimension(300, 300));
setBackground(Color.white);
addMouseMotionListener(this);
addMouseListener(this);
}//end constructor
public void clear() {
_points.clear();
this.repaint();
}//end clear
//==================================================x paintComponent
public void paintComponent(Graphics g) {
super.paintComponent(g);
for (int i=0; i < _points.size()-1; i++) {
Point previous = (Point)_points.get(i);
Point next = (Point)_points.get(i+1);
g.drawLine(previous.x, previous.y, next.x, next.y);
}
}//end paintComponent
public void mousePressed(MouseEvent e) {
_points.add(e.getPoint());
repaint();
}//end mousePressed
public void mouseDragged(MouseEvent e) {
_points.add(e.getPoint());
repaint();
}//end mouseDragged
//--- Ignore these events
public void mouseReleased(MouseEvent e) { }
public void mouseClicked (MouseEvent e) { }
public void mouseEntered (MouseEvent e) { }
public void mouseExited (MouseEvent e) { }
public void mouseMoved (MouseEvent e) { }
}//end class DrawingPanel
}//end class ScribbleGUI
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