RoundButton2

[k_o_bliss]

when i run this program nothing happens

// Imports for the GUI classes.
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;

/**
* RoundButton2.java -
* A custom JComponent that is a round button. The round button
* will be empty until the mouse enters the circle. When the
* mouse enters the circle it will be filled in with a specified
* color. Then when the mouse is pressed the color will change
* to a second specified color. Note that RoundButton "is a"
* MouseListener so it can handle its own MouseEvents.
*
* @author Grant William Braught
* @author Dickinson College
* @version 11/29/2000
*/
public class RoundButton2
extends JComponent
implements MouseListener, MouseMotionListener {

private Color mouseOverColor;
private Color mousePressedColor;

private boolean mouseOver;
private boolean mousePressed;

private int radius;

/**
* Construct a new RoundButton with the specified
* colors for mouse over and mouse pressed events.
*
* @param mouseOverColor the color the button should
* be filled with when the mouse is
* over the button.
* @param mousePressedColor the color the button should be
* filled with when the mouse
* is pressed on the button.
*/
public RoundButton2(Color mouseOverColor,
Color mousePressedColor) {
this.mouseOverColor = mouseOverColor;
this.mousePressedColor = mousePressedColor;
mouseOver = false;
mousePressed = false;
radius = 100;

// Register this obj. as a MouseListener for itself.
this.addMouseListener(this);
this.addMouseMotionListener(this);
}

/**
* Default constructor that sets the mouse over color
* to blue and the mouse pressed color to red.
*/
public RoundButton2() {
this(Color.blue, Color.red);
}

/**
* Paint the RoundButton on the screen each time the
* window is redrawn. Recall that the paint() method
* of each JComponent in the content pane is called
* automatically when the window is redrawn. This
* overrides paint() from JComponent so we have control
* over what the RoundButton will look like when it is
* painted.
*
* @param g the Graphics context on which to paint the
* button.
*/
public void paint(Graphics g) {
// Check mouse pressed first because if the mouse
// is pressed it will also be in the button.
if (mousePressed && mouseOver) {
g.setColor(mousePressedColor);
g.fillOval(0,0,2*radius,2*radius);
}
else if (mouseOver) {
g.setColor(mouseOverColor);
g.fillOval(0,0,2*radius,2*radius);
}
else {
g.setColor(Color.black);
g.drawOval(0,0,2*radius,2*radius);
}
}

/**
* Return the ideal size that our button would
* like to be. This overrides the getPreferredSize
* from JComponent which returns 0x0.
*
* @return the preferred size of the RoundButton.
*/
public Dimension getPreferredSize() {
return new Dimension(2*radius, 2*radius);
}

/**
* This method is called by the LayoutManager when it
* places and resizes the component. We'll use the
* information here to adjust the way the RoundButton is
* painted.
*
* @param x the new x coordinate of this RoundButton within
* its parent container.
* @param y the new y coordinate of this RoundButton within
* its parent container.
* @param width the new width of the RoundButton.
* @param height the new height of the RoundButton.
*/
public void setBounds(int x, int y, int width, int height) {
// Make the radius of the circle half as large as the
// smallest dimension.
radius = (int)Math.min(width,height) / 2;

// Pass the changes in the dimesions up to the JComponent
// class that uses them for generating MouseEvents and
// MouseMotion events.
super.setBounds(x,y,width,height);

// Repaint the component. Everytime the bounds are changed
// the component should be repainted.
repaint();
}

/**
* Private method used to determine if a point is inside
* the circle that represents the RoundButton.
*
* @param pt the Point that represents the current
* location of the mouse.
* @return true if pt is within the circle.
*/
private boolean isInside(Point pt) {
// If the distance between pt and the center of
// the circle (radius,radius) is less than or =
// the radius then the mouse is in the circle.
return (pt.distance(new Point(radius,radius)) <= radius);
}

// Methods from the MouseListener Interface.

/**
* Handler called when the mouse is clicked on
* the RoundButton.
*
* @param e reference to a MouseEvent object describing
* the mouse click.
*/
public void mouseClicked(MouseEvent e) {}

/**
* Handler called when the mouse enters the
* RoundButton.
*
* @param e reference to a MouseEvent object describing
* the mouse entry.
*/
public void mouseEntered(MouseEvent e) {}

/**
* Handler called when the mouse exits the
* RoundButton. Again, this is called when the
* mouse exits the bounding rectangle.
*
* @param e reference to a MouseEvent object describing
* the mouse exit.
*/
public void mouseExited(MouseEvent e) {
// This handles exiting at the points where the
// circle contacts the edges of the component.
// These points are missed by the mouseMoved method
// because they are on the circle.
mouseOver = false;
repaint();
}

/**
* Handler called when the mouse button is pressed
* over the RoundButton. Again this is called if the
* button is pressed anywhere within the bounding
* rectangle.
*
* @param e reference to a MouseEvent object describing
* the mouse press.
*/
public void mousePressed(MouseEvent e) {

Point mouseLoc = e.getPoint();

if (isInside(mouseLoc)) {
mousePressed = true;
repaint();
}
}

/**
* Handler called when the mosue button is released
* over the RoundButton. Blah... Blah.. bounding
* rectangle.
*
* @param e reference to a MouseEvent object describing
* the mouse release.
*/
public void mouseReleased(MouseEvent e) {
mousePressed = false;
repaint();
}


// Methods from the MouseMotionListener interface.

/**
* Called when the mouse is moved while over the
* RoundButton. This will check to see if the
* mouse has moved into or out of the circle.
*
* @param e MouseEvent that describes the mouse motion.
*/
public void mouseMoved(MouseEvent e) {
if (isInside(e.getPoint())) {
// Only repaint if the button changes.
if (!mouseOver) {
mouseOver = true;
repaint();
}
}
else {
if (mouseOver) {
mouseOver = false;
repaint();
}
}
}

/**
* Called when the mouse is dragged while over the
* RoundButton. This does the same thing that mouseMoved
* does.
*
* @param e MouseEvent that describes the mouse dragging.
*/
public void mouseDragged(MouseEvent e) {
mouseMoved(e);
}
}

[Phaelax]

Use [ code ] [ /code ] tags to make your code more readable for us in the future please.

[sjalle]

a test:

// Imports for the GUI classes.
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;

/**
 * RoundButton2.java -
 * A custom JComponent that is a round button. The round button
 * will be empty until the mouse enters the circle. When the
 * mouse enters the circle it will be filled in with a specified
 * color. Then when the mouse is pressed the color will change
 * to a second specified color. Note that RoundButton "is a"
 * MouseListener so it can handle its own MouseEvents.
 *
 * @author Grant William Braught
 * @author Dickinson College
 * @version 11/29/2000
 */
public class RoundButton2
    extends JComponent
    implements MouseListener, MouseMotionListener {

  private Color mouseOverColor;
  private Color mousePressedColor;

  private boolean mouseOver;
  private boolean mousePressed;

  private int radius;

  /**
   * Construct a new RoundButton with the specified
   * colors for mouse over and mouse pressed events.
   *
   * @param mouseOverColor the color the button should
   * be filled with when the mouse is
   * over the button.
   * @param mousePressedColor the color the button should be
   * filled with when the mouse
   * is pressed on the button.
   */
  public RoundButton2(Color mouseOverColor,
                      Color mousePressedColor) {
    this.mouseOverColor = mouseOverColor;
    this.mousePressedColor = mousePressedColor;
    mouseOver = false;
    mousePressed = false;
    radius = 100;

// Register this obj. as a MouseListener for itself.
    this.addMouseListener(this);
    this.addMouseMotionListener(this);
  }

  /**
   * Default constructor that sets the mouse over color
   * to blue and the mouse pressed color to red.
   */
  public RoundButton2() {
    this(Color.blue, Color.red);
  }

  /**
   * Paint the RoundButton on the screen each time the
   * window is redrawn. Recall that the paint() method
   * of each JComponent in the content pane is called
   * automatically when the window is redrawn. This
   * overrides paint() from JComponent so we have control
   * over what the RoundButton will look like when it is
   * painted.
   *
   * @param g the Graphics context on which to paint the
   * button.
   */
  public void update(Graphics g) {
    // Check mouse pressed first because if the mouse
    // is pressed it will also be in the button.
    Color c=g.getColor(); // get graphics default color & fill background
    g.setColor(Color.white);
    g.fillRect(0,0,2 * radius, 2 * radius);

    // now get the button color
    if (mousePressed && mouseOver) {
      g.setColor(mousePressedColor);
    }
    else if (mouseOver) {
      g.setColor(mouseOverColor);
    }
    else {
      g.setColor(Color.black);
    }
    // fill button click area using the button color
    g.fillOval(0, 0, 2 * radius, 2 * radius);

    g.setColor(c); // reset graphics default color
  }
  public void paint(Graphics g) {
    update(g);
  }

  /**
   * Return the ideal size that our button would
   * like to be. This overrides the getPreferredSize
   * from JComponent which returns 0x0.
   *
   * @return the preferred size of the RoundButton.
   */
  public Dimension getPreferredSize() {
    return new Dimension(2 * radius, 2 * radius);
  }

  /**
   * This method is called by the LayoutManager when it
   * places and resizes the component. We'll use the
   * information here to adjust the way the RoundButton is
   * painted.
   *
   * @param x the new x coordinate of this RoundButton within
   * its parent container.
   * @param y the new y coordinate of this RoundButton within
   * its parent container.
   * @param width the new width of the RoundButton.
   * @param height the new height of the RoundButton.
   */
  public void setBounds(int x, int y, int width, int height) {
// Make the radius of the circle half as large as the
// smallest dimension.
    radius = (int) Math.min(width, height) / 2;

// Pass the changes in the dimesions up to the JComponent
// class that uses them for generating MouseEvents and
// MouseMotion events.
    super.setBounds(x, y, width, height);

// Repaint the component. Everytime the bounds are changed
// the component should be repainted.
    repaint();
  }

  /**
   * Private method used to determine if a point is inside
   * the circle that represents the RoundButton.
   *
   * @param pt the Point that represents the current
   * location of the mouse.
   * @return true if pt is within the circle.
   */
  private boolean isInside(Point pt) {
// If the distance between pt and the center of
// the circle (radius,radius) is less than or =
// the radius then the mouse is in the circle.
    return (pt.distance(new Point(radius, radius)) <= radius);
  }

// Methods from the MouseListener Interface.

  /**
   * Handler called when the mouse is clicked on
   * the RoundButton.
   *
   * @param e reference to a MouseEvent object describing
   * the mouse click.
   */
  public void mouseClicked(MouseEvent e) {}

  /**
   * Handler called when the mouse enters the
   * RoundButton.
   *
   * @param e reference to a MouseEvent object describing
   * the mouse entry.
   */
  public void mouseEntered(MouseEvent e) {}

  /**
   * Handler called when the mouse exits the
   * RoundButton. Again, this is called when the
   * mouse exits the bounding rectangle.
   *
   * @param e reference to a MouseEvent object describing
   * the mouse exit.
   */
  public void mouseExited(MouseEvent e) {
// This handles exiting at the points where the
// circle contacts the edges of the component.
// These points are missed by the mouseMoved method
// because they are on the circle.
    mouseOver = false;
    repaint();
  }

  /**
   * Handler called when the mouse button is pressed
   * over the RoundButton. Again this is called if the
   * button is pressed anywhere within the bounding
   * rectangle.
   *
   * @param e reference to a MouseEvent object describing
   * the mouse press.
   */
  public void mousePressed(MouseEvent e) {

    Point mouseLoc = e.getPoint();

    if (isInside(mouseLoc)) {
      mousePressed = true;
      repaint();
    }
  }

  /**
   * Handler called when the mosue button is released
   * over the RoundButton. Blah... Blah.. bounding
   * rectangle.
   *
   * @param e reference to a MouseEvent object describing
   * the mouse release.
   */
  public void mouseReleased(MouseEvent e) {
    mousePressed = false;
    repaint();
  }

// Methods from the MouseMotionListener interface.

  /**
   * Called when the mouse is moved while over the
   * RoundButton. This will check to see if the
   * mouse has moved into or out of the circle.
   *
   * @param e MouseEvent that describes the mouse motion.
   */
  public void mouseMoved(MouseEvent e) {
    if (isInside(e.getPoint())) {
// Only repaint if the button changes.
      if (!mouseOver) {
        mouseOver = true;
        repaint();
      }
    }
    else {
      if (mouseOver) {
        mouseOver = false;
        repaint();
      }

    }
  }

  /**
   * Called when the mouse is dragged while over the
   * RoundButton. This does the same thing that mouseMoved
   * does.
   *
   * @param e MouseEvent that describes the mouse dragging.
   */
  public void mouseDragged(MouseEvent e) {
    mouseMoved(e);
  }
  public static void main (String [] args) {
    RoundButton2 rb=new RoundButton2(Color.red,Color.white);
    JFrame f=new JFrame("RoundButton");
    f.getContentPane().setLayout(new FlowLayout(FlowLayout.CENTER));
    f.getContentPane().add(rb);
    f.setBounds(20,20,300,300);
    f.addWindowListener(new WindowAdapter() {
      public void windowClosing(WindowEvent e) {
        System.exit(0);
      }
    });
    f.setVisible(true);
  }
}