Fading button : Fade « Advanced Graphics « Java

1. Java
2. Advanced Graphics
3. Fade

Fading button

 



import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.Timer;

/*
 * FadingButton_2008.java
 *
 * Created on May 2, 2007, 4:11 PM
 *
 * Copyright (c) 2007, Sun Microsystems, Inc
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above
 *     copyright notice, this list of conditions and the following
 *     disclaimer in the documentation and/or other materials provided
 *     with the distribution.
 *   * Neither the name of the TimingFramework project nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * 
 * @author Chet
 */
public class FadingButton_2008 extends JButton implements ActionListener {

  float alpha = 1.0f; // current opacity of button

  Timer timer; // for later start/stop actions

  int animationDuration = 2000; // each animation will take 2 seconds

  long animationStartTime; // start time for each animation

  BufferedImage buttonImage = null;

  /** Creates a new instance of FadingButton_2008 */
  public FadingButton_2008(String label) {
    super(label);
    setOpaque(false);
    timer = new Timer(30, this);
    addActionListener(this);
  }

  public void paint(Graphics g) {
    // Create an image for the button graphics if necessary
    if (buttonImage == null || buttonImage.getWidth() != getWidth()
        || buttonImage.getHeight() != getHeight()) {
      buttonImage = getGraphicsConfiguration().createCompatibleImage(getWidth(), getHeight());
    }
    Graphics gButton = buttonImage.getGraphics();
    gButton.setClip(g.getClip());

    // Have the superclass render the button for us
    super.paint(gButton);

    // Make the graphics object sent to this paint() method translucent
    Graphics2D g2d = (Graphics2D) g;
    AlphaComposite newComposite = AlphaComposite.getInstance(AlphaComposite.SRC_OVER, alpha);
    g2d.setComposite(newComposite);

    // Copy the button's image to the destination graphics, translucently
    g2d.drawImage(buttonImage, 0, 0, null);
  }

  /**
   * This method receives both click events (which start and stop the animation)
   * and Timer events (which animate the alpha of the button).
   */
  public void actionPerformed(ActionEvent ae) {
    if (ae.getSource().equals(this)) {
      // button click
      if (!timer.isRunning()) {
        animationStartTime = System.nanoTime() / 1000000;
        this.setText("Stop Animation");
        timer.start();
      } else {
        timer.stop();
        this.setText("Start Animation");
        // reset alpha to opaque
        alpha = 1.0f;
      }
    } else {
      // timer event
      // calculate the elapsed fraction
      long currentTime = System.nanoTime() / 1000000;
      long totalTime = currentTime - animationStartTime;
      if (totalTime > animationDuration) {
        animationStartTime = currentTime;
      }
      float fraction = (float) totalTime / animationDuration;
      fraction = Math.min(1.0f, fraction);
      // This calculation will cause alpha to go from 1 to 0 and back to 1
      // as the fraction goes from 0 to 1
      alpha = Math.abs(1 - (2 * fraction));
      // redisplay our button with its new alpha value
      repaint();
    }
  }

  private static void createAndShowGUI() {
    JFrame f = new JFrame("Fading Button");
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.setSize(300, 300);
    JPanel checkerboard = new Checkerboard();
    checkerboard.add(new FadingButton_2008("Start Animation"));
    f.add(checkerboard);
    f.setVisible(true);
  }

  public static void main(String args[]) {
    Runnable doCreateAndShowGUI = new Runnable() {
      public void run() {
        createAndShowGUI();
      }
    };
    SwingUtilities.invokeLater(doCreateAndShowGUI);
  }

  /**
   * Displays checkerboard background
   */
  private static class Checkerboard extends JPanel {
    private static final int DIVISIONS = 10;

    static final int CHECKER_SIZE = 60;

    public void paintComponent(Graphics g) {
      g.setColor(Color.white);
      g.fillRect(0, 0, getWidth(), getHeight());
      g.setColor(Color.BLACK);
      for (int stripeX = 0; stripeX < getWidth(); stripeX += CHECKER_SIZE) {
        for (int y = 0, row = 0; y < getHeight(); y += CHECKER_SIZE / 2, ++row) {
          int x = (row % 2 == 0) ? stripeX : (stripeX + CHECKER_SIZE / 2);
          g.fillRect(x, y, CHECKER_SIZE / 2, CHECKER_SIZE / 2);
        }
      }
    }
  }
}

 

 

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