package components;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
/*
* SliderDemo.java requires all the files in the images/doggy
* directory.
*/
public class SliderDemo extends JPanel
implements ActionListener,
WindowListener,
ChangeListener {
//Set up animation parameters.
static final int FPS_MIN = 0;
static final int FPS_MAX = 30;
static final int FPS_INIT = 15; //initial frames per second
int frameNumber = 0;
int NUM_FRAMES = 14;
ImageIcon[] images = new ImageIcon[NUM_FRAMES];
int delay;
Timer timer;
boolean frozen = false;
//This label uses ImageIcon to show the doggy pictures.
JLabel picture;
public SliderDemo() {
setLayout(new BoxLayout(this, BoxLayout.PAGE_AXIS));
delay = 1000 / FPS_INIT;
//Create the label.
JLabel sliderLabel = new JLabel("Frames Per Second", JLabel.CENTER);
sliderLabel.setAlignmentX(Component.CENTER_ALIGNMENT);
//Create the slider.
JSlider framesPerSecond = new JSlider(JSlider.HORIZONTAL,
FPS_MIN, FPS_MAX, FPS_INIT);
framesPerSecond.addChangeListener(this);
//Turn on labels at major tick marks.
framesPerSecond.setMajorTickSpacing(10);
framesPerSecond.setMinorTickSpacing(1);
framesPerSecond.setPaintTicks(true);
framesPerSecond.setPaintLabels(true);
framesPerSecond.setBorder(
BorderFactory.createEmptyBorder(0,0,10,0));
Font font = new Font("Serif", Font.ITALIC, 15);
framesPerSecond.setFont(font);
//Create the label that displays the animation.
picture = new JLabel();
picture.setHorizontalAlignment(JLabel.CENTER);
picture.setAlignmentX(Component.CENTER_ALIGNMENT);
picture.setBorder(BorderFactory.createCompoundBorder(
BorderFactory.createLoweredBevelBorder(),
BorderFactory.createEmptyBorder(10,10,10,10)));
updatePicture(0); //display first frame
//Put everything together.
add(sliderLabel);
add(framesPerSecond);
add(picture);
setBorder(BorderFactory.createEmptyBorder(10,10,10,10));
//Set up a timer that calls this object's action handler.
timer = new Timer(delay, this);
timer.setInitialDelay(delay * 7); //We pause animation twice per cycle
//by restarting the timer
timer.setCoalesce(true);
}
/** Add a listener for window events. */
void addWindowListener(Window w) {
w.addWindowListener(this);
}
//React to window events.
public void windowIconified(WindowEvent e) {
stopAnimation();
}
public void windowDeiconified(WindowEvent e) {
startAnimation();
}
public void windowOpened(WindowEvent e) {}
public void windowClosing(WindowEvent e) {}
public void windowClosed(WindowEvent e) {}
public void windowActivated(WindowEvent e) {}
public void windowDeactivated(WindowEvent e) {}
/** Listen to the slider. */
public void stateChanged(ChangeEvent e) {
JSlider source = (JSlider)e.getSource();
if (!source.getValueIsAdjusting()) {
int fps = (int)source.getValue();
if (fps == 0) {
if (!frozen) stopAnimation();
} else {
delay = 1000 / fps;
timer.setDelay(delay);
timer.setInitialDelay(delay * 10);
if (frozen) startAnimation();
}
}
}
public void startAnimation() {
//Start (or restart) animating!
timer.start();
frozen = false;
}
public void stopAnimation() {
//Stop the animating thread.
timer.stop();
frozen = true;
}
//Called when the Timer fires.
public void actionPerformed(ActionEvent e) {
//Advance the animation frame.
if (frameNumber == (NUM_FRAMES - 1)) {
frameNumber = 0;
} else {
frameNumber++;
}
updatePicture(frameNumber); //display the next picture
if ( frameNumber==(NUM_FRAMES - 1)
|| frameNumber==(NUM_FRAMES/2 - 1) ) {
timer.restart();
}
}
/** Update the label to display the image for the current frame. */
protected void updatePicture(int frameNum) {
//Get the image if we haven't already.
if (images[frameNumber] == null) {
images[frameNumber] = createImageIcon("images/doggy/T"
+ frameNumber
+ ".gif");
}
//Set the image.
if (images[frameNumber] != null) {
picture.setIcon(images[frameNumber]);
} else { //image not found
picture.setText("image #" + frameNumber + " not found");
}
}
/** Returns an ImageIcon, or null if the path was invalid. */
protected static ImageIcon createImageIcon(String path) {
java.net.URL imgURL = SliderDemo.class.getResource(path);
if (imgURL != null) {
return new ImageIcon(imgURL);
} else {
System.err.println("Couldn't find file: " + path);
return null;
}
}
/**
* Create the GUI and show it. For thread safety,
* this method should be invoked from the
* event-dispatching thread.
*/
private static void createAndShowGUI() {
//Create and set up the window.
JFrame frame = new JFrame("SliderDemo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
SliderDemo animator = new SliderDemo();
//Add content to the window.
frame.add(animator, BorderLayout.CENTER);
//Display the window.
frame.pack();
frame.setVisible(true);
animator.startAnimation();
}
public static void main(String[] args) {
/* Turn off metal's use of bold fonts */
UIManager.put("swing.boldMetal", Boolean.FALSE);
//Schedule a job for the event-dispatching thread:
//creating and showing this application's GUI.
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}
