Download Java Multimedia: Images, Animation, Audio and Video

Chapter 16 - Multimedia: Images,
Animation, Audio and Video
Outline
16.1
16.2
16.3
16.4
16.5
16.6
16.7
16.8
16.9
16.10
16.11
Introduction
Downloading the Java Media Framework
Loading, Displaying and Scaling Images
Loading and Playing Audio Clips
The Java Media Player
Animating a Series of Images
Animation Issues
Customizing Applets via the HTML param Tag
Image Maps
Java Plug-In
Internet and World Wide Web Resources
 2000 Prentice Hall, Inc. All rights reserved.
16.1 Introduction
• Revolution in computer industry
– Before, computers used for high-speed calculations
– Now, data manipulation important
• Multimedia
– "Sizzle" of Java - images, sound, video
– CDs, DVDs, video cards
– Demands extraordinary computing power
• Fast processors making multimedia possible
• Java
– Built-in multimedia capabilities
• Most programming languages do not
– Develop powerful multimedia applications
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16.2 Downloading the Java Media
Framework
• Java media framework (JMF)
–
–
–
–
Extension to Java API
Enhanced processing of images, audio, and video
Constantly evolving
Some examples required the JMF, not included in J2SDK
http://java.sun.com/products/java-media/jmf/1.1/
• JMF Downloads for Windows and Solaris
– At time of writing, early versions of JMF 2.0 available
http://java.sun.com/products/java-media/jmf/index.html
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16.2 Loading, Displaying and Scaling
Images
• Java Multimedia
– Discuss graphics, images, animations, sounds, and video
– Begin with images
• Class Image (java.awt)
– Abstract class, cannot create an object directly
• Request Image be loaded and returned
– getImage( imageLocation, filename );
• Of class Applet (superclass of JApplet)
• imageLocation
– getDocumentBase() is URL (address) of HTML file
• filename - .gif or .jpg (.jpeg)
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private Image logo1;
logo1 = getImage( getDocumentBase(), "logo.gif" );
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16.2 Loading, Displaying and Scaling
Images
• Displaying Images
– Method drawImage (class Graphics)
– Many overloaded versions
g.drawImage( myImage, x, y, ImageObserver );
• myImage - Image object
• x,y - coordinates to display image
• ImageObserver - object on which image is displayed
– Use "this" to indicate the applet
– Can be any object that implements ImageObserver
interface
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g.drawImage( logo1, 0, 0, this );
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16.2 Loading, Displaying and Scaling
Images
• Displaying Images
– g.drawImage( myImage, x, y, width, height,
ImageObserver );
• width and height
– Dimensions of image (automatically scaled)
• getWidth(), getHeight()
– Returns dimensions of applet
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g.drawImage( logo1, 0, 120,
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getWidth(), getHeight() - 120, this );
16.2 Loading, Displaying and Scaling
Images
• Class ImageIcon
– Concrete class (can create objects)
– Example constructor and initialization
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private ImageIcon logo2;
logo2 = new ImageIcon( "logo.gif" );
• Displaying Icons
– Method paintIcon (class Graphics)
myIcon.paintIcon( Component, Graphics, x, y )
• Component - Component object on which to display
image (this)
• Graphics - Graphics object used to render image (g)
• x, y - coordinates of Icon
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16.2 Loading, Displaying and Scaling
Images
• Usage
– ImageIcons simpler than Images
• Create objects directly
• No need for ImageObserver reference
– All components are ImageObservers
– Cannot scale ImageIcons
• Scaling
– Use ImageIcon method getImage
• Returns Image reference
• This can be used with drawImage and scaled
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1// Fig. 16.1: LoadImageAndScale.java
Outline
2// Load an image and display it in its original size
3// and scale it to twice its original width and height.
4// Load and display the same image as an ImageIcon.
5import java.applet.Applet;
6import java.awt.*;
1. Declare objects
7import javax.swing.*;
8
2. init()
9public class LoadImageAndScale extends JApplet {
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private Image logo1;
Notice the parameters to the
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private ImageIcon logo2;
constructors. Image objects
cannot objects
2.1 Initialize
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be created directly.
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// load the image when the applet is loaded
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public void init()
3. paint()
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{
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logo1 = getImage( getDocumentBase(), "logo.gif" );
3.1 drawImage
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logo2 = new ImageIcon( "logo.gif" );
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}
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// display the image
drawImage calls (second
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public void paint( Graphics g )
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{
call has scaling). this
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// draw the original image
means the image will be
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g.drawImage( logo1, 0, 0, this );
shown on the applet.
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// draw the image scaled to fit the width of the applet
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// and the height of the applet minus 120 pixels
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g.drawImage( logo1, 0, 120,
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getWidth(), getHeight() - 120, this );
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Outline
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// draw the icon using its paintIcon method
logo2.paintIcon( this, g, 180, 0 );
}
3.2 paintIcon
Call to paintIcon, displays icon
Program Output
on this applet (a Component).
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16.4 Loading and Playing Audio Clips
• Audio clips
– Require speakers and sound board
– Sound engine - plays audio clips
• Supports .au, .wav, .aif, .mid
• Java Media Framework supports additional formats
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16.4 Loading and Playing Audio Clips
• Playing audio clips
– play method in Applet
– Plays clip once, marked for garbage collection when finished
play( location, soundFileName );
location - getDocumentBase (URL of HTML file)
play( soundURL );
soundURL - URL that contains location and filename of clip
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16.4 Loading and Playing Audio Clips
• Playing audio clips
– Method play from AudioClip interface
• More flexible than Applet method play
• Audio stored in program, can be reused
– getAudioClip
• Returns reference to an AudioClip
• Same format as Applet method play
– getAudioClip( location, filename )
– getAudioClip( soundURL )
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sound1 = getAudioClip(
getDocumentBase(), "welcome.wav" );
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16.4 Loading and Playing Audio Clips
• Playing audio clips
– Once AudioClip loaded, use methods
• play - plays audio once
• loop - continuously loops audio in background
• stop - terminates clip that is currently playing
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currentSound.play();
currentSound.loop();
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currentSound.stop();
• Upcoming program
– Use a JComboBox to select between two sounds
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Outline
1// Fig. 16.2: LoadAudioAndPlay.java
2// Load an audio clip and play it.
3import java.applet.*;
4import java.awt.*;
5import java.awt.event.*;
1. Declare objects
6import javax.swing.*;
7
1.1 GUI
8public class LoadAudioAndPlay extends JApplet {
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private AudioClip sound1, sound2, currentSound;
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private JButton playSound, loopSound, stopSound;
1.2 Event handler
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private JComboBox chooseSound;
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1.2.1 stop
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// load the image when the applet begins executing
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public void init()
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{
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Container c = getContentPane();
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c.setLayout( new FlowLayout() );
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String choices[] = { "Welcome", "Hi" };
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chooseSound = new JComboBox( choices );
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chooseSound.addItemListener(
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new ItemListener() {
Once the selection changes, stop
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public void itemStateChanged( ItemEvent
e )
currentSound
and set it equal to
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{
either sound1 or sound2.
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currentSound.stop();
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currentSound =
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chooseSound.getSelectedIndex() == 0 ?
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sound1 : sound2;
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}
}
Outline
);
c.add( chooseSound );
ButtonHandler handler = new ButtonHandler();
playSound = new JButton( "Play" );
playSound.addActionListener( handler );
c.add( playSound );
loopSound = new JButton( "Loop" );
loopSound.addActionListener( handler );
c.add( loopSound );
stopSound = new JButton( "Stop" );
stopSound.addActionListener( handler );
c.add( stopSound );
1.3 Register event
handlers
2. Initialize
AudioClips
3. Method stop
Notice how AudioClips are
initialized.
sound1 = getAudioClip(
getDocumentBase(), "welcome.wav" );
sound2 = getAudioClip(
getDocumentBase(), "hi.au" );
currentSound = sound1;
}
// stop the sound when the user switches Web pages
// (i.e., be polite to the user)
public void stop()
{
currentSound.stop();
}
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Applet's stop method called when
user switches web pages. Ensures
clip stop playing (else could be
annoying to user).
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private class ButtonHandler implements ActionListener {
public void actionPerformed( ActionEvent e )
{
if ( e.getSource() == playSound )
currentSound.play();
else if ( e.getSource() == loopSound )
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currentSound.loop();
else if ( e.getSource() == stopSound )
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currentSound.stop();
}
}
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Outline
4. Event handler
Call methods play, loop, and
stop as appropriate.
4.1 play, loop, stop
16.5 The Java Media Player
• Java Media Player
– Comes with JMF
– Can play
• Audio: .au, .wav, .aiff, .mid
• Video: .avi, .gsm, .mpg (.mpeg), .mov, .rmf, .rtp,
.viv
Play/pause
Mute
Volume
Position
indicator
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Information
16.5 The Java Media Player
• JFileChooser (javax.swing)
– Allows you to select a file
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16.5 The Java Media Player
• JFileChooser (javax.swing)
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JFileChooser fileChooser = new JFileChooser();
– Create JFileChooser
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fileChooser.setFileSelectionMode(
JFileChooser.FILES_ONLY );
– Open only files (not directories)
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int result = fileChooser.showOpenDialog( this );
– Returns an integer indicating user's action (selected file or
cancel)
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if ( result == JFileChooser.CANCEL_OPTION )
file = null;
– If cancel, set file to null
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16.5 The Java Media Player
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else
file = fileChooser.getSelectedFile();
– Otherwise, call getSelectedFile and assign result to
file
• Class File discussed next chapter
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private Player player;
player = Manager.createPlayer( file.toURL() );
– Returns object that implements Player interface
(javax.media)
• If file of correct format, returns object
• Method toURL converts file name and location into URL
format
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16.5 The Java Media Player
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player.addControllerListener( new EventHandler() );
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player.start();
// start player
– Registers event handler
• Interface ControllerListener, must define
controllerUpdate
– Takes ControllerEvent objects
– Many subclasses, we use RealizeCompleteEvent
subclass
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Component visualComponent =
player.getVisualComponent();
if ( visualComponent != null )
c.add( visualComponent, BorderLayout.CENTER );
– Adds visual aspect of media clips
• Audio clips return null
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16.5 The Java Media Player
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Component controlsComponent =
player.getControlPanelComponent();
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if ( controlsComponent != null )
c.add( controlsComponent, BorderLayout.SOUTH );
– Display controls
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c.doLayout();
– Update content pane
– Programmer-defined method removePreviousPlayer
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player.close();
• Close current player
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16.5 The Java Media Player
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Component visual = player.getVisualComponent();
Component control = player.getControlPanelComponent();
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if ( visual != null )
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c.remove( visual );
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if ( control != null )
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c.remove( control );
– Get references to visual and control components
– Container method remove
• Remove Components from interface
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// Fig. 16.3: MediaPlayerDemo.java
// Uses a Java Media Player to play media files.
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import javax.swing.*;
import javax.media.*;
Outline
1. Declarations
1.1 Constructor
public class MediaPlayerDemo extends JFrame {
private Player player;
private File file;
public MediaPlayerDemo()
{
super( "Demonstrating the Java Media Player" );
JButton openFile = new JButton( "Open file to play" );
openFile.addActionListener(
new ActionListener() {
public void actionPerformed( ActionEvent e )
{
openFile();
createPlayer();
}
}
);
getContentPane().add( openFile, BorderLayout.NORTH );
setSize( 300, 300 );
show();
}
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private void openFile()
{
JFileChooser fileChooser = new JFileChooser();
fileChooser.setFileSelectionMode(
JFileChooser.FILES_ONLY );
int result = fileChooser.showOpenDialog( this );
Create a JFileChooser,
use it to select a file.
2. Method openFile
2.1 JFileChooser
// user clicked Cancel button on dialog
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if ( result == JFileChooser.CANCEL_OPTION )
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file = null;
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else
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Outline
file = fileChooser.getSelectedFile();
2.2 file
Test for cancel option. If
not, assign file to file.
3. Method createPlayer
}
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private void createPlayer()
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{
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if ( file == null )
return;
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removePreviousPlayer();
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try {
3.1 removePrevious
Player
Assign player
result of
3.2 createPlayer
createPlayer. Add event
handler (named inner class), call
3.3 Event
handler
start method
to being
playing
clip.
3.4 start
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// create a new player and add listener
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player = Manager.createPlayer( file.toURL() );
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player.addControllerListener( new EventHandler() );
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player.start();
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// start player
}
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catch ( Exception e ){
JOptionPane.showMessageDialog( this,
"Invalid file or location", "Error loading file",
JOptionPane.ERROR_MESSAGE );
}
}
private void removePreviousPlayer()
{
if ( player == null )
Close the
return;
Outline
4. removePrevious
Player
4.1 close
current player
4.2 remove
player.close();
Component visual = player.getVisualComponent();
Component control = player.getControlPanelComponent();
Container c = getContentPane();
if ( visual != null )
c.remove( visual );
Get references to
Components and
remove them from
content pane.
if ( control != null )
c.remove( control );
}
public static void main(String args[])
{
MediaPlayerDemo app = new MediaPlayerDemo();
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5. main
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app.addWindowListener(
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Outline
new WindowAdapter() {
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public void windowClosing( WindowEvent e )
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{
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System.exit(0);
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}
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}
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6. Event handler
6.1
getVisualComponent
);
}
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// inner class to handler events from media player
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private class EventHandler implements ControllerListener {
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public void controllerUpdate( ControllerEvent e ) {
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Components and attach to
content pane.
if ( e instanceof RealizeCompleteEvent )Get
{
Container c = getContentPane();
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// load Visual and Control components if they exist
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Component visualComponent =
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player.getVisualComponent();
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if ( visualComponent != null )
c.add( visualComponent, BorderLayout.CENTER );
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Component controlsComponent =
player.getControlPanelComponent();
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6.2 getControlPanel
Component
if ( controlsComponent != null )
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c.add( controlsComponent, BorderLayout.SOUTH );
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Outline
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c.doLayout();
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}
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}
}
6.3 doLayout
124 }
Program Output
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Outline
Program Output
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16.6 Animating a Series of Images
• Class Timer
– Generates ActionEvents at a fixed interval in
milliseconds
– Constructor:
Timer ( animationDelay, actionListener );
actionListener - ActionListener that will respond
to ActionEvents
– Methods
• start
• stop
• restart
• isRunning
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16.6 Animating a Series of Images
• Method repaint
– Calls update, which calls paintComponent
• Subclasses of JComponent should use paintComponent
• Call superclass paintComponent first to display
components properly
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super.paintComponent( g );
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16.6 Animating a Series of Images
• View area
– Width and height specify entire window, not just client area
• Client area - where components can be displayed
– Dimension objects
• Constructor
– Dimension( width, height )
• Contains width and height instance variables
– Method setSize( width, height )
• Class JFrame
• Sets size of window
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16.6 Animating a Series of Images
• getImageLoadStatus
– ImageIcon method
• Determines if image is completely loaded into memory
• Only complete images should be displayed (smooth animation)
– If loaded, returns MediaTracker.COMPLETE
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if ( images[ currentImage ].getImageLoadStatus() ==
MediaTracker.COMPLETE ) {
– MediaTracker
• Can determine when images are loaded, or force program to
wait
• ImageIcon creates our MediaTracker for us
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16.6 Animating a Series of Images
• Following example
– Use a series of images stored in an array
– Use Timer to generate ActionEvents
• Change image displayed
• Update content pane
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1// Fig. 16.3: LogoAnimator.java
2// Animation a series of images
3import java.awt.*;
4import java.awt.event.*;
5import javax.swing.*;
1.1 Class
6
7public class LogoAnimator extends JPanel
LogoAnimator (
8
implements ActionListener {
implements
9
protected ImageIcon images[];
ActionListener)
10
protected int totalImages = 30,
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currentImage = 0,
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animationDelay = 50; // 50 millisecond delay
1.2 Declare objects
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protected Timer animationTimer;
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1.3 Constructor
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public LogoAnimator()
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{
Load array of ImageIcons to
17
setSize( getPreferredSize() );
use for the animation.1.4 Initialize
18
ImageIcon array
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images = new ImageIcon[ totalImages ];
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for ( int i = 0; i < images.length; ++i )
2. paintComponent
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images[ i ] =
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new ImageIcon( "images/deitel" + i + ".gif" );Call to superclass
24
2.1 super.paint
paintComponent
ensures
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startAnimation();
Component
proper display.
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}
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public void paintComponent( Graphics g )
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{
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super.paintComponent( g );
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Outline
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if ( images[ currentImage ].getImageLoadStatus() ==
MediaTracker.COMPLETE ) {
images[ currentImage ].paintIcon( this, g, 0, 0 );
currentImage = ( currentImage + 1 ) % totalImages;
}
}
public void actionPerformed( ActionEvent e )
{
repaint();
}
Outline
2.2 getImage
LoadStatus
Check if the image
has
loaded, and if so, increment
currentImage.
2.3 Increment
currentImage
3. actionPerformed
Create new Timer, start. this
public void startAnimation()
{
applet listed as event handler.
if ( animationTimer == null ) {
3.1 startAnimation
currentImage = 0;
animationTimer = new Timer( animationDelay, this );
3.2 stopAnimation
animationTimer.start();
}
else // continue from last image displayed
if ( ! animationTimer.isRunning() )
animationTimer.restart();
If animationTimer is not
}
public void stopAnimation()
{
animationTimer.stop();
}
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running (i.e. user switched web
pages and returned), restart it.
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Outline
public Dimension getMinimumSize()
{
return getPreferredSize();
}
3.3 getMinimumSize
public Dimension getPreferredSize()
{
return new Dimension( 160, 80 );
}
public static void main( String args[] )
{
LogoAnimator anim = new LogoAnimator();
JFrame app = new JFrame( "Animator test" );
app.getContentPane().add( anim, fBorderLayout.CENTER );
app.addWindowListener(
new WindowAdapter() {
public void windowClosing( WindowEvent e )
{
System.exit( 0 );
}
}
);
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3.4.
getPreferredSize
4. main
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// The constants 10 and 30 are used below to size the
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// window 10 pixels wider than the animation and
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// 30 pixels taller than the animation.
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app.setSize( anim.getPreferredSize().width + 10,
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anim.getPreferredSize().height + 30 );
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Outline
app.show();
}
94}
Program Output
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16.7 Animation Issues
• Storing images
– Interlaced/non-interlaced formats
• Specifies order in which pixels are stored
• Non-interlaced - pixels stored in order they appear on screen
– Image appears in chunks from top to bottom as it is loaded
• Interlaced - pixels stored in rows, but out of order
– Image appears to fade in and become more clear
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16.7 Animation Issues
• Animation flickers
– Due to update being called in response to repaint
– In AWT GUI components
• Draws filled rectangle in background color where image was
• Draw image, sleep, clear background (flicker), draw next
image...
– Swing's JPanel overrides update to avoid this
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16.7 Animation Issues
• Double buffering
– Used to smooth animations
– Program renders one image on screen
• Builds next image in off-screen buffer
– When time to display next image, done smoothly
• Partial images user would have seen (while image loads) are
hidden
• All pixels for next image displayed at once
– Space/Time tradeoff
• Reduces flicker, but can slow animation speed and uses more
memory
– Used by Swing GUI components by default
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16.8 Customizing Applets via the HTML
param Tag
• Applets
– Customize through parameters in HTML file that invokes
it
<html>
<applet code="LogoApplet.class" width=400
height=400>
<param name="totalimages" value="30">
<param name="imagename" value="deitel">
<param name="animationdelay" value="200">
</applet>
</html>
– Invokes applet LogoApplet
– param tags
• Each has a name and a value
• Use Applet method getParameter (returns a String)
parameter = getParameter( "animationdelay" );
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16.8 Customizing Applets via the HTML
param Tag
• Following example
– Use the LogoAnimator class as before, but modified
slightly
• Include constructor to specify delay, name, number of images
– Create Applet LogoApplet
• Takes parameters
– totalimages
– imagename
– animationdelay
– Create LogoAnimator object using parameters (use new
constructor)
– Play animation
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7
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public class LogoAnimator extends JPanel
implements ActionListener {
public LogoAnimator( int num, int delay, String name )
Outline
127 import java.awt.*;
128 import javax.swing.*;
1. LogoAnimator
129
class as before, but
The LogoAnimator
130 public class LogoApplet extends JApplet{
class now has with
a newnew constructor
131
public void init()
constructor. --------------------132
{
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String parameter;
134
1.1 getParameter
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parameter = getParameter( "animationdelay" );
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int animationDelay = ( parameter == null ? 50 :
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Integer.parseInt( parameter ) );
1.2 LogoAnimator
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String imageName = getParameter( "imagename" );
Get parameters from HTML file,
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convert to integers.
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parameter = getParameter( "totalimages" );
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int totalImages = ( parameter == null ? 0 :
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Integer.parseInt( parameter ) );
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// Create an instance of LogoAnimator
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LogoAnimator animator;
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Create new
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if ( imageName == null || totalImages == 0 )
LogoAnimator, use
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animator = new LogoAnimator();
custom constructor if
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else
applicable.
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animator = new LogoAnimator( totalImages,
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animationDelay, imageName );
 2000 Prentice Hall, Inc. All rights reserved.
Outline
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160 }
setSize( animator.getPreferredSize().width,
animator.getPreferredSize().height );
getContentPane().add( animator, BorderLayout.CENTER );
2. setSize
animator.startAnimation();
}
2.3 startAnimation
Start the animation.
Program Output
 2000 Prentice Hall, Inc. All rights reserved.
16.9 Image Maps
• Image map
– Image that has hot areas
• User can click to accomplish a task
– Bubble help
• When mouse over particular point in screen, small message
displayed in status bar
• In the following example
– Load image containing several icons
– Use event handler mouseMoved to find x-coordinate
– Based on the x-coordinate, display a message
 2000 Prentice Hall, Inc. All rights reserved.
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// Fig. 16.7: ImageMap.java
// Demonstrating an image map.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
Outline
1. Declare objects
public class ImageMap extends JApplet {
private ImageIcon mapImage;
private int width, height;
2. init
2.1
public void init()
addMouseListener
{
addMouseListener(
new MouseAdapter() {
public void mouseExited( MouseEvent e )
{
showStatus( "Pointer outside applet" );
}
Pass the x coordinate to
}
translateLocation. This
);
returns a String, which is passed to
showStatus.
addMouseMotionListener(
new MouseMotionAdapter() {
public void mouseMoved( MouseEvent e )
{
showStatus( translateLocation( e.getX() ) );
}
}
);
 2000 Prentice Hall, Inc. All rights reserved.
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mapImage = new ImageIcon( "icons2.gif" );
width = mapImage.getIconWidth();
height = mapImage.getIconHeight();
setSize( width, height );
}
public void paint( Graphics g )
{
mapImage.paintIcon( this, g, 0, 0 );
}
Outline
Determine width of
2.2 Initialize
mapimage.
ImageIcon
public String translateLocation( int x )
{
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// determine width of each icon (there are 6)
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int iconWidth = width / 6;
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if ( x >= 0 && x <= iconWidth )
return "Common Programming Error";
else if ( x > iconWidth && x <= iconWidth * 2 )
return "Good Programming Practice";
else if ( x > iconWidth * 2 && x <= iconWidth * 3 )
return "Performance Tip";
else if ( x > iconWidth * 3 && x <= iconWidth * 4 )
return "Portability Tip";
else if ( x > iconWidth * 4 && x <= iconWidth * 5 )
return "Software Engineering Observation";
else if ( x > iconWidth * 5 && x <= iconWidth * 6 )
return "Testing and Debugging Tip";
 2000 Prentice Hall, Inc. All rights reserved.
3. paint
4.
translateLocation
Determine width of each icon
in image. Based on this,
display a message.
Outline
59
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return "";
}
62 }
Program Output
 2000 Prentice Hall, Inc. All rights reserved.
16.10 Java Plug-In
• Web browsers
– Many different browser versions
– Most support Java 1.0 and 1.1, but few support Java 2
• Inconsistent support of 1.1
– To use Java 2 in an applet, use the Java Plug-in
• Bypasses browser's Java support
• Installs complete version of Java Runtime Environment on
user's computer
• Large file - ideal for corporate intranets and high-speed
networks
 2000 Prentice Hall, Inc. All rights reserved.
16.10 Java Plug-In
• Using the Plug in with applets
– The <applet>, <param> and </applet> tags must be
converted
• Must indicate that Plug-in should be used to execute applet
– Java Plug-in 1.2 HTML Converter
• Performs conversion for us
• http://java.sun.com/products/plugin/
– Execution
• In install directory type java HTMLConverter
• Select file to convert and type of conversion
 2000 Prentice Hall, Inc. All rights reserved.
16.11 Internet and World Wide Web
Resources
• Internet and web resources
– Java Media Framework
– Download and documentation:
http://java.sun.com/products/java-media/jmf/
– javax.media API descriptions:
http://java.sun.com/products/java-media/
jmf/forDevelopers/
 2000 Prentice Hall, Inc. All rights reserved.
16.11 Internet and World Wide Web
Resources
• Downloadable image, audio, and video galleries
– Test your multimedia programs
http://www.nasa.gov/gallery/index.html
http://sunsite.sut.ac.jp/multimed/
 2000 Prentice Hall, Inc. All rights reserved.