javax.swing
Class ImageIcon

java.lang.Object
  extended byjavax.swing.ImageIcon
All Implemented Interfaces:
javax.accessibility.Accessible, Icon, Serializable

public class ImageIcon
extends Object
implements Icon, Serializable, javax.accessibility.Accessible

An implementation of the Icon interface that paints Icons from Images. Images that are created from a URL or filename are preloaded using MediaTracker to monitor the loaded state of the image.

For further information and examples of using image icons, see How to Use Icons in The Java Tutorial.

Warning: Serialized objects of this class will not be compatible with future Swing releases. The current serialization support is appropriate for short term storage or RMI between applications running the same version of Swing. As of 1.4, support for long term storage of all JavaBeansTM has been added to the java.beans package. Please see XMLEncoder.

Author:
Jeff Dinkins, Lynn Monsanto
See Also:
Serialized Form

Nested Class Summary
protected  class ImageIcon.AccessibleImageIcon
          This class implements accessibility support for the ImageIcon class.
 
Field Summary
private  ImageIcon.AccessibleImageIcon accessibleContext
          --- Accessibility Support ---
protected static Component component
           
(package private)  String description
           
private  String filename
           
(package private)  int height
           
(package private)  Image image
           
(package private)  ImageObserver imageObserver
           
(package private)  int loadStatus
           
private  URL location
           
private static int mediaTrackerID
          Id used in loading images from MediaTracker.
protected static MediaTracker tracker
           
(package private)  int width
           
 
Constructor Summary
ImageIcon()
          Creates an uninitialized image icon.
ImageIcon(byte[] imageData)
          Creates an ImageIcon from an array of bytes which were read from an image file containing a supported image format, such as GIF or JPEG.
ImageIcon(byte[] imageData, String description)
          Creates an ImageIcon from an array of bytes which were read from an image file containing a supported image format, such as GIF or JPEG.
ImageIcon(Image image)
          Creates an ImageIcon from an image object.
ImageIcon(Image image, String description)
          Creates an ImageIcon from the image.
ImageIcon(String filename)
          Creates an ImageIcon from the specified file.
ImageIcon(String filename, String description)
          Creates an ImageIcon from the specified file.
ImageIcon(URL location)
          Creates an ImageIcon from the specified URL.
ImageIcon(URL location, String description)
          Creates an ImageIcon from the specified URL.
 
Method Summary
 javax.accessibility.AccessibleContext getAccessibleContext()
          Gets the AccessibleContext associated with this ImageIcon.
 String getDescription()
          Gets the description of the image.
 int getIconHeight()
          Gets the height of the icon.
 int getIconWidth()
          Gets the width of the icon.
 Image getImage()
          Returns this icon's Image.
 int getImageLoadStatus()
          Returns the status of the image loading operation.
 ImageObserver getImageObserver()
          Returns the image observer for the image.
private  int getNextID()
          Returns an ID to use with the MediaTracker in loading an image.
protected  void loadImage(Image image)
          Loads the image, returning only when the image is loaded.
 void paintIcon(Component c, Graphics g, int x, int y)
          Paints the icon.
private  void readObject(ObjectInputStream s)
           
 void setDescription(String description)
          Sets the description of the image.
 void setImage(Image image)
          Sets the image displayed by this icon.
 void setImageObserver(ImageObserver observer)
          Sets the image observer for the image.
 String toString()
          Returns a string representation of this image.
private  void writeObject(ObjectOutputStream s)
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

filename

private transient String filename

location

private transient URL location

image

transient Image image

loadStatus

transient int loadStatus

imageObserver

ImageObserver imageObserver

description

String description

component

protected static final Component component

tracker

protected static final MediaTracker tracker

mediaTrackerID

private static int mediaTrackerID
Id used in loading images from MediaTracker.


width

int width

height

int height

accessibleContext

private ImageIcon.AccessibleImageIcon accessibleContext
--- Accessibility Support ---

Constructor Detail

ImageIcon

public ImageIcon(String filename,
                 String description)
Creates an ImageIcon from the specified file. The image will be preloaded by using MediaTracker to monitor the loading state of the image.

Parameters:
filename - the name of the file containing the image
description - a brief textual description of the image
See Also:
ImageIcon(String)

ImageIcon

public ImageIcon(String filename)
Creates an ImageIcon from the specified file. The image will be preloaded by using MediaTracker to monitor the loading state of the image. The specified String can be a file name or a file path. When specifying a path, use the Internet-standard forward-slash ("/") as a separator. (The string is converted to an URL, so the forward-slash works on all systems.) For example, specify:
    new ImageIcon("images/myImage.gif") 
The description is initialized to the filename string.

Parameters:
filename - a String specifying a filename or path
See Also:
getDescription()

ImageIcon

public ImageIcon(URL location,
                 String description)
Creates an ImageIcon from the specified URL. The image will be preloaded by using MediaTracker to monitor the loaded state of the image.

Parameters:
location - the URL for the image
description - a brief textual description of the image
See Also:
ImageIcon(String)

ImageIcon

public ImageIcon(URL location)
Creates an ImageIcon from the specified URL. The image will be preloaded by using MediaTracker to monitor the loaded state of the image. The icon's description is initialized to be a string representation of the URL.

Parameters:
location - the URL for the image
See Also:
getDescription()

ImageIcon

public ImageIcon(Image image,
                 String description)
Creates an ImageIcon from the image.

Parameters:
image - the image
description - a brief textual description of the image

ImageIcon

public ImageIcon(Image image)
Creates an ImageIcon from an image object. If the image has a "comment" property that is a string, then the string is used as the description of this icon.

Parameters:
image - the image
See Also:
getDescription(), Image.getProperty(java.lang.String, java.awt.image.ImageObserver)

ImageIcon

public ImageIcon(byte[] imageData,
                 String description)
Creates an ImageIcon from an array of bytes which were read from an image file containing a supported image format, such as GIF or JPEG. Normally this array is created by reading an image using Class.getResourceAsStream(), but the byte array may also be statically stored in a class.

Parameters:
imageData - an array of pixels in an image format supported by the AWT Toolkit, such as GIF or JPEG.
description - a brief textual description of the image
See Also:
Toolkit.createImage(java.lang.String)

ImageIcon

public ImageIcon(byte[] imageData)
Creates an ImageIcon from an array of bytes which were read from an image file containing a supported image format, such as GIF or JPEG. Normally this array is created by reading an image using Class.getResourceAsStream(), but the byte array may also be statically stored in a class. If the resulting image has a "comment" property that is a string, then the string is used as the description of this icon.

Parameters:
imageData - an array of pixels in an image format supported by the AWT Toolkit, such as GIF or JPEG
See Also:
Toolkit.createImage(java.lang.String), getDescription(), Image.getProperty(java.lang.String, java.awt.image.ImageObserver)

ImageIcon

public ImageIcon()
Creates an uninitialized image icon.

Method Detail

loadImage

protected void loadImage(Image image)
Loads the image, returning only when the image is loaded.

Parameters:
image - the image

getNextID

private int getNextID()
Returns an ID to use with the MediaTracker in loading an image.


getImageLoadStatus

public int getImageLoadStatus()
Returns the status of the image loading operation.

Returns:
the loading status as defined by java.awt.MediaTracker
See Also:
MediaTracker.ABORTED, MediaTracker.ERRORED, MediaTracker.COMPLETE

getImage

public Image getImage()
Returns this icon's Image.

Returns:
the Image object for this ImageIcon

setImage

public void setImage(Image image)
Sets the image displayed by this icon.

Parameters:
image - the image

getDescription

public String getDescription()
Gets the description of the image. This is meant to be a brief textual description of the object. For example, it might be presented to a blind user to give an indication of the purpose of the image. The description may be null.

Returns:
a brief textual description of the image

setDescription

public void setDescription(String description)
Sets the description of the image. This is meant to be a brief textual description of the object. For example, it might be presented to a blind user to give an indication of the purpose of the image.

Parameters:
description - a brief textual description of the image

paintIcon

public void paintIcon(Component c,
                      Graphics g,
                      int x,
                      int y)
Paints the icon. The top-left corner of the icon is drawn at the point (x, y) in the coordinate space of the graphics context g. If this icon has no image observer, this method uses the c component as the observer.

Specified by:
paintIcon in interface Icon
Parameters:
c - the component to be used as the observer if this icon has no image observer
g - the graphics context
x - the X coordinate of the icon's top-left corner
y - the Y coordinate of the icon's top-left corner

getIconWidth

public int getIconWidth()
Gets the width of the icon.

Specified by:
getIconWidth in interface Icon
Returns:
the width in pixels of this icon

getIconHeight

public int getIconHeight()
Gets the height of the icon.

Specified by:
getIconHeight in interface Icon
Returns:
the height in pixels of this icon

setImageObserver

public void setImageObserver(ImageObserver observer)
Sets the image observer for the image. Set this property if the ImageIcon contains an animated GIF, so the observer is notified to update its display. For example:
     icon = new ImageIcon(...)
     button.setIcon(icon);
     icon.setImageObserver(button);
 

Parameters:
observer - the image observer

getImageObserver

public ImageObserver getImageObserver()
Returns the image observer for the image.

Returns:
the image observer, which may be null

toString

public String toString()
Returns a string representation of this image.

Overrides:
toString in class Object
Returns:
a string representing this image

readObject

private void readObject(ObjectInputStream s)
                 throws ClassNotFoundException,
                        IOException
Throws:
ClassNotFoundException
IOException

writeObject

private void writeObject(ObjectOutputStream s)
                  throws IOException
Throws:
IOException

getAccessibleContext

public javax.accessibility.AccessibleContext getAccessibleContext()
Gets the AccessibleContext associated with this ImageIcon. For image icons, the AccessibleContext takes the form of an AccessibleImageIcon. A new AccessibleImageIcon instance is created if necessary.

Specified by:
getAccessibleContext in interface javax.accessibility.Accessible
Returns:
an AccessibleImageIcon that serves as the AccessibleContext of this ImageIcon