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Java AWT

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java.awt Reference
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Image

Name

Image

[Graphic: Figure from the text]

Description

The Image class represents a displayable object maintained in memory. Because Image is an abstract class, you never work with the Image class itself, but with a platform specific subclass. However, you should never need to know what that subclass is. To draw on an Image, get its graphics context.

Class Definition

public abstract class java.awt.Image
    extends java.lang.Object
    implements java.io.Serializable {
  
  // Constants
  public final static int SCALE_AREA_AVERAGING; (New)
  public final static int SCALE_DEFAULT; (New)
  public final static int SCALE_FAST; (New)
  public final static int SCALE_REPLICATE; (New)
  public final static int SCALE_SMOOTH; (New)
  public final static Object UndefinedProperty;
  
  // Instance Methods
  public abstract void flush();
  public abstract Graphics getGraphics();
  public abstract int getHeight (ImageObserver observer);
  public abstract Object getProperty (String name, ImageObserver observer);
  public Image getScaledInstance (int width, int height, int hints); (New)
  public abstract ImageProducer getSource();
  public abstract int getWidth (ImageObserver observer);
}

Constants

SCALE_AREA_AVERAGING

public final static int SCALE_AREA_AVERAGING (New)

Flag that requests use of AreaAveragingScaleFilter.

SCALE_DEFAULT

public final static int SCALE_DEFAULT (New)

Flag that requests use of the default image scaling algorithm.

SCALE_FAST

public final static int SCALE_FAST (New)

Flag that requests use of an image scaling algorithm that is faster rather than smoother.

SCALE_REPLICATE

public final static int SCALE_REPLICATE (New)

Flag that requests use of ReplicateScaleFilter.

SCALE_SMOOTH

public final static int SCALE_SMOOTH (New)

Flag that requests use of an image scaling algorithm that is smoother rather than faster.

UndefinedProperty

public final static Object UndefinedProperty

Possible return object from getProperty().

Instance Methods

flush

public abstract void flush()

Description

Resets image to initial state.

getGraphics

public abstract Graphics getGraphics()

Throws

ClassCastException

If image created from file or URL.

Returns

The graphics context of the image.

Description

Gets the graphics context of the image for drawing.

getHeight

public abstract int getHeight (ImageObserver observer)

Parameters

observer

An image observer; usually the Component on which the image is rendered.

Returns

Image height, or -1 if the height is not yet available.

getProperty

public abstract Object getProperty (String name, ImageObserver observer)

Parameters

name

Name of the property to fetch.

observer

An image observer; usually the Component on which the image is rendered.

Returns

Object representing the requested property, null, or UndefinedProperty.

Throws

ArrayIndexOutOfBoundsException

If offset or length is invalid.

Description

Retrieves a property from the image's private property list.

getScaledInstance

public Image getScaledInstance (int width, int height, int hints) (New)

Parameters

width

The width for the scaled image. Use -1 to preserve the aspect ratio with reference to height.

height

The height for the scaled image. Use -1 to preserve the aspect ratio with reference to width.

hints

One or more of the SCALE_ constants.

Returns

The scaled image. It may be loaded asynchronously, even if the original image was fully loaded.

Description

Creates a copy of an image, scaled to width x height and using an algorithm chosen based on the hints given.

getSource

public abstract ImageProducer getSource()

Returns

The ImageProducer of the image.

getWidth

public abstract int getWidth (ImageObserver observer)

Parameters

observer

An image observer; usually the Component on which the image is rendered.

Returns

Image width, or -1 if the width is not yet available.

See Also

Graphics, ImageObserver, ImageProducer, Object, Properties, String


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