java.awt

Class Image

public abstract class Image extends Object

This is the abstract superclass of all image objects in Java.

Since: 1.0

UNKNOWN: updated to 1.5

Field Summary
protected float	accelerationPriority The acceleration priority of the image
static int	SCALE_AREA_AVERAGING Constant indicating that the area averaging scaling algorithm should be used.
static int	SCALE_DEFAULT Constant indicating that the default scaling algorithm should be used.
static int	SCALE_FAST Constant indicating that a fast scaling algorithm should be used.
static int	SCALE_REPLICATE Constant indicating that the `ReplicateScaleFilter` class algorithm should be used for scaling.
static int	SCALE_SMOOTH Constant indicating that a smooth scaling algorithm should be used.
static Object	UndefinedProperty This variable is returned whenever a property that is not defined is requested.

Constructor Summary
	Image() A default constructor for subclasses.

Method Summary
abstract void	flush() Flushes (that is, destroys) any resources used for this image.
float	getAccelerationPriority() Returns the acceleration priority of the image.
abstract Graphics	getGraphics() Returns a graphics context object for drawing an off-screen object.
abstract int	getHeight(ImageObserver observer) Returns the height of the image, or -1 if it is unknown.
abstract Object	getProperty(String name, ImageObserver observer) This method requests a named property for an object.
Image	getScaledInstance(int width, int height, int flags) Scales the image to the requested dimension.
abstract ImageProducer	getSource() Returns the image producer object for this object.
abstract int	getWidth(ImageObserver observer) Returns the width of the image, or -1 if it is unknown.
void	setAccelerationPriority(float priority) Sets the acceleration priority of the image.

Field Detail

accelerationPriority

protected float accelerationPriority

The acceleration priority of the image

Since: 1.5

SCALE_AREA_AVERAGING

public static final int SCALE_AREA_AVERAGING

Constant indicating that the area averaging scaling algorithm should be used.

Since: 1.1

SCALE_DEFAULT

public static final int SCALE_DEFAULT

Constant indicating that the default scaling algorithm should be used.

Since: 1.1

SCALE_FAST

public static final int SCALE_FAST

Constant indicating that a fast scaling algorithm should be used.

Since: 1.1

SCALE_REPLICATE

public static final int SCALE_REPLICATE

Constant indicating that the ReplicateScaleFilter class algorithm should be used for scaling.

Since: 1.1

SCALE_SMOOTH

public static final int SCALE_SMOOTH

Constant indicating that a smooth scaling algorithm should be used.

Since: 1.1

UndefinedProperty

public static final Object UndefinedProperty

This variable is returned whenever a property that is not defined is requested.

Constructor Detail

Image

public Image()

A default constructor for subclasses.

Method Detail

flush

public abstract void flush()

Flushes (that is, destroys) any resources used for this image. This includes the actual image data.

getAccelerationPriority

public float getAccelerationPriority()

Returns the acceleration priority of the image.

Since: 1.5

getGraphics

public abstract Graphics getGraphics()

Returns a graphics context object for drawing an off-screen object. This method is only valid for off-screen objects.

Returns: a graphics context object for an off-screen object

getHeight

public abstract int getHeight(ImageObserver observer)

Returns the height of the image, or -1 if it is unknown. If the image height is unknown, the observer object will be notified when the value is known.

Parameters: observer the image observer for this object

Returns: the height in pixels

getProperty

public abstract Object getProperty(String name, ImageObserver observer)

This method requests a named property for an object. The value of the property is returned. The value UndefinedProperty is returned if there is no property with the specified name. The value null is returned if the properties for the object are not yet known. In this case, the specified image observer is notified when the properties are known.

Parameters: name the requested property name observer the image observer for this object

Returns: the named property, if available

getScaledInstance

public Image getScaledInstance(int width, int height, int flags)

Scales the image to the requested dimension. A new Image with asynchronous loading will be produced according to the hints of the algorithm requested. If either the width or height is non-positive, it is adjusted to preserve the original aspect ratio. If an illegal value of flags is passed, the default algorithm is used.

Parameters: width the width of the scaled image height the height of the scaled image flags a value indicating the algorithm to use

Returns: the scaled Image object

Since: 1.1

getSource

public abstract ImageProducer getSource()

Returns the image producer object for this object. The producer is the object which generates pixels for this image.

Returns: the image producer for this object

getWidth

public abstract int getWidth(ImageObserver observer)

Returns the width of the image, or -1 if it is unknown. If the image width is unknown, the observer object will be notified when the value is known.

Parameters: observer the image observer for this object

Returns: the width in pixels

setAccelerationPriority

public void setAccelerationPriority(float priority)

Sets the acceleration priority of the image. This is a value from 0 (lowest) to 1 (highest), which may be used as a hint for image acceleration. E.g. higher priority images may be stored in video memory.

Parameters: priority - the priority

Throws: IllegalArgumentException if priority is not >= 0 and <= 1.

Since: 1.5