Class java.awt.Image
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Class java.awt.Image
Object
|
+----java.awt.Image
- public abstract class Image
- extends Object
The abstract class Image
is the superclass of all
classes that represent graphical images. The image must be
obtained in a platform-specific manner.
- Version:
- 1.24, 07/01/98
- Author:
- Sami Shaio, Arthur van Hoff
- Since:
- JDK1.0
-
SCALE_AREA_AVERAGING
- Use the Area Averaging image scaling algorithm.
-
SCALE_DEFAULT
- Use the default image-scaling algorithm.
-
SCALE_FAST
- Choose an image-scaling algorithm that gives higher priority
to scaling speed than smoothness of the scaled image.
-
SCALE_REPLICATE
- Use the image scaling algorithm embodied in the
ReplicateScaleFilter
class.
-
SCALE_SMOOTH
- Choose an image-scaling algorithm that gives higher priority
to image smoothness than scaling speed.
-
UndefinedProperty
- The
UndefinedProperty
object should be returned whenever a
property which was not defined for a particular image is fetched.
-
java.awt.Image()
-
-
flush()
- Flushes all resources being used by this Image object.
-
getGraphics()
- Creates a graphics context for drawing to an off-screen image.
-
getHeight(ImageObserver)
- Determines the height of the image.
-
getProperty(String, ImageObserver)
- Gets a property of this image by name.
-
getScaledInstance(int, int, int)
- Creates a scaled version of this image.
-
getSource()
- Gets the object that produces the pixels for the image.
-
getWidth(ImageObserver)
- Determines the width of the image.
SCALE_AREA_AVERAGING
public static final int SCALE_AREA_AVERAGING
- Use the Area Averaging image scaling algorithm. The
image object is free to substitute a different filter that
performs the same algorithm yet integrates more efficiently
into the image infrastructure supplied by the toolkit.
- Since:
JDK1.1
- See Also:
- AreaAveragingScaleFilter
SCALE_DEFAULT
public static final int SCALE_DEFAULT
- Use the default image-scaling algorithm.
- Since:
JDK1.1
SCALE_FAST
public static final int SCALE_FAST
- Choose an image-scaling algorithm that gives higher priority
to scaling speed than smoothness of the scaled image.
- Since:
JDK1.1
SCALE_REPLICATE
public static final int SCALE_REPLICATE
- Use the image scaling algorithm embodied in the
ReplicateScaleFilter
class.
The Image
object is free to substitute a different filter
that performs the same algorithm yet integrates more efficiently
into the imaging infrastructure supplied by the toolkit.
- Since:
JDK1.1
- See Also:
- ReplicateScaleFilter
SCALE_SMOOTH
public static final int SCALE_SMOOTH
- Choose an image-scaling algorithm that gives higher priority
to image smoothness than scaling speed.
- Since:
JDK1.1
UndefinedProperty
public static final java.lang.Object UndefinedProperty
- The
UndefinedProperty
object should be returned whenever a
property which was not defined for a particular image is fetched.
- Since:
JDK1.0
Image
public Image()
flush
public abstract void flush()
- Flushes all resources being used by this Image object. This
includes any pixel data that is being cached for rendering to
the screen as well as any system resources that are being used
to store data or pixels for the image. The image is reset to
a state similar to when it was first created so that if it is
again rendered, the image data will have to be recreated or
fetched again from its source.
- Since:
- JDK1.0
getGraphics
public abstract java.awt.Graphics getGraphics()
- Creates a graphics context for drawing to an off-screen image.
This method can only be called for off-screen images.
- Returns:
- a graphics context to draw to the off-screen image.
- Since:
- JDK1.0
- See Also:
- Graphics, createImage(int, int)
getHeight
public abstract int getHeight(ImageObserver observer)
- Determines the height of the image. If the height is not yet known,
this method returns
-1
and the specified
ImageObserver
object is notified later.
- Parameters:
- observer - an object waiting for the image to be loaded.
- Returns:
- the height of this image, or
-1
if the height is not yet known.
- Since:
- JDK1.0
- See Also:
- getWidth, ImageObserver
getProperty
public abstract java.lang.Object getProperty(String name,
ImageObserver observer)
- Gets a property of this image by name.
Individual property names are defined by the various image
formats. If a property is not defined for a particular image, this
method returns the UndefinedProperty
object.
If the properties for this image are not yet known, this method
returns null
, and the ImageObserver
object is notified later.
The property name "comment"
should be used to store
an optional comment which can be presented to the application as a
description of the image, its source, or its author.
- Parameters:
- name - a property name.
- observer - an object waiting for this image to be loaded.
- Returns:
- the value of the named property.
- Since:
- JDK1.0
- See Also:
- ImageObserver, UndefinedProperty
getScaledInstance
public java.awt.Image getScaledInstance(int width,
int height,
int hints)
- Creates a scaled version of this image.
A new
Image
object is returned which will render
the image at the specified width
and
height
by default. The new Image
object
may be loaded asynchronously even if the original source image
has already been loaded completely. If either the width
or height
is a negative number then a value is
substituted to maintain the aspect ratio of the original image
dimensions.
- Parameters:
- width - the width to which to scale the image.
- height - the height to which to scale the image.
- hints - flags to indicate the type of algorithm to use
for image resampling.
- Returns:
- a scaled version of the image.
- Since:
- JDK1.1
- See Also:
- SCALE_DEFAULT, SCALE_FAST, SCALE_SMOOTH, SCALE_REPLICATE, SCALE_AVERAGE
getSource
public abstract java.awt.image.ImageProducer getSource()
- Gets the object that produces the pixels for the image.
This method is called by the image filtering classes and by
methods that perform image conversion and scaling.
- Returns:
- the image producer that produces the pixels
for this image.
- See Also:
- ImageProducer
getWidth
public abstract int getWidth(ImageObserver observer)
- Determines the width of the image. If the width is not yet known,
this method returns
-1
and the specified
ImageObserver
object is notified later.
- Parameters:
- observer - an object waiting for the image to be loaded.
- Returns:
- the width of this image, or
-1
if the width is not yet known.
- Since:
- JDK1.0
- See Also:
- getHeight, ImageObserver
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