java.lang.Object | |
↳ | java.awt.Image |
Known Direct Subclasses |
Known Indirect Subclasses |
The abstract class Image
is the superclass of all
classes that represent graphical images. The image must be
obtained in a platform-specific manner.
Constants | |||||||||||
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int | SCALE_AREA_AVERAGING | Use the Area Averaging image scaling algorithm. | |||||||||
int | SCALE_DEFAULT | Use the default image-scaling algorithm. | |||||||||
int | SCALE_FAST | Choose an image-scaling algorithm that gives higher priority to scaling speed than smoothness of the scaled image. | |||||||||
int | SCALE_REPLICATE | Use the image scaling algorithm embodied in the
ReplicateScaleFilter class. |
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int | SCALE_SMOOTH | Choose an image-scaling algorithm that gives higher priority to image smoothness than scaling speed. |
Fields | |||||||||||
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UndefinedProperty | The UndefinedProperty object should be returned whenever a
property which was not defined for a particular image is fetched. |
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accelerationPriority | Priority for accelerating this image. |
Public Constructors | |||||||||||
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Public Methods | |||||||||||
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Flushes all reconstructable resources being used by this Image object.
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Returns the current value of the acceleration priority hint.
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Returns an ImageCapabilities object which can be
inquired as to the capabilities of this
Image on the specified GraphicsConfiguration.
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Creates a graphics context for drawing to an off-screen image.
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Determines the height of the image.
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Gets a property of this image by name.
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Creates a scaled version of this image.
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Gets the object that produces the pixels for the image.
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Determines the width of the image.
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Sets a hint for this image about how important acceleration is.
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Inherited Methods | |||||||||||
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From class
java.lang.Object
|
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.
Use the default image-scaling algorithm.
Choose an image-scaling algorithm that gives higher priority to scaling speed than smoothness of the scaled image.
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.
Choose an image-scaling algorithm that gives higher priority to image smoothness than scaling speed.
The UndefinedProperty
object should be returned whenever a
property which was not defined for a particular image is fetched.
Priority for accelerating this image. Subclasses are free to
set different default priorities and applications are free to
set the priority for specific images via the
setAccelerationPriority(float)
method.
Flushes all reconstructable 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 if they can be recreated. 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.
Examples of how this method affects specific types of Image object:
validate
method.
ImageProducer
are unloaded and all local resources are released.
These objects can later be reloaded from their original source
as needed when they are rendered, just as when they were first
created.
Returns the current value of the acceleration priority hint.
Returns an ImageCapabilities object which can be inquired as to the capabilities of this Image on the specified GraphicsConfiguration. This allows programmers to find out more runtime information on the specific Image object that they have created. For example, the user might create a BufferedImage but the system may have no video memory left for creating an image of that size on the given GraphicsConfiguration, so although the object may be acceleratable in general, it does not have that capability on this GraphicsConfiguration.
gc | a GraphicsConfiguration object. A value of null
for this parameter will result in getting the image capabilities
for the default GraphicsConfiguration . |
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ImageCapabilities
object that contains
the capabilities of this Image
on the specified
GraphicsConfiguration.Creates a graphics context for drawing to an off-screen image. This method can only be called for off-screen images.
UnsupportedOperationException | if called for a non-off-screen image. |
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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.
observer | an object waiting for the image to be loaded. |
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-1
if the height is not yet known.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.
name | a property name. |
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observer | an object waiting for this image to be loaded. |
if the property name is null. |
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 width
or height
is a negative number then a value is
substituted to maintain the aspect ratio of the original image
dimensions. If both width
and height
are negative, then the original image dimensions are used.
width | the width to which to scale the image. |
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height | the height to which to scale the image. |
hints | flags to indicate the type of algorithm to use for image resampling. |
IllegalArgumentException | if width
or height is zero. |
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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.
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.
observer | an object waiting for the image to be loaded. |
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-1
if the width is not yet known.Sets a hint for this image about how important acceleration is. This priority hint is used to compare to the priorities of other Image objects when determining how to use scarce acceleration resources such as video memory. When and if it is possible to accelerate this Image, if there are not enough resources available to provide that acceleration but enough can be freed up by de-accelerating some other image of lower priority, then that other Image may be de-accelerated in deference to this one. Images that have the same priority take up resources on a first-come, first-served basis.
priority | a value between 0 and 1, inclusive, where higher values indicate more importance for acceleration. A value of 0 means that this Image should never be accelerated. Other values are used simply to determine acceleration priority relative to other Images. |
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IllegalArgumentException | if priority is less
than zero or greater than 1. |
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