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| java.lang.Object
 java.awt.Image
All known Subclasses: java.awt.image.VolatileImage, java.awt.image.BufferedImage,
| Image | | abstract public class Image (Code) | | 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:
1.50, 05/05/07
author:
Sami Shaio
author:
Arthur van Hoff
since:
JDK1.0 |
| Field Summary | |
| final public static int | SCALE_AREA_AVERAGING
Use the Area Averaging image scaling algorithm. | | final public static int | SCALE_DEFAULT
Use the default image-scaling algorithm. | | final public static int | SCALE_FAST
Choose an image-scaling algorithm that gives higher priority
to scaling speed than smoothness of the scaled image. | | final public static int | SCALE_REPLICATE
Use the image scaling algorithm embodied in the
ReplicateScaleFilter class. | | final public static int | SCALE_SMOOTH
Choose an image-scaling algorithm that gives higher priority
to image smoothness than scaling speed. | | final public static Object | UndefinedProperty
The UndefinedProperty object should be returned whenever a
property which was not defined for a particular image is fetched. | | protected float | accelerationPriority
Priority for accelerating this image. | | SurfaceManager | surfaceManager
|
| Method Summary | |
| public void | flush()
Flushes all reconstructable resources being used by this Image object. | | public float | getAccelerationPriority()
Returns the current value of the acceleration priority hint. | | public ImageCapabilities | getCapabilities(GraphicsConfiguration gc)
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. | | abstract public Graphics | getGraphics()
Creates a graphics context for drawing to an off-screen image. | | abstract public int | getHeight(ImageObserver observer)
Determines the height of the image. | | abstract public Object | getProperty(String name, ImageObserver observer)
Gets a property of this image by name. | | public 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. | | abstract public ImageProducer | getSource()
Gets the object that produces the pixels for the image. | | abstract public int | getWidth(ImageObserver observer)
Determines the width of the image. | | public void | setAccelerationPriority(float priority)
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. |
| SCALE_AREA_AVERAGING | | final public static int SCALE_AREA_AVERAGING(Code) | | 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.
See Also: java.awt.image.AreaAveragingScaleFilter
since:
JDK1.1 |
| SCALE_DEFAULT | | final public static int SCALE_DEFAULT(Code) | | Use the default image-scaling algorithm.
since:
JDK1.1 |
| SCALE_FAST | | final public static int SCALE_FAST(Code) | | Choose an image-scaling algorithm that gives higher priority
to scaling speed than smoothness of the scaled image.
since:
JDK1.1 |
| SCALE_REPLICATE | | final public static int SCALE_REPLICATE(Code) | | 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.
See Also: java.awt.image.ReplicateScaleFilter
since:
JDK1.1 |
| SCALE_SMOOTH | | final public static int SCALE_SMOOTH(Code) | | Choose an image-scaling algorithm that gives higher priority
to image smoothness than scaling speed.
since:
JDK1.1 |
| UndefinedProperty | | final public static Object UndefinedProperty(Code) | | The UndefinedProperty object should be returned whenever a
property which was not defined for a particular image is fetched.
|
| accelerationPriority | | protected float accelerationPriority(Code) | | 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.
since:
1.5 |
| surfaceManager | | SurfaceManager surfaceManager(Code) | | |
| flush | | public void flush()(Code) | | 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:
-
BufferedImage objects leave the primary Raster which stores their
pixels untouched, but flush any information cached about those
pixels such as copies uploaded to the display hardware for
accelerated blits.
-
Image objects created by the Component methods which take a
width and height leave their primary buffer of pixels untouched,
but have all cached information released much like is done for
BufferedImage objects.
-
VolatileImage objects release all of their pixel resources
including their primary copy which is typically stored on
the display hardware where resources are scarce.
These objects can later be restored using their
java.awt.image.VolatileImage.validate validate method.
-
Image objects created by the Toolkit and Component classes which are
loaded from files, URLs or produced by an
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.
|
| getAccelerationPriority | | public float getAccelerationPriority()(Code) | | Returns the current value of the acceleration priority hint.
See Also: Image.setAccelerationPriority(float priority)
See Also: setAccelerationPriority value between 0 and 1, inclusive, which represents the currentpriority value
since:
1.5 |
| getCapabilities | | public ImageCapabilities getCapabilities(GraphicsConfiguration gc)(Code) | | 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.
Parameters:
gc - a GraphicsConfiguration object. A value of nullfor this parameter will result in getting the image capabilitiesfor the default GraphicsConfiguration. an ImageCapabilities object that containsthe capabilities of this Image on the specifiedGraphicsConfiguration.
See Also: java.awt.image.VolatileImage.getCapabilities
See Also: VolatileImage.getCapabilities()
since:
1.5 |
| getHeight | | abstract public int getHeight(ImageObserver observer)(Code) | | 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. the height of this image, or -1 if the height is not yet known.
See Also: java.awt.Image.getWidth
See Also: java.awt.image.ImageObserver |
| getProperty | | abstract public Object getProperty(String name, ImageObserver observer)(Code) | | 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.
Parameters:
observer - an object waiting for this image to be loaded. the value of the named property. NullPointerException if the property name is null.
See Also: java.awt.image.ImageObserver
See Also: java.awt.Image.UndefinedProperty |
| getScaledInstance | | public Image getScaledInstance(int width, int height, int hints)(Code) | | 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.
Parameters:
width - the width to which to scale the image.
Parameters:
height - the height to which to scale the image.
Parameters:
hints - flags to indicate the type of algorithm to usefor image resampling. a scaled version of the image.
exception:
IllegalArgumentException - if widthor height is zero.
See Also: java.awt.Image.SCALE_DEFAULT
See Also: java.awt.Image.SCALE_FAST
See Also:
See Also: java.awt.Image.SCALE_SMOOTH
See Also: java.awt.Image.SCALE_REPLICATE
See Also: java.awt.Image.SCALE_AREA_AVERAGING
since:
JDK1.1 |
| getSource | | abstract public ImageProducer getSource()(Code) | | 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.
the image producer that produces the pixels for this image.
See Also: java.awt.image.ImageProducer |
| getWidth | | abstract public int getWidth(ImageObserver observer)(Code) | | 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. the width of this image, or -1 if the width is not yet known.
See Also: java.awt.Image.getHeight
See Also: java.awt.image.ImageObserver |
| setAccelerationPriority | | public void setAccelerationPriority(float priority)(Code) | | 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.
Parameters:
priority - a value between 0 and 1, inclusive, where highervalues indicate more importance for acceleration. A value of 0means that this Image should never be accelerated. Other valuesare used simply to determine acceleration priority relative to otherImages.
throws:
IllegalArgumentException - if priority is lessthan zero or greater than 1.
since:
1.5 |
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