java.awt.Image Maven / Gradle / Ivy
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This work corresponds to the API signatures of JSR 217: Personal Basis
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package java.awt;
import java.awt.image.ImageProducer;
import java.awt.image.ImageObserver;
import java.awt.image.ImageFilter;
import java.awt.image.FilteredImageSource;
import java.awt.image.AreaAveragingScaleFilter;
import java.awt.image.ReplicateScaleFilter;
/**
* 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 1.33, 01/23/03
* @author Sami Shaio
* @author Arthur van Hoff
* @since JDK1.0
*/
public abstract class Image
{
/**
* The UndefinedProperty
object should be returned whenever a
* property which was not defined for a particular image is fetched.
*/
public static final Object UndefinedProperty = null;
/**
* Use the default image-scaling algorithm.
* @since JDK1.1
*/
public static final int SCALE_DEFAULT = 1;
/**
* Choose an image-scaling algorithm that gives higher priority
* to scaling speed than smoothness of the scaled image.
* @since JDK1.1
*/
public static final int SCALE_FAST = 2;
/**
* Choose an image-scaling algorithm that gives higher priority
* to image smoothness than scaling speed.
* @since JDK1.1
*/
public static final int SCALE_SMOOTH = 4;
/**
* 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 java.awt.image.ReplicateScaleFilter
* @since JDK1.1
*/
public static final int SCALE_REPLICATE = 8;
/**
* 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 java.awt.image.AreaAveragingScaleFilter
* @since JDK1.1
*/
public static final int SCALE_AREA_AVERAGING = 16;
/**
*/
public Image() { }
/**
* 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.
* @param observer an object waiting for the image to be loaded.
* @return the width of this image, or -1
* if the width is not yet known.
* @see java.awt.Image#getHeight
* @see java.awt.image.ImageObserver
*/
public abstract int getWidth(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.
* @param observer an object waiting for the image to be loaded.
* @return the height of this image, or -1
* if the height is not yet known.
* @see java.awt.Image#getWidth
* @see java.awt.image.ImageObserver
*/
public abstract int getHeight(ImageObserver observer);
/**
* 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.
* @return the image producer that produces the pixels
* for this image.
* @see java.awt.image.ImageProducer
*/
public abstract ImageProducer getSource();
/**
* Creates a graphics context for drawing to an off-screen image.
* This method can only be called for off-screen images.
* @return a graphics context to draw to the off-screen image.
* @see java.awt.Graphics
* @see java.awt.Component#createImage(int, int)
*/
public abstract Graphics getGraphics();
/**
* 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.
* @param name a property name.
* @param observer an object waiting for this image to be loaded.
* @return the value of the named property.
* @see java.awt.image.ImageObserver
* @see java.awt.Image#UndefinedProperty
*/
public abstract Object getProperty(String name, ImageObserver observer);
/**
* 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.
* @param width the width to which to scale the image.
* @param height the height to which to scale the image.
* @param hints flags to indicate the type of algorithm to use
* for image resampling.
* @return a scaled version of the image.
* @see java.awt.Image#SCALE_DEFAULT
* @see java.awt.Image#SCALE_FAST
* @see java.awt.Image#SCALE_SMOOTH
* @see java.awt.Image#SCALE_REPLICATE
* @see java.awt.Image#SCALE_AREA_AVERAGING
* @since JDK1.1
*/
public Image getScaledInstance(int width, int height, int hints) { return null; }
/**
* 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.
*
* This method always leaves the image in a state such that it can
* be reconstructed. This means the method applies only to cached
* or other secondary representations of images such as those that
* have been generated from an ImageProducer (read from a
* file, for example). It does nothing for off-screen images that
* have only one copy of their data.
*/
public abstract void flush();
}