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Class java.awt.Image
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View: ClientSubclassPackageImplementation
java.awt

Class Image

  • java.lang.Object
    • java.awt.Image
  • public abstract class Image extends java.lang.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.
    Since:
    JDK1.0
    • Fields 
      Modifier and Type Field and Description
      Ordinary member indicator accelerationPriority Reveal DetailHide Detail
      protected float accelerationPriority
      Priority for accelerating this image.
      protected float accelerationPriority
      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
      Ordinary member indicator SCALE_AREA_AVERAGING Reveal DetailHide Detail
      static int SCALE_AREA_AVERAGING
      Use the Area Averaging image scaling algorithm.
      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, Constant Field Values
      Ordinary member indicator SCALE_DEFAULT Reveal DetailHide Detail
      static int SCALE_DEFAULT
      Use the default image-scaling algorithm.
      public static final int SCALE_DEFAULT
      Use the default image-scaling algorithm.
      Since:
      JDK1.1
      See Also:
      Constant Field Values
      Ordinary member indicator SCALE_FAST Reveal DetailHide Detail
      static int SCALE_FAST
      Choose an image-scaling algorithm that gives higher priority to scaling speed than smoothness of the scaled image.
      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
      See Also:
      Constant Field Values
      Ordinary member indicator SCALE_REPLICATE Reveal DetailHide Detail
      static int SCALE_REPLICATE
      Use the image scaling algorithm embodied in the ReplicateScaleFilter class.
      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, Constant Field Values
      Ordinary member indicator SCALE_SMOOTH Reveal DetailHide Detail
      static int SCALE_SMOOTH
      Choose an image-scaling algorithm that gives higher priority to image smoothness than scaling speed.
      public static final int SCALE_SMOOTH
      Choose an image-scaling algorithm that gives higher priority to image smoothness than scaling speed.
      Since:
      JDK1.1
      See Also:
      Constant Field Values
      Ordinary member indicator UndefinedProperty Reveal DetailHide Detail
      static java.lang.Object UndefinedProperty
      The UndefinedProperty object should be returned whenever a property which was not defined for a particular image is fetched.
      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.
    • Constructors 
      Constructor and Description
      Ordinary member indicator Image Reveal DetailHide Detail
      Image()
       
      public Image()
    • Methods 
      Modifier and Type Method and Description
      Ordinary member indicator flush Reveal DetailHide Detail
      void flush()
      Flushes all reconstructable resources being used by this Image object.
      public void flush()
      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 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.
      Ordinary member indicator getAccelerationPriority Reveal DetailHide Detail
      float getAccelerationPriority()
      Returns the current value of the acceleration priority hint.
      public float getAccelerationPriority()
      Returns the current value of the acceleration priority hint.
      Returns:
      value between 0 and 1, inclusive, which represents the current priority value
      Since:
      1.5
      See Also:
      setAccelerationPriority
      Ordinary member indicator getCapabilities Reveal DetailHide Detail
      ImageCapabilities getCapabilities(GraphicsConfiguration gc)
      Returns an ImageCapabilities object which can be inquired as to the capabilities of this Image on the specified GraphicsConfiguration.
      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. 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 null for this parameter will result in getting the image capabilities for the default GraphicsConfiguration.
      Returns:
      an ImageCapabilities object that contains the capabilities of this Image on the specified GraphicsConfiguration.
      Since:
      1.5
      See Also:
      VolatileImage.getCapabilities()
      Ordinary member indicator getGraphics Reveal DetailHide Detail
      abstract Graphics getGraphics()
      Creates a graphics context for drawing to an off-screen image.
      public abstract 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.
      Throws:
      java.lang.UnsupportedOperationException - if called for a non-off-screen image.
      See Also:
      Graphics, Component.createImage(int, int)
      Ordinary member indicator getHeight Reveal DetailHide Detail
      abstract int getHeight(java.awt.image.ImageObserver observer)
      Determines the height of the image.
      public abstract int getHeight(java.awt.image.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.
      See Also:
      getWidth(java.awt.image.ImageObserver), ImageObserver
      Ordinary member indicator getProperty Reveal DetailHide Detail
      abstract java.lang.Object getProperty(java.lang.String name, java.awt.image.ImageObserver observer)
      Gets a property of this image by name.
      public abstract java.lang.Object getProperty(java.lang.String name, java.awt.image.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.
      Throws:
      NullPointerException - if the property name is null.
      See Also:
      ImageObserver, UndefinedProperty
      Ordinary member indicator getScaledInstance Reveal DetailHide Detail
      Image getScaledInstance(int width, int height, int hints)
      Creates a scaled version of this image.
      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. 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.
      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.
      Throws:
      java.lang.IllegalArgumentException - if width or height is zero.
      Since:
      JDK1.1
      See Also:
      SCALE_DEFAULT, SCALE_FAST, SCALE_SMOOTH, SCALE_REPLICATE, SCALE_AREA_AVERAGING
      Ordinary member indicator getSource Reveal DetailHide Detail
      abstract java.awt.image.ImageProducer getSource()
      Gets the object that produces the pixels for the image.
      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
      Ordinary member indicator getWidth Reveal DetailHide Detail
      abstract int getWidth(java.awt.image.ImageObserver observer)
      Determines the width of the image.
      public abstract int getWidth(java.awt.image.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.
      See Also:
      getHeight(java.awt.image.ImageObserver), ImageObserver
      Ordinary member indicator setAccelerationPriority Reveal DetailHide Detail
      void setAccelerationPriority(float priority)
      Sets a hint for this image about how important acceleration is.
      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. 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 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.
      Throws:
      java.lang.IllegalArgumentException - if priority is less than zero or greater than 1.
      Since:
      1.5
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
This document was created by Dulcet from the OpenJDK sources. Copyright © 1993, 2012 Oracle and/or its affiliates. All rights reserved.

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