gnu.java.awt.peer.gtk

Class GtkVolatileImage

Implemented Interfaces:
Transparency

public class GtkVolatileImage
extends VolatileImage

Field Summary

Fields inherited from class java.awt.image.VolatileImage

IMAGE_INCOMPATIBLE, IMAGE_OK, IMAGE_RESTORED, transparency

Fields inherited from class java.awt.Image

SCALE_AREA_AVERAGING, SCALE_DEFAULT, SCALE_FAST, SCALE_REPLICATE, SCALE_SMOOTH, UndefinedProperty, accelerationPriority

Fields inherited from interface java.awt.Transparency

BITMASK, OPAQUE, TRANSLUCENT

Constructor Summary

GtkVolatileImage(GtkComponentPeer component, int width, int height, ImageCapabilities caps)
GtkVolatileImage(int width, int height)
GtkVolatileImage(int width, int height, ImageCapabilities caps)

Method Summary

boolean
contentsLost()
Returns true if the contents of the image buffer have been damaged or if the image buffer's resources have been reclaimed by the graphics system.
void
copyArea(int x, int y, int w, int h, int dx, int dy)
Graphics2D
createGraphics()
Returns a Graphics2D object that can be used to draw onto this image.
void
dispose()
void
drawVolatile(long srcPtr, int x, int y, int w, int h)
void
finalize()
Called on an object by the Virtual Machine at most once, at some point after the Object is determined unreachable but before it is destroyed.
ImageCapabilities
getCapabilities()
Returns the capabilities of this image buffer.
Graphics
getGraphics()
Returns a Graphics2D object that can be used to draw onto this image.
int
getHeight()
Returns the height of this image buffer.
int
getHeight(ImageObserver observer)
Returns the height of the image, or -1 if it is unknown.
int[]
getPixels()
Object
getProperty(String name, ImageObserver observer)
This method requests a named property for an object.
BufferedImage
getSnapshot()
Returns an image representing the current state of the volatile image buffer.
int
getWidth()
Returns the width of this image buffer.
int
getWidth(ImageObserver observer)
Returns the width of the image, or -1 if it is unknown.
int
validate(GraphicsConfiguration gc)
Validates and restores this image.

Methods inherited from class java.awt.image.VolatileImage

contentsLost, createGraphics, flush, getCapabilities, getGraphics, getHeight, getSnapshot, getSource, getTransparency, getWidth, validate

Methods inherited from class java.awt.Image

flush, getAccelerationPriority, getGraphics, getHeight, getProperty, getScaledInstance, getSource, getWidth, setAccelerationPriority

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

GtkVolatileImage

public GtkVolatileImage(GtkComponentPeer component,
                        int width,
                        int height,
                        ImageCapabilities caps)

GtkVolatileImage

public GtkVolatileImage(int width,
                        int height)

GtkVolatileImage

public GtkVolatileImage(int width,
                        int height,
                        ImageCapabilities caps)

Method Details

contentsLost

public boolean contentsLost()
Returns true if the contents of the image buffer have been damaged or if the image buffer's resources have been reclaimed by the graphics system. You should call this method after a series of rendering operations to or from the image, to see if the image buffer needs to be revalidated or the image re-rendered.
Overrides:
contentsLost in interface VolatileImage
Returns:
true if the validate should be called, false otherwise

copyArea

public void copyArea(int x,
                     int y,
                     int w,
                     int h,
                     int dx,
                     int dy)

createGraphics

public Graphics2D createGraphics()
Returns a Graphics2D object that can be used to draw onto this image.
Overrides:
createGraphics in interface VolatileImage
Returns:
a Graphics2D object that can be used to draw onto this image

dispose

public void dispose()

drawVolatile

public void drawVolatile(long srcPtr,
                         int x,
                         int y,
                         int w,
                         int h)

finalize

public void finalize()
Called on an object by the Virtual Machine at most once, at some point after the Object is determined unreachable but before it is destroyed. You would think that this means it eventually is called on every Object, but this is not necessarily the case. If execution terminates abnormally, garbage collection does not always happen. Thus you cannot rely on this method to always work. For finer control over garbage collection, use references from the java.lang.ref package.

Virtual Machines are free to not call this method if they can determine that it does nothing important; for example, if your class extends Object and overrides finalize to do simply super.finalize().

finalize() will be called by a Thread that has no locks on any Objects, and may be called concurrently. There are no guarantees on the order in which multiple objects are finalized. This means that finalize() is usually unsuited for performing actions that must be thread-safe, and that your implementation must be use defensive programming if it is to always work.

If an Exception is thrown from finalize() during garbage collection, it will be patently ignored and the Object will still be destroyed.

It is allowed, although not typical, for user code to call finalize() directly. User invocation does not affect whether automatic invocation will occur. It is also permitted, although not recommended, for a finalize() method to "revive" an object by making it reachable from normal code again.

Unlike constructors, finalize() does not get called for an object's superclass unless the implementation specifically calls super.finalize().

The default implementation does nothing.

Overrides:
finalize in interface Object

getCapabilities

public ImageCapabilities getCapabilities()
Returns the capabilities of this image buffer.
Overrides:
getCapabilities in interface VolatileImage
Returns:
the capabilities of this image buffer

getGraphics

public Graphics getGraphics()
Returns a Graphics2D object that can be used to draw onto this image. This method is present for backwards-compatibility. It simply returns the result of createGraphics.
Overrides:
getGraphics in interface VolatileImage
Returns:
a Graphics2D object that can be used to draw onto this image

getHeight

public int getHeight()
Returns the height of this image buffer.
Overrides:
getHeight in interface VolatileImage
Returns:
the height of this VolatileImage

getHeight

public int getHeight(ImageObserver observer)
Returns the height of the image, or -1 if it is unknown. If the image height is unknown, the observer object will be notified when the value is known.
Overrides:
getHeight in interface Image
Parameters:
observer - the image observer for this object
Returns:
the height in pixels

getPixels

public int[] getPixels()

getProperty

public Object getProperty(String name,
                          ImageObserver observer)
This method requests a named property for an object. The value of the property is returned. The value UndefinedProperty is returned if there is no property with the specified name. The value null is returned if the properties for the object are not yet known. In this case, the specified image observer is notified when the properties are known.
Overrides:
getProperty in interface Image
Parameters:
name - the requested property name
observer - the image observer for this object
Returns:
the named property, if available

getSnapshot

public BufferedImage getSnapshot()
Returns an image representing the current state of the volatile image buffer. The returned image is static meaning that it is not updated after being created. It is a snapshot of the volatile image buffer at the time getSnapshot is called. This method, which reads pixels from the volatile image buffer, may be less-performant than methods that write pixels since VolatileImages are typically optimized for writing.
Overrides:
getSnapshot in interface VolatileImage
Returns:
a BufferedImage representing this VolatileImage

getWidth

public int getWidth()
Returns the width of this image buffer.
Overrides:
getWidth in interface VolatileImage
Returns:
the width of this VolatileImage

getWidth

public int getWidth(ImageObserver observer)
Returns the width of the image, or -1 if it is unknown. If the image width is unknown, the observer object will be notified when the value is known.
Overrides:
getWidth in interface Image
Parameters:
observer - the image observer for this object
Returns:
the width in pixels

validate

public int validate(GraphicsConfiguration gc)
Validates and restores this image. If the image buffer has become unavailable for further use since the last call to validate, validate will allocate a new image buffer. The image is also "validated" against the GraphicsConfiguration parameter. "Validating" the image means checking that the capabilities it requires of the output device are indeed supported by the given output device. If the image's characteristics, which can be highly output device-specific, are not supported by the graphics configuration, then IMAGE_INCOMPATIBLE will be returned. This can happen, for example, if this image was created on one output device, then validated against a different output device with different capabilities. Calling validate with a NULL gc argument causes validate to skip the validation test.
Overrides:
validate in interface VolatileImage
Parameters:
gc - graphics configuration against which to validate or NULL
Returns:
a code indicating the result of validation. One of:
  • IMAGE_OK if the image did not need to be validated and didn't need to be restored
  • IMAGE_RESTORED if the image may need to be re-rendered.
  • IMAGE_INCOMPATIBLE if this image's requirements are not fulfilled by the graphics configuration parameter. This implies that you need to create a new VolatileImage for the different GraphicsConfiguration or Component. This return value implies nothing about whether the image is valid or needs to be re-rendered.

GtkVolatileImage.java -- wraps an X pixmap Copyright (C) 2005 Free Software Foundation, Inc. This file is part of GNU Classpath. GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNU Classpath is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNU Classpath; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version.