Class WritableImage

java.lang.Object

javafx.scene.image.Image

javafx.scene.image.WritableImage

public class WritableImage
extends Image

The WritableImage class represents a custom graphical image that is constructed from pixels supplied by the application, and possibly from PixelReader objects from any number of sources, including images read from a file or URL.

Since:

JavaFX 2.2

Property Summary

Properties declared in class javafx.scene.image.Image

error, exception, height, progress, width

Constructor Summary

Constructors

Constructor	Description
WritableImage(int width, int height)	Constructs an empty image of the specified dimensions.
WritableImage(PixelBuffer<? extends Buffer> pixelBuffer)	Constructs a WritableImage using the specified PixelBuffer.
WritableImage(PixelReader reader, int width, int height)	Constructs an image of the specified dimensions, initialized from the indicated PixelReader.
WritableImage(PixelReader reader, int x, int y, int width, int height)	Constructs an image of the specified dimensions, initialized from the indicated region of the PixelReader.

Method Summary

Modifier and Type	Method	Description
final PixelWriter	getPixelWriter()	This method returns a PixelWriter that provides access to write the pixels of the image.

Methods declared in class javafx.scene.image.Image

cancel, errorProperty, exceptionProperty, getException, getHeight, getPixelReader, getProgress, getRequestedHeight, getRequestedWidth, getUrl, getWidth, heightProperty, isBackgroundLoading, isError, isPreserveRatio, isSmooth, progressProperty, widthProperty

Methods declared in class java.lang.Object

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

Constructor Details

WritableImage

public WritableImage(int width,
 int height)

Constructs an empty image of the specified dimensions. The image will initially be filled with transparent pixels. Images constructed this way will always be readable and writable so the corresponding getPixelReader() and getPixelWriter() will always return valid objects. The dimensions must both be positive numbers (> 0).

Parameters:

width - the desired width of the writable image

height - the desired height of the desired image

Throws:

IllegalArgumentException - if either dimension is negative or zero.

WritableImage

public WritableImage(PixelBuffer<? extends Buffer> pixelBuffer)

Constructs a WritableImage using the specified PixelBuffer. The Buffer provided by the PixelBuffer will be used directly as the pixel data for this image. The PixelBuffer can be shared by multiple WritableImages. Images constructed this way are readable using Image.getPixelReader(), but are not writable using WritableImage.getPixelWriter().

Parameters:

pixelBuffer - the PixelBuffer used to construct this image

Throws:

NullPointerException - if pixelBuffer is null

Since:

13

WritableImage

public WritableImage(PixelReader reader,
 int width,
 int height)

Constructs an image of the specified dimensions, initialized from the indicated PixelReader. The image will initially be filled with data returned from the PixelReader. If the PixelReader accesses a surface that does not contain the necessary number of pixel rows and columns then an ArrayIndexOutOfBoundsException will be thrown. Images constructed this way will always be readable and writable so the corresponding getPixelReader() and getPixelWriter() will always return valid objects. The dimensions must both be positive numbers (> 0).

Parameters:

reader - the PixelReader to construct from

width - the desired width of the writable image and the width of the region to be read from the reader

height - the desired height of the desired image and the width of the region to be read from the reader

Throws:

ArrayIndexOutOfBoundsException - if the reader does not access a surface of at least the requested dimensions

IllegalArgumentException - if either dimension is negative or zero.

WritableImage

public WritableImage(PixelReader reader,
 int x,
 int y,
 int width,
 int height)

Constructs an image of the specified dimensions, initialized from the indicated region of the PixelReader. The image will initially be filled with data returned from the PixelReader for the specified region. If the PixelReader accesses a surface that does not contain the necessary number of pixel rows and columns then an ArrayIndexOutOfBoundsException will be thrown. Images constructed this way will always be readable and writable so the corresponding getPixelReader() and getPixelWriter() will always return valid objects. The dimensions must both be positive numbers (> 0).

Parameters:

reader - the PixelReader to construct from

x - the X coordinate of the upper left corner of the region to read from the reader

y - the Y coordinate of the upper left corner of the region to read from the reader

width - the desired width of the writable image and the width of the region to be read from the reader

height - the desired height of the desired image and the width of the region to be read from the reader

Throws:

ArrayIndexOutOfBoundsException - if the reader does not access a surface containing at least the indicated region

IllegalArgumentException - if either dimension is negative or zero.

Method Details

getPixelWriter

public final PixelWriter getPixelWriter()

This method returns a PixelWriter that provides access to write the pixels of the image. This method is not supported for images constructed using a PixelBuffer.

Returns:

the PixelWriter for writing pixels to the image

Throws:

UnsupportedOperationException - if this image was created using a PixelBuffer