Interface Composite
- All Known Implementing Classes:
AlphaComposite
public interface Composite
The Composite
interface, along with CompositeContext
, defines the methods to compose a draw primitive with the underlying graphics area. After the Composite
is set in the Graphics2D
context, it combines a shape, text, or an image being rendered with the colors that have already been rendered according to pre-defined rules. The classes implementing this interface provide the rules and a method to create the context for a particular operation. CompositeContext
is an environment used by the compositing operation, which is created by the Graphics2D
prior to the start of the operation. CompositeContext
contains private information and resources needed for a compositing operation. When the CompositeContext
is no longer needed, the Graphics2D
object disposes of it in order to reclaim resources allocated for the operation.
Instances of classes implementing Composite
must be immutable because the Graphics2D
does not clone these objects when they are set as an attribute with the setComposite
method or when the Graphics2D
object is cloned. This is to avoid undefined rendering behavior of Graphics2D
, resulting from the modification of the Composite
object after it has been set in the Graphics2D
context.
Since this interface must expose the contents of pixels on the target device or image to potentially arbitrary code, the use of custom objects which implement this interface when rendering directly to a screen device is governed by the readDisplayPixels
AWTPermission
. The permission check will occur when such a custom object is passed to the setComposite
method of a Graphics2D
retrieved from a Component
.
Method Summary
Modifier and Type | Method | Description |
---|---|---|
CompositeContext | createContext(ColorModel srcColorModel,
ColorModel dstColorModel,
RenderingHints hints) | Creates a context containing state that is used to perform the compositing operation. |
Method Detail
createContext
CompositeContext createContext(ColorModel srcColorModel, ColorModel dstColorModel, RenderingHints hints)
Creates a context containing state that is used to perform the compositing operation. In a multi-threaded environment, several contexts can exist simultaneously for a single Composite
object.
- Parameters:
-
srcColorModel
- theColorModel
of the source -
dstColorModel
- theColorModel
of the destination -
hints
- the hint that the context object uses to choose between rendering alternatives - Returns:
- the
CompositeContext
object used to perform the compositing operation.