Interface Composite
- All Known Implementing Classes:
AlphaComposite
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
.
- See Also:
-
Method Summary
Modifier and TypeMethodDescriptioncreateContext
(ColorModel srcColorModel, ColorModel dstColorModel, RenderingHints hints) Creates a context containing state that is used to perform the compositing operation.
-
Method Details
-
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 singleComposite
object.- Parameters:
srcColorModel
- theColorModel
of the sourcedstColorModel
- theColorModel
of the destinationhints
- the hint that the context object uses to choose between rendering alternatives- Returns:
- the
CompositeContext
object used to perform the compositing operation.
-