META-INF.modules.java.desktop.classes.java.awt.Composite Maven / Gradle / Ivy
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package java.awt;
import java.awt.image.ColorModel;
/**
* The {@code Composite} interface, along with
* {@link CompositeContext}, defines the methods to compose a draw
* primitive with the underlying graphics area.
* After the {@code Composite} is set in the
* {@link 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.
* {@code CompositeContext} is an environment used by the
* compositing operation, which is created by the {@code Graphics2D}
* prior to the start of the operation. {@code CompositeContext}
* contains private information and resources needed for a compositing
* operation. When the {@code CompositeContext} is no longer needed,
* the {@code Graphics2D} object disposes of it in order to reclaim
* resources allocated for the operation.
*
* Instances of classes implementing {@code Composite} must be
* immutable because the {@code Graphics2D} does not clone
* these objects when they are set as an attribute with the
* {@code setComposite} method or when the {@code Graphics2D}
* object is cloned. This is to avoid undefined rendering behavior of
* {@code Graphics2D}, resulting from the modification of
* the {@code Composite} object after it has been set in the
* {@code 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 {@code readDisplayPixels}
* {@link AWTPermission}. The permission check will occur when such
* a custom object is passed to the {@code setComposite} method
* of a {@code Graphics2D} retrieved from a {@link Component}.
* @see AlphaComposite
* @see CompositeContext
* @see Graphics2D#setComposite
*/
public interface Composite {
/**
* 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
* {@code Composite} object.
* @param srcColorModel the {@link ColorModel} of the source
* @param dstColorModel the {@code ColorModel} of the destination
* @param hints the hint that the context object uses to choose between
* rendering alternatives
* @return the {@code CompositeContext} object used to perform the
* compositing operation.
*/
public CompositeContext createContext(ColorModel srcColorModel,
ColorModel dstColorModel,
RenderingHints hints);
}