RenderContext (Java SE 13 & JDK 13 )
Description: declaration: module: java.desktop, package: java.awt.image.renderable, class: RenderContext
Keywords: java.awt.image.renderable.RenderContext class

Module java.desktop
Package java.awt.image.renderable

# Class RenderContext

java.lang.Object
java.awt.image.renderable.RenderContext

All Implemented Interfaces:
  `Cloneable`

    public class RenderContext
    extends Object
    implements Cloneable

A RenderContext encapsulates the information needed to produce a specific rendering from a RenderableImage. It contains the area to be rendered specified in rendering-independent terms, the resolution at which the rendering is to be performed, and hints used to control the rendering process.

Users create RenderContexts and pass them to the RenderableImage via the createRendering method. Most of the methods of RenderContexts are not meant to be used directly by applications, but by the RenderableImage and operator classes to which it is passed.

The AffineTransform parameter passed into and out of this class are cloned. The RenderingHints and Shape parameters are not necessarily cloneable and are therefore only reference copied. Altering RenderingHints or Shape instances that are in use by instances of RenderContext may have undesired side effects.

- ## Constructor Summary

  Constructors
  Constructor | Description
  --- | ---
  `RenderContext​(AffineTransform usr2dev)` | Constructs a RenderContext with a given transform.
  `RenderContext​(AffineTransform usr2dev, RenderingHints hints)` | Constructs a RenderContext with a given transform and rendering hints.
  `RenderContext​(AffineTransform usr2dev, Shape aoi)` | Constructs a RenderContext with a given transform and area of interest.
  `RenderContext​(AffineTransform usr2dev, Shape aoi, RenderingHints hints)` | Constructs a RenderContext with a given transform.

- ## Method Summary

  Modifier and Type | Method | Description
  --- | --- | ---
  `Object` | `clone()` | Makes a copy of a RenderContext.
  `void` | `concatenateTransform​(AffineTransform modTransform)` | Modifies the current user-to-device transform by appending another transform.
  `void` | `concetenateTransform​(AffineTransform modTransform)` | Deprecated. replaced by `concatenateTransform(AffineTransform)`.
  `Shape` | `getAreaOfInterest()` | Gets the ares of interest currently contained in the RenderContext.
  `RenderingHints` | `getRenderingHints()` | Gets the rendering hints of this `RenderContext`.
  `AffineTransform` | `getTransform()` | Gets the current user-to-device AffineTransform.
  `void` | `preConcatenateTransform​(AffineTransform modTransform)` | Modifies the current user-to-device transform by prepending another transform.
  `void` | `preConcetenateTransform​(AffineTransform modTransform)` | Deprecated. replaced by `preConcatenateTransform(AffineTransform)`.
  `void` | `setAreaOfInterest​(Shape newAoi)` | Sets the current area of interest.
  `void` | `setRenderingHints​(RenderingHints hints)` | Sets the rendering hints of this `RenderContext`.
  `void` | `setTransform​(AffineTransform newTransform)` | Sets the current user-to-device AffineTransform contained in the RenderContext to a given transform.

  ### Methods declared in class java.lang.Object

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

- ## Constructor Details

  - ### RenderContext

    public RenderContext​(AffineTransform usr2dev, Shape aoi, RenderingHints hints)
    Constructs a RenderContext with a given transform. The area of interest is supplied as a Shape, and the rendering hints are supplied as a RenderingHints object.
    Parameters:
      `usr2dev` - an AffineTransform.
      `aoi` - a Shape representing the area of interest.
      `hints` - a RenderingHints object containing rendering hints.

  - ### RenderContext

    public RenderContext​(AffineTransform usr2dev)
    Constructs a RenderContext with a given transform. The area of interest is taken to be the entire renderable area. No rendering hints are used.
    Parameters:
      `usr2dev` - an AffineTransform.

  - ### RenderContext

    public RenderContext​(AffineTransform usr2dev, RenderingHints hints)
    Constructs a RenderContext with a given transform and rendering hints. The area of interest is taken to be the entire renderable area.
    Parameters:
      `usr2dev` - an AffineTransform.
      `hints` - a RenderingHints object containing rendering hints.

  - ### RenderContext

    public RenderContext​(AffineTransform usr2dev, Shape aoi)
    Constructs a RenderContext with a given transform and area of interest. The area of interest is supplied as a Shape. No rendering hints are used.
    Parameters:
      `usr2dev` - an AffineTransform.
      `aoi` - a Shape representing the area of interest.

- ## Method Details

  - ### getRenderingHints

    public RenderingHints getRenderingHints()
    Gets the rendering hints of this `RenderContext`.
    Returns:
      a `RenderingHints` object that represents the rendering hints of this `RenderContext`.
    See Also:
      `setRenderingHints(RenderingHints)`

  - ### setRenderingHints

    public void setRenderingHints​(RenderingHints hints)
    Sets the rendering hints of this `RenderContext`.
    Parameters:
      `hints` - a `RenderingHints` object that represents the rendering hints to assign to this `RenderContext`.
    See Also:
      `getRenderingHints()`

  - ### setTransform

    public void setTransform​(AffineTransform newTransform)
    Sets the current user-to-device AffineTransform contained in the RenderContext to a given transform.
    Parameters:
      `newTransform` - the new AffineTransform.
    See Also:
      `getTransform()`

  - ### preConcatenateTransform

    public void preConcatenateTransform​(AffineTransform modTransform)
    Modifies the current user-to-device transform by prepending another transform. In matrix notation the operation is:

         [this] = [modTransform] x [this]

    Parameters:
      `modTransform` - the AffineTransform to prepend to the current usr2dev transform.
    Since:
      1.3

  - ### preConcetenateTransform

    @Deprecated public void preConcetenateTransform​(AffineTransform modTransform)
    Deprecated.
    replaced by `preConcatenateTransform(AffineTransform)`.
    Modifies the current user-to-device transform by prepending another transform. In matrix notation the operation is:

         [this] = [modTransform] x [this]

    This method does the same thing as the preConcatenateTransform method. It is here for backward compatibility with previous releases which misspelled the method name.
    Parameters:
      `modTransform` - the AffineTransform to prepend to the current usr2dev transform.

  - ### concatenateTransform

    public void concatenateTransform​(AffineTransform modTransform)
    Modifies the current user-to-device transform by appending another transform. In matrix notation the operation is:

         [this] = [this] x [modTransform]

    Parameters:
      `modTransform` - the AffineTransform to append to the current usr2dev transform.
    Since:
      1.3

  - ### concetenateTransform

    @Deprecated public void concetenateTransform​(AffineTransform modTransform)
    Deprecated.
    replaced by `concatenateTransform(AffineTransform)`.
    Modifies the current user-to-device transform by appending another transform. In matrix notation the operation is:

         [this] = [this] x [modTransform]

    This method does the same thing as the concatenateTransform method. It is here for backward compatibility with previous releases which misspelled the method name.
    Parameters:
      `modTransform` - the AffineTransform to append to the current usr2dev transform.

  - ### getTransform

    public AffineTransform getTransform()
    Gets the current user-to-device AffineTransform.
    Returns:
      a reference to the current AffineTransform.
    See Also:
      `setTransform(AffineTransform)`

  - ### setAreaOfInterest

    public void setAreaOfInterest​(Shape newAoi)
    Sets the current area of interest. The old area is discarded.
    Parameters:
      `newAoi` - The new area of interest.
    See Also:
      `getAreaOfInterest()`

  - ### getAreaOfInterest

    public Shape getAreaOfInterest()
    Gets the ares of interest currently contained in the RenderContext.
    Returns:
      a reference to the area of interest of the RenderContext, or null if none is specified.
    See Also:
      `setAreaOfInterest(Shape)`

  - ### clone

    public Object clone()
    Makes a copy of a RenderContext. The area of interest is copied by reference. The usr2dev AffineTransform and hints are cloned, while the area of interest is copied by reference.
    Overrides:
      `clone` in class `Object`
    Returns:
      the new cloned RenderContext.
    See Also:
      `Cloneable`