ParameterBlock (Java SE 22 & JDK 22)
Description: declaration: module: java.desktop, package: java.awt.image.renderable, class: ParameterBlock
Keywords: java.awt.image.renderable.ParameterBlock class

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

# Class ParameterBlock

java.lang.Object
java.awt.image.renderable.ParameterBlock

All Implemented Interfaces:
  `Serializable`, `Cloneable`

public class ParameterBlock extends Object implements Cloneable, Serializable
A `ParameterBlock` encapsulates all the information about sources and parameters (Objects) required by a RenderableImageOp, or other classes that process images.

Although it is possible to place arbitrary objects in the source Vector, users of this class may impose semantic constraints such as requiring all sources to be RenderedImages or RenderableImage. `ParameterBlock` itself is merely a container and performs no checking on source or parameter types.

All parameters in a `ParameterBlock` are objects; convenience add and set methods are available that take arguments of base type and construct the appropriate subclass of Number (such as Integer or Float). Corresponding get methods perform a downward cast and have return values of base type; an exception will be thrown if the stored values do not have the correct type. There is no way to distinguish between the results of "short s; add(s)" and "add(Short.valueOf(s))".

Note that the get and set methods operate on references. Therefore, one must be careful not to share references between `ParameterBlock`s when this is inappropriate. For example, to create a new `ParameterBlock` that is equal to an old one except for an added source, one might be tempted to write:

     ParameterBlock addSource(ParameterBlock pb, RenderableImage im) {
         ParameterBlock pb1 = new ParameterBlock(pb.getSources());
         pb1.addSource(im);
         return pb1;
     }

This code will have the side effect of altering the original `ParameterBlock`, since the getSources operation returned a reference to its source Vector. Both pb and pb1 share their source Vector, and a change in either is visible to both.

A correct way to write the addSource function is to clone the source Vector:

     ParameterBlock addSource (ParameterBlock pb, RenderableImage im) {
         ParameterBlock pb1 = new ParameterBlock(pb.getSources().clone());
         pb1.addSource(im);
         return pb1;
     }

The clone method of `ParameterBlock` has been defined to perform a clone of both the source and parameter Vectors for this reason. A standard, shallow clone is available as shallowClone.

The addSource, setSource, add, and set methods are defined to return 'this' after adding their argument. This allows use of syntax like:

     ParameterBlock pb = new ParameterBlock();
     op = new RenderableImageOp("operation", pb.add(arg1).add(arg2));

See Also:
  - Serialized Form

- ## Field Summary

  Fields
  Modifier and Type
  Field
  Description
  `protected Vector<Object>`
  `parameters`
  A Vector of non-source parameters, stored as arbitrary Objects.
  `protected Vector<Object>`
  `sources`
  A Vector of sources, stored as arbitrary Objects.

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `ParameterBlock()`
  A dummy constructor.
  `ParameterBlock(Vector<Object> sources)`
  Constructs a `ParameterBlock` with a given Vector of sources.
  `ParameterBlock(Vector<Object> sources, Vector<Object> parameters)`
  Constructs a `ParameterBlock` with a given Vector of sources and Vector of parameters.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `ParameterBlock`
  `add(byte b)`
  Adds a Byte to the list of parameters.
  `ParameterBlock`
  `add(char c)`
  Adds a Character to the list of parameters.
  `ParameterBlock`
  `add(double d)`
  Adds a Double to the list of parameters.
  `ParameterBlock`
  `add(float f)`
  Adds a Float to the list of parameters.
  `ParameterBlock`
  `add(int i)`
  Adds a Integer to the list of parameters.
  `ParameterBlock`
  `add(long l)`
  Adds a Long to the list of parameters.
  `ParameterBlock`
  `add(short s)`
  Adds a Short to the list of parameters.
  `ParameterBlock`
  `add(Object obj)`
  Adds an object to the list of parameters.
  `ParameterBlock`
  `addSource(Object source)`
  Adds an image to end of the list of sources.
  `Object`
  `clone()`
  Creates a copy of a `ParameterBlock`.
  `byte`
  `getByteParameter(int index)`
  A convenience method to return a parameter as a byte.
  `char`
  `getCharParameter(int index)`
  A convenience method to return a parameter as a char.
  `double`
  `getDoubleParameter(int index)`
  A convenience method to return a parameter as a double.
  `float`
  `getFloatParameter(int index)`
  A convenience method to return a parameter as a float.
  `int`
  `getIntParameter(int index)`
  A convenience method to return a parameter as an int.
  `long`
  `getLongParameter(int index)`
  A convenience method to return a parameter as a long.
  `int`
  `getNumParameters()`
  Returns the number of parameters (not including source images).
  `int`
  `getNumSources()`
  Returns the number of source images.
  `Object`
  `getObjectParameter(int index)`
  Gets a parameter as an object.
  `Class<?>[]`
  `getParamClasses()`
  Returns an array of Class objects describing the types of the parameters.
  `Vector<Object>`
  `getParameters()`
  Returns the entire Vector of parameters.
  `RenderableImage`
  `getRenderableSource(int index)`
  Returns a source as a RenderableImage.
  `RenderedImage`
  `getRenderedSource(int index)`
  Returns a source as a `RenderedImage`.
  `short`
  `getShortParameter(int index)`
  A convenience method to return a parameter as a short.
  `Object`
  `getSource(int index)`
  Returns a source as a general Object.
  `Vector<Object>`
  `getSources()`
  Returns the entire Vector of sources.
  `void`
  `removeParameters()`
  Clears the list of parameters.
  `void`
  `removeSources()`
  Clears the list of source images.
  `ParameterBlock`
  `set(byte b, int index)`
  Replaces an Object in the list of parameters with a Byte.
  `ParameterBlock`
  `set(char c, int index)`
  Replaces an Object in the list of parameters with a Character.
  `ParameterBlock`
  `set(double d, int index)`
  Replaces an Object in the list of parameters with a Double.
  `ParameterBlock`
  `set(float f, int index)`
  Replaces an Object in the list of parameters with a Float.
  `ParameterBlock`
  `set(int i, int index)`
  Replaces an Object in the list of parameters with an Integer.
  `ParameterBlock`
  `set(long l, int index)`
  Replaces an Object in the list of parameters with a Long.
  `ParameterBlock`
  `set(short s, int index)`
  Replaces an Object in the list of parameters with a Short.
  `ParameterBlock`
  `set(Object obj, int index)`
  Replaces an Object in the list of parameters.
  `void`
  `setParameters(Vector<Object> parameters)`
  Sets the entire Vector of parameters to a given Vector.
  `ParameterBlock`
  `setSource(Object source, int index)`
  Replaces an entry in the list of source with a new source.
  `void`
  `setSources(Vector<Object> sources)`
  Sets the entire Vector of sources to a given Vector.
  `Object`
  `shallowClone()`
  Creates a shallow copy of a `ParameterBlock`.

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

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

- ## Field Details

  - ### sources

    protected Vector<Object> sources
    A Vector of sources, stored as arbitrary Objects.

  - ### parameters

    protected Vector<Object> parameters
    A Vector of non-source parameters, stored as arbitrary Objects.

- ## Constructor Details

  - ### ParameterBlock

    public ParameterBlock()
    A dummy constructor.

  - ### ParameterBlock

    public ParameterBlock(Vector<Object> sources)
    Constructs a `ParameterBlock` with a given Vector of sources.
    Parameters:
      `sources` - a `Vector` of source images

  - ### ParameterBlock

    public ParameterBlock(Vector<Object> sources, Vector<Object> parameters)
    Constructs a `ParameterBlock` with a given Vector of sources and Vector of parameters.
    Parameters:
      `sources` - a `Vector` of source images
      `parameters` - a `Vector` of parameters to be used in the rendering operation

- ## Method Details

  - ### shallowClone

    public Object shallowClone()
    Creates a shallow copy of a `ParameterBlock`. The source and parameter Vectors are copied by reference -- additions or changes will be visible to both versions.
    Returns:
      an Object clone of the `ParameterBlock`.

  - ### clone

    public Object clone()
    Creates a copy of a `ParameterBlock`. The source and parameter Vectors are cloned, but the actual sources and parameters are copied by reference. This allows modifications to the order and number of sources and parameters in the clone to be invisible to the original `ParameterBlock`. Changes to the shared sources or parameters themselves will still be visible.
    Overrides:
      `clone` in class `Object`
    Returns:
      an Object clone of the `ParameterBlock`.
    See Also:
      - `Cloneable`

  - ### addSource

    public ParameterBlock addSource(Object source)
    Adds an image to end of the list of sources. The image is stored as an object in order to allow new node types in the future.
    Parameters:
      `source` - an image object to be stored in the source list.
    Returns:
      a new `ParameterBlock` containing the specified `source`.

  - ### getSource

    public Object getSource(int index)
    Returns a source as a general Object. The caller must cast it into an appropriate type.
    Parameters:
      `index` - the index of the source to be returned.
    Returns:
      an `Object` that represents the source located at the specified index in the `sources` `Vector`.
    See Also:
      - `setSource(Object, int)`

  - ### setSource

    public ParameterBlock setSource(Object source, int index)
    Replaces an entry in the list of source with a new source. If the index lies beyond the current source list, the list is extended with nulls as needed.
    Parameters:
      `source` - the specified source image
      `index` - the index into the `sources` `Vector` at which to insert the specified `source`
    Returns:
      a new `ParameterBlock` that contains the specified `source` at the specified `index`.
    See Also:
      - `getSource(int)`

  - ### getRenderedSource

    public RenderedImage getRenderedSource(int index)
    Returns a source as a `RenderedImage`. This method is a convenience method. An exception will be thrown if the source is not a RenderedImage.
    Parameters:
      `index` - the index of the source to be returned
    Returns:
      a `RenderedImage` that represents the source image that is at the specified index in the `sources Vector`.

  - ### getRenderableSource

    public RenderableImage getRenderableSource(int index)
    Returns a source as a RenderableImage. This method is a convenience method. An exception will be thrown if the sources is not a RenderableImage.
    Parameters:
      `index` - the index of the source to be returned
    Returns:
      a `RenderableImage` that represents the source image that is at the specified index in the `sources Vector`.

  - ### getNumSources

    public int getNumSources()
    Returns the number of source images.
    Returns:
      the number of source images in the `sources` `Vector`.

  - ### getSources

    public Vector<Object> getSources()
    Returns the entire Vector of sources.
    Returns:
      the `sources Vector`.
    See Also:
      - `setSources(Vector)`

  - ### setSources

    public void setSources(Vector<Object> sources)
    Sets the entire Vector of sources to a given Vector.
    Parameters:
      `sources` - the `Vector` of source images
    See Also:
      - `getSources()`

  - ### removeSources

    public void removeSources()
    Clears the list of source images.

  - ### getNumParameters

    public int getNumParameters()
    Returns the number of parameters (not including source images).
    Returns:
      the number of parameters in the `parameters` `Vector`.

  - ### getParameters

    public Vector<Object> getParameters()
    Returns the entire Vector of parameters.
    Returns:
      the `parameters Vector`.
    See Also:
      - `setParameters(Vector)`

  - ### setParameters

    public void setParameters(Vector<Object> parameters)
    Sets the entire Vector of parameters to a given Vector.
    Parameters:
      `parameters` - the specified `Vector` of parameters
    See Also:
      - `getParameters()`

  - ### removeParameters

    public void removeParameters()
    Clears the list of parameters.

  - ### add

    public ParameterBlock add(Object obj)
    Adds an object to the list of parameters.
    Parameters:
      `obj` - the `Object` to add to the `parameters Vector`
    Returns:
      a new `ParameterBlock` containing the specified parameter.

  - ### add

    public ParameterBlock add(byte b)
    Adds a Byte to the list of parameters.
    Parameters:
      `b` - the byte to add to the `parameters Vector`
    Returns:
      a new `ParameterBlock` containing the specified parameter.

  - ### add

    public ParameterBlock add(char c)
    Adds a Character to the list of parameters.
    Parameters:
      `c` - the char to add to the `parameters Vector`
    Returns:
      a new `ParameterBlock` containing the specified parameter.

  - ### add

    public ParameterBlock add(short s)
    Adds a Short to the list of parameters.
    Parameters:
      `s` - the short to add to the `parameters Vector`
    Returns:
      a new `ParameterBlock` containing the specified parameter.

  - ### add

    public ParameterBlock add(int i)
    Adds a Integer to the list of parameters.
    Parameters:
      `i` - the int to add to the `parameters Vector`
    Returns:
      a new `ParameterBlock` containing the specified parameter.

  - ### add

    public ParameterBlock add(long l)
    Adds a Long to the list of parameters.
    Parameters:
      `l` - the long to add to the `parameters Vector`
    Returns:
      a new `ParameterBlock` containing the specified parameter.

  - ### add

    public ParameterBlock add(float f)
    Adds a Float to the list of parameters.
    Parameters:
      `f` - the float to add to the `parameters Vector`
    Returns:
      a new `ParameterBlock` containing the specified parameter.

  - ### add

    public ParameterBlock add(double d)
    Adds a Double to the list of parameters.
    Parameters:
      `d` - the double to add to the `parameters Vector`
    Returns:
      a new `ParameterBlock` containing the specified parameter.

  - ### set

    public ParameterBlock set(Object obj, int index)
    Replaces an Object in the list of parameters. If the index lies beyond the current source list, the list is extended with nulls as needed.
    Parameters:
      `obj` - the parameter that replaces the parameter at the specified index in the `parameters Vector`
      `index` - the index of the parameter to be replaced with the specified parameter
    Returns:
      a new `ParameterBlock` containing the specified parameter.

  - ### set

    public ParameterBlock set(byte b, int index)
    Replaces an Object in the list of parameters with a Byte. If the index lies beyond the current source list, the list is extended with nulls as needed.
    Parameters:
      `b` - the parameter that replaces the parameter at the specified index in the `parameters Vector`
      `index` - the index of the parameter to be replaced with the specified parameter
    Returns:
      a new `ParameterBlock` containing the specified parameter.

  - ### set

    public ParameterBlock set(char c, int index)
    Replaces an Object in the list of parameters with a Character. If the index lies beyond the current source list, the list is extended with nulls as needed.
    Parameters:
      `c` - the parameter that replaces the parameter at the specified index in the `parameters Vector`
      `index` - the index of the parameter to be replaced with the specified parameter
    Returns:
      a new `ParameterBlock` containing the specified parameter.

  - ### set

    public ParameterBlock set(short s, int index)
    Replaces an Object in the list of parameters with a Short. If the index lies beyond the current source list, the list is extended with nulls as needed.
    Parameters:
      `s` - the parameter that replaces the parameter at the specified index in the `parameters Vector`
      `index` - the index of the parameter to be replaced with the specified parameter
    Returns:
      a new `ParameterBlock` containing the specified parameter.

  - ### set

    public ParameterBlock set(int i, int index)
    Replaces an Object in the list of parameters with an Integer. If the index lies beyond the current source list, the list is extended with nulls as needed.
    Parameters:
      `i` - the parameter that replaces the parameter at the specified index in the `parameters Vector`
      `index` - the index of the parameter to be replaced with the specified parameter
    Returns:
      a new `ParameterBlock` containing the specified parameter.

  - ### set

    public ParameterBlock set(long l, int index)
    Replaces an Object in the list of parameters with a Long. If the index lies beyond the current source list, the list is extended with nulls as needed.
    Parameters:
      `l` - the parameter that replaces the parameter at the specified index in the `parameters Vector`
      `index` - the index of the parameter to be replaced with the specified parameter
    Returns:
      a new `ParameterBlock` containing the specified parameter.

  - ### set

    public ParameterBlock set(float f, int index)
    Replaces an Object in the list of parameters with a Float. If the index lies beyond the current source list, the list is extended with nulls as needed.
    Parameters:
      `f` - the parameter that replaces the parameter at the specified index in the `parameters Vector`
      `index` - the index of the parameter to be replaced with the specified parameter
    Returns:
      a new `ParameterBlock` containing the specified parameter.

  - ### set

    public ParameterBlock set(double d, int index)
    Replaces an Object in the list of parameters with a Double. If the index lies beyond the current source list, the list is extended with nulls as needed.
    Parameters:
      `d` - the parameter that replaces the parameter at the specified index in the `parameters Vector`
      `index` - the index of the parameter to be replaced with the specified parameter
    Returns:
      a new `ParameterBlock` containing the specified parameter.

  - ### getObjectParameter

    public Object getObjectParameter(int index)
    Gets a parameter as an object.
    Parameters:
      `index` - the index of the parameter to get
    Returns:
      an `Object` representing the the parameter at the specified index into the `parameters` `Vector`.

  - ### getByteParameter

    public byte getByteParameter(int index)
    A convenience method to return a parameter as a byte. An exception is thrown if the parameter is `null` or not a `Byte`.
    Parameters:
      `index` - the index of the parameter to be returned.
    Returns:
      the parameter at the specified index as a `byte` value.
    Throws:
      `ClassCastException` - if the parameter at the specified index is not a `Byte`
      `NullPointerException` - if the parameter at the specified index is `null`
      `ArrayIndexOutOfBoundsException` - if `index` is negative or not less than the current size of this `ParameterBlock` object

  - ### getCharParameter

    public char getCharParameter(int index)
    A convenience method to return a parameter as a char. An exception is thrown if the parameter is `null` or not a `Character`.
    Parameters:
      `index` - the index of the parameter to be returned.
    Returns:
      the parameter at the specified index as a `char` value.
    Throws:
      `ClassCastException` - if the parameter at the specified index is not a `Character`
      `NullPointerException` - if the parameter at the specified index is `null`
      `ArrayIndexOutOfBoundsException` - if `index` is negative or not less than the current size of this `ParameterBlock` object

  - ### getShortParameter

    public short getShortParameter(int index)
    A convenience method to return a parameter as a short. An exception is thrown if the parameter is `null` or not a `Short`.
    Parameters:
      `index` - the index of the parameter to be returned.
    Returns:
      the parameter at the specified index as a `short` value.
    Throws:
      `ClassCastException` - if the parameter at the specified index is not a `Short`
      `NullPointerException` - if the parameter at the specified index is `null`
      `ArrayIndexOutOfBoundsException` - if `index` is negative or not less than the current size of this `ParameterBlock` object

  - ### getIntParameter

    public int getIntParameter(int index)
    A convenience method to return a parameter as an int. An exception is thrown if the parameter is `null` or not an `Integer`.
    Parameters:
      `index` - the index of the parameter to be returned.
    Returns:
      the parameter at the specified index as an `int` value.
    Throws:
      `ClassCastException` - if the parameter at the specified index is not an `Integer`
      `NullPointerException` - if the parameter at the specified index is `null`
      `ArrayIndexOutOfBoundsException` - if `index` is negative or not less than the current size of this `ParameterBlock` object

  - ### getLongParameter

    public long getLongParameter(int index)
    A convenience method to return a parameter as a long. An exception is thrown if the parameter is `null` or not a `Long`.
    Parameters:
      `index` - the index of the parameter to be returned.
    Returns:
      the parameter at the specified index as a `long` value.
    Throws:
      `ClassCastException` - if the parameter at the specified index is not a `Long`
      `NullPointerException` - if the parameter at the specified index is `null`
      `ArrayIndexOutOfBoundsException` - if `index` is negative or not less than the current size of this `ParameterBlock` object

  - ### getFloatParameter

    public float getFloatParameter(int index)
    A convenience method to return a parameter as a float. An exception is thrown if the parameter is `null` or not a `Float`.
    Parameters:
      `index` - the index of the parameter to be returned.
    Returns:
      the parameter at the specified index as a `float` value.
    Throws:
      `ClassCastException` - if the parameter at the specified index is not a `Float`
      `NullPointerException` - if the parameter at the specified index is `null`
      `ArrayIndexOutOfBoundsException` - if `index` is negative or not less than the current size of this `ParameterBlock` object

  - ### getDoubleParameter

    public double getDoubleParameter(int index)
    A convenience method to return a parameter as a double. An exception is thrown if the parameter is `null` or not a `Double`.
    Parameters:
      `index` - the index of the parameter to be returned.
    Returns:
      the parameter at the specified index as a `double` value.
    Throws:
      `ClassCastException` - if the parameter at the specified index is not a `Double`
      `NullPointerException` - if the parameter at the specified index is `null`
      `ArrayIndexOutOfBoundsException` - if `index` is negative or not less than the current size of this `ParameterBlock` object

  - ### getParamClasses

    public Class<?>[] getParamClasses()
    Returns an array of Class objects describing the types of the parameters.
    Returns:
      an array of `Class` objects.