ParameterBlock (Java Platform SE 8 )

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(new Short(s))".
Note that the get and set methods operate on references. Therefore, one must be careful not to share references between ParameterBlocks 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

All Methods Instance Methods Concrete Methods
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(Object obj)`	Adds an object to the list of parameters.
`ParameterBlock`	`add(short s)`	Adds a Short 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`

Class ParameterBlock

Field Summary

Constructor Summary

Method Summary