com.levigo.jadice.document.instruction

Class AbstractInstructionExecutor<I extends Instruction,C>

java.lang.Object

com.levigo.jadice.document.instruction.AbstractInstructionExecutor<I,C>

Type Parameters:

I - Instruction—the specific subtype of Instruction we deal with

C - Context—The type of Object which holds information that an implementation needs for actually executing instructions.

All Implemented Interfaces:

InstructionExecutor<C>

Direct Known Subclasses:

ChangePageLayoutExecutor, DocumentByWeakRefExecutor, ExternalTargetExecutor, FitExcecutor, PageByIndexExecutor, PageByWeakRefExecutor, PanExecutor, RotateExecutor, ZoomExecutor

public abstract class AbstractInstructionExecutor<I extends Instruction,C>
extends Object
implements InstructionExecutor<C>

An abstract base class for implementations that deal with exactly one type of Instruction

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractInstructionExecutor(Class<I> instructionClass)

Method Summary

Modifier and Type	Method and Description
boolean	canExecute(Instruction instruction, C context) Indicates whether or not this instance is able to execute the given Instruction, using the given context object where necessary.
protected boolean	canExecuteSpecific(I instruction, C context) Template method for implementors.
void	execute(Instruction instruction, C context) Perform that which is described by the given Instruction.
protected abstract void	executeSpecific(I instruction, C context) Template method for implementors.
boolean	pertainsTo(Class<? extends Instruction> clazz) Returns whether or not this InstructionExecutor knows how to deal with a given type of Instruction.

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractInstructionExecutor

protected AbstractInstructionExecutor(Class<I> instructionClass)

Method Detail

pertainsTo

public boolean pertainsTo(Class<? extends Instruction> clazz)

Description copied from interface: InstructionExecutor

Returns whether or not this InstructionExecutor knows how to deal with a given type of Instruction.

Specified by:

pertainsTo in interface InstructionExecutor<C>

Parameters:

clazz - the type of Instruction for which information is requested

Returns:

true if this InstructionExecutor is able to handle Instructions of the given type, false otherwise.

canExecute

public final boolean canExecute(Instruction instruction,
                                C context)

Description copied from interface: InstructionExecutor

Indicates whether or not this instance is able to execute the given Instruction, using the given context object where necessary.

Specified by:

canExecute in interface InstructionExecutor<C>

Parameters:

instruction - the instruction in question

context - holds additional, implementation-specific information

Returns:

true if this instance is able to execute the given Instruction using the given context object where necessary; false otherwise.

canExecuteSpecific

protected boolean canExecuteSpecific(I instruction,
                                     C context)

Template method for implementors. Indicates whether or not this instance is able to execute the given Instruction, using the given context object where necessary. The default implementation does nothing and returns true.

Parameters:

instruction - the instruction in question. It is guaranteed to be non-null.

context - holds additional, implementation-specific information

Returns:

true if this instance is able to execute the given Instruction using the given context object where necessary; false otherwise.

execute

public final void execute(Instruction instruction,
                          C context)

Description copied from interface: InstructionExecutor

Perform that which is described by the given Instruction.

Specified by:

execute in interface InstructionExecutor<C>

Parameters:

instruction - holds the information which specifies what to perform

context - holds additional, implementation-specific information

executeSpecific

protected abstract void executeSpecific(I instruction,
                                        C context)

Template method for implementors. Perform that which is described by the given Instruction.

Parameters:

instruction - holds the information which specifies what to perform. This Instruction is guaranteed to be non-null.

context - holds additional, implementation-specific information