operators
Class PSStroke

java.lang.Object
  operators.PSStroke

All Implemented Interfaces:

PSObject, PSOperator, PSPathOperator

public class PSStroke

extends java.lang.Object

implements PSPathOperator

Implements PSPathOperator interface.

Methods such as getOperatorToken() are inherited from PSPathOperator interface which are inherited from PSOperator. This concrete class is responsible for drawing the contents of a path.

Constructor Summary

PSStroke()

Method Summary

void	action(PSStack s, PSPath p) Adds a on top of the Graphics Stack.
java.lang.String	getOperatorToken() Returns the token identifying this operator.
boolean	isValid(PSStack s) Checks if it valid to use this operator now.

Methods inherited from class java.lang.Object

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

Constructor Detail

PSStroke

public PSStroke()

Method Detail

getOperatorToken

public java.lang.String getOperatorToken()

Returns the token identifying this operator.

Returns the name of the operand that this concrete class simulates, here "stroke".

Precondition : A valid operator class has been created.
Postcondition : A string is returned,labeling the semantics of this class.

Specified by:

getOperatorToken in interface PSOperator

Returns:

The token identifying this operator.

isValid

public boolean isValid(PSStack s)
                throws PSSyntaxException

Checks if it valid to use this operator now.

Is is not invalid to call a stroke if the Graphics Stack is empty but there is no result.

Precondition : A valid instance of PSStack is given.
Postcondition : A reply to the question whether the operator can perfom its defined behaviour.

Specified by:

isValid in interface PSOperator

Parameters:

s - A reference to an instance of PSStack.

Returns:

True if the operation can be executed, false otherwise.

Throws:

PSSyntaxException - The syntax of the token is wrong.

action

public void action(PSStack s,
                   PSPath p)

Adds a on top of the Graphics Stack.

Stroke informs the Graphics Machine that it can draw everything in the stack under it.

Precondition : A valid Runtime Stack and Graphics Stack are given.
Postcondition : Stroke will be added in the Graphics Stack and everything below it wil be drawn.

Specified by:

action in interface PSPathOperator

Parameters:

s - The Runtime Stack which serves no purpose here.

p - The Graphics Stack.