com.flagstone.transform
Class FSRegisterCopy

java.lang.Object
  extended by com.flagstone.transform.FSTransformObject
      extended by com.flagstone.transform.FSActionObject
          extended by com.flagstone.transform.FSRegisterCopy
All Implemented Interfaces:
java.lang.Cloneable

public class FSRegisterCopy
extends FSActionObject

FSRegisterCopy is used to copy the item at the top of the stack to one of the Flash Player's internal registers.

The value is not removed from the stack. The number of registers supported was expanded in Flash 7 to 256.

The Flash Player uses a stack to store values when executing the actions associated with a button being pushed, frame being played, etc. If a value is used repeatedly in a calculation, it must be pushed onto the stack each time using an FSPush action. To speed up the execution of the calculation and reduce the amount of code required the value can be saved to one of the internal registers of the Flash Player using the FSRegisterCopy action. This copies the value currently at the top of the stack into the specified register. Pushing an FSRegisterIndex object onto the stack creates a reference to the register so the Flash Player uses the value directly rather than pushing the value onto the stack then immediately popping to use the value in a calculation.

To copy a value from the top of the stack to a register, specify the number of the register, 0..255, in the constructor:

 // Copy a useful value into one of the Flash Player's registers
 
 actions.add(new FSPush(3.1415296));
 actions.add(new FSRegisterCopy(0));
 
 // Use a FSRegisterIndex to look it up later
 
 actions.add(new FSPush(FSRegisterIndex(0)));
 

History

The FSRegisterCopy action represents the ActionStoreRegister action in the Macromedia Flash (SWF) File Format Specification. It was introduced in Flash 5 and expanded in Flash 7 to support up to 256 registers.


Field Summary
 
Fields inherited from class com.flagstone.transform.FSActionObject
Call, ExceptionHandler, GetUrl, GetUrl2, GotoFrame, GotoFrame2, GotoLabel, If, Jump, length, NewFunction, NewFunction2, Push, RegisterCopy, SetTarget, Table, type, WaitForFrame, WaitForFrame2, With
 
Constructor Summary
FSRegisterCopy(FSCoder coder)
          Construct an FSRegisterCopy object, initialising it with values decoded from an encoded object.
FSRegisterCopy(FSRegisterCopy obj)
          Constructs an FSRegisterCopy object by copying values from an existing object.
FSRegisterCopy(int anIndex)
          Constructs an FSRegisterCopy object with the register number.
 
Method Summary
 void appendDescription(java.lang.StringBuffer buffer, int depth)
          AppendDescription is used to present a string description of the object including all nested objects up to a specified depth.
 void decode(FSCoder coder)
           
 void encode(FSCoder coder)
           
 boolean equals(java.lang.Object anObject)
          Returns true if anObject is equal to this one.
 int getRegisterNumber()
          Gets the number of the Player register that the value on the stack will be copied to.
 int length(FSCoder coder)
           
 void setRegisterNumber(int anIndex)
          Gets the number of the Player register that the value on the stack will be copied to.
 
Methods inherited from class com.flagstone.transform.FSActionObject
getType, length
 
Methods inherited from class com.flagstone.transform.FSTransformObject
clone, name, toString
 
Methods inherited from class java.lang.Object
finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

FSRegisterCopy

public FSRegisterCopy(FSCoder coder)
Construct an FSRegisterCopy object, initialising it with values decoded from an encoded object.

Parameters:
coder - an FSCoder containing the binary data.

FSRegisterCopy

public FSRegisterCopy(int anIndex)
Constructs an FSRegisterCopy object with the register number.

Parameters:
anIndex - the number of one of the Flash Player's internal registers.

FSRegisterCopy

public FSRegisterCopy(FSRegisterCopy obj)
Constructs an FSRegisterCopy object by copying values from an existing object.

Parameters:
obj - an FSRegisterCopy object.
Method Detail

getRegisterNumber

public int getRegisterNumber()
Gets the number of the Player register that the value on the stack will be copied to.

Returns:
the register number in the range 0..3.

setRegisterNumber

public void setRegisterNumber(int anIndex)
Gets the number of the Player register that the value on the stack will be copied to.

Parameters:
anIndex - the number of one of the Flash Player's internal registers.

equals

public boolean equals(java.lang.Object anObject)
Description copied from class: FSActionObject
Returns true if anObject is equal to this one. Objects are considered equal if they would generate identical binary data when they are encoded to a Flash file.

Overrides:
equals in class FSActionObject
Returns:
true if this object would be identical to anObject when encoded.

appendDescription

public void appendDescription(java.lang.StringBuffer buffer,
                              int depth)
Description copied from class: FSTransformObject
AppendDescription is used to present a string description of the object including all nested objects up to a specified depth. This method provide a more controlled way of creating a string representation of an object since large objects such as font or shape definitions can contain dozens of nested objects. The representation of the object is appended to the StringBuffer, showing the name of the class and values of the attributes it contains. If the object contains any attributes that are objects then the object graph will be traversed up to the specified depth. If objects are nested at a level less than specified depth then the full string representation of the object is displayed. For objects at the specified depth only the name of the class is displayed. Any objects below this depth are not displayed.

Specified by:
appendDescription in class FSTransformObject
Parameters:
buffer - a StringBuffer to which the description of each object is appended.
depth - the maximum level of nesting up to which objects will be displayed.

length

public int length(FSCoder coder)
Overrides:
length in class FSActionObject

encode

public void encode(FSCoder coder)
Overrides:
encode in class FSActionObject

decode

public void decode(FSCoder coder)
Overrides:
decode in class FSActionObject