LAttachment

LAttachment is a PowerPlant class that is used for forming relataionships between objects. An Attachment is usually an object that modifies the runtime behavior of another object.

Methods :

The methods in this class are:

LAttachment()	~LAttachment()
Execute()	ExecuteSelf()
GetExecuteHost()	GetMessage()
GetOwnerHost()	SetExecuteHost()
SetMessage()	SetOwnerHost()

Data Members:

The data members in this class are:

mOwnerHost	mMessage
mExecuteHost

Operation:

The concept of an Attachment is a powerful underlying concept of PowerPlant's inner workings. For a detailed discussion on this topic, refer to The PowerPlant Book.

Source files:

(Feature Classes)

LAttachment.h

LAttachment.cp

See also:

LAttachable

LPaintAttachment

LYieldAttachment

LAttachment()

Purpose:

The constructors create the object and initialize the data members to the passed-in values.

Access:

Public

Prototype:

LAttachment( MessageT inMessage,

Boolean inExecuteHost);

LAttachment( LStream *inStream );

The parameters for the constructors are:

MessageT	inMessage	The value to set mMessage to.
Boolean	inExecuteHost	The value to set mExecuteHost to.
LStream*	inStream	The data in Stream must be:   MessageT-Message that Attachment responds to. Boolean-Should we execute the Host? (mExecuteHost) Boolean-Does the Host own this object? (mOwnerHost)

~LAttachment()

Purpose:

The destructor destroys the object, removing itself from any Attachments.

Access:

Virtual, Public

Prototype:

virtual ~LAttachment();

None

Execute()

Purpose:

If the message passed to this method is the message for which the Attachment is designed, this method calls ExecuteSelf().

Access:

Virtual, Public

Prototype:

virtual Boolean Execute( MessageT inMessage,

void *ioParam);

This method has the following parameters:

MessageT	inMessage	The message to which the attachment responds.
void*	ioParam	A pointer to the host attachable object.

Return:

A Boolean with the value of mExecuteHost. The PowerPlant framework uses this value to decide whether the host object should also perform the task in question.

Remarks:

You do not typically need to override this function.

ExecuteSelf()

Purpose:

This method performs the attachment task. You typically want to override this method in your class that inherits from LAttachment.

Access:

Virtual, Public

Prototype:

void ExecuteSelf(MessageT inMessage, 

void* ioParam );

This method has the following parameters:

MessageT	inMessage	The message to which the attachment responds.
void*	ioParam	A pointer to the host attachable object.

Return:

None

Remarks:

To get an idea of how to implement this method in your class override, look at classes like LPaintAttachment to see how it is implemented.

GetExecuteHost()

Purpose:

This method is an accessor for the value of mExecuteHost.

Access:

Inline, Public

Prototype:

Boolean GetExecuteHost();

None

Return:

A Boolean indicating the value of mExecuteHost.

GetMessage()

Purpose:

This method is an accessor for the value of mMessage.

Access:

Public, Inline

Prototype:

MessageT GetMessage();

None

Return:

A MessageT indicating the value of mMessage.

GetOwnerHost()

Purpose:

This method is an accessor for the value of mOwnerHost.

Access:

Public, Inline

Prototype:

LAttachable* GetOwnerHost();

None

Return:

An LAttachable pointer indicating the value of mOwnerHost.

SetExecuteHost()

Purpose:

Sets the value of mExecuteHost, that specifies whether the host action should execute after executing all Attachments.

Access:

Virtual, Public

Prototype:

void SetExecuteHost( Boolean inExecuteHost );

This method takes a Boolean to assign to mExecuteHost.

Return:

None

SetMessage()

Purpose:

Sets the value of mMessage.

Access:

Virtual, Public

Prototype:

void SetMessage( MessageT inMessage );

A MessageT to assign to mMessage.

Return:

None

SetOwnerHost()

Purpose:

Sets the value of mOwnerHost.

Access:

Virtual, Public

Prototype:

void SetOwnerHost( LAttachable *inHost );

A pointer to an LAttachable to assign to mOwnerHost.

Return:

None

mOwnerHost

Purpose:

This data member points to the host attachable object.

Access:

Protected

Prototype:

LAttachable *mOwnerHost;

mMessage

Purpose:

This data member contains the message value to which the attachable object responds.

Access:

Protected

Prototype:

MessageT mMessage;

mExecuteHost

Purpose:

This data member indicates whether or not to execute the host object action.

Access:

Protected

Prototype:

Boolean mExecuteHost;