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NAME
- CxMsgData
-
obtain a pointer to a commodity message's data area. (V36)
SYNOPSIS
data = CxMsgData(cxm);
D0 A0
APTR CxMsgData(struct CxMsg *);
D0 A0
APTR CxMsgData(struct CxMsg *);
FUNCTION
Most commodity messages contain meaningful data such as an InputEvent structure. This function returns a pointer to this data.
You may get a commodity message from a synchronous (custom object) or asynchronous (sender object) source. In the second case, 'data' is not valid after you have replied to the message.
You may get a commodity message from a synchronous (custom object) or asynchronous (sender object) source. In the second case, 'data' is not valid after you have replied to the message.
INPUTS
- cxm
-
the commodity message to get the data pointer from (may be NULL)
RESULT
- data
-
a pointer to the message's data, or NULL if 'cxm' is NULL. The meaning of the data varies depending on which kind of object is being inspected.
BUGS
Until V38, passing a NULL 'cxm' parameter would cause low-memory access and unpredictable results.
Until V40, whenever the data pointer is a (struct InputEvent), the ie_EventAddress field of these structures was not reliable whenever the message was generated by a sender object.
Until V40, whenever the data pointer is a (struct InputEvent), the ie_EventAddress field of these structures was not reliable whenever the message was generated by a sender object.