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Wimp_SendMessage
Programmer's Reference Manuals
» Part 7 - The Desktop
» The Window Manager
» SWI Calls
» Wimp_SendMessage
Wimp_SendMessage
(SWI &400E7)
| Entry | |
|---|---|
| R0 | Reason Code |
| R1 | Pointer to message block |
| R2 | Destination task handle, or |
| Destination window handle, or | |
| – 2 for creator of icon handle in R3, or |
| Exit | |
|---|---|
| R0 | Corrupt |
| R2 | Handle of destination task (if not broadcast) |
| Block | Updated |
Use
The purpose of this call is to send a message either a particular task or to all tasks.
Notes
All messages passed around the Wimp is achieved using this call.
Tasks are notified of incoming messages via Wimp_Poll.
The type of message to be sent is dependant on the reason code value.
The message block in R1 should be in the format specified by the particular Reason Code being used in R0.
Reason code values of 1 to 12 can be used to inform another task about a window, mouse, icon etc…
Reason codes of 17 to 19 are user messages are the most common type of message to send.
- User_Message (reason code 17) and is used to inform a task of something.
- User_Message_Recorded? (reason code 18) and is used to inform a task of something but requires a message of acknowledgement in return. If no acknowledged message is received, the Wimp will send the message back to the originator.
- User_Message_Acknowledge is reason code 19 and is used to reply back to a task that sent a User_Message_Recorded message.
See also
- Reason Codes
- User_Message
- User_Message_Recorded?
- User_Message_Acknowledge
- Wimp_Poll