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Filter_RegisterPostFilter
Programmer's Reference Manuals
» Part 7 - The Desktop
» The Filter Manager
» SWI Calls
» Filter_RegisterPostFilter
Filter_RegisterPostFilter
(SWI &42641)
| Entry | |
|---|---|
| R0 | Pointer to zero terminated filter name |
| R1 | Address of Post Filter Code |
| R2 | Value to be passed to R12 |
| R3 | Task handle of task to which filter is applied, or 0 for all tasks |
| R4 | Poll Mask (value of 1 masks the event – same as Wimp_Poll) |
| Exit |
|---|
| All registers preserved |
Use
The purpose of this call is to add a new filter to the list of post-filters.
Notes
The address pointed to by R1 will be called whenever the Wimp is about to return to the task who’s handle is passed in R3 from Wimp_Poll with R12 equal to the value of R2 when this SWI is called.
| Entry | On entry to the routine pointed to by R1 |
|---|---|
| R0 |<^. Event reason code (as from Wimp_Poll) |
|
| R1 | Pointer to User’s event buffer. |
| R2 | Task handle for task to which the return is made |
| Exit | |
|---|---|
| The routine may modify the reason code in r0 and the contents of the buffer pointed to by R1 to provide a new event | |
| It must preserve R1 and R2 |