h6. [[FilterManager]] h6(. » [[FilterManager SWI Calls|SWI Calls]] h6((. » [[Filter_RegisterPreFilter]] h6(((. » Pre Filter Code |_<^. Entry | | |<^. R0 |<^. Event mask | |<^. R1 |<^. -Users event buffer- | |<^. R2 |<^. Task handle of task that called [[Wimp_Poll]] | |<^. R3 |<^. Pointer to poll word if applicable| |<^. R12 |<^. Value of R2 when filter registered| |_<^. Exit | |<. It must preserve all registers (other than R0)| h4. Notes You may clear bits in R0 to provide a new event mask. Please note: You must preserve all other registers (other than R0). h4. See also * [[Filter_RegisterPreFilter]]