RISC OS Open

RISC OS  OPEN


A fast and easily customised operating system for devices using ARM processor cores.

Documentation: Wimp_Poll

Programmer’s Reference Manuals
» Part 7 – The Desktop
» The Window Manager
» SWI Calls
» Wimp_Poll

Wimp_Poll

(SWI &400C7)

Entry
R0 Poll Mask
R1 Pointer to 256 byte block
R3 Pointer to pollword in RMA (if R0 bit22 is set)

Exit
R0 Reason Code
R1 Pointer to block of data
R2 Senders task handle

Use

The purpose of this call is poll the Wimp to check for any system wide events that the application may need to respond to. i.e. windows, menus, mouse, keyboard handling.

Notes

Every application must have poll loop whereby it calls Wimp_Poll.

The call returns specific event codes, and the application must then decide whether it wishes to respond to it.

If upon calling Wimp_Poll an escape condition is detected, the Wimp will cancel and disable future escape conditions.

Any errors that occur inside Wimp_Poll are reported by the Wimp itself and not passed back to the applications. The only exception to this rule is when an error was caused due to bad parameter usage.

See also

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