The Wimp



Icon Transitions


The Window Manager has been updated to provide notifications of the pointer entering and leaving icons. These transition messages are similar to those provided by the 'pointer entering/leaving window' messages. Most clients will not need to receive such notifications.

Wimp_Poll reason codes and masks

The new reasons codes have been allocated as event codes 14 (pointer leaving icon) and 15 (pointer entering icon). Because most applications will not have these bits masked in their Wimp_Poll mask it is necessary to set bit 25 in the mask to indicate that the events are required. Thus, the mask definition has been updated to add the following bits :

    bit 14 if set, ignore 'pointer leaving icon' events
    bit 15 if set, ignore 'pointer entering icon' events
    bit 25 if clear, ignore all 'pointer entering/leaving icon' events, if set, obey bits 14 and 15

Wimp_Poll event codes 14 and 15 are returned whenever the above conditions have been met, and the mouse has moved in or out of an icon's bounding box.

Event codes 14 and 15 return the same structure in the user's event block :

    +0 = window handle
    +4 = icon handle

Icon transition events will never be returned for the logical window backgound, which is usually indicated by icon handle -1. When windows are closed beneath the pointer the events will be delivered in the logical manner as if the pointer had left the window naturally. Thus, the usual sequence of events for a pointer moving into a window, to a 'Close' button, and clicking it would be :

  1. Pointer entering window
  2. Pointer entering close icon [mouse clicked, window closed]
  3. Pointer leaving close icon
  4. Pointer leaving window

This documentation is copyright 3QD Developments Ltd 2013 and may not be reproduced or published in any form without the copyright holders permission. RISC OS is subject to continuous development and improvement as such all information is reproduced by 3QD Developments Ltd in good faith and is believed to be correct at the time of publication E&OE. 3QD Developments Ltd cannot accept any liability for any loss or damage arising from the use of any information provided as part of the RISC OS Documentation.

HTML document version 1.03 3rd November 2015