KeyboardFilter Class Reference

Detailed Description

The KeyboardFilter class is a base class for global keyboard event filters in Qt for Embedded Linux.

Note that this class is only available in Qt for Embedded Linux.

In Qt for Embedded Linux, all system generated events, including keyboard events, are passed to the server application which then propagates the event to the appropriate client. The KeyboardFilter class is used to implement a global, low-level filter on the server side. The server applies the filter to all keyboard events before passing them on to the clients:

This feature can, for example, be used to filter things like APM (advanced power management) suspended from a button without having to filter for it in all applications.

To add a new keyboard filter you must first create the filter by deriving from this class, reimplementing the pure virtual filter() function. Then you can install the filter on the server using QWSServer's addKeyboardFilter() function. QWSServer also provides a removeKeyboardFilter() function.