Features/InputDeviceProperties

Input Device Properties

Summary

With X server 1.6, input devices provide a generic mechanism to change driver settings at runtime. The same mechanism may be used by applications to store information directly on device.

Owner

• Name: Peter Hutterer

Current status

• Targeted release: Fedora 11
• Last updated: (2009-02-26)
• Percentage of completion: 100%

Detailed Description

X server 1.6 (as shipped in F11) provides new X Protocol requests to list, change and query input device properties. Properties as information exchange mechanism have a long tradition: they are used extensively on windows to provide information exchange between applications (including the window manager). For example, even closing a window is usually performed through setting properties. With the RandR extension, properties became available on output devices, and now, with server 1.6 and the X Input Extension 1.5, such properties are now available on input devices as well.

Input device properties provide two benefits for applications and users:

• Properties initialized and recognized by the driver or the server can be used to modify device settings at run-time.
• Properties initialized by an application can be used to store information globally on a device. This information is available through a generic interface to all other applications and can thus be used to annotate devices.

Run-time manageable device properties reduce the need for configuration in the xorg.conf/HAL's fdi files and supersede custom mechanisms such as synaptics's SHM mechanism.

Benefit to Fedora

Run-time manageable device properties reduce the need for configuration in the xorg.conf/HAL's fdi files and supersede custom mechanisms such as synaptics's SHM areas. They further allow for easily extendable GUI configuration tools and for new ways of exchanging device-related information between applications.

Scope

Requires rebasing to X.Org X11 server 1.6.

Test Plan

No specific test-plan, this feature comes built-in with server 1.6.

User Experience

This is a low-level interface that has no direct impact on the user. However, some tools are being converted to use input properties instead of custom mechanisms, and a generic tool ('xinput') is available to enable users to change properties in the absence of GUI tools. The drivers xorg-x11-drv-evdev and xorg-x11-drv-synaptics expose configuration settings as properties and can thus be configured at runtime.

Dependencies

• xorg-x11-server 1.6 (RCs already in rawhide)
• libXi 1.2 (already in rawhide)

For run-time configuration of drivers:

• evdev 2.1 (in F10)
• synaptics 1.0 (already in rawhide)

Contingency Plan

• none, this feature comes built-in with server 1.6

Documentation

• http://who-t.blogspot.com/2008/10/device-properties-have-landed.html
• XChangeDeviceProperty (3)
• XGetDeviceProperty (3)
• XDeleteDeviceProperty (3)
• XListDeviceProperties (3)

Release Notes

The new X server 1.6 includes Input Device Properties, a new mechanism to store information on input devices. This new API allows for run-time configuration of drivers as well as enabling applications to globally store information on an input device.

The drivers xorg-x11-drv-evdev and xorg-x11-drv-synaptics already expose configuration settings as properties and can thus be configured at runtime.

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