By Tablet Support, we mean support for laptops that transform into pen-tablet computers with or without touch-screens, as well as dedicated web-tablet computers that do not transform into a laptop with a keyboard.

The primary issues are:

  • When the laptop is converted to a tablet, the screen orientation should change to match. It is also necessary to support changing the screen rotation while in tablet mode. Generally, all rotation of the X Windows display is accomplished via the RandR extension.
  • When the RandR extension is used to rotate the screen, the Wacom tablet driver needs to change it's logical orientation to match the screen, since the screen is the tablet. In the general case, the tablet and screen are not the same, so this rotation cannot be automatically performed; the functionality needs to be enabled only when it makes sense.
  • If there are directional navigation buttons on the tablet, then they need to be remapped to match the new logical orientation.
  • The Wacom driver seems to have issues, sometimes, with recovering it's configuration state after suspend or hibernate, and so there sometimes needs to be intervention during those events as a work-around.
  • When the screen is rotated, does the sub-pixel order need to be changed for nicest text rendering? Will simply changing the gconf key affect the update of all drawn text using the new setting?

Since any application can potentially call for a RandR Rotation -- xrandr, gnome-settings, etc. -- it's not appropriate to put the calling of these fix-ups in the same command or applet that calls for the RandR Rotation. The solution calls for a program that connects to the display then registers to be notified when the RandR Rotation event occurs. When that event happens, it calls on a handler that affects the necessary changes. See the Tablet Screen Rotation Support code and README for more details.

Other UI Ideas for Tablet Computing

Attic/ScratchPad/TabletSupport (last edited 2013-12-03 19:46:30 by WilliamJonMcCann)