Proposal to add new XSETTINGS

[Padraig O'Briain]

I would like to propose adding the following new settings to shared 
settings which are currently under the control of the XSETTINGS system.

Net/MinimizeCPUUsage
  Bool False

The value would be set to True for SunRay or other multi-user systems.

Net/DisplayCapability
  String "hw_accel_none"

We have identified the following possible values:

"hw_accel_full", i.e. hardware 2D and 3D acceleration
"hw_accel_partial", i.e. hardware 2D acceleration
"hw_accel_none", i.e. no hardware acceleration
"network_display", e.g. remote display
"persistent_display", i.e. as proposed for $100 laptop

These values being determined at the start of a user session and may 
change during a user session, e.g. when a user connects to the display 
using Vino.

The idea is to allow applications to modify their behavior depending on 
the environment they are running in.

If Net/MinimizeCPUUsage is true then xscreensaver could just blank the 
screen instead of running programs which draw interesting patterns on 
the screen and consume CPU.

Another possibility is where an application does expensive processing at 
regular intervals, e.g. GNOME System Monitor processing /proc entries 
very frequently is expensive and so it should only do so on demand.

The Net/DisplayCapability setting can be used by different applications 
to adapt its UI rendering, (e.g screen update, animation, composite 
feature) to the apprporiate level.

For instance the stock ticker would not scroll the text all the time if 
Net/DisplayCapability were set to network_display and only update at a 
preset interval or pop up a dialog warning the user that this applet 
should not be used in a network display environment.

The window manager, metacity, could enable its composite manager if 
Net/DisplayCapability were set to hw-accel_full and otherwise disable it.

If Net/DisplayCapability were set to hw_accel_partial font antialiasing 
would be set but it were set to a lower capability then font 
antialiasing would be disabled.

Padraig