Ideal screen rotation

Carsten Haitzler (The Rasterman) raster at
Tue Nov 10 17:33:40 CET 2009

On Tue, 10 Nov 2009 16:11:40 +0000 Dave Ball <openmoko at> said:

> Warren Baird wrote:
> > perhaps the landscape / portrait flag should just contrain the 
> > rotation?   So if you flip the phone 180 degrees, you get the 
> > 'expected' behaviour, but if you just flip it 90 degrees nothing changes?
> Given that these properties are for the orientation an application 
> requests (to the WM) should ideally be used, I'm not sure how the actual 
> rotation would help?  Working from rotation would also complicate the 
> behaviour on devices that are normally landscape - such as the Nokia N900. 
> What I'm suggesting is that the application just says "landscape" or 
> "portrait", and then the WM would decide the most appropriate way to 
> orient the screen for that device.
> If an application doesn't request either landscape or portrait, then the 
> WM would rotate the screen according to the device orientation, through 
> each of the positions the device could be held (including inverted).  So 
> the WM definitely needs to know the actual orientation of the device 
> (such as from the FSO api), but I think the application itself only 
> needs to request Landscape, Portrait or neither.

you want a bitmask for 4 rotations as well as flips. why? because this is what
xrandr supports. you want to give a mask for which rotations the app "wants"
why do u need both 90 and 270 degrees for example?

look at a g1. u slide kbd open to one side of the screen. now imaging if u slid
the screen the other way you have a different button set along the other side.
eg a set of psp-style game-pad controllers for games. so games would request
270 and aps rthat are built for text input with hw kbd are 90. etc. etc.

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The Rasterman (Carsten Haitzler)    raster at

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