[osg-users] BUG?: mouse coordinate changes after window move

Leif Delgass ldelgass at gmail.com
Thu Sep 20 11:40:29 PDT 2007

On 9/20/07, Robert Osfield <robert.osfield at gmail.com> wrote:
> On 9/20/07, Anders Backman <andersb at cs.umu.se> wrote:
> > Problem 2 (windowed):
> >
> > We are using gnome on Ubuntu, and
> >   osgviewer --window 100 100 500 500 cow.osg
> >
> > works fine, but after 'f' is pressed two times (first into fullscreen, and
> > then back to windows), we dont get a window.
> > So it seems that it is not possible to go back from fullscreen  windowed
> > mode.
> This is a bug in the window manager ignoring request to add decoration
> back in.  It might be possible to code a workaround for working with
> such windowing managers but alas I can't divine what the problem might
> be as everything works just fine on all my linux boxes.
>  Robert.

Hi Robert,

I have been experimenting with window manager hints regarding a
different but related issue.  I'm running GNOME under Fedora 5, and
the fullscreen mode in osgviewer creates a window that stays under the
top and bottom toolbar panels.   For me, switching to windowed mode
properly adds the window decorations.  But what I discovered is that
to get true fullscreen windows in GNOME, I need to use the Extended
Window Manager Hints (EWMH):


Sending a ClientMessage event (or using XChangeProperty before mapping
the window) to toggle the _NET_WM_STATE_FULLSCREEN Atom for the
_NET_WM_STATE property works as expected -- the window is undecorated
and appears on top of the toolbars in fullscreen state.  I was looking
into the OSG implementation and it seems that fullscreen is
implemented using a window resize to screen dimensions + the Motif
window manager hints to remove decorations.  The EWMH spec is intended
to replace Motif hints, and it has a slightly different philosophy.
You specify the usage/type of window rather than directly controlling
the use of decorations.

I think what would be needed is a virtual fullscreen() method in
GraphicsWindow that can be overriden in GraphicsWindowX11 using this
implementation if the window manager supports it, and then the
toggleFullscreen() method in ViewerEventHandler could call this
function rather than setting the window rectangle and decoration (in
the EWMH spec, the window manager is responsible for restoring the
original window geometry and decoration when leaving fullscreen

Leif Delgass
ldelgass at gmail.com

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