bug#2715: 23.0.60; Changing font size

bug#2715: 23.0.60; Changing font size

[Chong Yidong]

Hi Jan,

This is not strictly a GTK bug, but could you take a look at bug#2715?

http://emacsbugs.donarmstrong.com/cgi-bin/bugreport.cgi?bug=2715

The basic problem, I think, is that when the font size changes, Emacs
tries to change the pixel width and height of the frame, keeping the row
and column numbers unchanged (xterm.c:8116).  However, this fails when
the frame is maximized---in that case, we can only change the row and
column numbers, and the pixel width and height cannot be changed.
However, I am not sure how to fix this.  Maybe you can suggest a
solution?

bug#2715: 23.0.60; Changing font size

[Jan Djärv]

Chong Yidong skrev:
> Hi Jan,
> 
> This is not strictly a GTK bug, but could you take a look at bug#2715?
> 
> http://emacsbugs.donarmstrong.com/cgi-bin/bugreport.cgi?bug=2715
> 
> The basic problem, I think, is that when the font size changes, Emacs
> tries to change the pixel width and height of the frame, keeping the row
> and column numbers unchanged (xterm.c:8116).  However, this fails when
> the frame is maximized---in that case, we can only change the row and
> column numbers, and the pixel width and height cannot be changed.
> However, I am not sure how to fix this.  Maybe you can suggest a
> solution?

The problem is that generally you can't really be sure if you are maximized or 
just big.

But with a relative new window manager, there are properties we can look at to 
deduce what to do or not do, so we can cover those cases at least (i.e. all 
KDE, Gnome, XFCE and some more).  I'll see what I can come up with.

	Jan D.

bug#2715: 23.0.60; Changing font size

[Jan Djärv]

I've added a fix for the case when extended window manager hints are used,
which should cover 90 to 95% of the X11 environments in use today.  I'm
planning to change fullscreen handling after the release so Emacs only
supports extended window manager hints or the case where no window manager is
present.  The other cases are too much work for too little gain, and is also a
bit timing dependant so it may fail sometimes.

I don't want to close this yet, because I found another redrawing bug, that is
present even before my change.  It could be the theme I use, so it may not be
Emacs fault.  I'll investigate and if Eamcs is not to blame I will close this bug.