Hi there.
Comments below:
On Tue, May 07, 2002 at 04:36:13PM +0200, Dominik Vogt wrote:
> On Tue, May 07, 2002 at 04:53:59PM +0300, Tom Alsberg wrote:
> > Hi there.
> > I am using FVWM 2.5.2 (current CVS, as of 2002/05/06, but it happened
> > before too), and there seems to be a problem - when changing the fonts
> > in a running XTerm, i.e. with Shift + Keypad Plus (KP_Add), Shift +
> > Keypad Minus (KP_Subtract), or the Control + Right click menu, when
> > the font resizes, the geometry (that is - in characters - lines and
> > columns) of the XTerm also changes somewhat.
> >
> > For example, with default XTerm (no custom X resources), it starts
> > 80x24. If I then change the font to Large, the geometry changes to
> > 120x27. When I then change the font to back to Default, the geometry
> > changes to 80x23 (not back to 80x24).
> > <snip />
>
> It's not really a bug in fvwm, but a combination of bugs in xterm
> with a lack of functionality in X.
Uhmm... That sounds weird... Both since that problem is new in the
FVWM 2.5 CVS code (didn't exist in FVWM 2.4), and it doesn't happen in
other window managers...
> When an application changes
> its font size, the window manager is informed that the font size
> has changed, but not to which height and width.
Uh... Well, I didn't even know that applications notify X that their
font size has changed... I thought only the general (pixel-based, and
geometry) size is reported... But well, the size of the window isn't
exactly the font's size multiplied by the geometry... There can be
other widgets not counted, for example... Take For example XTerm and
Emacs, both with the same font size, both with the same geometry, the
pixel size of the window is different...
I thought that the geometry's meaning is defined by the application,
so the application, given a geometry, decides on the window's size by
itself, and reports that to X...
> So, fvwm looks up that information on its own - but at the time it
> get to it, the size may already have changed again. For exampe:
>
> - Start with font width 9x15, window is 90 by 15 pixels (10x10)
> - App changes its font size to 10x18
> - App resizes its window to 100x180 (10x10)
> - App changes its font size to 12x24
>
> If all requests are sent one by one to the X server and fvwm
> processes them before the next is issued, the resulting window
> will be 120x240 pixels (10x10). If all requests are sent to the
> X server before fvwm handles them, this happens:
>
> - Fvwm gets a PropertyNotify event indicating the font size has
> changed.
> - Fvwm reads the font size (12x24) and resizes the window to
> 120x240 (10x10).
> - Fvwm reads the resize request and resizes the window to
> 96x168 (8x7).
> - Fvwm ignores the next PropertyNotify event because the font
> size did not change.
>
Uh... well, but in my example, there is only one font change... so why
does it really matter? The font size changes only once, and while FVWM
is informed on it, there are no further size changes...
> It is impossible to prevent this reliably in fvwm, only the
> application could do that.
So why does it only happen in CVS versions of FVWM 2.5? It does not
happen in FVWM 2.4, TWM, CTWM, MWM, Enlightenment, etc... There must
be something in FVWM too...
> But unfortunately the xterm Programmers were not aware of this
> problem and issue a host of font size changes and window size
> changes in a single batch without waiting for a reply from the
> window manager.
But how does this matter if the size changes only once?
> I have changed the part of the logic in fvwm that surfaced this
> particular bug at the cost of similar problems in other
> applications.
What do you mean by that?
Isn't it possible to just do it the way FVWM 2.4 did it?
> Maybe I'll rewrite that stuff so that it can be set individually for
> each window.
I didn't yet quite understand why that is needed...
> Bye
>
> Dominik ^_^ ^_^
Thank you,
-- Tom
--
Tom Alsberg - certified insane, complete illiterate.
e-mail: <alsbergt_at_softhome.net>
Homepage: http://www.cs.huji.ac.il/~alsbergt/
* An idea is not responsible for the people who believe in it.
--
Visit the official FVWM web page at <URL: http://www.fvwm.org/>.
To unsubscribe from the list, send "unsubscribe fvwm" in the body of a
message to majordomo_at_fvwm.org.
To report problems, send mail to fvwm-owner_at_fvwm.org.
Received on Tue May 07 2002 - 11:27:02 BST