#1700 wm geometry contradictions (and inadequately documented

[Vince Darley]

The documentation of "wm geometry $win" doesn't make
clear whether the quantities referred to are relative
to the toplevel window's border or the window manager
decoration (titlebar, menubar with configure -menu, etc).

In fact on windows, the returned value is:

contentsWidth x contentsHeight
+ decorationLeft + decorationTop

which is rather surprising. This means to find the
total number of vertical pixels covered by the
toplevel, including any menubar/titlebar/border, we
must perform a complex calculation (and must actually
assume the bottom edge and right edge decoration are
the same thickness as the left edge decoration). So,
here's a function to determine, as best possible, the
total geometry covered by a window:

proc default::totalGeometry {{w .}} {
set geom [wm geometry $w]
regexp -- {([0-9]+)x([0-9]+)\+([0-9]+)\+([0-9]+)}
$geom -> \
width height decorationLeft decorationTop
set contentsTop [winfo rooty $w]
set contentsLeft [winfo rootx $w]

# Measure left edge, and assume all edges except
top are the
# same thickness
set decorationThickness [expr {$contentsLeft -
$decorationLeft}]

# Find titlebar and menubar thickness
set menubarThickness [expr {$contentsTop -
$decorationTop}]

incr width [expr {2 * $decorationThickness}]
incr height $decorationThickness
incr height $menubarThickness

return [list $width $height $decorationLeft
$decorationTop]
}

Nowhere in the documentation are these issues/terms
made clear. So, while I know the above works on
Windows, I really cannot be sure it works on other
platforms. The documentation should be fixed (and this
proc could be used as an example, perhaps).

[Vince Darley]

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Furthermore, on X11, the behaviour is totally different! On
X11 it is impossible to get the decoration sizes, and in
fact 'wm geometry' operates only on the window contents.

This means, for example, that 'wm geometry +0+0' performs
totally differently on Windows vs X11.

[Vince Darley]

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According to http://mini.net/tcl/11502,

This depends on the window manager. Under metacity (Gnome's
WM), twm, and others, wm geometry . +$x+$y places the
upper-left corner of the window decoration at $x,$y; under
MWM and 4DWM, it places the upper-left corner of the window
contents there. I'm pretty sure this is because tkUnixWm.c
isn't doing the right thing according to the ICCCM -- it
looks like it's trying to implement the first behaviour
(place window decorations), but it does so by attempting to
second-guess what the WM is going to do. Under many WMs, it
guesses wrong.

This means even between different X11 wm's the behaviour is
inconsistent for something as simple as 'wm geometry . +0+0'

[Joe English]

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Reassigning to me; see also #220791.