Window coordinates

jt1122 · 01-25-2024, 03:13 AM

Hi,

I'm trying to write a script to align several windows. I'm using the XFCE desktop.4.18, GTK 3.24.39 .

I have a top panel of height 40px. Running xprop on the panel gives:

Code:

 _NET_FRAME_EXTENTS(CARDINAL) = 0, 0, 0, 0

so there are no borders/padding added.

Running xprop on an xfce4-terminal gives:

Code:

 (_NET_FRAME_EXTENT(CARDINAL) = 4, 4, 24, 4

so there is a 24px (top) + 4px (bottom) frame added.

Now I'd like to move the terminal to 200,0 with a size of 500X500. Running wmctrl:

Code:

 wmctrl -r terminal -e 0,200,0,500,500

places the terminal at X=200 Y=88.

Why is it placed at Y=88? there are 40px from top due to the the top panel so why not Y=40?.
Even adding the top + bottom frame thickness (24+4=28) doesn't add up to 88.

My question: how do I determine a window's final geometry given a top panel + desired window geometry + frame extensions (_NET_FRAME_EXTENT) ?.

Thanks

Keith Hedger · 01-25-2024, 06:35 AM

works fine here, could be its your window manager getting in the way, do you have any sort 'smart' or 'snap' placement switched on?

jt1122 · 01-25-2024, 06:53 AM

Thanks, which specific settings do you suggest checking?

I've tried xfce4-terminal --hide-borders & it works as I would have expected , i.e. placed at Y=40, just below the top panel.

Keith Hedger · 01-25-2024, 07:14 AM

I'm guessing you are using xfwm4, I haven't used it in quite a few years but if I remember its in settings->window manager tweaks, have an explore!

Keith Hedger · 01-25-2024, 07:20 AM

In xfce4-settings-manager check xfwm4->general->snap_to_border/snap_width etc.

jt1122 · 01-25-2024, 07:23 AM

Thanks.

I am using xfwm4, it the stock xfce WM.
In "window manager tweaks" there is "minimum size of window to trigger smart placement". The slider is at about 25% (close to small).

I ticked-off Window snapping>To screen borders but no effect.

The wmctrl shows the window's top Y coordinate is 88 but it's placed just flush against the top panel which ends at Y=40.

Keith Hedger · 01-25-2024, 08:45 AM

Well as I said I don't use xfce any more but my last suggestion is to use xfce4-settings-editor as you can sometimes do things you can't do in the other settings managers.

jt1122 · 01-26-2024, 12:52 PM

I've scanned the options in "Window Manager" & "Window Manager Tweaks". Nothing affected the placement.

One interesting find: If I change the theme then the Y position reported (by wmctrl) also changes, e.g.
setting the "greyleigh"

Code:

wmctrl -r xterm -e 0,100,0,500,500
wmctrl -lG

shows Y=48 for xterm.
Setting the theme to "Default" & repeating these steps gives Y=58.

What is still a mystery is why the Y coordinate isn't 0 when the xterm window is visibly flush against the top of the screen.

Keith Hedger · 01-26-2024, 02:19 PM

Quote:

Originally Posted by jt1122

...
What is still a mystery is why the Y coordinate isn't 0 when the xterm window is visibly flush against the top of the screen.

Dont forget the height of the title bar.

jt1122 · 01-27-2024, 04:57 AM

Quote:

Originally Posted by Keith Hedger

Dont forget the height of the title bar.

Isn't this defined in the "_NET_FRAME_EXTENTS" property?

xprop on the xterm window gives:

Code:

_NET_FRAME_EXTENTS(CARDINAL) = 4, 4, 24, 4

so it seems the titlebar height is 24px. The bottom border thickness is 4px so that's a total of 28px.

There are still 20px missing since wmctrl reports the window is at Y=48.

Isn't the reported value the position of top left corner of the window border?.