FvwmPager with bad aspect ratio on dual-head display

[harridu]

Upfront Information

• Fvwm3 version (run: fvwm3 --version)

fvwm3 1.0.3 (released)
with support for:  ReadLine, XPM, PNG, Shape, XShm, SM, Bidi text, XRandR, XRender, XCursor, XFT, NLS

• Linux distribution or BSD name/version
  Debian Testing

• Platform (run: uname -sp)

Linux dpcl082.ac.aixigo.de 5.10.0-7-amd64 #1 SMP Debian 5.10.40-1 (2021-05-28) x86_64 GNU/Linux

Expected Behaviour

The mini desktop shown by FvwmPager should keep the aspect ratio of the real desktop, even for a dual-head display.

Actual Behaviour

The FvwmPager gives me a bad aspect ration on a dual-head setup (2 monitors side by side). Seems that only one monitor has been taken into account. It looks like the pager has been squeezed horizontally to half of the usual size (as known from fvwm2).

DesktopConfiguration    global
DeskTopSize             4x3
Style   "FvwmPager"             NoTitle, BorderWidth 0, HandleWidth 0, WindowListSkip, Sticky, StaysOnBottom
AddToFunc StartFunction         "I" Module FvwmPager *
*FvwmPagerBack black
*FvwmPagerFore black
*FvwmPagerHilight gray10
*FvwmPagerWindowColors black #404040 black #c06000
*FvwmPagerGeometry -0-0@g
*FvwmPagerFont none
*FvwmPagerLabel 0 Virtual Desktop

What should have happened, but didn't?

The Pager should have kept the aspect ratio of my desktop.

config.txt

[ThomasAdam]

Hey @harridu

Yes. Can you take a screenshot for me, so I can see how this looks?

[somiaj]

AFIAK, FvwmPager doesn't preserve the aspect ratio of the display, it just fills whatever window it is in and uses that aspect ratio and will shrink/stretch things to fit. Change the size of the FvwmPager window to match the aspect ratio (including DesktopSize).

*FvwmPagerGeometry -0-0@g

You can set the geometry there to make this work (Though I guess the issue is FvwmPager should figure this geometry out better int his case).

[harridu]

But this makes my .fvwmrc hardware-dependent. I would highly appreciate if this could be avoided, as it was for fvwm2

[harridu]

Hey @harridu

Yes. Can you take a screenshot for me, so I can see how this looks?

See below. You can find the 4 by 3 Pager in the lower right corner. For fvwm2 it was twice as wide, up to the right edge of the xterm at the bottom.

[ThomasAdam]

OK. This would always have been broken in fvwm2 as well. I am not sure how best to solve this -- does tweaking the DesktopScale in FvwmPager help?

[harridu]

No, it just changes the size, not the aspect ratio.

But it worked fine for fvwm2, so I am not sure what you mean. Something fundamental has been changed for fvwm3 wrt what is considered as a "desktop". Did you notice that all the icons are shown on the right screen? This is unusual, too. For fvwm2 they popped up on the left screen even if the mouse pointer is in the right one.

BTW, xdpyinfo gives me the correct aspect ratio:

% xdpyinfo | grep dimensions
  dimensions:    3840x1200 pixels (1016x317 millimeters)

[somiaj]

There will also be the issue of per-monitor vs global mode.

But I could see that if the window size if the pager is not set, you could use the aspect ratio of the virtual desktop (global) or specific monitor (per-monitor) to determine the window size. I'm just unsure how FvwmPager determins the window size if one is not set (I have always explicitly set the size). Note you could use PipeRead and some shell math to make this not hardware dependent, just grab $[vp.width] and $[vp.height].

[ThomasAdam]

Yeah -- @harridu -- try doing that first so you get it right, with PipeRead and then we can look at getting this logic in to the pager.

[harridu]

I am not sure what this magic is supposed to achieve. "Look for the aspect ratio of the X display and keep it"?

Surely I understand that fvwm3 is pretty new. I don't expect a perfect solution. I came here just to report an inconsistency compared to the old fvwm2. Its your choice how to proceed. Thank you very much for your help

[ThomasAdam]

@harridu

It's got nothing to do with fwm3 being new.

Please take a look at the js/pager-window-size -- do nothing with your existing FvwmPager config, and hopefully the magic contained therein will correctly handle the aspect ratio.

Please do let me know how you get on testing this.