Swallowing FvwmPager inside FvwmButtons breaks resizing FvwmButtons when aspect ratio resizing is used

[ThomasAdam]

When FvwmButtons is told to swallow FvwmPager, where the FvwmPager doesn't have a geometry set in its module configuration, FvwmButtons doesn't respect the aspect ratio size of FvwmPager when resizing FvwmButtons, and the results look very odd.

Here's a configuration snippet to reproduce this:

Style FP* !Title, BorderWidth 4, Sticky, WindowListSkip

DestroyModuleConfig FP1:*
*FP1: Font "Xft:Book:size=8"
*FP1: Columns 1
*FP1: SmallFont none
*FP1: DeskHilight
*FP1: Back SlateBlue
*FP1: Fore Black
*FP1: Hilight Orchid
*FP1: WindowColors Black '#60A0C0' Black '#c06077'
*FP1: UseSkipList

KillModule FvwmPager FP1

DestroyModuleConfig FB-FP1:*
*FB-FP1: (Swallow "FP1" "Module FvwmPager FP1 0 4")

Module FvwmButtons FB-FP1

This is because when FvwmPager doesn't have a geometry set, it defaults to using aspect ratio resize hints. I think in this case, aspect ratio should still be preserved.

[somiaj]

The issue here is that FvwmPager is correctly keeping the aspect ratio preserved, but when it is swallowed in FvwmButtons, FvwmButtons makes the pager fit the button size. This results in the pager being bigger than the button (if the button aspect ratio doesn't match the pagers), and thus the pager is getting cut off, then when you resize how it is getting cut off changes with the size of the button (causing the strange look).

So FvwmPager is preserving the aspect ratio, but FvwmButtons is making the window to big, maybe swallow needs to be adjusted so when it resizes the window, it doesn't grow a window bigger than the button, allowing it to preserve its aspect ratio.

Note: Using Swallow (NoHints) correctly ignores the hints, making the pager correctly fit the button size. So I think the issue is when using Hints, FvwmButtons should make sure the window is smaller than the button (not bigger).

[somiaj]

@ThomasAdam Checkout out js/gh-573. I reverse the logic in FvwmButtons, so when honoring window Hints, windows are shrunk to fit inside of the button (instead of growing them). This will make things inside the button fit and preserve the aspect ratio. Note if you make the window too small, and shrinking would make the window smaller than its min-size, it will then revert to the old method of growing the window to be bigger than the button (thus cutting off parts of the pager -- or any other window). So you will see some strange behavior in the extreme cases.

[ThomasAdam]

Thanks, @somiaj. I think this change is definitely good enough. Can you open a PR, please?

[dirteat]

Interestingly, for a Pager which is 3x3 virtual desktop, I have the bug now with 1.0.4. With Hints, the pager is reduced in sized and does not fit the button any more. I have to use NoHints to make it fit again!