On a small screen (1024x768, default size in VirtualBox), the Edit Brush settings window is not usable; I did some measurements: The horizontal sliders take 360 pixels, which is way beyond what is actually needed. The right widget, (the area where the user can test the settings on an actual brush), is < 90 pixels wide. And some controls are not even visible. See on the attached screenshot.
Created attachment 70083 [details] Krita on a small screen Screenshot mentioned in the original bug report.
There is no way to fix that. The brush setting are exactly as big as is needed to show the setting without adding scrollbars. Krita simply isn't suitable for 1024x768.
Most of the controls inside the brush settings are: a/ sliders : some of them are way too wide.. just because they can. In a more compact version, they could be replaced by a single spinEdit or a dial, or a spinEdit with advanced functionality, like changing the value with a vertical click and drag. The Y offset between the initial click position and current position is added to the initial value. b/ grid views ( when each cell contains a brush) can be sized down c/ spline editors could be smaller if needed The TreeViews also waste some horizontal space because they are not as narrow as their narrowest element. A better use of vertical space could be made. This would benefit to everybody; even if I have a lot of space on my 1920x1200 monitor, I feel a little frustrated when I can't have a test zone wider than 256 pixels.
a) These sliders are made to replace spinboxes everywhere. Key feature there is that you can direct click on the slider to get the value, without need to drag. But the slider are not a problem for the size of as the can get shorter than, b) Yep c) I think that is still the biggest issue as you want keep it as big as possible to make editing easier and also keep it square. Measuring the size of the listviews is pointless as e.g. in the german version the string get much longer.
If the brush settings window cannot be changed, then on small screens it should be detached by default. This is not optimal, but at least it allows users to use everything inside this window.
Created attachment 70144 [details] Screenshot with smaller settings I have experimented a bit with the size, it's not down to 1024 as that starts to look a bit ugly.
One reason it's fairly big is because we wanted the size to stay the same no matter which page is shown, and some pages have to be quite big, like the pattern selection page. (If we could have a popup pop up from a popup that wouldn't be necessary, but that's apparently not feasible.) So I'm all for fixing the layout and making it as small as possible, but not at the cost of resizing when jumping to another option.
I have pushed a branch to experiment with that: krita-smallsettings-langkamp
Branch has been merged.