Fix stretched yaru togglables

[Jupi007]

• Center the painter to fix the stretch effect ;
• Add RepaintBoundary widget around the painter to keep a sharp look ;
• Correct weird logic of putting a Padding in a SizedBox, which was require to add up padding value to the dimensions.

@jpnurmi as you can see, I'm now using a personal fork ;)

Before:

After:

Pull request checklist

• This PR does not introduce visual changes

Fixes #484

[jpnurmi]

Thanks, LGTM! 👍

Is the RepaintBoundary absolutely necessary? The Material toggleables don't seem to use one either. I git a bit cautious because I debugged earlier what it does under the hood...

[Jupi007]

Is the RepaintBoundary absolutely necessary? The Material toggleables don't seem to use one either. I git a bit cautious because I debugged earlier what it does under the hood...

Well yes, because the togglable becomes blurry in the horizontal direction without one.
And I sadly don't know any other way to fix that problem...

[jpnurmi]

Well yes, because the togglable becomes blurry in the horizontal direction without one.

Does it happen with the Material togglables too?

And I sadly don't know any other way to fix that problem...

I think it's more like a coincidence that RepaintBoundary force-aligns to pixels because it creates a separate GtkWidget that cannot have floating point coordinates. It's just that using this trick for every checkbox is almost like creating floating GTK checkboxes on top of the Flutter view. 😀

[Jupi007]

Does it happen with the Material togglables too?

Well no, and I don't understand why, but material togglables are not affected by the pixel alignment problem.

I think it's more like a coincidence that RepaintBoundary force-aligns to pixels because it creates a separate GtkWidget that cannot have floating point coordinates. It's just that using this trick for every checkbox is almost like creating floating GTK checkboxes on top of the Flutter view. grinning

I will try to find another solution then.