Add RowWrap layout

[ErikKalkoken]

Description:

Adds a new layout for dynamically arranging objects with same height in rows with wrapping.

In my opinion this layout solves a common layout problem and would be a good addition the Fyne toolkit. For example it would allow to dynamically arranging a set of filter chips in multiple rows:

I went with "RowWrap", because it arranges objects in rows and wraps them. This layout is similar to the existing GridWrap layout, so a similar name makes sense (i.e. it arranges in rows instead of a grid). But I am of course open to other suggestions.

Demo

Here is an example render:

Screencast.from.17.03.2025.15.39.08.webm

Code to reproduce the example:

package main

import (
	"fyne.io/fyne/v2"
	"fyne.io/fyne/v2/app"
	"fyne.io/fyne/v2/container"
	"fyne.io/fyne/v2/layout"
	"fyne.io/fyne/v2/widget"
)

func main() {
	a := app.New()
	w := a.NewWindow("RowWrap layout")
	c := container.New(
		layout.NewRowWrapLayout(),
		widget.NewButton("Alpha", nil),
		widget.NewButton("Bravo Charlie", nil),
		widget.NewButton("Delta", nil),
		widget.NewButton("Echo Foxtrott Golf Hotel", nil),
		widget.NewButton("India Juliet", nil),
		widget.NewButton("Kilo Limo Mike November", nil),
	)
	w.SetContent(c)
	w.Resize(fyne.NewSize(50, 50))
	w.ShowAndRun()
}

Checklist:

• Tests included.
• Lint and formatter run with no errors.
• Tests all pass.

Where applicable:

• Public APIs match existing style and have Since: line.

Open

• Add tests for custom padding variant

[coveralls]

coverage: 62.378% (+0.02%) from 62.357%
when pulling 48e3034 on ErikKalkoken:add-rowwrap-layout
into b66cb98 on fyne-io:develop.

[Jacalz]

I really like the idea of this. Just left a few minor suggestions inline before I noticed it was a draft PR but I'm attaching them anyway :)

[Jacalz]

Cleaner to just return directly:

Suggested change

	s := fyne.NewSize(width, rowHeight*float32(rows)+l.verticalPadding*float32(rows-1))
	return s
	return fyne.NewSize(width, rowHeight*float32(rows)+l.verticalPadding*float32(rows-1))

[Jacalz]

I think there is a fyne.Max() function you can use here instead.

[andydotxyz]

Do try not to force-push after reviews, it means that every review has to be from scratch not incremental.

[Jacalz]

Generally yes, though I'd say that it makes sense to force push for changes in a PR that is still in draft. I only submitted my review because I didn't realise it being drafted at the time

[ErikKalkoken]

This PR is now finally ready for review.

All review comments so far have been addressed. I am expecting the reviewers to resolve their issues if they agree.

[Jacalz]

Thanks. Just a few minor suggestions inline.

[Jacalz]

Nice one. Thanks 👍