Add support for Wrapping for RadioGroup option strings

[qiulaidongfeng]

add field Wrapping to RadioGroup.
In order to enable word wrapping
for text exceeding the screen
when creating a single choice question UI,
similar to the TextWrapBreak for widget.Label

Fixes #5656

[andydotxyz]

Thanks for looking at this. It is too late for 2.8 unfortunately as we have passed feature freeze, but if you target 2.9 we can land it after release.

It is worrying that there are so many layout changes for an optional new parameter - can you comment on that?

A few inline comments about things that don't seem quite right too.

[andydotxyz]

This makes no sense...

[qiulaidongfeng]

This is because previously we set txt.TextSize = i.Theme().Size(theme.SizeNameText) in radioItemRenderer.Refresh, but RichText does not have this field. so my do r.label.Segments[0].(*TextSegment).Style.SizeName = theme.SizeNameText,but it not change Size() result. If there is a better way to do this, please let me know. Thank you

[andydotxyz]

Sorry, I meant more literally - it makes no sense to have a fyne.Theme that is called customTextSize.

[andydotxyz]

If you want to check the text size output for a widget you can use WidgetRenderer(...) to get the renderer and then call Objects() on that to get the canvas.Text.

[andydotxyz]

It looks like this does not propagate change if Wrapping is set after initial creation

[qiulaidongfeng]

Fixed

[andydotxyz]

This looks incorrect - the minSize of an object should not be set to its current size

[qiulaidongfeng]

I revised the code to demonstrate my intention. Specifically, when RichText uses fyne.TextWrapBreak, its MinSize might not occupy enough screen space, resulting in unexpected line breaks.

[coveralls]

coverage: 59.817% (+0.01%) from 59.806% — qiulaidongfeng:develop into fyne-io:develop

[qiulaidongfeng]

Thanks for your quick reply.

It is worrying that there are so many layout changes for an optional new parameter - can you comment on that?

This is inevitable as radioItemRenderer has been changed from using canvas.Text to widget.RichText.
However, I believe the following benefits make it worthwhile to do so:
It improves the readability and development efficiency of the code. Previously, for similar UI, I needed to write

func newRadio(options []string, onclick func(string)) (*fyne.Container, func(tf bool, sigle int, typ int)) {
	var selected string
	var checkboxes []*widget.Check
	content := container.NewVBox()
	for i, option := range options {
		label := widget.NewLabel(option)
		label.Wrapping = fyne.TextWrapBreak 

		check := widget.NewCheck("", func(checked bool) {
			if checked {
				for j, cb := range checkboxes {
					if j != i {
						cb.SetChecked(false)
					} else {
						selected = options[j]
						onclick(selected)
					}
				}
			} else {
				selected = ""
			}
		})
		checkboxes = append(checkboxes, check)
		hbox := container.NewVBox(check, label)
		content.Add(hbox)
	}
	return content, func(b bool, single int, typ int) {
		if typ == 0 {
			if b {
				checkboxes[0].SetChecked(true)
			} else {
				checkboxes[1].SetChecked(true)
			}
			return
		}
		checkboxes[single].SetChecked(true)
	}
}

This is just to make text display using the existing fyne.TextWrapBreak.

Secondly, this is similar to word-break: break-all and only requires one line, which is easy to learn.
If we can accomplish roughly the same thing more simply,
it will help Go programmers with HTML experience like me learn Fyne faster.

[andydotxyz]

With this the type of Wrapping is now different for RadioItem vs RadioGroup - inconsistency is bad.
I think you'll need a different approach to updating (typically a render retains a reference to the type it renders, perhaps that works here?

[andydotxyz]

Just a couple of comments inline.

However the big issue here is what you see in all the test changes - the widget is no longer the same size. Moving text -> RichText does make sizing changes but they need to be handled internally. I suspect your usage of InlineIconSize are trying to approximate, but it looks wrong.

[andydotxyz]

Sorry, I meant more literally - it makes no sense to have a fyne.Theme that is called customTextSize.

[andydotxyz]

If you want to check the text size output for a widget you can use WidgetRenderer(...) to get the renderer and then call Objects() on that to get the canvas.Text.