SetMinSize() on anything with a MinSize()

[AlbinoGeek]

Is your feature request related to a problem? Please describe:

Currently, I find myself "extending" widgets literally only to override the MinSize()

Examples include List and Table when used in any compacting layout.

Is it possible to construct a solution with the existing API?

Perhaps I don't understand this question.

Describe the solution you'd like to see:

	t := time.Now()
	data := []struct{ Name, Size, Format, Created, Updated, Accessed string }{
		{"index.html", "21.4 KiB", "text/html", t.AddDate(0, 0, -2).String(), t.AddDate(0, 0, -1).String(), t.String()},
	}

	createLabel := func() fyne.CanvasObject {
		label := widget.NewLabel("X")
		label.SetMinSize(fyne.NewSize(100, 20))
		return label
	}

	list := widget.NewList(func() int { return len(data) }, createLabel, func(lii widget.ListItemID, f fyne.CanvasObject) {
		f.(*widget.Label).Text = data[lii].Name
	})
	list.SetMinSize(fyne.NewSize(200, 100))

	table := widget.NewTable(func() (int, int) { return len(data), 6 }, createLabel, func(tci widget.TableCellID, f fyne.CanvasObject) {
		atom := data[tci.Row]
		switch tci.Col {
		case 1:
			f.(*widget.Label).Text = atom.Name
		case 2:
			f.(*widget.Label).Text = atom.Size
		case 3:
			f.(*widget.Label).Text = atom.Format
		case 4:
			f.(*widget.Label).Text = atom.Created
		case 5:
			f.(*widget.Label).Text = atom.Updated
		case 6:
			f.(*widget.Label).Text = atom.Accessed
		}
	})
	table.SetMinSize(fyne.NewSize(600, 300))

	w.SetContent(container.NewVBox(
		widget.NewCard("Title", "Subtitle", list),
		widget.NewCard("Title2", "Subtitle2", table),
	))

[andydotxyz]

The Minimum size of any widget is defined as the size which it cannot be smaller than. This is essetial for laying out complex layouts whilst allowing users to resize windows up or down. Whhen you change the MinSize of an item it cannot become smaller. This is a big problem when scaling down to small screen sizes, like for mobile devices.

Table cells and items of List and Tree are special - they are sized based on the template MinSize. Instead of using your desired MinSize hack you should set an indicative template value instead:

		label := widget.NewLabel("Average string")

That is how they are designed.
In v1.4.1 there is an additional Table.SetColumnWidth that gives more fine-grained control.

For all elements their actual size is set by the container as a result of various calculations.
If you do not want your widget to shrink do not put it in a layout that shrinks the content.
There are various layouts available or you can provide your own.

• https://developer.fyne.io/started/layouts
• https://developer.fyne.io/tutorial/custom-layout

[AlbinoGeek]

Right, but this also is the issue of Table and List currently have a MinSize that is less than one template element tall -- resulting in an unusable table/list when put inside a compacting layout such as VBox or Card.

[andydotxyz]

Developers choose the layouts in containers as well as the widgets that get put in them - so can you apply a layout that expands the component you would like to be larger?

Without more concrete example or description of what cannot be done with the current design it is difficult to provide a more constructive solution, sorry.

[stuartmscott]

Table and List currently have a MinSize that is less than one template element tall

@andydotxyz there is an inconsistency here:

func (l *listRenderer) MinSize() fyne.Size {
	return l.scroller.MinSize()
}

func (t *tableRenderer) MinSize() fyne.Size {
	return t.cellSize
}

func (r *treeRenderer) MinSize() (min fyne.Size) {
	min = r.scroller.MinSize()
	min = min.Max(r.tree.branchMinSize)
	min = min.Max(r.tree.leafMinSize)
	return
}

I think Tree does it correctly

[andydotxyz]

There will be some inconsistency, but you're right these have deviated too far.
List does have the correct width - it is set indirectly by the Scroll being in vertical-only mode.

Possible changes:

• List minHeight to be equal to template item height
• Table minHeight and minWidth to match the template cell (plus padding)

That will fix up the inconsistency I think.

[AlbinoGeek]

^ Agreed, at least that would make them usable in a compact layout.

Currently, Table inside VBox gives you a .5 height and (seemingly unrelated) width.

[andydotxyz]

Looking into this further @stuartmscott, I think that Table is calculating it correctly - I thought it was maybe missing padding but seems not.
List min height may still be wrong.

I have re-run the image tests requesting that tables be minimum size, and they come out as expected...

I don't know what issue you are hitting @AlbinoGeek but it does not seem to be caused by Table.MinSize()

[AlbinoGeek]

@andydotxyz

• Very squished

	data := [][]string{
		{"Foo", "Bar", "Baz"},
		{"Foo", "Bar", "Baz"},
		{"Foo", "Bar", "Baz"},
	}
	table := widget.NewTable(
		func() (int, int) { return len(data), len(data[0]) },
		func() fyne.CanvasObject {
			return widget.NewLabel("@@@")
		},
		func(tci widget.TableCellID, f fyne.CanvasObject) {
			f.(*widget.Label).SetText(data[tci.Row][tci.Col])
		},
	)

	tc := container.NewAppTabs(
		container.NewTabItem("Table Issue",
			container.NewVBox(
				widget.NewCard("Title", "Subtitle", table),
			),
		),
	)
	w.SetContent(tc)

The issue pops up once you put Table inside a Card inside a VBox

---

Reducing Variables, without the AppTabs

• Very squished

	w.SetContent(
		container.NewVBox(
			widget.NewCard("Title", "Subtitle", table),
		),
	)

---

Only a VBox

• Works as expected

	w.SetContent(
		container.NewVBox(
			table,
		),
	)

---

Only a Card

• Significantly too much padding

	w.SetContent(
		widget.NewCard("Title", "Subtitle", table),
	)

[stuartmscott]

@AlbinoGeek thanks for sharing this code

@andydotxyz, @okratitan the collections should all return scroller.MinSize().Max(cell|item|branch|leaf.MinSize()+padding)

[andydotxyz]

Aha! Thanks @AlbinoGeek looks like this is a Card MinSize/Layout bug!
I can get that fixed in the morning

[andydotxyz]

The bug reported is now fixed on release/v1.4.x, and will be available in v1.4.2 in a few weeks.
Please test it and let me know if we can mark this ticket is resolved now @AlbinoGeek.

[AlbinoGeek]

Just noticed that canvas.Text has a SetMinSize and also draws at the correct baseline, where widget.Label does not.

[andydotxyz]

the correct baseline is only true as long as you don't expand the height of the text I think?
Because it is rendering only the pixels necessary. It has no vertical alignment so it's your usage of it that is correctly aligning, rather than the text ;)

[andydotxyz]

SetMinSize is required for Text and Image because the driver will discover the minimum size when it actually renders (due to font loading or image parsing).
In this regard canvas primitives are different to widgets - they don't really have implicit minimum (i.e. how big should a line be) so it allows the minimum setting.

[AlbinoGeek]

Gitcha! I can then say this is now fixed, save for the vertical baseline issue [covered elsewhere].

[ivoras]

Resurrecting this issue because entries in dialogs are sized weirdly. This is how a dialog.ShowForm() looks like with this code:

	dialog.ShowForm(
		"Password",
		"Ok",
		"Cancel",
		[]*widget.FormItem{
			{Text: "Password", Widget: passwordEntry},
		},
		func(b bool) {
			if !b {
				return
			}
			win.doOpenFile(frc.URI().String(), passwordEntry.Text)
		},
		win.win,
	)

The password entry is too small, and there's no SetMinSize() to correctly size it. But it gets even worse when the text label is longer:

[Jacalz]

@ivoras Please don’t resurrect old issues that have been closed. It is better to open a new issue or a discussion depending on the context. In this case however, there is a .Resize() method on the dialog and that will solve your issues mentioned above.