Scrolled List bad redraw when window is maximized

[matwachich]

To Reproduce:

1. Run the code
2. Scroll the list a little bit down
3. Maximize the window

Example code:

package main

import (
	"fmt"
	"time"

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

type Person struct {
	ID           int
	Nom, Prenom  string
	DOB          time.Time
	LastActivity time.Time
}

func main() {
	a := app.New()
	w := a.NewWindow("Test")

	data := make([]Person, 10)
	for i := 0; i < 10; i++ {
		data[i].ID = i
		data[i].Nom = "AAAAAAAA"
		data[i].Prenom = "Aaaaaaaa"
		data[i].DOB = time.Now()
		data[i].DOB = time.Now()
	}

	lst := widget.NewList(
		func() int {
			return len(data)
		},
		func() fyne.CanvasObject {
			co := container.NewHBox(
				widget.NewLabel("id"),
				widget.NewLabel("nom prenom"),
				widget.NewLabel("dob\r\nage"),
				layout.NewSpacer(),
				widget.NewLabel("last activity:\r\ndate"),
			)
			co.Objects[1].(*widget.Label).TextStyle.Bold = true
			return co
		},
		func(i widget.ListItemID, co fyne.CanvasObject) {
			co.(*fyne.Container).Objects[0].(*widget.Label).SetText(fmt.Sprintf("%02d", data[i].ID))
			co.(*fyne.Container).Objects[1].(*widget.Label).SetText(fmt.Sprintf("%s %s", data[i].Nom, data[i].Prenom))
			co.(*fyne.Container).Objects[2].(*widget.Label).SetText(fmt.Sprintf("%s\r\n(00 years old)", data[i].DOB.Format("02/01/2006")))
			co.(*fyne.Container).Objects[4].(*widget.Label).SetText(fmt.Sprintf("Last activity:\r\n%s", data[i].LastActivity.Format("02/01/2006 à 15h04m05s")))
		},
	)

	w.SetContent(container.NewMax(lst))

	w.Resize(fyne.NewSize(800, 400))
	w.ShowAndRun()
}

Device (please complete the following information):

• OS: Windows
• Version: 10
• Go version: 1.18.2
• Fyne version: 2.1.4

[Jacalz]

Would you mind checking if you can replicate this issue on the develop branch? I think this might have been solved by #3012. You should be able to just update your local module using go get fyne.io/fyne/v2@develop && go mod tidy.

[cmitsakis]

I can confirm this bug.

The top elements (that were hidden because of scrolling) do not appear when I maximize. They are replaced by empty space. But when I click at any element they appear. This happens even on develop.

This doesn't happen if you increase the number of elements enough so that the maximized window can keep scroll at the same position.

If you can't replicate, you can change the number of elements (or the window resolution) so there is scroll when the window is small and there is no scroll when maximized.

[cmitsakis]

this bug happens in Table too

[andydotxyz]

Argh I hate that Windows manages to make maximise and minimise somehow different on their OS than all others

[andydotxyz]

On develop for testing, thanks @cmitsakis