Window doesn't render when called for the first time from system tray and the last window was closed

[mbaklor]

Checklist

• I have searched the issue tracker for open issues that relate to the same problem, before opening a new one.
• This issue only relates to a single bug. I will open new issues for any other problems.

Describe the bug

I have an app set up with a system tray and splash screen, where the main window is hidden on startup until you open it from the systray. What I found is that if I don't render the window before the splash screen closes the window won't render. On windows by resizing it renders, on ubuntu it doesn't even do that.

I did find that using Hide on the splash screen instead of Close avoids the issue, so it's something about the last visibly window calling Close I guess? Couldn't find anything I could understand in the sources.

How to reproduce

build an app with a splash screen, no other window showing on startup, and a systray to open a window.

Screenshots

I'm not on my windows machine now so I'll grab that later but here's the linux:

Example code

func main() {
	a := app.New()
	label := widget.NewLabel("Window with content!")
	win := a.NewWindow("Render Test")
	win.SetContent(label)
	showWin := fyne.NewMenuItem("Show win", func() {
		win.Show()
	})
	menu := fyne.NewMenu("tray", showWin)

	if desk, ok := a.(desktop.App); ok {
		desk.SetSystemTrayMenu(menu)
	}
	if drv, ok := a.Driver().(desktop.Driver); ok {
		splash := drv.CreateSplashWindow()
		splash.SetContent(widget.NewLabel("Splash with content!"))
		splash.Show()
		go func() {
			time.Sleep(time.Second * 3)
			splash.Close()
		}()
	}
	win.SetCloseIntercept(func() {
		win.Hide()
	})
	a.Run()
}

Fyne version

both latest (2.3.5) and develop (v2.3.6-0.20230815202934-6f2c727d711a)

Go compiler version

1.20.5

Operating system and version

windows 11, 10, kubuntu 5.27.4

Additional Information

No response

[andydotxyz]

Fixed on develop

[mbaklor]

@andydotxyz looks like this is still happening on develop (v2.3.6-0.20230824093032-28ab69056a4c), I think the problem isn't a window being reused but a window being rendered for the first time after the last existing window (besides the systray monitor) is closed

This is what it looks like on my windows machine

[andydotxyz]

I have re-tweaked the order of the code since other changes landed. Fix should be back again.