This splash screen OK button might be exiting without causing a GTK panic

Signed-off-by: Jeff Carr <jcarr@wit.com>

example-splash/main.go

@@ -10,7 +10,6 @@ import _ "github.com/andlabs/ui/winmanifest"
 var mainwin *ui.Window
 var hbox *ui.Box
 var vbox *ui.Box
-var newgroup *ui.Group
 
 func makeSplashPage() ui.Control {
 	hbox = ui.NewHorizontalBox()
@@ -43,8 +42,48 @@ func makeSplashPage() ui.Control {
 	return hbox
 }
 
+func showSplash() {
+	splashWin := ui.NewWindow("Splash Screen", 640, 480, false)
+	splashWin.OnClosing(func(*ui.Window) bool {
+		ui.Quit()
+		return true
+	})
+	ui.OnShouldQuit(func() bool {
+		splashWin.Destroy()
+		return true
+	})
+
+	tab := ui.NewTab()
+	splashWin.SetChild(tab)
+	splashWin.SetMargined(true)
+
+	hbox := ui.NewHorizontalBox()
+	hbox.SetPadded(true)
+
+	group := ui.NewGroup("Numbers")
+	group.SetMargined(true)
+	hbox.Append(group, true)
+
+	vbox = ui.NewVerticalBox()
+	vbox.SetPadded(true)
+	group.SetChild(vbox)
+
+	okButton := ui.NewButton("OK")
+		okButton.OnClicked(func(*ui.Button) {
+		log.Println("OK. Closing window.")
+		splashWin.Destroy()
+		ui.Quit()
+	})
+	vbox.Append(okButton, false)
+
+	tab.Append("WIT Splash", hbox)
+	tab.SetMargined(0, true)
+
+	splashWin.Show()
+}
+
 func setupUI() {
-	mainwin = ui.NewWindow("gui-example1", 300, 200, false)
+	mainwin := ui.NewWindow("gui-example1", 300, 200, false)
 	mainwin.OnClosing(func(*ui.Window) bool {
 		ui.Quit()
 		return true
@@ -65,29 +104,35 @@ func setupUI() {
 }
 
 func main() {
-	go ui.Main(setupUI)
+	ui.Main(showSplash)
+
+	ui.Main(setupUI)
 
 	// locks up GTK after a while (50 times)
 	time.Sleep(1000 * time.Millisecond)
 	count := 0
-	for {
-		time.Sleep(300 * time.Millisecond)
-		log.Println("sleep")
 
-		if (newgroup == nil) {
+	var newgroup *ui.Group
+
 	name := "Test " + fmt.Sprintf("%d", count)
 	log.Println("name=",name)
 	newgroup = ui.NewGroup(name)
 	newgroup.SetMargined(true)
 	hbox.Append(newgroup, false)
-			// newgroup = append(newgroup, group)
+
-			count += 1
+	// display the splash screen info
-		} else {
+	log.Println("sleep for 3")
+	time.Sleep(3000 * time.Millisecond)
+
 	hbox.Delete(1)
 	// newgroup.Delete()
 	// can't destroy when there is a parent
 	newgroup.Destroy()
 	newgroup = nil
-		}
+
+	// wait forever here
+	for {
+		log.Println("sleep for 3 forever here")
+		time.Sleep(3000 * time.Millisecond)
 	}
 }

test1/Makefile

@@ -0,0 +1,2 @@
+run:
+	go run *.go

test1/crash1

@@ -0,0 +1,35 @@
+2019/05/17 10:59:15 name= Test 128
+2019/05/17 10:59:15 sleep
+2019/05/17 10:59:15 sleep
+2019/05/17 10:59:15 name= Test 129
+2019/05/17 10:59:16 sleep
+fatal error: unexpected signal during runtime execution
+[signal SIGSEGV: segmentation violation code=0x1 addr=0x7f8c000000b8 pc=0x7f8cbfb2f8e5]
+
+runtime stack:
+runtime.throw(0x50c4b8, 0x2a)
+	/usr/lib/go-1.11/src/runtime/panic.go:608 +0x72
+runtime.sigpanic()
+	/usr/lib/go-1.11/src/runtime/signal_unix.go:374 +0x2f2
+
+goroutine 19 [syscall]:
+runtime.cgocall(0x4b5490, 0xc00004df78, 0xc0000ac048)
+	/usr/lib/go-1.11/src/runtime/cgocall.go:128 +0x5e fp=0xc00004df48 sp=0xc00004df10 pc=0x41688e
+github.com/andlabs/ui._Cfunc_uiMain()
+	_cgo_gotypes.go:2518 +0x41 fp=0xc00004df78 sp=0xc00004df48 pc=0x4a9711
+github.com/andlabs/ui.Main(0x50d890, 0xc00003a701, 0xc0000842c0)
+	/home/jcarr/go/src/github.com/andlabs/ui/main.go:41 +0xfd fp=0xc00004dfc8 sp=0xc00004df78 pc=0x4ad6cd
+runtime.goexit()
+	/usr/lib/go-1.11/src/runtime/asm_amd64.s:1333 +0x1 fp=0xc00004dfd0 sp=0xc00004dfc8 pc=0x466461
+created by main.main
+	/home/jcarr/go/src/git.wit.com/wit/cloud-control-panel/example-splash/main.go:68 +0x53
+
+goroutine 1 [sleep, locked to thread]:
+time.Sleep(0x11e1a300)
+	/usr/lib/go-1.11/src/runtime/time.go:105 +0x14f
+main.main()
+	/home/jcarr/go/src/git.wit.com/wit/cloud-control-panel/example-splash/main.go:74 +0x74
+exit status 2
+make: *** [Makefile:2: run] Error 1
+jcarr@librem15:~/go/src/git.wit.com/wit/cloud-control-panel/example-splash$ git diff
+

test1/main.go

@@ -0,0 +1,93 @@
+package main
+
+import "time"
+import "log"
+import "fmt"
+
+import "github.com/andlabs/ui"
+import _ "github.com/andlabs/ui/winmanifest"
+
+var mainwin *ui.Window
+var hbox *ui.Box
+var vbox *ui.Box
+var newgroup *ui.Group
+
+func makeSplashPage() ui.Control {
+	hbox = ui.NewHorizontalBox()
+	hbox.SetPadded(true)
+
+	group := ui.NewGroup("Numbers")
+	group.SetMargined(true)
+	hbox.Append(group, true)
+
+	vbox = ui.NewVerticalBox()
+	vbox.SetPadded(true)
+	group.SetChild(vbox)
+
+	spinbox := ui.NewSpinbox(47, 100)
+	slider  := ui.NewSlider(21, 100)
+	pbar    := ui.NewProgressBar()
+
+	spinbox.OnChanged(func(*ui.Spinbox) {
+		slider.SetValue(spinbox.Value())
+		pbar.SetValue(spinbox.Value())
+	})
+	slider.OnChanged(func(*ui.Slider) {
+		spinbox.SetValue(slider.Value())
+		pbar.SetValue(slider.Value())
+	})
+	vbox.Append(spinbox, false)
+	vbox.Append(slider, false)
+	vbox.Append(pbar, false)
+
+	return hbox
+}
+
+func setupUI() {
+	mainwin = ui.NewWindow("gui-example1", 300, 200, false)
+	mainwin.OnClosing(func(*ui.Window) bool {
+		ui.Quit()
+		return true
+	})
+	ui.OnShouldQuit(func() bool {
+		mainwin.Destroy()
+		return true
+	})
+
+	tab := ui.NewTab()
+	mainwin.SetChild(tab)
+	mainwin.SetMargined(true)
+
+	tab.Append("WIT Splash", makeSplashPage())
+	tab.SetMargined(0, true)
+
+	mainwin.Show()
+}
+
+func main() {
+	go ui.Main(setupUI)
+
+	// locks up GTK after a while (50 times)
+	time.Sleep(1000 * time.Millisecond)
+	count := 0
+	for {
+		time.Sleep(300 * time.Millisecond)
+		log.Println("sleep")
+
+		if (newgroup == nil) {
+			name := "Test " + fmt.Sprintf("%d", count)
+			log.Println("name=",name)
+			newgroup = ui.NewGroup(name)
+			newgroup.SetMargined(true)
+			hbox.Append(newgroup, false)
+			// newgroup = append(newgroup, group)
+			count += 1
+		} else {
+			hbox.Delete(1)
+			// newgroup.Delete()
+			// can't destroy when there is a parent
+			newgroup.Destroy()
+			newgroup = nil
+		}
+	}
+}