playing around with Destroy() & Delete()

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

example-splash/Makefile

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

example-splash/main.go

@@ -0,0 +1,92 @@
+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)
+
+	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
+		}
+	}
+}