cmd/tailscale: close overflow menu when the Android back button is pressed

Signed-off-by: Elias Naur <mail@eliasnaur.com>

cmd/tailscale/main.go

@@ -550,6 +550,12 @@ func (a *App) runUI() error {
 			switch e := e.(type) {
 			case system.DestroyEvent:
 				return e.Err
+			case *system.CommandEvent:
+				if e.Type == system.CommandBack {
+					if ui.onBack() {
+						e.Cancel = true
+					}
+				}
 			case system.FrameEvent:
 				gtx := layout.NewContext(&ops, e)
 				events := ui.layout(gtx, e.Insets, state)

cmd/tailscale/ui.go

@@ -168,6 +168,14 @@ func newUI(store *stateStore) (*UI, error) {
 	return ui, nil
 }
 
+func (ui *UI) onBack() bool {
+	if !ui.menu.show {
+		return false
+	}
+	ui.menu.show = false
+	return true
+}
+
 func (ui *UI) layout(gtx layout.Context, sysIns system.Insets, state *clientState) []UIEvent {
 	ui.events = nil
 	if ui.enabled.Changed() {