base auto stop bug fix (#152)

* fix base auto stop bug

* fix touchActive logic

lib/widgets/joystick.dart

@@ -1,3 +1,5 @@
+import 'dart:async';
+
 import 'package:flutter/widgets.dart';
 import 'package:flutter_joystick/flutter_joystick.dart';
 import 'package:viam_sdk/viam_sdk.dart';
@@ -19,6 +21,7 @@ class ViamBaseJoystick extends StatefulWidget {
 class _ViamBaseJoystickState extends State<ViamBaseJoystick> {
   num y = 0;
   num z = 0;
+  bool touchActive = false;
 
   @override
   Widget build(BuildContext context) {
@@ -28,12 +31,14 @@ class _ViamBaseJoystickState extends State<ViamBaseJoystick> {
         const SizedBox(height: 16),
         Joystick(
           listener: callSetPower,
+          onStickDragEnd: () => callSetPower(StickDragDetails(0, 0)),
         )
       ],
     );
   }
 
   void callSetPower(StickDragDetails details) {
+    touchActive = (details.x != 0 || details.y != 0);
     widget.base.setPower(
       Vector3()..y = details.y * -1,
       Vector3()..z = details.x * -1,
@@ -42,5 +47,19 @@ class _ViamBaseJoystickState extends State<ViamBaseJoystick> {
       y = details.y * -100;
       z = details.x * -100;
     });
+
+    // When the client has spotty network conditions,
+    // the joystick has a tendency to cause the machine
+    // to hang on the most recent setPower call and keep moving
+    // after the touch has been released. This is a workaround that
+    // will work faster than the session being canceled,
+    // if network conditions allowed. The session being canceled
+    // will eventually stop the base if network conditions become too spotty.
+    Future.delayed(const Duration(milliseconds: 100)).then((_) async {
+      final isMoving = await widget.base.isMoving();
+      if (isMoving && !touchActive) {
+        unawaited(widget.base.stop());
+      }
+    });
   }
 }