fix: disable drawing on app hide

Author: zinstack625

packages/onyxsdk_pen/android/src/main/kotlin/com/example/onyxsdk_pen/OnyxsdkPenArea.kt

@@ -231,11 +231,15 @@ internal class OnyxsdkPenArea(context: Context, messenger: BinaryMessenger, id:
             val params = call.arguments<Map<String, Any>?>()
             updateStroke(params)
             result.success(null)
+        } else if (call.method == "setDraw") {
+            val param = call.arguments<Boolean>()
+            touchHelper.setRawDrawingEnabled(param!!)
+            result.success(null)
         } else {
             result.notImplemented()
         }
     }
-    
+
     override fun dispose() {
         touchHelper.closeRawDrawing()
     }

packages/onyxsdk_pen/lib/onyxsdk_pen_area.dart

@@ -44,7 +44,7 @@ class OnyxSdkPenArea extends StatefulWidget {
   }
 }
 
-class _OnyxSdkPenAreaState extends State<OnyxSdkPenArea> {
+class _OnyxSdkPenAreaState extends State<OnyxSdkPenArea> with WidgetsBindingObserver {
   static bool? _isOnyxDevice = (kIsWeb || !Platform.isAndroid) ? false : null;
   static Future<bool> _findIsOnyxDevice() async {
     if (_isOnyxDevice != null) return _isOnyxDevice!;
@@ -91,6 +91,25 @@ class _OnyxSdkPenAreaState extends State<OnyxSdkPenArea> {
     channel.invokeMethod('updateStroke', creationParams).catchError((e) {});
   }
 
+  @override
+  void initState() {
+    WidgetsBinding.instance.addObserver(this);
+    super.initState();
+  }
+
+  @override
+  void didChangeAppLifecycleState(AppLifecycleState state) async {
+    switch (state) {
+      case AppLifecycleState.resumed:
+        channel.invokeMethod('setDraw', true).catchError((e) {});
+        break;
+      case AppLifecycleState.paused:
+        channel.invokeMethod('setDraw', false).catchError((e) {});
+        break;
+      default:
+    }
+}
+
   @override
   Widget build(BuildContext context) {
     if (!isOnyxDevice) return widget.child;