Merge pull request #400 from juliansteenbakker/imp/error-handling

imp: error handling

@@ -15,16 +15,22 @@ Breaking changes:
 
 Improvements:
 * Toggling the device torch now does nothing if the device has no torch, rather than throwing an error.
+* Removed `called stop while already stopped` messages.
 
 Features:
 * Added a new `placeholderBuilder` function to the `MobileScanner` widget to customize the preview placeholder.
 * Added `autoStart` parameter to MobileScannerController(). If set to false, controller won't start automatically.
-
-Fixed:
-* Fixed a memory leak where the `MobileScanner` widget would never close its subscription to the barcode events.
-* Fixed a dependency on all properties of `MediaQueryData` to build the preview widget. Now the preview only depends on its layout constraints.
+* Added `hasTorch` function on MobileScannerController(). After starting the controller, you can check if the device has a torch.
+
+Fixes:
+* Fixes the missing gradle setup for the Android project, which prevented gradle sync from working.
+* Fixes `MobileScannerController.stop()` throwing when already stopped.
+* Fixes `MobileScannerController.toggleTorch()` throwing if the device has no torch.
+  Now it does nothing if the torch is not available.
+* Fixes a memory leak where the `MobileScanner` would keep listening to the barcode events.
+* Fixes the `MobileScanner` preview depending on all attributes of `MediaQueryData`.
+  Now it only depends on its layout constraints.
 * Fixed a potential crash when the scanner is restarted due to the app being resumed.
-* Various documentation improvements.
   
 ## 3.0.0-beta.2
 Breaking changes:

@@ -101,6 +101,19 @@ class MobileScannerController {
 
   bool? _hasTorch;
 
+  /// Returns whether the device has a torch.
+  ///
+  /// Throws an error if the controller is not initialized.
+  bool get hasTorch {
+    if (_hasTorch == null) {
+      throw const MobileScannerException(
+        errorCode: MobileScannerErrorCode.controllerUninitialized,
+      );
+    }
+
+    return _hasTorch!;
+  }
+
   /// Set the starting arguments for the camera
   Map<String, dynamic> _argumentsToMap({CameraFacing? cameraFacingOverride}) {
     final Map<String, dynamic> arguments = {};

@@ -238,9 +238,7 @@ public class MobileScannerPlugin: NSObject, FlutterPlugin, FlutterStreamHandler,
     
     func toggleTorch(_ call: FlutterMethodCall, _ result: @escaping FlutterResult) {
         if (device == nil) {
-            result(FlutterError(code: "MobileScanner",
-                                    message: "Called toggleTorch() while stopped!",
-                                    details: nil))
+            result(nil)
             return
         }
         do {