handle errors from start() in callback

@@ -165,7 +165,6 @@ class MobileScannerHandler(
 
         val detectionSpeed: DetectionSpeed = DetectionSpeed.values().first { it.intValue == speed}
 
-        try {
         mobileScanner!!.start(
             barcodeScannerOptions,
             returnImage,
@@ -183,41 +182,44 @@ class MobileScannerHandler(
                     ))
                 }
             },
-                timeout.toLong(),
-                cameraResolution,
-            )
-        } catch (e: AlreadyStarted) {
+            mobileScannerErrorCallback = {
+                Handler(Looper.getMainLooper()).post {
+                    when (it) {
+                        is AlreadyStarted -> {
                             result.error(
                                 "MobileScanner",
                                 "Called start() while already started",
                                 null
                             )
-        } catch (e: NoCamera) {
-            result.error(
-                "MobileScanner",
-                "No camera found or failed to open camera!",
-                null
-            )
-        } catch (e: TorchError) {
+                        }
+                        is CameraError -> {
                             result.error(
                                 "MobileScanner",
-                "Error occurred when setting torch!",
+                                "Error occurred when setting up camera!",
                                 null
                             )
-        } catch (e: CameraError) {
+                        }
+                        is NoCamera -> {
                             result.error(
                                 "MobileScanner",
-                "Error occurred when setting up camera!",
+                                "No camera found or failed to open camera!",
                                 null
                             )
-        } catch (e: Exception) {
+                        }
+                        else -> {
                             result.error(
                                 "MobileScanner",
-                "Unknown error occurred..",
+                                "Unknown error occurred.",
                                 null
                             )
                         }
                     }
+                }
+            },
+            timeout.toLong(),
+            cameraResolution,
+        )
+    }
 
     private fun stop(result: MethodChannel.Result) {
         try {