Merge pull request #40 from juliansteenbakker/image-picker

Feature: Image picker

+## 0.2.0
+You can provide a path to controller.analyzeImage(path) in order to scan a local photo from the gallery!
+Check out the example app to see how you can use the image_picker plugin to retrieve a photo from
+the gallery. Please keep in mind that this feature is only supported on Android and iOS.
+
 ## 0.1.3
 * Fixed crash after asking permission. [#29](https://github.com/juliansteenbakker/mobile_scanner/issues/29)
 * Upgraded cameraX from 1.1.0-beta01 to 1.1.0-beta02

@@ -11,11 +11,30 @@ A universal barcode and QR code scanner for Flutter based on MLKit. Uses CameraX
 | :-----: | :-: | :---: | :-: | :---: | :-----: |
 |   ✔️    | ✔️   |  ✔️  |   |     |      |
 
-CameraX for Android requires at least SDK 21.
+### Android
+SDK 21 and newer. Reason: CameraX requires at least SDK 21.
 
-MLKit for iOS requires at least iOS 11 and a [64bit device](https://developers.google.com/ml-kit/migration/ios).
+### iOS
+iOS 11 and newer. Reason: MLKit for iOS requires at least iOS 11 and a [64bit device](https://developers.google.com/ml-kit/migration/ios).
 
-# Usage
+**Add the following keys to your Info.plist file, located in <project root>/ios/Runner/Info.plist:**
+
+NSCameraUsageDescription - describe why your app needs access to the camera. This is called Privacy - Camera Usage Description in the visual editor.
+
+**If you want to use the local gallery feature from [image_picker](https://pub.dev/packages/image_picker)**
+  
+NSPhotoLibraryUsageDescription - describe why your app needs permission for the photo library. This is called Privacy - Photo Library Usage Description in the visual editor.
+  
+### macOS
+macOS 10.13 or newer. Reason: Apple Vision library.
+
+## Features Supported
+
+| Features               | Android            | iOS                | macOS | Web |
+|------------------------|--------------------|--------------------|-------|-----|
+| analyzeImage (Gallery) | :heavy_check_mark: | :heavy_check_mark: |   :x:    |  :x:   |
+
+## Usage
 
 Import `package:mobile_scanner/mobile_scanner.dart`, and use the widget with or without the controller.
 

@@ -4,6 +4,7 @@ import android.Manifest
 import android.app.Activity
 import android.content.pm.PackageManager
 import android.graphics.Point
+import android.net.Uri
 import android.util.Log
 import android.util.Size
 import android.view.Surface
@@ -22,6 +23,8 @@ import io.flutter.plugin.common.MethodCall
 import io.flutter.plugin.common.MethodChannel
 import io.flutter.plugin.common.PluginRegistry
 import io.flutter.view.TextureRegistry
+import java.io.File
+import java.net.URI
 
 
 class MobileScanner(private val activity: Activity, private val textureRegistry: TextureRegistry)
@@ -50,6 +53,7 @@ class MobileScanner(private val activity: Activity, private val textureRegistry:
             "torch" -> toggleTorch(call, result)
 //            "analyze" -> switchAnalyzeMode(call, result)
             "stop" -> stop(result)
+            "analyzeImage" -> analyzeImage(call, result)
             else -> result.notImplemented()
         }
     }
@@ -205,6 +209,24 @@ class MobileScanner(private val activity: Activity, private val textureRegistry:
 //        result.success(null)
 //    }
 
+    private fun analyzeImage(call: MethodCall, result: MethodChannel.Result) {
+        val uri = Uri.fromFile( File(call.arguments.toString()))
+        val inputImage = InputImage.fromFilePath(activity, uri)
+
+        var barcodeFound = false
+        scanner.process(inputImage)
+            .addOnSuccessListener { barcodes ->
+                for (barcode in barcodes) {
+                    barcodeFound = true
+                    sink?.success(mapOf("name" to "barcode", "data" to barcode.data))
+                }
+            }
+            .addOnFailureListener { e -> Log.e(TAG, e.message, e)
+                result.error(TAG, e.message, e)}
+            .addOnCompleteListener { result.success(barcodeFound) }
+
+    }
+
     private fun stop(result: MethodChannel.Result) {
         if (camera == null) {
             result.error(TAG,"Called stop() while already stopped!", null)

@@ -2,6 +2,8 @@
 <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 <plist version="1.0">
 <dict>
+	<key>NSPhotoLibraryUsageDescription</key>
+	<string>We need access in order to open photos of barcodes</string>
 	<key>NSCameraUsageDescription</key>
 	<string>We use the camera to scan barcodes</string>
 	<key>CFBundleDevelopmentRegion</key>

 import 'package:flutter/material.dart';
+import 'package:image_picker/image_picker.dart';
 import 'package:mobile_scanner/mobile_scanner.dart';
 
 class BarcodeScannerWithController extends StatefulWidget {
@@ -85,7 +86,7 @@ class _BarcodeScannerWithControllerState
                               })),
                       Center(
                         child: SizedBox(
-                          width: MediaQuery.of(context).size.width - 160,
+                          width: MediaQuery.of(context).size.width - 200,
                           height: 50,
                           child: FittedBox(
                             child: Text(
@@ -115,6 +116,32 @@ class _BarcodeScannerWithControllerState
                         iconSize: 32.0,
                         onPressed: () => controller.switchCamera(),
                       ),
+                      IconButton(
+                        color: Colors.white,
+                        icon: const Icon(Icons.image),
+                        iconSize: 32.0,
+                        onPressed: () async {
+                          final ImagePicker _picker = ImagePicker();
+                          // Pick an image
+                          final XFile? image = await _picker.pickImage(
+                              source: ImageSource.gallery);
+                          if (image != null) {
+                            if (await controller.analyzeImage(image.path)) {
+                              ScaffoldMessenger.of(context)
+                                  .showSnackBar(const SnackBar(
+                                content: Text('Barcode found!'),
+                                backgroundColor: Colors.green,
+                              ));
+                            } else {
+                              ScaffoldMessenger.of(context)
+                                  .showSnackBar(const SnackBar(
+                                content: Text('No barcode found!'),
+                                backgroundColor: Colors.red,
+                              ));
+                            }
+                          }
+                        },
+                      ),
                     ],
                   ),
                 ),

@@ -6,6 +6,7 @@ environment:
   sdk: ">=2.12.0 <3.0.0"
 
 dependencies:
+  image_picker: ^0.8.4+9
   flutter:
     sdk: flutter
 

@@ -22,11 +22,12 @@ public class SwiftMobileScannerPlugin: NSObject, FlutterPlugin, FlutterStreamHan
     // Image to be sent to the texture
     var latestBuffer: CVImageBuffer!
     
-    
 //    var analyzeMode: Int = 0
     var analyzing: Bool = false
     var position = AVCaptureDevice.Position.back
     
+    let scanner = BarcodeScanner.barcodeScanner()
+    
     public static func register(with registrar: FlutterPluginRegistrar) {
         let instance = SwiftMobileScannerPlugin(registrar.textures())
         
@@ -58,6 +59,8 @@ public class SwiftMobileScannerPlugin: NSObject, FlutterPlugin, FlutterStreamHan
 //            switchAnalyzeMode(call, result)
         case "stop":
             stop(result)
+        case "analyzeImage":
+            analyzeImage(call, result)
         default:
             result(FlutterMethodNotImplemented)
         }
@@ -102,7 +105,6 @@ public class SwiftMobileScannerPlugin: NSObject, FlutterPlugin, FlutterStreamHan
               defaultOrientation: .portrait
             )
 
-            let scanner = BarcodeScanner.barcodeScanner()
             scanner.process(image) { [self] barcodes, error in
                 if error == nil && barcodes != nil {
                     for barcode in barcodes! {
@@ -255,6 +257,42 @@ public class SwiftMobileScannerPlugin: NSObject, FlutterPlugin, FlutterStreamHan
 //        result(nil)
 //    }
     
+    func analyzeImage(_ call: FlutterMethodCall, _ result: @escaping FlutterResult) {
+        let uiImage = UIImage(contentsOfFile: call.arguments as! String)
+        
+        if (uiImage == nil) {
+            result(FlutterError(code: "MobileScanner",
+                                    message: "No image found in analyzeImage!",
+                                    details: nil))
+            return
+        }
+        
+        let image = VisionImage(image: uiImage!)
+        image.orientation = imageOrientation(
+          deviceOrientation: UIDevice.current.orientation,
+          defaultOrientation: .portrait
+        )
+        
+        var barcodeFound = false
+
+        scanner.process(image) { [self] barcodes, error in
+            if error == nil && barcodes != nil {
+                for barcode in barcodes! {
+                    barcodeFound = true
+                    let event: [String: Any?] = ["name": "barcode", "data": barcode.data]
+                    sink?(event)
+                }
+            } else if error != nil {
+                result(FlutterError(code: "MobileScanner",
+                                    message: error?.localizedDescription,
+                                    details: "analyzeImage()"))
+            }
+            analyzing = false
+            result(barcodeFound)
+        }
+
+    }
+    
     func stop(_ result: FlutterResult) {
         if (device == nil) {
             result(FlutterError(code: "MobileScanner",

@@ -208,7 +208,16 @@ class MobileScannerController {
     await start();
   }
 
-  /// Disposes the controller and closes all listeners.
+  /// Handles a local image file.
+  /// Returns true if a barcode or QR code is found.
+  /// Returns false if nothing is found.
+  ///
+  /// [path] The path of the image on the devices
+  Future<bool> analyzeImage(String path) async {
+    return await methodChannel.invokeMethod('analyzeImage', path);
+  }
+
+  /// Disposes the MobileScannerController and closes all listeners.
   void dispose() {
     if (hashCode == _controllerHashcode) {
       stop();
@@ -219,11 +228,11 @@ class MobileScannerController {
     barcodesController.close();
   }
 
-  /// Checks if the controller is bound to the correct MobileScanner object.
+  /// Checks if the MobileScannerController is bound to the correct MobileScanner object.
   void ensure(String name) {
     final message =
-        'CameraController.$name called after CameraController.dispose\n'
-        'CameraController methods should not be used after calling dispose.';
+        'MobileScannerController.$name called after MobileScannerController.dispose\n'
+        'MobileScannerController methods should not be used after calling dispose.';
     assert(hashCode == _controllerHashcode, message);
   }
 }

 name: mobile_scanner
 description: A universal barcode and QR code scanner for Flutter based on MLKit. Uses CameraX on Android, AVFoundation on iOS and Apple Vision & AVFoundation on macOS.
-version: 0.1.3
+version: 0.2.0
 repository: https://github.com/juliansteenbakker/mobile_scanner
 
 environment:
   sdk: ">=2.12.0 <3.0.0"
-  flutter: ">=2.2.0"
 
 dependencies:
   flutter: