Merge pull request #176 from casvanluijtelaar/master

Add scanWindow to optionally limit scan area

Merge pull request #176 from casvanluijtelaar/master
Add scanWindow to optionally limit scan area
Julian Steenbakker · GitHub
Commit 730026f6fa4fa9b1251a6e91bb15b93203ba57c7 730026f6 2 parents e5b455c0 3b58ef12
Showing 10 changed files with 488 additions and 36 deletions
android/src/main/kotlin/dev/steenbakker/mobile_scanner/MobileScanner.kt
example/ios/Runner.xcodeproj/project.pbxproj
example/ios/Runner/Info.plist
example/lib/barcode_scanner_window.dart
example/lib/main.dart
ios/Classes/SwiftMobileScannerPlugin.swift
lib/src/mobile_scanner.dart
lib/src/mobile_scanner_controller.dart
lib/src/objects/barcode_utility.dart
macos/Classes/MobileScannerPlugin.swift
--- a/android/src/main/kotlin/dev/steenbakker/mobile_scanner/MobileScanner.kt
View file @730026f
+++ b/android/src/main/kotlin/dev/steenbakker/mobile_scanner/MobileScanner.kt
View file @730026f
@@ -4,9 +4,12 @@ import android.Manifest
 import android.app.Activity
 import android.content.pm.PackageManager
 import android.graphics.Point
+import android.graphics.Rect
+import android.graphics.RectF
 import android.net.Uri
 import android.util.Log
 import android.util.Size
+import android.media.Image
 import android.view.Surface
 import androidx.annotation.NonNull
 import androidx.camera.core.*
@@ -18,12 +21,14 @@ import com.google.mlkit.vision.barcode.BarcodeScannerOptions
 import com.google.mlkit.vision.barcode.BarcodeScanning
 import com.google.mlkit.vision.barcode.common.Barcode
 import com.google.mlkit.vision.common.InputImage
+import com.google.mlkit.vision.common.InputImage.IMAGE_FORMAT_NV21
 import io.flutter.plugin.common.EventChannel
 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 kotlin.math.roundToInt
 class MobileScanner(private val activity: Activity, private val textureRegistry: TextureRegistry)
@@ -40,6 +45,7 @@ class MobileScanner(private val activity: Activity, private val textureRegistry:
     private var camera: Camera? = null
     private var preview: Preview? = null
     private var textureEntry: TextureRegistry.SurfaceTextureEntry? = null
+    private var scanWindow: List<Float>? = null;
 //    @AnalyzeMode
 //    private var analyzeMode: Int = AnalyzeMode.NONE
@@ -54,6 +60,7 @@ class MobileScanner(private val activity: Activity, private val textureRegistry:
 //            "analyze" -> switchAnalyzeMode(call, result)
             "stop" -> stop(result)
             "analyzeImage" -> analyzeImage(call, result)
+            "updateScanWindow" -> updateScanWindow(call)
             else -> result.notImplemented()
         }
     }
@@ -99,11 +106,17 @@ class MobileScanner(private val activity: Activity, private val textureRegistry:
 //        when (analyzeMode) {
 //            AnalyzeMode.BARCODE -> {
                 val mediaImage = imageProxy.image ?: return@Analyzer
-                val inputImage = InputImage.fromMediaImage(mediaImage, imageProxy.imageInfo.rotationDegrees)
+                var inputImage = InputImage.fromMediaImage(mediaImage, imageProxy.imageInfo.rotationDegrees)
                 scanner.process(inputImage)
                         .addOnSuccessListener { barcodes ->
                             for (barcode in barcodes) {
+
+                                if(scanWindow != null) {
+                                    val match = isbarCodeInScanWindow(scanWindow!!, barcode, inputImage)
+                                    if(!match) continue
+                                }
+
                                 val event = mapOf("name" to "barcode", "data" to barcode.data)
                                 sink?.success(event)
                             }
@@ -115,9 +128,32 @@ class MobileScanner(private val activity: Activity, private val textureRegistry:
 //        }
     }
-
     private var scanner = BarcodeScanning.getClient()
+    private fun updateScanWindow(call: MethodCall) {
+        scanWindow = call.argument<List<Float>>("rect")
+    }
+
+    // scales the scanWindow to the provided inputImage and checks if that scaled
+    // scanWindow contains the barcode
+    private fun isbarCodeInScanWindow(scanWindow: List<Float>, barcode: Barcode, inputImage: InputImage): Boolean {
+        val barcodeBoundingBox = barcode.getBoundingBox()
+        if(barcodeBoundingBox == null) return false
+
+        val imageWidth = inputImage.getWidth();
+        val imageHeight = inputImage.getHeight();
+
+        val left = (scanWindow[0] * imageWidth).roundToInt()
+        val top = (scanWindow[1] * imageHeight).roundToInt()
+        val right = (scanWindow[2] * imageWidth).roundToInt()
+        val bottom = (scanWindow[3] * imageHeight).roundToInt()
+
+        val scaledScanWindow = Rect(left, top, right, bottom)                
+        return scaledScanWindow.contains(barcodeBoundingBox)
+    }
+
+
+
     @ExperimentalGetImage
     private fun start(call: MethodCall, result: MethodChannel.Result) {
         if (camera?.cameraInfo != null && preview != null && textureEntry != null) {
@@ -130,7 +166,7 @@ class MobileScanner(private val activity: Activity, private val textureRegistry:
             result.success(answer)
         } else {
             val facing: Int = call.argument<Int>("facing") ?: 0
-            val ratio: Int? = call.argument<Int>("ratio")
+            val ratio: Int = call.argument<Int>("ratio") ?: 1
             val torch: Boolean = call.argument<Boolean>("torch") ?: false
             val formats: List<Int>? = call.argument<List<Int>>("formats")
@@ -161,6 +197,7 @@ class MobileScanner(private val activity: Activity, private val textureRegistry:
                     result.error("textureEntry", "textureEntry is null", null)
                     return@addListener
                 }
+                
                 // Preview
                 val surfaceProvider = Preview.SurfaceProvider { request ->
                     val texture = textureEntry!!.surfaceTexture()
@@ -171,17 +208,15 @@ class MobileScanner(private val activity: Activity, private val textureRegistry:
                 // Build the preview to be shown on the Flutter texture
                 val previewBuilder = Preview.Builder()
-                if (ratio != null) {
-                    previewBuilder.setTargetAspectRatio(ratio)
-                }
+                        .setTargetAspectRatio(ratio)
+                
                 preview = previewBuilder.build().apply { setSurfaceProvider(surfaceProvider) }
                 // Build the analyzer to be passed on to MLKit
                 val analysisBuilder = ImageAnalysis.Builder()
                         .setBackpressureStrategy(ImageAnalysis.STRATEGY_KEEP_ONLY_LATEST)
-                if (ratio != null) {
-                    analysisBuilder.setTargetAspectRatio(ratio)
-                }
+                        .setTargetAspectRatio(ratio) 
+
                 val analysis = analysisBuilder.build().apply { setAnalyzer(executor, analyzer) }
                 // Select the correct camera
@@ -191,6 +226,7 @@ class MobileScanner(private val activity: Activity, private val textureRegistry:
                 val analysisSize = analysis.resolutionInfo?.resolution ?: Size(0, 0)
                 val previewSize = preview!!.resolutionInfo?.resolution ?: Size(0, 0)
+                
                 Log.i("LOG", "Analyzer: $analysisSize")
                 Log.i("LOG", "Preview: $previewSize")
@@ -241,6 +277,11 @@ class MobileScanner(private val activity: Activity, private val textureRegistry:
         scanner.process(inputImage)
             .addOnSuccessListener { barcodes ->
                 for (barcode in barcodes) {
+                    if(scanWindow != null) {
+                        val match = isbarCodeInScanWindow(scanWindow!!, barcode, inputImage)
+                        if(!match) continue
+                    }
+
                     barcodeFound = true
                     sink?.success(mapOf("name" to "barcode", "data" to barcode.data))
                 }
--- a/example/ios/Runner.xcodeproj/project.pbxproj
View file @730026f
+++ b/example/ios/Runner.xcodeproj/project.pbxproj
View file @730026f
@@ -354,16 +354,19 @@
 			buildSettings = {
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				CLANG_ENABLE_MODULES = YES;
+				CODE_SIGN_IDENTITY = "Apple Development";
+				CODE_SIGN_STYLE = Automatic;
 				CURRENT_PROJECT_VERSION = "$(FLUTTER_BUILD_NUMBER)";
-				DEVELOPMENT_TEAM = 75Y2P2WSQQ;
+				DEVELOPMENT_TEAM = QAJQ4586J2;
 				ENABLE_BITCODE = NO;
 				INFOPLIST_FILE = Runner/Info.plist;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/Frameworks",
 				);
-				PRODUCT_BUNDLE_IDENTIFIER = dev.steenbakker.mobileScannerExample;
+				PRODUCT_BUNDLE_IDENTIFIER = dev.casvanluijtelaar.mobileScannerExample;
 				PRODUCT_NAME = "$(TARGET_NAME)";
+				PROVISIONING_PROFILE_SPECIFIER = "";
 				SWIFT_OBJC_BRIDGING_HEADER = "Runner/Runner-Bridging-Header.h";
 				SWIFT_VERSION = 5.0;
 				VERSIONING_SYSTEM = "apple-generic";
@@ -483,16 +486,19 @@
 			buildSettings = {
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				CLANG_ENABLE_MODULES = YES;
+				CODE_SIGN_IDENTITY = "Apple Development";
+				CODE_SIGN_STYLE = Automatic;
 				CURRENT_PROJECT_VERSION = "$(FLUTTER_BUILD_NUMBER)";
-				DEVELOPMENT_TEAM = 75Y2P2WSQQ;
+				DEVELOPMENT_TEAM = QAJQ4586J2;
 				ENABLE_BITCODE = NO;
 				INFOPLIST_FILE = Runner/Info.plist;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/Frameworks",
 				);
-				PRODUCT_BUNDLE_IDENTIFIER = dev.steenbakker.mobileScannerExample;
+				PRODUCT_BUNDLE_IDENTIFIER = dev.casvanluijtelaar.mobileScannerExample;
 				PRODUCT_NAME = "$(TARGET_NAME)";
+				PROVISIONING_PROFILE_SPECIFIER = "";
 				SWIFT_OBJC_BRIDGING_HEADER = "Runner/Runner-Bridging-Header.h";
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
 				SWIFT_VERSION = 5.0;
@@ -506,16 +512,19 @@
 			buildSettings = {
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				CLANG_ENABLE_MODULES = YES;
+				CODE_SIGN_IDENTITY = "Apple Development";
+				CODE_SIGN_STYLE = Automatic;
 				CURRENT_PROJECT_VERSION = "$(FLUTTER_BUILD_NUMBER)";
-				DEVELOPMENT_TEAM = 75Y2P2WSQQ;
+				DEVELOPMENT_TEAM = QAJQ4586J2;
 				ENABLE_BITCODE = NO;
 				INFOPLIST_FILE = Runner/Info.plist;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/Frameworks",
 				);
-				PRODUCT_BUNDLE_IDENTIFIER = dev.steenbakker.mobileScannerExample;
+				PRODUCT_BUNDLE_IDENTIFIER = dev.casvanluijtelaar.mobileScannerExample;
 				PRODUCT_NAME = "$(TARGET_NAME)";
+				PROVISIONING_PROFILE_SPECIFIER = "";
 				SWIFT_OBJC_BRIDGING_HEADER = "Runner/Runner-Bridging-Header.h";
 				SWIFT_VERSION = 5.0;
 				VERSIONING_SYSTEM = "apple-generic";
--- a/example/ios/Runner/Info.plist
View file @730026f
+++ b/example/ios/Runner/Info.plist
View file @730026f
@@ -2,10 +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>CADisableMinimumFrameDurationOnPhone</key>
+	<true/>
 	<key>CFBundleDevelopmentRegion</key>
 	<string>$(DEVELOPMENT_LANGUAGE)</string>
 	<key>CFBundleDisplayName</key>
@@ -28,6 +26,10 @@
 	<string>$(FLUTTER_BUILD_NUMBER)</string>
 	<key>LSRequiresIPhoneOS</key>
 	<true/>
+	<key>NSCameraUsageDescription</key>
+	<string>We use the camera to scan barcodes</string>
+	<key>NSPhotoLibraryUsageDescription</key>
+	<string>We need access in order to open photos of barcodes</string>
 	<key>UILaunchStoryboardName</key>
 	<string>LaunchScreen</string>
 	<key>UIMainStoryboardFile</key>
@@ -47,7 +49,5 @@
 	</array>
 	<key>UIViewControllerBasedStatusBarAppearance</key>
 	<false/>
-	<key>CADisableMinimumFrameDurationOnPhone</key>
-	<true/>
 </dict>
 </plist>
--- a/example/lib/barcode_scanner_window.dart 0 → 100644
View file @730026f
+++ b/example/lib/barcode_scanner_window.dart 0 → 100644
View file @730026f
+import 'package:flutter/material.dart';
+import 'package:mobile_scanner/mobile_scanner.dart';
+
+class BarcodeScannerWithScanWindow extends StatefulWidget {
+  const BarcodeScannerWithScanWindow({Key? key}) : super(key: key);
+
+  @override
+  _BarcodeScannerWithScanWindowState createState() =>
+      _BarcodeScannerWithScanWindowState();
+}
+
+class _BarcodeScannerWithScanWindowState
+    extends State<BarcodeScannerWithScanWindow> {
+  late MobileScannerController controller;
+  String? barcode;
+
+  @override
+  void initState() {
+    super.initState();
+    controller = MobileScannerController();
+    restart();
+  }
+
+  Future<void> restart() async {
+    // await controller.stop();
+    await controller.start();
+  }
+
+  Future<void> onDetect(Barcode barcode, MobileScannerArguments? _) async {
+    setState(() => this.barcode = barcode.rawValue);
+    await Future.delayed(const Duration(seconds: 1));
+    setState(() => this.barcode = '');
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final scanWindow = Rect.fromCenter(
+      center: MediaQuery.of(context).size.center(Offset.zero),
+      width: 200,
+      height: 200,
+    );
+
+    return Scaffold(
+      backgroundColor: Colors.black,
+      body: Builder(
+        builder: (context) {
+          return Stack(
+            children: [
+              MobileScanner(
+                fit: BoxFit.cover,
+                scanWindow: scanWindow,
+                controller: controller,
+                onDetect: onDetect,
+                allowDuplicates: true,
+              ),
+              CustomPaint(
+                painter: ScannerOverlay(scanWindow),
+              ),
+              Align(
+                alignment: Alignment.bottomCenter,
+                child: Container(
+                  alignment: Alignment.bottomCenter,
+                  height: 100,
+                  color: Colors.black.withOpacity(0.4),
+                  child: Row(
+                    mainAxisAlignment: MainAxisAlignment.spaceEvenly,
+                    children: [
+                      Center(
+                        child: SizedBox(
+                          width: MediaQuery.of(context).size.width - 120,
+                          height: 50,
+                          child: FittedBox(
+                            child: Text(
+                              barcode ?? 'Scan something!',
+                              overflow: TextOverflow.fade,
+                              style: Theme.of(context)
+                                  .textTheme
+                                  .headline4!
+                                  .copyWith(color: Colors.white),
+                            ),
+                          ),
+                        ),
+                      ),
+                    ],
+                  ),
+                ),
+              ),
+            ],
+          );
+        },
+      ),
+    );
+  }
+}
+
+class ScannerOverlay extends CustomPainter {
+  ScannerOverlay(this.scanWindow);
+
+  final Rect scanWindow;
+
+  @override
+  void paint(Canvas canvas, Size size) {
+    final backgroundPath = Path()..addRect(Rect.largest);
+    final cutoutPath = Path()..addRect(scanWindow);
+
+    final backgroundPaint = Paint()
+      ..color = Colors.black.withOpacity(0.5)
+      ..style = PaintingStyle.fill
+      ..blendMode = BlendMode.dstOut;
+
+    final backgroundWithCutout = Path.combine(
+      PathOperation.difference,
+      backgroundPath,
+      cutoutPath,
+    );
+    canvas.drawPath(backgroundWithCutout, backgroundPaint);
+  }
+
+  @override
+  bool shouldRepaint(covariant CustomPainter oldDelegate) {
+    return false;
+  }
+}
--- a/example/lib/main.dart
View file @730026f
+++ b/example/lib/main.dart
View file @730026f
 import 'package:flutter/material.dart';
 import 'package:mobile_scanner_example/barcode_scanner_controller.dart';
+import 'package:mobile_scanner_example/barcode_scanner_window.dart';
 import 'package:mobile_scanner_example/barcode_scanner_without_controller.dart';
 void main() => runApp(const MaterialApp(home: MyHome()));
@@ -31,6 +32,16 @@ class MyHome extends StatelessWidget {
               onPressed: () {
                 Navigator.of(context).push(
                   MaterialPageRoute(
+                    builder: (context) => const BarcodeScannerWithScanWindow(),
+                  ),
+                );
+              },
+              child: const Text('MobileScanner with ScanWindow'),
+            ),
+            ElevatedButton(
+              onPressed: () {
+                Navigator.of(context).push(
+                  MaterialPageRoute(
                     builder: (context) =>
                         const BarcodeScannerWithoutController(),
                   ),
--- a/ios/Classes/SwiftMobileScannerPlugin.swift
View file @730026f
+++ b/ios/Classes/SwiftMobileScannerPlugin.swift
View file @730026f
@@ -2,6 +2,7 @@ import AVFoundation
 import Flutter
 import MLKitVision
 import MLKitBarcodeScanning
+import UIKit
 public class SwiftMobileScannerPlugin: NSObject, FlutterPlugin, FlutterStreamHandler, FlutterTexture, AVCaptureVideoDataOutputSampleBufferDelegate {
@@ -25,6 +26,8 @@ public class SwiftMobileScannerPlugin: NSObject, FlutterPlugin, FlutterStreamHan
 //    var analyzeMode: Int = 0
     var analyzing: Bool = false
     var position = AVCaptureDevice.Position.back
+
+    var scanWindow: CGRect?
     var scanner = BarcodeScanner.barcodeScanner()
@@ -61,6 +64,8 @@ public class SwiftMobileScannerPlugin: NSObject, FlutterPlugin, FlutterStreamHan
             stop(result)
         case "analyzeImage":
             analyzeImage(call, result)
+        case "updateScanWindow":
+            updateScanWindow(call)
         default:
             result(FlutterMethodNotImplemented)
         }
@@ -98,8 +103,9 @@ public class SwiftMobileScannerPlugin: NSObject, FlutterPlugin, FlutterStreamHan
                 return
             }
             analyzing = true
-            let buffer = CMSampleBufferGetImageBuffer(sampleBuffer)
-            let image = VisionImage(image: buffer!.image)
+            let buffer = CMSampleBufferGetImageBuffer(sampleBuffer)            
+            var image = VisionImage(image: buffer!.image)
+
             image.orientation = imageOrientation(
               deviceOrientation: UIDevice.current.orientation,
               defaultOrientation: .portrait
@@ -108,6 +114,14 @@ public class SwiftMobileScannerPlugin: NSObject, FlutterPlugin, FlutterStreamHan
             scanner.process(image) { [self] barcodes, error in
                 if error == nil && barcodes != nil {
                     for barcode in barcodes! {
+
+                        if scanWindow != nil {
+                            let match = isbarCodeInScanWindow(scanWindow!, barcode, buffer!.image)
+                            if (!match) {
+                                continue
+                            }
+                        }
+
                         let event: [String: Any?] = ["name": "barcode", "data": barcode.data]
                         sink?(event)
                     }
@@ -155,6 +169,38 @@ public class SwiftMobileScannerPlugin: NSObject, FlutterPlugin, FlutterStreamHan
         AVCaptureDevice.requestAccess(for: .video, completionHandler: { result($0) })
     }
+    func updateScanWindow(_ call: FlutterMethodCall) {
+        let argReader = MapArgumentReader(call.arguments as? [String: Any])
+        let scanWindowData: Array? = argReader.floatArray(key: "rect")
+
+        if (scanWindowData == nil) {
+            return 
+        }
+
+        let minX = scanWindowData![0] 
+        let minY = scanWindowData![1]
+
+        let width = scanWindowData![2]  - minX
+        let height = scanWindowData![3] - minY
+
+        scanWindow = CGRect(x: minX, y: minY, width: width, height: height)
+    }
+
+   func isbarCodeInScanWindow(_ scanWindow: CGRect, _ barcode: Barcode, _ inputImage: UIImage) -> Bool {
+        let barcodeBoundingBox = barcode.frame
+
+        let imageWidth = inputImage.size.width;
+        let imageHeight = inputImage.size.height;
+
+        let minX = scanWindow.minX * imageWidth
+        let minY = scanWindow.minY * imageHeight
+        let width = scanWindow.width * imageWidth
+        let height = scanWindow.height * imageHeight
+
+        let scaledScanWindow = CGRect(x: minX, y: minY, width: width, height: height)
+        return scaledScanWindow.contains(barcodeBoundingBox)
+   }
+
     func start(_ call: FlutterMethodCall, _ result: @escaping FlutterResult) {
         if (device != nil) {
             result(FlutterError(code: "MobileScanner",
@@ -172,7 +218,7 @@ public class SwiftMobileScannerPlugin: NSObject, FlutterPlugin, FlutterStreamHan
         let torch: Bool = argReader.bool(key: "torch") ?? false
         let facing: Int = argReader.int(key: "facing") ?? 1
         let formats: Array = argReader.intArray(key: "formats") ?? []
-        
+               
         let formatList: NSMutableArray = []
         for index in formats {
             formatList.add(BarcodeFormat(rawValue: index))
@@ -229,6 +275,7 @@ public class SwiftMobileScannerPlugin: NSObject, FlutterPlugin, FlutterStreamHan
         videoOutput.alwaysDiscardsLateVideoFrames = true
         videoOutput.setSampleBufferDelegate(self, queue: DispatchQueue.main)
+        
         captureSession.addOutput(videoOutput)
         for connection in videoOutput.connections {
             connection.videoOrientation = .portrait
@@ -238,6 +285,7 @@ public class SwiftMobileScannerPlugin: NSObject, FlutterPlugin, FlutterStreamHan
         }
         captureSession.commitConfiguration()
         captureSession.startRunning()
+
         let demensions = CMVideoFormatDescriptionGetDimensions(device.activeFormat.formatDescription)
         let width = Double(demensions.height)
         let height = Double(demensions.width)
@@ -289,6 +337,14 @@ public class SwiftMobileScannerPlugin: NSObject, FlutterPlugin, FlutterStreamHan
         scanner.process(image) { [self] barcodes, error in
             if error == nil && barcodes != nil {
                 for barcode in barcodes! {
+
+                    if scanWindow != nil {
+                        let match = isbarCodeInScanWindow(scanWindow!, barcode, uiImage!)
+                        if (!match) {
+                            continue
+                        }
+                    }
+
                     barcodeFound = true
                     let event: [String: Any?] = ["name": "barcode", "data": barcode.data]
                     sink?(event)
@@ -368,8 +424,12 @@ class MapArgumentReader {
     return args?[key] as? [String]
   }
-    func intArray(key: String) -> [Int]? {
-      return args?[key] as? [Int]
-    }
+  func intArray(key: String) -> [Int]? {
+    return args?[key] as? [Int]
+  }
+
+  func floatArray(key: String) -> [CGFloat]? {
+    return args?[key] as? [CGFloat]
+  }
 }
--- a/lib/src/mobile_scanner.dart
View file @730026f
+++ b/lib/src/mobile_scanner.dart
View file @730026f
 import 'package:flutter/foundation.dart';
-import 'package:flutter/material.dart';
+import 'package:flutter/material.dart' hide applyBoxFit;
 import 'package:mobile_scanner/mobile_scanner.dart';
+import 'package:mobile_scanner/src/objects/barcode_utility.dart';
 enum Ratio { ratio_4_3, ratio_16_9 }
@@ -27,6 +28,13 @@ class MobileScanner extends StatefulWidget {
   /// Set to false if you don't want duplicate scans.
   final bool allowDuplicates;
+  /// if set barcodes will only be scanned if they fall within this [Rect]
+  /// useful for having a cut-out overlay for example. these [Rect]
+  /// coordinates are relative to the widget size, so by how much your
+  /// rectangle overlays the actual image can depend on things like the
+  /// [BoxFit]
+  final Rect? scanWindow;
+
   /// Create a [MobileScanner] with a [controller], the [controller] must has been initialized.
   const MobileScanner({
     Key? key,
@@ -34,6 +42,7 @@ class MobileScanner extends StatefulWidget {
     this.controller,
     this.fit = BoxFit.cover,
     this.allowDuplicates = false,
+    this.scanWindow,
   }) : super(key: key);
   @override
@@ -67,6 +76,55 @@ class _MobileScannerState extends State<MobileScanner>
   String? lastScanned;
+  /// the [scanWindow] rect will be relative and scaled to the [widgetSize] not the texture. so it is possible,
+  /// depending on the [fit], for the [scanWindow] to partially or not at all overlap the [textureSize]
+  ///
+  /// since when using a [BoxFit] the content will always be centered on its parent. we can convert the rect
+  /// to be relative to the texture.
+  ///
+  /// since the textures size and the actuall image (on the texture size) might not be the same, we also need to
+  /// calculate the scanWindow in terms of percentages of the texture, not pixels.
+  Rect calculateScanWindowRelativeToTextureInPercentage(
+    BoxFit fit,
+    Rect scanWindow,
+    Size textureSize,
+    Size widgetSize,
+  ) {
+    /// map the texture size to get its new size after fitted to screen
+    final fittedTextureSize = applyBoxFit(fit, textureSize, widgetSize);
+
+    /// create a new rectangle that represents the texture on the screen
+    final minX = widgetSize.width / 2 - fittedTextureSize.width / 2;
+    final minY = widgetSize.height / 2 - fittedTextureSize.height / 2;
+    final textureWindow = Offset(minX, minY) & fittedTextureSize;
+
+    /// create a new scan window and with only the area of the rect intersecting the texture window
+    final scanWindowInTexture = scanWindow.intersect(textureWindow);
+
+    /// update the scanWindow left and top to be relative to the texture not the widget
+    final newLeft = scanWindowInTexture.left - textureWindow.left;
+    final newTop = scanWindowInTexture.top - textureWindow.top;
+    final newWidth = scanWindowInTexture.width;
+    final newHeight = scanWindowInTexture.height;
+
+    /// new scanWindow that is adapted to the boxfit and relative to the texture
+    final windowInTexture = Rect.fromLTWH(newLeft, newTop, newWidth, newHeight);
+
+    /// get the scanWindow as a percentage of the texture
+    final percentageLeft = windowInTexture.left / fittedTextureSize.width;
+    final percentageTop = windowInTexture.top / fittedTextureSize.height;
+    final percentageRight = windowInTexture.right / fittedTextureSize.width;
+    final percentagebottom = windowInTexture.bottom / fittedTextureSize.height;
+
+    /// this rectangle can be send to native code and used to cut out a rectangle of the scan image
+    return Rect.fromLTRB(
+      percentageLeft,
+      percentageTop,
+      percentageRight,
+      percentagebottom,
+    );
+  }
+
   @override
   Widget build(BuildContext context) {
     return LayoutBuilder(
@@ -78,12 +136,21 @@ class _MobileScannerState extends State<MobileScanner>
             if (value == null) {
               return Container(color: Colors.black);
             } else {
+              if (widget.scanWindow != null) {
+                final window = calculateScanWindowRelativeToTextureInPercentage(
+                  widget.fit,
+                  widget.scanWindow!,
+                  value.size,
+                  Size(constraints.maxWidth, constraints.maxHeight),
+                );
+                controller.updateScanWindow(window);
+              }
+
               controller.barcodes.listen((barcode) {
                 if (!widget.allowDuplicates) {
-                  if (lastScanned != barcode.rawValue) {
-                    lastScanned = barcode.rawValue;
-                    widget.onDetect(barcode, value! as MobileScannerArguments);
-                  }
+                  if (lastScanned == barcode.rawValue) return;
+                  lastScanned = barcode.rawValue;
+                  widget.onDetect(barcode, value! as MobileScannerArguments);
                 } else {
                   widget.onDetect(barcode, value! as MobileScannerArguments);
                 }
--- a/lib/src/mobile_scanner_controller.dart
View file @730026f
+++ b/lib/src/mobile_scanner_controller.dart
View file @730026f
@@ -156,6 +156,14 @@ class MobileScannerController {
     // Set the starting arguments for the camera
     final Map arguments = {};
     arguments['facing'] = facing.index;
+    /*    if (scanWindow != null) {
+      arguments['scanWindow'] = [
+        scanWindow!.left,
+        scanWindow!.top,
+        scanWindow!.right,
+        scanWindow!.bottom,
+      ];
+    } */
     if (ratio != null) arguments['ratio'] = ratio;
     if (torchEnabled != null) arguments['torch'] = torchEnabled;
@@ -283,4 +291,10 @@ class MobileScannerController {
         'MobileScannerController methods should not be used after calling dispose.';
     assert(hashCode == _controllerHashcode, message);
   }
+
+  /// updates the native scanwindow
+  Future<void> updateScanWindow(Rect window) async {
+    final data = [window.left, window.top, window.right, window.bottom];
+    await methodChannel.invokeMethod('updateScanWindow', {'rect': data});
+  }
 }
--- a/lib/src/objects/barcode_utility.dart
View file @730026f
+++ b/lib/src/objects/barcode_utility.dart
View file @730026f
+import 'dart:math' as math;
+
 import 'package:flutter/material.dart';
 import 'package:mobile_scanner/mobile_scanner.dart';
@@ -147,3 +149,79 @@ WiFi? toWiFi(Map? data) {
     return null;
   }
 }
+
+Size applyBoxFit(BoxFit fit, Size input, Size output) {
+  if (input.height <= 0.0 ||
+      input.width <= 0.0 ||
+      output.height <= 0.0 ||
+      output.width <= 0.0) {
+    return Size.zero;
+  }
+
+  Size destination;
+
+  final inputAspectRatio = input.width / input.height;
+  final outputAspectRatio = output.width / output.height;
+
+  switch (fit) {
+    case BoxFit.fill:
+      destination = output;
+      break;
+    case BoxFit.contain:
+      if (outputAspectRatio > inputAspectRatio) {
+        destination = Size(
+          input.width * output.height / input.height,
+          output.height,
+        );
+      } else {
+        destination = Size(
+          output.width,
+          input.height * output.width / input.width,
+        );
+      }
+      break;
+
+    case BoxFit.cover:
+      if (outputAspectRatio > inputAspectRatio) {
+        destination = Size(
+          output.width,
+          input.height * (output.width / input.width),
+        );
+      } else {
+        destination = Size(
+          input.width * (output.height / input.height),
+          output.height,
+        );
+      }
+      break;
+    case BoxFit.fitWidth:
+      destination = Size(
+        output.width,
+        input.height * (output.width / input.width),
+      );
+      break;
+    case BoxFit.fitHeight:
+      destination = Size(
+        input.width * (output.height / input.height),
+        output.height,
+      );
+      break;
+    case BoxFit.none:
+      destination = Size(
+        math.min(input.width, output.width),
+        math.min(input.height, output.height),
+      );
+      break;
+    case BoxFit.scaleDown:
+      destination = input;
+      if (destination.height > output.height) {
+        destination = Size(output.height * inputAspectRatio, output.height);
+      }
+      if (destination.width > output.width) {
+        destination = Size(output.width, output.width / inputAspectRatio);
+      }
+      break;
+  }
+
+  return destination;
+}
--- a/macos/Classes/MobileScannerPlugin.swift
View file @730026f
+++ b/macos/Classes/MobileScannerPlugin.swift
View file @730026f
 import AVFoundation
 import FlutterMacOS
 import Vision
+import UIKit
 public class MobileScannerPlugin: NSObject, FlutterPlugin, FlutterStreamHandler, FlutterTexture, AVCaptureVideoDataOutputSampleBufferDelegate {
@@ -20,6 +21,9 @@ public class MobileScannerPlugin: NSObject, FlutterPlugin, FlutterStreamHandler,
     // Image to be sent to the texture
     var latestBuffer: CVImageBuffer!
+
+    // optional window to limit scan search
+    var scanWindow: CGRect?
 //    var analyzeMode: Int = 0
@@ -57,6 +61,8 @@ public class MobileScannerPlugin: NSObject, FlutterPlugin, FlutterStreamHandler,
 //            switchAnalyzeMode(call, result)
         case "stop":
             stop(result)
+        case "updateScanWindow":
+            updateScanWindow(call)
         default:
             result(FlutterMethodNotImplemented)
         }
@@ -109,10 +115,17 @@ public class MobileScannerPlugin: NSObject, FlutterPlugin, FlutterStreamHandler,
               try imageRequestHandler.perform([VNDetectBarcodesRequest { (request, error) in
                   if error == nil {
                       if let results = request.results as? [VNBarcodeObservation] {
-                                  for barcode in results {
-                                      let barcodeType = String(barcode.symbology.rawValue).replacingOccurrences(of: "VNBarcodeSymbology", with: "")
-                                      let event: [String: Any?] = ["name": "barcodeMac", "data" : ["payload": barcode.payloadStringValue, "symbology": barcodeType]]
-                                      self.sink?(event)
+                            for barcode in results {
+                                if scanWindow != nil {
+                                    let match = isbarCodeInScanWindow(scanWindow!, barcode, buffer!.image)
+                                    if (!match) {
+                                        continue
+                                    }
+                                }
+
+                                let barcodeType = String(barcode.symbology.rawValue).replacingOccurrences(of: "VNBarcodeSymbology", with: "")
+                                let event: [String: Any?] = ["name": "barcodeMac", "data" : ["payload": barcode.payloadStringValue, "symbology": barcodeType]]
+                                self.sink?(event)
   //                                    if barcodeType == "QR" {
   //                                        let image = CIImage(image: source)
@@ -158,6 +171,38 @@ public class MobileScannerPlugin: NSObject, FlutterPlugin, FlutterStreamHandler,
         }
     }
+    func updateScanWindow(_ call: FlutterMethodCall) {
+        let argReader = MapArgumentReader(call.arguments as? [String: Any])
+        let scanWindowData: Array? = argReader.floatArray(key: "rect")
+
+        if (scanWindowData == nil) {
+            return 
+        }
+
+        let minX = scanWindowData![0] 
+        let minY = scanWindowData![1]
+
+        let width = scanWindowData![2]  - minX
+        let height = scanWindowData![3] - minY
+
+        scanWindow = CGRect(x: minX, y: minY, width: width, height: height)
+    }
+
+   func isbarCodeInScanWindow(_ scanWindow: CGRect, _ barcode: Barcode, _ inputImage: UIImage) -> Bool {
+        let barcodeBoundingBox = barcode.frame
+
+        let imageWidth = inputImage.size.width;
+        let imageHeight = inputImage.size.height;
+
+        let minX = scanWindow.minX * imageWidth
+        let minY = scanWindow.minY * imageHeight
+        let width = scanWindow.width * imageWidth
+        let height = scanWindow.height * imageHeight
+
+        let scaledScanWindow = CGRect(x: minX, y: minY, width: width, height: height)
+        return scaledScanWindow.contains(barcodeBoundingBox)
+    }
+
     func start(_ call: FlutterMethodCall, _ result: @escaping FlutterResult) {
         if (device != nil) {
             result(FlutterError(code: "MobileScanner",
@@ -321,5 +366,9 @@ class MapArgumentReader {
   func stringArray(key: String) -> [String]? {
     return args?[key] as? [String]
   }
+
+  func floatArray(key: String) -> [CGFloat]? {
+    return args?[key] as? [CGFloat]
+  }
 }