Moved permission request from plugin initialization to view initialization.

android/src/main/kotlin/net/touchcapture/qr/flutterqr/FlutterQrPlugin.kt

@@ -1,25 +1,15 @@
 package net.touchcapture.qr.flutterqr
 
-import android.Manifest
 import android.app.Activity
-import android.content.pm.PackageManager
-import android.os.Build
 import androidx.annotation.NonNull
 import io.flutter.embedding.engine.plugins.FlutterPlugin
 import io.flutter.embedding.engine.plugins.activity.ActivityAware
 import io.flutter.embedding.engine.plugins.activity.ActivityPluginBinding
 import io.flutter.plugin.common.BinaryMessenger
-import io.flutter.plugin.common.MethodCall
-import io.flutter.plugin.common.MethodChannel.MethodCallHandler
-import io.flutter.plugin.common.MethodChannel.Result
 import io.flutter.plugin.common.PluginRegistry
 import io.flutter.plugin.platform.PlatformViewRegistry
 
-
-class FlutterQrPlugin : FlutterPlugin, MethodCallHandler, ActivityAware {
-
-    var cameraPermissionContinuation: Runnable? = null
-    var requestingPermission = false
+class FlutterQrPlugin : FlutterPlugin, ActivityAware {
 
     /** Plugin registration embedding v1 */
     companion object {
@@ -31,7 +21,6 @@ class FlutterQrPlugin : FlutterPlugin, MethodCallHandler, ActivityAware {
 
     private fun onAttachedToV1(registrar: PluginRegistry.Registrar) {
         registrar.addRequestPermissionsResultListener(CameraRequestPermissionsListener())
-        checkAndRequestPermission(null)
         onAttachedToEngines(registrar.platformViewRegistry(), registrar.messenger(), registrar.activity())
     }
 
@@ -53,16 +42,9 @@ class FlutterQrPlugin : FlutterPlugin, MethodCallHandler, ActivityAware {
                         "net.touchcapture.qr.flutterqr/qrview", QRViewFactory(messenger))
     }
 
-    override fun onMethodCall(call: MethodCall, result: Result) {
-        when (call.method) {
-            "checkAndRequestPermission" -> checkAndRequestPermission(result)
-        }
-    }
-
     override fun onAttachedToActivity(activityPluginBinding: ActivityPluginBinding) {
         Shared.activity = activityPluginBinding.activity
         activityPluginBinding.addRequestPermissionsResultListener(CameraRequestPermissionsListener())
-        checkAndRequestPermission(null)
     }
 
     override fun onDetachedFromActivityForConfigChanges() {
@@ -76,46 +58,4 @@ class FlutterQrPlugin : FlutterPlugin, MethodCallHandler, ActivityAware {
     override fun onDetachedFromActivity() {
         Shared.activity = null
     }
-
-    private inner class CameraRequestPermissionsListener : PluginRegistry.RequestPermissionsResultListener {
-        override fun onRequestPermissionsResult(id: Int, permissions: Array<String>, grantResults: IntArray): Boolean {
-            if (id == QRView.CAMERA_REQUEST_ID && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
-                cameraPermissionContinuation?.run()
-                return true
-            }
-            return false
-        }
-    }
-
-    private fun hasCameraPermission(): Boolean {
-        return Build.VERSION.SDK_INT < Build.VERSION_CODES.M ||
-                Shared.activity?.checkSelfPermission(Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED
-    }
-
-    private fun checkAndRequestPermission(result: Result?) {
-        if (cameraPermissionContinuation != null) {
-            result?.error("cameraPermission", "Camera permission request ongoing", null)
-        }
-
-        cameraPermissionContinuation = Runnable {
-            cameraPermissionContinuation = null
-            if (!hasCameraPermission()) {
-                result?.error(
-                        "cameraPermission", "MediaRecorderCamera permission not granted", null)
-                return@Runnable
-            }
-        }
-
-        requestingPermission = false
-        if (hasCameraPermission()) {
-            cameraPermissionContinuation?.run()
-        } else {
-            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
-                requestingPermission = true
-                Shared.activity?.requestPermissions(
-                        arrayOf(Manifest.permission.CAMERA),
-                        QRView.CAMERA_REQUEST_ID)
-            }
-        }
-    }
 }

android/src/main/kotlin/net/touchcapture/qr/flutterqr/QRView.kt

@@ -1,5 +1,6 @@
 package net.touchcapture.qr.flutterqr
 
+import android.Manifest
 import android.app.Activity
 import android.app.Application
 import android.content.Context
@@ -8,26 +9,25 @@ import android.os.Bundle
 import android.view.View
 import com.google.zxing.ResultPoint
 import android.hardware.Camera.CameraInfo
+import android.os.Build
 import com.journeyapps.barcodescanner.BarcodeCallback
 import com.journeyapps.barcodescanner.BarcodeResult
 import com.journeyapps.barcodescanner.BarcodeView
 import io.flutter.plugin.common.BinaryMessenger
 import io.flutter.plugin.common.MethodCall
 import io.flutter.plugin.common.MethodChannel
+import io.flutter.plugin.common.PluginRegistry
 import io.flutter.plugin.platform.PlatformView
 class QRView(messenger: BinaryMessenger, id: Int, private val context: Context) :
         PlatformView, MethodChannel.MethodCallHandler {
 
-    companion object {
-        const val CAMERA_REQUEST_ID = 513469796
-    }
-
-    var barcodeView: BarcodeView? = null
-
     private var isTorchOn: Boolean = false
-    val channel: MethodChannel
+    private var barcodeView: BarcodeView? = null
+    private var requestingPermission = false
+    private val channel: MethodChannel
 
     init {
+        checkAndRequestPermission(null)
         channel = MethodChannel(messenger, "net.touchcapture.qr.flutterqr/qrview_$id")
         channel.setMethodCallHandler(this)
         Shared.activity?.application?.registerActivityLifecycleCallbacks(object : Application.ActivityLifecycleCallbacks {
@@ -60,6 +60,28 @@ class QRView(messenger: BinaryMessenger, id: Int, private val context: Context)
         })
     }
 
+    override fun dispose() {
+        barcodeView?.pause()
+        barcodeView = null
+    }
+
+    override fun onMethodCall(call: MethodCall, result: MethodChannel.Result) {
+        when(call.method){
+            "flipCamera" -> {
+                flipCamera()
+            }
+            "toggleFlash" -> {
+                toggleFlash()
+            }
+            "pauseCamera" -> {
+                pauseCamera()
+            }
+            "resumeCamera" -> {
+                resumeCamera()
+            }
+        }
+    }
+
     fun flipCamera() {
         barcodeView?.pause()
         var settings = barcodeView?.cameraSettings
@@ -126,28 +148,46 @@ class QRView(messenger: BinaryMessenger, id: Int, private val context: Context)
         return barcode
     }
 
-    override fun dispose() {
-        barcodeView?.pause()
-        barcodeView = null
+    private fun hasCameraPermission(): Boolean {
+        return Build.VERSION.SDK_INT < Build.VERSION_CODES.M ||
+                Shared.activity?.checkSelfPermission(Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED
     }
 
-    override fun onMethodCall(call: MethodCall, result: MethodChannel.Result) {
-        when(call.method){
-            "flipCamera" -> {
-                flipCamera()
-            }
-            "toggleFlash" -> {
-                toggleFlash()
-            }
-            "pauseCamera" -> {
-                pauseCamera()
+    private fun checkAndRequestPermission(result: MethodChannel.Result?) {
+        if (Shared.cameraPermissionContinuation != null) {
+            result?.error("cameraPermission", "Camera permission request ongoing", null)
+        }
+
+        Shared.cameraPermissionContinuation = Runnable {
+            Shared.cameraPermissionContinuation = null
+            if (!hasCameraPermission()) {
+                result?.error(
+                        "cameraPermission", "MediaRecorderCamera permission not granted", null)
+                return@Runnable
             }
-            "resumeCamera" -> {
-                resumeCamera()
+        }
+
+        requestingPermission = false
+        if (hasCameraPermission()) {
+            Shared.cameraPermissionContinuation?.run()
+        } else {
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+                requestingPermission = true
+                Shared.activity?.requestPermissions(
+                        arrayOf(Manifest.permission.CAMERA),
+                        Shared.CAMERA_REQUEST_ID)
             }
         }
     }
 
+}
 
-
+class CameraRequestPermissionsListener : PluginRegistry.RequestPermissionsResultListener {
+    override fun onRequestPermissionsResult(id: Int, permissions: Array<String>, grantResults: IntArray): Boolean {
+        if (id == Shared.CAMERA_REQUEST_ID && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
+            Shared.cameraPermissionContinuation?.run()
+            return true
+        }
+        return false
+    }
 }

android/src/main/kotlin/net/touchcapture/qr/flutterqr/Shared.kt

@@ -1,9 +1,9 @@
 package net.touchcapture.qr.flutterqr
 
 import android.app.Activity
-import io.flutter.embedding.engine.plugins.activity.ActivityPluginBinding
-
 
 object Shared {
+    const val CAMERA_REQUEST_ID = 513469796
     var activity: Activity? = null
+    var cameraPermissionContinuation: Runnable? = null
 }