[camera]handle access permission

hellohuanlin · hellohuanlin · commit 32694923d953 · 2022-04-11T12:58:04.000-07:00
diff --git a/packages/camera/camera/CHANGELOG.md b/packages/camera/camera/CHANGELOG.md
@@ -1,6 +1,10 @@
+## 0.9.5
+
+* Adds camera access permission handling on iOS to fix a related crash when first time using the camera. 
+
 ## 0.9.4+19
 
-* Migrate deprecated Scaffold SnackBar methods to ScaffoldMessenger.
+* Migrates deprecated Scaffold SnackBar methods to ScaffoldMessenger.
 
 ## 0.9.4+18
 
diff --git a/packages/camera/camera/example/ios/Runner.xcodeproj/project.pbxproj b/packages/camera/camera/example/ios/Runner.xcodeproj/project.pbxproj
@@ -3,7 +3,7 @@
 	archiveVersion = 1;
 	classes = {
 	};
-	objectVersion = 50;
+	objectVersion = 46;
 	objects = {
 
 /* Begin PBXBuildFile section */
@@ -26,6 +26,7 @@
 		E04F108627A87CA600573D0C /* FLTSavePhotoDelegateTests.m in Sources */ = {isa = PBXBuildFile; fileRef = E04F108527A87CA600573D0C /* FLTSavePhotoDelegateTests.m */; };
 		E071CF7227B3061B006EF3BA /* FLTCamPhotoCaptureTests.m in Sources */ = {isa = PBXBuildFile; fileRef = E071CF7127B3061B006EF3BA /* FLTCamPhotoCaptureTests.m */; };
 		E071CF7427B31DE4006EF3BA /* FLTCamSampleBufferTests.m in Sources */ = {isa = PBXBuildFile; fileRef = E071CF7327B31DE4006EF3BA /* FLTCamSampleBufferTests.m */; };
+		E0B0D2BB27DFF2AF00E71E4B /* CameraAccessPermissionTests.m in Sources */ = {isa = PBXBuildFile; fileRef = E0B0D2BA27DFF2AF00E71E4B /* CameraAccessPermissionTests.m */; };
 		E0C6E2002770F01A00EA6AA3 /* ThreadSafeMethodChannelTests.m in Sources */ = {isa = PBXBuildFile; fileRef = E0C6E1FD2770F01A00EA6AA3 /* ThreadSafeMethodChannelTests.m */; };
 		E0C6E2012770F01A00EA6AA3 /* ThreadSafeTextureRegistryTests.m in Sources */ = {isa = PBXBuildFile; fileRef = E0C6E1FE2770F01A00EA6AA3 /* ThreadSafeTextureRegistryTests.m */; };
 		E0C6E2022770F01A00EA6AA3 /* ThreadSafeEventChannelTests.m in Sources */ = {isa = PBXBuildFile; fileRef = E0C6E1FF2770F01A00EA6AA3 /* ThreadSafeEventChannelTests.m */; };
@@ -91,6 +92,7 @@
 		E04F108527A87CA600573D0C /* FLTSavePhotoDelegateTests.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = FLTSavePhotoDelegateTests.m; sourceTree = "<group>"; };
 		E071CF7127B3061B006EF3BA /* FLTCamPhotoCaptureTests.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = FLTCamPhotoCaptureTests.m; sourceTree = "<group>"; };
 		E071CF7327B31DE4006EF3BA /* FLTCamSampleBufferTests.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = FLTCamSampleBufferTests.m; sourceTree = "<group>"; };
+		E0B0D2BA27DFF2AF00E71E4B /* CameraAccessPermissionTests.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = CameraAccessPermissionTests.m; sourceTree = "<group>"; };
 		E0C6E1FD2770F01A00EA6AA3 /* ThreadSafeMethodChannelTests.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = ThreadSafeMethodChannelTests.m; sourceTree = "<group>"; };
 		E0C6E1FE2770F01A00EA6AA3 /* ThreadSafeTextureRegistryTests.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = ThreadSafeTextureRegistryTests.m; sourceTree = "<group>"; };
 		E0C6E1FF2770F01A00EA6AA3 /* ThreadSafeEventChannelTests.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = ThreadSafeEventChannelTests.m; sourceTree = "<group>"; };
@@ -136,6 +138,7 @@
 				E04F108527A87CA600573D0C /* FLTSavePhotoDelegateTests.m */,
 				E071CF7127B3061B006EF3BA /* FLTCamPhotoCaptureTests.m */,
 				E071CF7327B31DE4006EF3BA /* FLTCamSampleBufferTests.m */,
+				E0B0D2BA27DFF2AF00E71E4B /* CameraAccessPermissionTests.m */,
 				E01EE4A72799F3A5008C1950 /* QueueUtilsTests.m */,
 				E0CDBAC027CD9729002561D9 /* CameraTestUtils.h */,
 				E0CDBAC127CD9729002561D9 /* CameraTestUtils.m */,
@@ -422,6 +425,7 @@
 				788A065A27B0E02900533D74 /* StreamingTest.m in Sources */,
 				E0C6E2022770F01A00EA6AA3 /* ThreadSafeEventChannelTests.m in Sources */,
 				E0C6E2012770F01A00EA6AA3 /* ThreadSafeTextureRegistryTests.m in Sources */,
+				E0B0D2BB27DFF2AF00E71E4B /* CameraAccessPermissionTests.m in Sources */,
 				E0C6E2002770F01A00EA6AA3 /* ThreadSafeMethodChannelTests.m in Sources */,
 				E01EE4A82799F3A5008C1950 /* QueueUtilsTests.m in Sources */,
 			);
diff --git a/packages/camera/camera/example/ios/RunnerTests/CameraAccessPermissionTests.m b/packages/camera/camera/example/ios/RunnerTests/CameraAccessPermissionTests.m
@@ -0,0 +1,128 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+@import camera;
+@import camera.Test;
+@import AVFoundation;
+@import XCTest;
+#import <OCMock/OCMock.h>
+#import "CameraTestUtils.h"
+
+@interface CameraAccessPermissionTests : XCTestCase
+
+@end
+
+@implementation CameraAccessPermissionTests
+
+- (void)testRequestCameraAccessPermission_completeWithoutErrorIfPrevoiuslyAuthorized {
+  XCTestExpectation *expectation =
+      [self expectationWithDescription:
+                @"Must copmlete without error if camera access was previously authorized."];
+
+  CameraPlugin *camera = [[CameraPlugin alloc] initWithRegistry:nil messenger:nil];
+  id mockDevice = OCMClassMock([AVCaptureDevice class]);
+  OCMStub([mockDevice authorizationStatusForMediaType:AVMediaTypeVideo])
+      .andReturn(AVAuthorizationStatusAuthorized);
+  [camera requestCameraAccessPermissionWithCompletionHandler:^(FlutterError *error) {
+    if (error == nil) {
+      [expectation fulfill];
+    }
+  }];
+  [self waitForExpectationsWithTimeout:1 handler:nil];
+}
+- (void)testRequestCameraAccessPermission_completeWithErrorIfPreviouslyDenied {
+  XCTestExpectation *expectation =
+      [self expectationWithDescription:
+                @"Must complete with error if camera access was previously denied."];
+  FlutterError *expectedError =
+      [FlutterError errorWithCode:@"CameraAccessDeniedWithoutPrompt"
+                          message:@"User has previously denied the camera access request. Go to "
+                                  @"Settings to enable camera access."
+                          details:nil];
+
+  CameraPlugin *camera = [[CameraPlugin alloc] initWithRegistry:nil messenger:nil];
+  id mockDevice = OCMClassMock([AVCaptureDevice class]);
+  OCMStub([mockDevice authorizationStatusForMediaType:AVMediaTypeVideo])
+      .andReturn(AVAuthorizationStatusDenied);
+  [camera requestCameraAccessPermissionWithCompletionHandler:^(FlutterError *error) {
+    if ([error isEqual:expectedError]) {
+      [expectation fulfill];
+    }
+  }];
+  [self waitForExpectationsWithTimeout:1 handler:nil];
+}
+
+- (void)testRequestCameraAccessPermission_completeWithErrorIfRestricted {
+  XCTestExpectation *expectation =
+      [self expectationWithDescription:@"Must complete with error if camera access is restricted."];
+  FlutterError *expectedError = [FlutterError errorWithCode:@"CameraAccessRestricted"
+                                                    message:@"Camera access is restricted. "
+                                                    details:nil];
+
+  CameraPlugin *camera = [[CameraPlugin alloc] initWithRegistry:nil messenger:nil];
+
+  id mockDevice = OCMClassMock([AVCaptureDevice class]);
+  OCMStub([mockDevice authorizationStatusForMediaType:AVMediaTypeVideo])
+      .andReturn(AVAuthorizationStatusRestricted);
+  [camera requestCameraAccessPermissionWithCompletionHandler:^(FlutterError *error) {
+    if ([error isEqual:expectedError]) {
+      [expectation fulfill];
+    }
+  }];
+  [self waitForExpectationsWithTimeout:1 handler:nil];
+}
+
+- (void)testRequestCameraAccessPermission_completeWithoutErrorIfUserGrantAccess {
+  XCTestExpectation *grantedExpectation = [self
+      expectationWithDescription:@"Must complete without error if user choose to grant access"];
+
+  CameraPlugin *camera = [[CameraPlugin alloc] initWithRegistry:nil messenger:nil];
+
+  id mockDevice = OCMClassMock([AVCaptureDevice class]);
+  OCMStub([mockDevice authorizationStatusForMediaType:AVMediaTypeVideo])
+      .andReturn(AVAuthorizationStatusNotDetermined);
+  // Mimic user choosing "allow" in permission dialog.
+  OCMStub([mockDevice requestAccessForMediaType:AVMediaTypeVideo
+                              completionHandler:[OCMArg checkWithBlock:^BOOL(void (^block)(BOOL)) {
+                                block(YES);
+                                return YES;
+                              }]]);
+
+  [camera requestCameraAccessPermissionWithCompletionHandler:^(FlutterError *error) {
+    if (error == nil) {
+      [grantedExpectation fulfill];
+    }
+  }];
+  [self waitForExpectationsWithTimeout:1 handler:nil];
+}
+
+- (void)testRequestCameraAccessPermission_completeWithErrorIfUserDenyAccess {
+  XCTestExpectation *expectation =
+      [self expectationWithDescription:@"Must complete with error if user choose to deny access"];
+  CameraPlugin *camera = [[CameraPlugin alloc] initWithRegistry:nil messenger:nil];
+  FlutterError *expectedError =
+      [FlutterError errorWithCode:@"CameraAccessDenied"
+                          message:@"User denied the camera access request."
+                          details:nil];
+
+  id mockDevice = OCMClassMock([AVCaptureDevice class]);
+  OCMStub([mockDevice authorizationStatusForMediaType:AVMediaTypeVideo])
+      .andReturn(AVAuthorizationStatusNotDetermined);
+
+  // Mimic user choosing "deny" in permission dialog.
+  OCMStub([mockDevice requestAccessForMediaType:AVMediaTypeVideo
+                              completionHandler:[OCMArg checkWithBlock:^BOOL(void (^block)(BOOL)) {
+                                block(NO);
+                                return YES;
+                              }]]);
+  [camera requestCameraAccessPermissionWithCompletionHandler:^(FlutterError *error) {
+    if ([error isEqual:expectedError]) {
+      [expectation fulfill];
+    }
+  }];
+
+  [self waitForExpectationsWithTimeout:1 handler:nil];
+}
+
+@end
diff --git a/packages/camera/camera/example/ios/RunnerTests/CameraCaptureSessionQueueRaceConditionTests.m b/packages/camera/camera/example/ios/RunnerTests/CameraCaptureSessionQueueRaceConditionTests.m
@@ -29,10 +29,11 @@ - (void)testFixForCaptureSessionQueueNullPointerCrashDueToRaceCondition {
                     result:^(id _Nullable result) {
                       [disposeExpectation fulfill];
                     }];
-  [camera handleMethodCall:createCall
-                    result:^(id _Nullable result) {
-                      [createExpectation fulfill];
-                    }];
+  [camera createCameraWithCreateMethodCall:createCall
+                                    result:[[FLTThreadSafeFlutterResult alloc]
+                                               initWithResult:^(id _Nullable result) {
+                                                 [createExpectation fulfill];
+                                               }]];
   [self waitForExpectationsWithTimeout:1 handler:nil];
   // `captureSessionQueue` must not be nil after `create` call. Otherwise a nil
   // `captureSessionQueue` passed into `AVCaptureVideoDataOutput::setSampleBufferDelegate:queue:`
diff --git a/packages/camera/camera/example/ios/RunnerTests/CameraMethodChannelTests.m b/packages/camera/camera/example/ios/RunnerTests/CameraMethodChannelTests.m
@@ -37,7 +37,7 @@ - (void)testCreate_ShouldCallResultOnMainThread {
       methodCallWithMethodName:@"create"
                      arguments:@{@"resolutionPreset" : @"medium", @"enableAudio" : @(1)}];
 
-  [camera handleMethodCallAsync:call result:resultObject];
+  [camera createCameraWithCreateMethodCall:call result:resultObject];
 
   // Verify the result
   NSDictionary *dictionaryResult = (NSDictionary *)resultObject.receivedResult;
diff --git a/packages/camera/camera/example/lib/main.dart b/packages/camera/camera/example/lib/main.dart
@@ -631,7 +631,14 @@ class _CameraExampleHomeState extends State<CameraExampleHome>
 
   Future<void> onNewCameraSelected(CameraDescription cameraDescription) async {
     if (controller != null) {
-      await controller!.dispose();
+      final cameraController = controller!;
+      // `controller` needs to be set to null before getting disposed,
+      // to avoid a race condition when we use the controller that is being
+      // disposed. This happens when camera permission dialog shows up,
+      // which triggers `didChangeAppLifecycleState`, which disposes and
+      // re-creates the controller.
+      controller = null;
+      await cameraController.dispose();
     }
 
     final CameraController cameraController = CameraController(
diff --git a/packages/camera/camera/ios/Classes/CameraPlugin.m b/packages/camera/camera/ios/Classes/CameraPlugin.m
@@ -131,31 +131,18 @@ - (void)handleMethodCallAsync:(FlutterMethodCall *)call
       [result sendNotImplemented];
     }
   } else if ([@"create" isEqualToString:call.method]) {
-    NSString *cameraName = call.arguments[@"cameraName"];
-    NSString *resolutionPreset = call.arguments[@"resolutionPreset"];
-    NSNumber *enableAudio = call.arguments[@"enableAudio"];
-    NSError *error;
-    FLTCam *cam = [[FLTCam alloc] initWithCameraName:cameraName
-                                    resolutionPreset:resolutionPreset
-                                         enableAudio:[enableAudio boolValue]
-                                         orientation:[[UIDevice currentDevice] orientation]
-                                 captureSessionQueue:_captureSessionQueue
-                                               error:&error];
-
-    if (error) {
-      [result sendError:error];
-    } else {
-      if (_camera) {
-        [_camera close];
+    [self requestCameraAccessPermissionWithCompletionHandler:^(FlutterError *error) {
+      // Create FLTCam only if granted camera access.
+      if (error) {
+        [result sendFlutterError:error];
+      } else {
+        // completionHandle may be called on an arbitrary dispatch queue.
+        // Dispatch back to the capture session queue to create the camera.
+        dispatch_async(self.captureSessionQueue, ^{
+          [self createCameraWithCreateMethodCall:call result:result];
+        });
       }
-      _camera = cam;
-      [self.registry registerTexture:cam
-                          completion:^(int64_t textureId) {
-                            [result sendSuccessWithData:@{
-                              @"cameraId" : @(textureId),
-                            }];
-                          }];
-    }
+    }];
   } else if ([@"startImageStream" isEqualToString:call.method]) {
     [_camera startImageStreamWithMessenger:_messenger];
     [result sendSuccess];
@@ -274,4 +261,65 @@ - (void)handleMethodCallAsync:(FlutterMethodCall *)call
   }
 }
 
+- (void)requestCameraAccessPermissionWithCompletionHandler:(void (^)(FlutterError *))handler {
+  switch ([AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo]) {
+    case AVAuthorizationStatusAuthorized:
+      handler(nil);
+      break;
+    case AVAuthorizationStatusNotDetermined: {
+      [AVCaptureDevice
+          requestAccessForMediaType:AVMediaTypeVideo
+                  completionHandler:^(BOOL granted) {
+                    // handler can be invoked on an arbitrary dispatch queue.
+                    handler(granted ? nil
+                                    : [FlutterError
+                                          errorWithCode:@"CameraAccessDenied"
+                                                message:@"User denied the camera access request."
+                                                details:nil]);
+                  }];
+      break;
+    }
+    case AVAuthorizationStatusDenied:
+      handler([FlutterError errorWithCode:@"CameraAccessDeniedWithoutPrompt"
+                                  message:@"User has previously denied the camera access request. "
+                                          @"Go to Settings to enable camera access."
+                                  details:nil]);
+      break;
+    case AVAuthorizationStatusRestricted:
+      handler([FlutterError errorWithCode:@"CameraAccessRestricted"
+                                  message:@"Camera access is restricted. "
+                                  details:nil]);
+      break;
+  }
+}
+
+- (void)createCameraWithCreateMethodCall:(FlutterMethodCall *)createMethodCall
+                                  result:(FLTThreadSafeFlutterResult *)result {
+  NSString *cameraName = createMethodCall.arguments[@"cameraName"];
+  NSString *resolutionPreset = createMethodCall.arguments[@"resolutionPreset"];
+  NSNumber *enableAudio = createMethodCall.arguments[@"enableAudio"];
+  NSError *error;
+  FLTCam *cam = [[FLTCam alloc] initWithCameraName:cameraName
+                                  resolutionPreset:resolutionPreset
+                                       enableAudio:[enableAudio boolValue]
+                                       orientation:[[UIDevice currentDevice] orientation]
+                               captureSessionQueue:_captureSessionQueue
+                                             error:&error];
+
+  if (error) {
+    [result sendError:error];
+  } else {
+    if (_camera) {
+      [_camera close];
+    }
+    _camera = cam;
+    [self.registry registerTexture:cam
+                        completion:^(int64_t textureId) {
+                          [result sendSuccessWithData:@{
+                            @"cameraId" : @(textureId),
+                          }];
+                        }];
+  }
+}
+
 @end
diff --git a/packages/camera/camera/ios/Classes/CameraPlugin_Test.h b/packages/camera/camera/ios/Classes/CameraPlugin_Test.h
@@ -38,4 +38,22 @@
 /// that triggered the orientation change.
 - (void)orientationChanged:(NSNotification *)notification;
 
+/// Creates FLTCam and reports the creation result. In production it should be called only after
+/// camera access has been granted by the user. Exposed for unit tests to skip the camera access
+/// permission dialog.
+/// @param createMethodCall the create method call
+/// @param result a thread safe flutter result wrapper object to report creation result.
+- (void)createCameraWithCreateMethodCall:(FlutterMethodCall *)createMethodCall
+                                  result:(FLTThreadSafeFlutterResult *)result;
+
+/// Requests camera access permission.
+/// If it is the first time requesting camera access, a permission dialog will show up on the
+/// screen. Otherwise AVFoundation simply returns the user's previous choice, and in this case the
+/// user will have to update the choice in Settings app.
+/// @param handler if access permission is (or was previously) granted, completion handler will be
+/// called without error; Otherwise completion handler will be called with error. Handler can be
+/// called on an arbitrary dispatch queue.
+- (void)requestCameraAccessPermissionWithCompletionHandler:
+    (void (^_Nonnull)(FlutterError *))handler;
+
 @end
diff --git a/packages/camera/camera/ios/Classes/FLTThreadSafeFlutterResult.h b/packages/camera/camera/ios/Classes/FLTThreadSafeFlutterResult.h
diff --git a/packages/camera/camera/ios/Classes/FLTThreadSafeFlutterResult.m b/packages/camera/camera/ios/Classes/FLTThreadSafeFlutterResult.m
diff --git a/packages/camera/camera/pubspec.yaml b/packages/camera/camera/pubspec.yaml
diff --git a/packages/video_player/video_player/example/ios/Runner.xcodeproj/project.pbxproj b/packages/video_player/video_player/example/ios/Runner.xcodeproj/project.pbxproj
