[camera] Add implementations for camera_platform_interface package. (flutter#3302)

* First suggestion for camera platform interface

* Remove test coverage folder

* Renamed onLatestImageAvailableHandler definition

* Split CameraEvents into separate streams

* Implemented & tested first parts of method channel implementation

* Remove unused EventChannelMock class

* Add missing unit tests

* Added placeholders in default method channel implementation

* Updated platform interface

* Update packages/camera/camera_platform_interface/lib/src/platform_interface/camera_platform.dart

Co-authored-by: Maurits van Beusekom <[email protected]>

* Add unit test for availableCameras

* Expand availableCameras unit test. Added unit test for takePicture.

* Add unit test for startVideoRecording

* Add unit test for prepareForVideoRecording

* Add unit test for stopVideoRecording

* Add unit test for pauseVideoRecording

* Add unit test for buildView

* WIP: Dart and Android implementation

* Fix formatting

* Have resolution stream replay last value on subscription. Replace stream_transform with rxdart.

* Added reverse method channel to replace event channel. Updated initialise and takePicture implementations for android. WIP implementation for startVideoRecording

* Fixed example app for Android. Removed isRecordingVideo and isStreamingImages from buildView method.

* Added some first tests for camera/camera

* More tests and some feedback

* iOS implementation: Removed standard event channel. Added reverse method channel. Updated initialize method. Added resolution changed event. Updated error reporting to use new method channel.

* Started splitting initialize method

* Finish splitting up initialize for iOS

* Update unit tests

* Fix takePicture method on iOS

* Split initialize method on Android

* Fix video recording on iOS. Updated platform interface.

* Update unit tests

* Update error handling of video methods in iOS code. Make iOS code more consistent.

* Updated startVideoRecording documentation

* Make sure file is returned by stopVideoRecording

* Use correct event-type after initializing

* Fix DartMessenger unit-tests

* Change cast

* Fix formatting

* Fixed tests, formatting and analysis warnings

* Added missing license to Dart files

* Updated CHANGELOG and version

* Added additional unit-tests to platform_interface

* Added more tests

* Formatted code

* Re-added the CameraPreview widget

* Use import/export instead of part implementation

* fixed formatting

* Resolved additional feedback

* Update dependency to git repo

* Depend on pub.dev for camera_platform_interface

* Fix JAVA formatting

* Fix changelog

* Make sure camera package can be published

* Assert when stream methods are called from wrong platform

* Add dev_dependency on plugin_platform_interface package, required by tests.

* Remove pedantic requirement from initialize() method. Remove unnecessary completers.

* Remove dependency on dart:io

* Restrict exposed types from platform interface

* Moved test for image stream in separate file

* Fixed formatting issue

* Fix deprecation warning

* Apply feedback from bparrishMines

* Fix formatting issues

* Removed redundant podspec files

* Removed redundant ios files

* Handle SecurityException

Co-authored-by: Maurits van Beusekom <[email protected]>
Co-authored-by: Maurits van Beusekom <[email protected]>
Co-authored-by: daniel <[email protected]>
Co-authored-by: David Iglesias Teixeira <[email protected]>

Author: 4 people

packages/camera/camera/CHANGELOG.md

@@ -1,3 +1,13 @@
+## 0.6.0
+
+As part of implementing federated architecture and making the interface compatible with the web this version contains the following **breaking changes**:
+
+Method changes in `CameraController`:
+- The `takePicture` method no longer accepts the `path` parameter, but instead returns the captured image as an instance of the `XFile` class;
+- The `startVideoRecording` method no longer accepts the `filePath`. Instead the recorded video is now returned as a `XFile` instance when the `stopVideoRecording` method completes; 
+- The `stopVideoRecording` method now returns the captured video when it completes;
+- Added the `buildPreview` method which is now used to implement the CameraPreview widget.
+
 ## 0.5.8+19
 
 * Update Flutter SDK constraint.

packages/camera/camera/android/src/main/java/io/flutter/plugins/camera/Camera.java

@@ -65,8 +65,10 @@ public class Camera {
   private CaptureRequest.Builder captureRequestBuilder;
   private MediaRecorder mediaRecorder;
   private boolean recordingVideo;
+  private File videoRecordingFile;
   private CamcorderProfile recordingProfile;
   private int currentOrientation = ORIENTATION_UNKNOWN;
+  private Context applicationContext;
 
   // Mirrors camera.dart
   public enum ResolutionPreset {
@@ -94,6 +96,7 @@ public Camera(
     this.flutterTexture = flutterTexture;
     this.dartMessenger = dartMessenger;
     this.cameraManager = (CameraManager) activity.getSystemService(Context.CAMERA_SERVICE);
+    this.applicationContext = activity.getApplicationContext();
     orientationEventListener =
         new OrientationEventListener(activity.getApplicationContext()) {
           @Override
@@ -135,7 +138,7 @@ private void prepareMediaRecorder(String outputFilePath) throws IOException {
   }
 
   @SuppressLint("MissingPermission")
-  public void open(@NonNull final Result result) throws CameraAccessException {
+  public void open() throws CameraAccessException {
     pictureImageReader =
         ImageReader.newInstance(
             captureSize.getWidth(), captureSize.getHeight(), ImageFormat.JPEG, 2);
@@ -154,15 +157,13 @@ public void onOpened(@NonNull CameraDevice device) {
             try {
               startPreview();
             } catch (CameraAccessException e) {
-              result.error("CameraAccess", e.getMessage(), null);
+              dartMessenger.sendCameraErrorEvent(e.getMessage());
               close();
               return;
             }
-            Map<String, Object> reply = new HashMap<>();
-            reply.put("textureId", flutterTexture.id());
-            reply.put("previewWidth", previewSize.getWidth());
-            reply.put("previewHeight", previewSize.getHeight());
-            result.success(reply);
+
+            dartMessenger.sendCameraInitializedEvent(
+                previewSize.getWidth(), previewSize.getHeight());
           }
 
           @Override
@@ -174,7 +175,7 @@ public void onClosed(@NonNull CameraDevice camera) {
           @Override
           public void onDisconnected(@NonNull CameraDevice cameraDevice) {
             close();
-            dartMessenger.send(DartMessenger.EventType.ERROR, "The camera was disconnected.");
+            dartMessenger.sendCameraErrorEvent("The camera was disconnected.");
           }
 
           @Override
@@ -200,7 +201,7 @@ public void onError(@NonNull CameraDevice cameraDevice, int errorCode) {
               default:
                 errorDescription = "Unknown camera error";
             }
-            dartMessenger.send(DartMessenger.EventType.ERROR, errorDescription);
+            dartMessenger.sendCameraErrorEvent(errorDescription);
           }
         },
         null);
@@ -218,12 +219,13 @@ SurfaceTextureEntry getFlutterTexture() {
     return flutterTexture;
   }
 
-  public void takePicture(String filePath, @NonNull final Result result) {
-    final File file = new File(filePath);
-
-    if (file.exists()) {
-      result.error(
-          "fileExists", "File at path '" + filePath + "' already exists. Cannot overwrite.", null);
+  public void takePicture(@NonNull final Result result) {
+    final File outputDir = applicationContext.getCacheDir();
+    final File file;
+    try {
+      file = File.createTempFile("CAP", ".jpg", outputDir);
+    } catch (IOException | SecurityException e) {
+      result.error("cannotCreateFile", e.getMessage(), null);
       return;
     }
 
@@ -232,7 +234,7 @@ public void takePicture(String filePath, @NonNull final Result result) {
           try (Image image = reader.acquireLatestImage()) {
             ByteBuffer buffer = image.getPlanes()[0].getBuffer();
             writeToFile(buffer, file);
-            result.success(null);
+            result.success(file.getAbsolutePath());
           } catch (IOException e) {
             result.error("IOError", "Failed saving image", null);
           }
@@ -308,8 +310,7 @@ private void createCaptureSession(
           public void onConfigured(@NonNull CameraCaptureSession session) {
             try {
               if (cameraDevice == null) {
-                dartMessenger.send(
-                    DartMessenger.EventType.ERROR, "The camera was closed during configuration.");
+                dartMessenger.sendCameraErrorEvent("The camera was closed during configuration.");
                 return;
               }
               cameraCaptureSession = session;
@@ -320,14 +321,13 @@ public void onConfigured(@NonNull CameraCaptureSession session) {
                 onSuccessCallback.run();
               }
             } catch (CameraAccessException | IllegalStateException | IllegalArgumentException e) {
-              dartMessenger.send(DartMessenger.EventType.ERROR, e.getMessage());
+              dartMessenger.sendCameraErrorEvent(e.getMessage());
             }
           }
 
           @Override
           public void onConfigureFailed(@NonNull CameraCaptureSession cameraCaptureSession) {
-            dartMessenger.send(
-                DartMessenger.EventType.ERROR, "Failed to configure camera session.");
+            dartMessenger.sendCameraErrorEvent("Failed to configure camera session.");
           }
         };
 
@@ -369,18 +369,24 @@ private void createCaptureSession(
     cameraDevice.createCaptureSession(surfaces, callback, null);
   }
 
-  public void startVideoRecording(String filePath, Result result) {
-    if (new File(filePath).exists()) {
-      result.error("fileExists", "File at path '" + filePath + "' already exists.", null);
+  public void startVideoRecording(Result result) {
+    final File outputDir = applicationContext.getCacheDir();
+    try {
+      videoRecordingFile = File.createTempFile("REC", ".mp4", outputDir);
+    } catch (IOException | SecurityException e) {
+      result.error("cannotCreateFile", e.getMessage(), null);
       return;
     }
+
     try {
-      prepareMediaRecorder(filePath);
+      prepareMediaRecorder(videoRecordingFile.getAbsolutePath());
       recordingVideo = true;
       createCaptureSession(
           CameraDevice.TEMPLATE_RECORD, () -> mediaRecorder.start(), mediaRecorder.getSurface());
       result.success(null);
     } catch (CameraAccessException | IOException e) {
+      recordingVideo = false;
+      videoRecordingFile = null;
       result.error("videoRecordingFailed", e.getMessage(), null);
     }
   }
@@ -396,7 +402,8 @@ public void stopVideoRecording(@NonNull final Result result) {
       mediaRecorder.stop();
       mediaRecorder.reset();
       startPreview();
-      result.success(null);
+      result.success(videoRecordingFile.getAbsolutePath());
+      videoRecordingFile = null;
     } catch (CameraAccessException | IllegalStateException e) {
       result.error("videoRecordingFailed", e.getMessage(), null);
     }

packages/camera/camera/android/src/main/java/io/flutter/plugins/camera/DartMessenger.java

@@ -3,49 +3,56 @@
 import android.text.TextUtils;
 import androidx.annotation.Nullable;
 import io.flutter.plugin.common.BinaryMessenger;
-import io.flutter.plugin.common.EventChannel;
+import io.flutter.plugin.common.MethodChannel;
 import java.util.HashMap;
 import java.util.Map;
 
 class DartMessenger {
-  @Nullable private EventChannel.EventSink eventSink;
+  @Nullable private MethodChannel channel;
 
   enum EventType {
     ERROR,
     CAMERA_CLOSING,
+    INITIALIZED,
   }
 
-  DartMessenger(BinaryMessenger messenger, long eventChannelId) {
-    new EventChannel(messenger, "flutter.io/cameraPlugin/cameraEvents" + eventChannelId)
-        .setStreamHandler(
-            new EventChannel.StreamHandler() {
-              @Override
-              public void onListen(Object arguments, EventChannel.EventSink sink) {
-                eventSink = sink;
-              }
-
-              @Override
-              public void onCancel(Object arguments) {
-                eventSink = null;
-              }
-            });
+  DartMessenger(BinaryMessenger messenger, long cameraId) {
+    channel = new MethodChannel(messenger, "flutter.io/cameraPlugin/camera" + cameraId);
+  }
+
+  void sendCameraInitializedEvent(Integer previewWidth, Integer previewHeight) {
+    this.send(
+        EventType.INITIALIZED,
+        new HashMap<String, Object>() {
+          {
+            if (previewWidth != null) put("previewWidth", previewWidth.doubleValue());
+            if (previewHeight != null) put("previewHeight", previewHeight.doubleValue());
+          }
+        });
   }
 
   void sendCameraClosingEvent() {
-    send(EventType.CAMERA_CLOSING, null);
+    send(EventType.CAMERA_CLOSING);
   }
 
-  void send(EventType eventType, @Nullable String description) {
-    if (eventSink == null) {
-      return;
-    }
+  void sendCameraErrorEvent(@Nullable String description) {
+    this.send(
+        EventType.ERROR,
+        new HashMap<String, Object>() {
+          {
+            if (!TextUtils.isEmpty(description)) put("description", description);
+          }
+        });
+  }
+
+  void send(EventType eventType) {
+    send(eventType, new HashMap<>());
+  }
 
-    Map<String, String> event = new HashMap<>();
-    event.put("eventType", eventType.toString().toLowerCase());
-    // Only errors have a description.
-    if (eventType == EventType.ERROR && !TextUtils.isEmpty(description)) {
-      event.put("errorDescription", description);
+  void send(EventType eventType, Map<String, Object> args) {
+    if (channel == null) {
+      return;
     }
-    eventSink.success(event);
+    channel.invokeMethod(eventType.toString().toLowerCase(), args);
   }
 }

packages/camera/camera/android/src/main/java/io/flutter/plugins/camera/MethodCallHandlerImpl.java

@@ -11,6 +11,8 @@
 import io.flutter.plugin.common.MethodChannel.Result;
 import io.flutter.plugins.camera.CameraPermissions.PermissionsRegistry;
 import io.flutter.view.TextureRegistry;
+import java.util.HashMap;
+import java.util.Map;
 
 final class MethodCallHandlerImpl implements MethodChannel.MethodCallHandler {
   private final Activity activity;
@@ -49,11 +51,12 @@ public void onMethodCall(@NonNull MethodCall call, @NonNull final Result result)
           handleException(e, result);
         }
         break;
-      case "initialize":
+      case "create":
         {
           if (camera != null) {
             camera.close();
           }
+
           cameraPermissions.requestPermissions(
               activity,
               permissionsRegistry,
@@ -69,12 +72,28 @@ public void onMethodCall(@NonNull MethodCall call, @NonNull final Result result)
                   result.error(errCode, errDesc, null);
                 }
               });
-
+          break;
+        }
+      case "initialize":
+        {
+          if (camera != null) {
+            try {
+              camera.open();
+              result.success(null);
+            } catch (Exception e) {
+              handleException(e, result);
+            }
+          } else {
+            result.error(
+                "cameraNotFound",
+                "Camera not found. Please call the 'create' method before calling 'initialize'.",
+                null);
+          }
           break;
         }
       case "takePicture":
         {
-          camera.takePicture(call.argument("path"), result);
+          camera.takePicture(result);
           break;
         }
       case "prepareForVideoRecording":
@@ -85,7 +104,7 @@ public void onMethodCall(@NonNull MethodCall call, @NonNull final Result result)
         }
       case "startVideoRecording":
         {
-          camera.startVideoRecording(call.argument("filePath"), result);
+          camera.startVideoRecording(result);
           break;
         }
       case "stopVideoRecording":
@@ -157,7 +176,9 @@ private void instantiateCamera(MethodCall call, Result result) throws CameraAcce
             resolutionPreset,
             enableAudio);
 
-    camera.open(result);
+    Map<String, Object> reply = new HashMap<>();
+    reply.put("cameraId", flutterSurfaceTexture.id());
+    result.success(reply);
   }
 
   // We move catching CameraAccessException out of onMethodCall because it causes a crash