[camera] Fix picture capture causing a crash on some Huawei devices. (flutter#3414)

Author: BeMacized

packages/camera/camera/CHANGELOG.md

@@ -1,3 +1,8 @@
+## 0.6.5+1
+
+* Fixes picture captures causing a crash on some Huawei devices.
+
+
 ## 0.6.5
 
 * Adds ImageFormat selection for ImageStream and Video(iOS only).
@@ -15,7 +20,7 @@
 
 ## 0.6.4+2
 
-* Set ImageStreamReader listener to null to prevent stale images when streaming images. 
+* Set ImageStreamReader listener to null to prevent stale images when streaming images.
 
 ## 0.6.4+1
 
@@ -75,7 +80,7 @@ As part of implementing federated architecture and making the interface compatib
 
 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 `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.
 

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

@@ -455,17 +455,20 @@ public void onCaptureFailed(
             return;
           }
           String reason;
+          boolean fatalFailure = false;
           switch (failure.getReason()) {
             case CaptureFailure.REASON_ERROR:
               reason = "An error happened in the framework";
               break;
             case CaptureFailure.REASON_FLUSHED:
               reason = "The capture has failed due to an abortCaptures() call";
+              fatalFailure = true;
               break;
             default:
               reason = "Unknown reason";
           }
-          pictureCaptureRequest.error("captureFailure", reason, null);
+          Log.w("Camera", "pictureCaptureCallback.onCaptureFailed(): " + reason);
+          if (fatalFailure) pictureCaptureRequest.error("captureFailure", reason, null);
         }
 
         private void processCapture(CaptureResult result) {

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

@@ -1,5 +1,7 @@
 package io.flutter.plugins.camera;
 
+import android.os.Handler;
+import android.os.Looper;
 import androidx.annotation.Nullable;
 import io.flutter.plugin.common.MethodChannel;
 
@@ -15,17 +17,36 @@ enum State {
     error,
   }
 
+  private final Runnable timeoutCallback =
+      new Runnable() {
+        @Override
+        public void run() {
+          error("captureTimeout", "Picture capture request timed out", state.toString());
+        }
+      };
+
   private final MethodChannel.Result result;
+  private final TimeoutHandler timeoutHandler;
   private State state;
 
   public PictureCaptureRequest(MethodChannel.Result result) {
+    this(result, new TimeoutHandler());
+  }
+
+  public PictureCaptureRequest(MethodChannel.Result result, TimeoutHandler timeoutHandler) {
     this.result = result;
-    state = State.idle;
+    this.state = State.idle;
+    this.timeoutHandler = timeoutHandler;
   }
 
   public void setState(State state) {
     if (isFinished()) throw new IllegalStateException("Request has already been finished");
     this.state = state;
+    if (state != State.idle && state != State.finished && state != State.error) {
+      this.timeoutHandler.resetTimeout(timeoutCallback);
+    } else {
+      this.timeoutHandler.clearTimeout(timeoutCallback);
+    }
   }
 
   public State getState() {
@@ -38,14 +59,34 @@ public boolean isFinished() {
 
   public void finish(String absolutePath) {
     if (isFinished()) throw new IllegalStateException("Request has already been finished");
+    this.timeoutHandler.clearTimeout(timeoutCallback);
     result.success(absolutePath);
     state = State.finished;
   }
 
   public void error(
       String errorCode, @Nullable String errorMessage, @Nullable Object errorDetails) {
     if (isFinished()) throw new IllegalStateException("Request has already been finished");
+    this.timeoutHandler.clearTimeout(timeoutCallback);
     result.error(errorCode, errorMessage, errorDetails);
     state = State.error;
   }
+
+  static class TimeoutHandler {
+    private static final int REQUEST_TIMEOUT = 5000;
+    private final Handler handler;
+
+    TimeoutHandler() {
+      this.handler = new Handler(Looper.getMainLooper());
+    }
+
+    public void resetTimeout(Runnable runnable) {
+      clearTimeout(runnable);
+      handler.postDelayed(runnable, REQUEST_TIMEOUT);
+    }
+
+    public void clearTimeout(Runnable runnable) {
+      handler.removeCallbacks(runnable);
+    }
+  }
 }

packages/camera/camera/android/src/test/java/io/flutter/plugins/camera/PictureCaptureRequestTest.java

@@ -3,7 +3,10 @@
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
+import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 
 import io.flutter.plugin.common.MethodChannel;
@@ -34,6 +37,32 @@ public void setState_sets_state() {
         "State is awaitingPreCapture", req.getState(), PictureCaptureRequest.State.capturing);
   }
 
+  @Test
+  public void setState_resets_timeout() {
+    PictureCaptureRequest.TimeoutHandler mockTimeoutHandler =
+        mock(PictureCaptureRequest.TimeoutHandler.class);
+    PictureCaptureRequest req = new PictureCaptureRequest(null, mockTimeoutHandler);
+    req.setState(PictureCaptureRequest.State.focusing);
+    req.setState(PictureCaptureRequest.State.preCapture);
+    req.setState(PictureCaptureRequest.State.waitingPreCaptureReady);
+    req.setState(PictureCaptureRequest.State.capturing);
+    verify(mockTimeoutHandler, times(4)).resetTimeout(any());
+    verify(mockTimeoutHandler, never()).clearTimeout(any());
+  }
+
+  @Test
+  public void setState_clears_timeout() {
+    PictureCaptureRequest.TimeoutHandler mockTimeoutHandler =
+        mock(PictureCaptureRequest.TimeoutHandler.class);
+    PictureCaptureRequest req = new PictureCaptureRequest(null, mockTimeoutHandler);
+    req.setState(PictureCaptureRequest.State.idle);
+    req.setState(PictureCaptureRequest.State.finished);
+    req = new PictureCaptureRequest(null, mockTimeoutHandler);
+    req.setState(PictureCaptureRequest.State.error);
+    verify(mockTimeoutHandler, never()).resetTimeout(any());
+    verify(mockTimeoutHandler, times(3)).clearTimeout(any());
+  }
+
   @Test
   public void finish_sets_result_and_state() {
     // Setup
@@ -46,6 +75,17 @@ public void finish_sets_result_and_state() {
     assertEquals("State is finished", req.getState(), PictureCaptureRequest.State.finished);
   }
 
+  @Test
+  public void finish_clears_timeout() {
+    PictureCaptureRequest.TimeoutHandler mockTimeoutHandler =
+        mock(PictureCaptureRequest.TimeoutHandler.class);
+    MethodChannel.Result mockResult = mock(MethodChannel.Result.class);
+    PictureCaptureRequest req = new PictureCaptureRequest(mockResult, mockTimeoutHandler);
+    req.finish("/test/path");
+    verify(mockTimeoutHandler, never()).resetTimeout(any());
+    verify(mockTimeoutHandler).clearTimeout(any());
+  }
+
   @Test
   public void isFinished_is_true_When_state_is_finished_or_error() {
     // Setup
@@ -86,6 +126,17 @@ public void error_sets_result_and_state() {
     assertEquals("State is error", req.getState(), PictureCaptureRequest.State.error);
   }
 
+  @Test
+  public void error_clears_timeout() {
+    PictureCaptureRequest.TimeoutHandler mockTimeoutHandler =
+        mock(PictureCaptureRequest.TimeoutHandler.class);
+    MethodChannel.Result mockResult = mock(MethodChannel.Result.class);
+    PictureCaptureRequest req = new PictureCaptureRequest(mockResult, mockTimeoutHandler);
+    req.error("ERROR_CODE", "Error Message", null);
+    verify(mockTimeoutHandler, never()).resetTimeout(any());
+    verify(mockTimeoutHandler).clearTimeout(any());
+  }
+
   @Test(expected = IllegalStateException.class)
   public void error_throws_When_already_finished() {
     // Setup

packages/camera/camera/pubspec.yaml

@@ -2,7 +2,7 @@ name: camera
 description: A Flutter plugin for getting information about and controlling the
   camera on Android and iOS. Supports previewing the camera feed, capturing images, capturing video,
   and streaming image buffers to dart.
-version: 0.6.5
+version: 0.6.5+1
 homepage: https://github.com/flutter/plugins/tree/master/packages/camera/camera
 
 dependencies: