[camera] Add iOS and Android implementations for managing auto focus. (flutter#3370)

* Added platform interface methods for setting auto exposure.

* Added platform interface methods for setting auto exposure.

* Remove workspace files

* Added auto exposure implementations for Android and iOS

* Added platform interface methods for managing auto focus.

* Formatted code

* Export focus mode

* Add Android and iOS implementations (WIP)

* Update platform interface for changes to autofocus methods

* WIP

* Revert "Update platform interface for changes to autofocus methods"

This reverts commit bdeed1d.

* Finish android implementation

* Fix iOS implementation

* iOS fix for setting the exposure point

* Removed unnecessary check

* Updated changelog and pubspec.yaml

* Updated changelog and pubspec.yaml

* Update platform interface dependency

* Implement PR feedback

* Restore test

* Revert test change

* Update camera pubspec

* Update platform interface to prevent breaking changes with current master

* Update test to match platform interface updates

* Code format

* Fixed compilation error

* Fix formatting

* Add missing license headers to java source files.

* Update platform interface dependency

* Change fps range determination

* Fix analysis warnings

Co-authored-by: Maurits van Beusekom <maurits@baseflow.com>

Author: 2 people

packages/camera/camera/CHANGELOG.md

@@ -1,6 +1,11 @@
+## 0.6.6
+
+* Adds auto focus support for Android and iOS implementations.
+
 ## 0.6.5
 
 * Adds ImageFormat selection for ImageStream and Video(iOS only).
+
 ## 0.6.4+5
 
 * Update the example app: remove the deprecated `RaisedButton` and `FlatButton` widgets.

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

@@ -1,3 +1,7 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
 package io.flutter.plugins.camera;
 
 import static android.view.OrientationEventListener.ORIENTATION_UNKNOWN;
@@ -47,6 +51,7 @@
 import io.flutter.plugins.camera.media.MediaRecorderBuilder;
 import io.flutter.plugins.camera.types.ExposureMode;
 import io.flutter.plugins.camera.types.FlashMode;
+import io.flutter.plugins.camera.types.FocusMode;
 import io.flutter.plugins.camera.types.ResolutionPreset;
 import io.flutter.view.TextureRegistry.SurfaceTextureEntry;
 import java.io.File;
@@ -95,6 +100,7 @@ public class Camera {
   private int currentOrientation = ORIENTATION_UNKNOWN;
   private FlashMode flashMode;
   private ExposureMode exposureMode;
+  private FocusMode focusMode;
   private PictureCaptureRequest pictureCaptureRequest;
   private CameraRegions cameraRegions;
   private int exposureOffset;
@@ -128,6 +134,7 @@ public Camera(
     this.applicationContext = activity.getApplicationContext();
     this.flashMode = FlashMode.auto;
     this.exposureMode = ExposureMode.auto;
+    this.focusMode = FocusMode.auto;
     this.exposureOffset = 0;
     orientationEventListener =
         new OrientationEventListener(activity.getApplicationContext()) {
@@ -168,7 +175,7 @@ private void initFps(CameraCharacteristics cameraCharacteristics) {
           int upper = range.getUpper();
           Log.i("Camera", "[FPS Range Available] is:" + range);
           if (upper >= 10) {
-            if (fpsRange == null || upper < fpsRange.getUpper()) {
+            if (fpsRange == null || upper > fpsRange.getUpper()) {
               fpsRange = range;
             }
           }
@@ -221,7 +228,9 @@ public void onOpened(@NonNull CameraDevice device) {
                   previewSize.getWidth(),
                   previewSize.getHeight(),
                   exposureMode,
-                  isExposurePointSupported());
+                  focusMode,
+                  isExposurePointSupported(),
+                  isFocusPointSupported());
             } catch (CameraAccessException e) {
               dartMessenger.sendCameraErrorEvent(e.getMessage());
               close();
@@ -309,7 +318,7 @@ public void onConfigured(@NonNull CameraCaptureSession session) {
             cameraCaptureSession = session;
 
             updateFpsRange();
-            updateAutoFocus();
+            updateFocus(focusMode);
             updateFlash(flashMode);
             updateExposure(exposureMode);
 
@@ -510,7 +519,7 @@ private void runPictureAutoFocus() {
     assert (pictureCaptureRequest != null);
 
     pictureCaptureRequest.setState(PictureCaptureRequest.State.focusing);
-    lockAutoFocus();
+    lockAutoFocus(pictureCaptureCallback);
   }
 
   private void runPicturePreCapture() {
@@ -570,7 +579,7 @@ public void onCaptureCompleted(
     }
   }
 
-  private void lockAutoFocus() {
+  private void lockAutoFocus(CaptureCallback callback) {
     captureRequestBuilder.set(
         CaptureRequest.CONTROL_AF_TRIGGER, CaptureRequest.CONTROL_AF_TRIGGER_START);
 
@@ -581,7 +590,7 @@ private void lockAutoFocus() {
   private void unlockAutoFocus() {
     captureRequestBuilder.set(
         CaptureRequest.CONTROL_AF_TRIGGER, CameraMetadata.CONTROL_AF_TRIGGER_CANCEL);
-    updateAutoFocus();
+    updateFocus(focusMode);
     try {
       cameraCaptureSession.capture(captureRequestBuilder.build(), null, null);
     } catch (CameraAccessException ignored) {
@@ -764,25 +773,72 @@ public void setExposurePoint(@NonNull final Result result, Double x, Double y)
           "setExposurePointFailed", "Device does not have exposure point capabilities", null);
       return;
     }
-    // Check if we are doing a reset or not
-    if (x == null || y == null) {
-      x = 0.5;
-      y = 0.5;
-    }
-    // Get the current region boundaries.
-    Size maxBoundaries = getRegionBoundaries();
-    if (maxBoundaries == null) {
+    // Check if the current region boundaries are known
+    if (cameraRegions.getMaxBoundaries() == null) {
       result.error("setExposurePointFailed", "Could not determine max region boundaries", null);
       return;
     }
     // Set the metering rectangle
-    cameraRegions.setAutoExposureMeteringRectangleFromPoint(x, y);
+    if (x == null || y == null) cameraRegions.resetAutoExposureMeteringRectangle();
+    else cameraRegions.setAutoExposureMeteringRectangleFromPoint(x, y);
     // Apply it
     updateExposure(exposureMode);
     refreshPreviewCaptureSession(
         () -> result.success(null), (code, message) -> result.error("CameraAccess", message, null));
   }
 
+  public void setFocusMode(@NonNull final Result result, FocusMode mode)
+      throws CameraAccessException {
+    this.focusMode = mode;
+
+    updateFocus(mode);
+
+    switch (mode) {
+      case auto:
+        refreshPreviewCaptureSession(
+            null, (code, message) -> result.error("setFocusMode", message, null));
+        break;
+      case locked:
+        lockAutoFocus(
+            new CaptureCallback() {
+              @Override
+              public void onCaptureCompleted(
+                  @NonNull CameraCaptureSession session,
+                  @NonNull CaptureRequest request,
+                  @NonNull TotalCaptureResult result) {
+                unlockAutoFocus();
+              }
+            });
+        break;
+    }
+    result.success(null);
+  }
+
+  public void setFocusPoint(@NonNull final Result result, Double x, Double y)
+      throws CameraAccessException {
+    // Check if focus point functionality is available.
+    if (!isFocusPointSupported()) {
+      result.error("setFocusPointFailed", "Device does not have focus point capabilities", null);
+      return;
+    }
+
+    // Check if the current region boundaries are known
+    if (cameraRegions.getMaxBoundaries() == null) {
+      result.error("setFocusPointFailed", "Could not determine max region boundaries", null);
+      return;
+    }
+
+    // Set the metering rectangle
+    if (x == null || y == null) {
+      cameraRegions.resetAutoFocusMeteringRectangle();
+    } else {
+      cameraRegions.setAutoFocusMeteringRectangleFromPoint(x, y);
+    }
+
+    // Apply the new metering rectangle
+    setFocusMode(result, focusMode);
+  }
+
   @TargetApi(VERSION_CODES.P)
   private boolean supportsDistortionCorrection() throws CameraAccessException {
     int[] availableDistortionCorrectionModes =
@@ -832,6 +888,14 @@ private boolean isExposurePointSupported() throws CameraAccessException {
     return supportedRegions != null && supportedRegions > 0;
   }
 
+  private boolean isFocusPointSupported() throws CameraAccessException {
+    Integer supportedRegions =
+        cameraManager
+            .getCameraCharacteristics(cameraDevice.getId())
+            .get(CameraCharacteristics.CONTROL_MAX_REGIONS_AF);
+    return supportedRegions != null && supportedRegions > 0;
+  }
+
   public double getMinExposureOffset() throws CameraAccessException {
     Range<Integer> range =
         cameraManager
@@ -912,7 +976,7 @@ private void updateFpsRange() {
     captureRequestBuilder.set(CaptureRequest.CONTROL_AE_TARGET_FPS_RANGE, fpsRange);
   }
 
-  private void updateAutoFocus() {
+  private void updateFocus(FocusMode mode) {
     if (useAutoFocus) {
       int[] modes = cameraCharacteristics.get(CameraCharacteristics.CONTROL_AF_AVAILABLE_MODES);
       // Auto focus is not supported
@@ -923,8 +987,25 @@ private void updateAutoFocus() {
         captureRequestBuilder.set(
             CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_OFF);
       } else {
+        // Applying auto focus
+        switch (mode) {
+          case locked:
+            captureRequestBuilder.set(
+                CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_AUTO);
+            break;
+          case auto:
+            captureRequestBuilder.set(
+                CaptureRequest.CONTROL_AF_MODE,
+                recordingVideo
+                    ? CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_VIDEO
+                    : CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);
+          default:
+            break;
+        }
+        MeteringRectangle afRect = cameraRegions.getAFMeteringRectangle();
         captureRequestBuilder.set(
-            CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);
+            CaptureRequest.CONTROL_AF_REGIONS,
+            afRect == null ? null : new MeteringRectangle[] {afRect});
       }
     } else {
       captureRequestBuilder.set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_OFF);

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

@@ -1,3 +1,7 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
 package io.flutter.plugins.camera;
 
 import android.Manifest;

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

@@ -1,10 +1,15 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
 package io.flutter.plugins.camera;
 
 import android.hardware.camera2.params.MeteringRectangle;
 import android.util.Size;
 
 public final class CameraRegions {
   private MeteringRectangle aeMeteringRectangle;
+  private MeteringRectangle afMeteringRectangle;
   private Size maxBoundaries;
 
   public CameraRegions(Size maxBoundaries) {
@@ -17,6 +22,10 @@ public MeteringRectangle getAEMeteringRectangle() {
     return aeMeteringRectangle;
   }
 
+  public MeteringRectangle getAFMeteringRectangle() {
+    return afMeteringRectangle;
+  }
+
   public Size getMaxBoundaries() {
     return this.maxBoundaries;
   }
@@ -29,6 +38,14 @@ public void setAutoExposureMeteringRectangleFromPoint(double x, double y) {
     this.aeMeteringRectangle = getMeteringRectangleForPoint(maxBoundaries, x, y);
   }
 
+  public void resetAutoFocusMeteringRectangle() {
+    this.afMeteringRectangle = null;
+  }
+
+  public void setAutoFocusMeteringRectangleFromPoint(double x, double y) {
+    this.afMeteringRectangle = getMeteringRectangleForPoint(maxBoundaries, x, y);
+  }
+
   public MeteringRectangle getMeteringRectangleForPoint(Size maxBoundaries, double x, double y) {
     assert (x >= 0 && x <= 1);
     assert (y >= 0 && y <= 1);

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

@@ -1,3 +1,7 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
 package io.flutter.plugins.camera;
 
 import android.app.Activity;

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

@@ -1,3 +1,7 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
 package io.flutter.plugins.camera;
 
 import android.graphics.Rect;

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

@@ -1,10 +1,15 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
 package io.flutter.plugins.camera;
 
 import android.text.TextUtils;
 import androidx.annotation.Nullable;
 import io.flutter.plugin.common.BinaryMessenger;
 import io.flutter.plugin.common.MethodChannel;
 import io.flutter.plugins.camera.types.ExposureMode;
+import io.flutter.plugins.camera.types.FocusMode;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -25,19 +30,25 @@ void sendCameraInitializedEvent(
       Integer previewWidth,
       Integer previewHeight,
       ExposureMode exposureMode,
-      Boolean exposurePointSupported) {
+      FocusMode focusMode,
+      Boolean exposurePointSupported,
+      Boolean focusPointSupported) {
     assert (previewWidth != null);
     assert (previewHeight != null);
     assert (exposureMode != null);
+    assert (focusMode != null);
     assert (exposurePointSupported != null);
+    assert (focusPointSupported != null);
     this.send(
         EventType.INITIALIZED,
         new HashMap<String, Object>() {
           {
             put("previewWidth", previewWidth.doubleValue());
             put("previewHeight", previewHeight.doubleValue());
             put("exposureMode", exposureMode.toString());
+            put("focusMode", focusMode.toString());
             put("exposurePointSupported", exposurePointSupported);
+            put("focusPointSupported", focusPointSupported);
           }
         });
   }

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

@@ -1,3 +1,7 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
 package io.flutter.plugins.camera;
 
 import android.app.Activity;
@@ -12,6 +16,7 @@
 import io.flutter.plugins.camera.CameraPermissions.PermissionsRegistry;
 import io.flutter.plugins.camera.types.ExposureMode;
 import io.flutter.plugins.camera.types.FlashMode;
+import io.flutter.plugins.camera.types.FocusMode;
 import io.flutter.view.TextureRegistry;
 import java.util.HashMap;
 import java.util.Map;
@@ -206,6 +211,37 @@ public void onMethodCall(@NonNull MethodCall call, @NonNull final Result result)
           }
           break;
         }
+      case "setFocusMode":
+        {
+          String modeStr = call.argument("mode");
+          FocusMode mode = FocusMode.getValueForString(modeStr);
+          if (mode == null) {
+            result.error("setFocusModeFailed", "Unknown focus mode " + modeStr, null);
+            return;
+          }
+          try {
+            camera.setFocusMode(result, mode);
+          } catch (Exception e) {
+            handleException(e, result);
+          }
+          break;
+        }
+      case "setFocusPoint":
+        {
+          Boolean reset = call.argument("reset");
+          Double x = null;
+          Double y = null;
+          if (reset == null || !reset) {
+            x = call.argument("x");
+            y = call.argument("y");
+          }
+          try {
+            camera.setFocusPoint(result, x, y);
+          } catch (Exception e) {
+            handleException(e, result);
+          }
+          break;
+        }
       case "startImageStream":
         {
           try {