[camera] android-rework part 2: Android auto focus feature

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

@@ -0,0 +1,350 @@
+// 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.
+
+package io.flutter.plugins.camera;
+
+import android.graphics.Rect;
+import android.hardware.camera2.CameraAccessException;
+import android.hardware.camera2.CameraCharacteristics;
+import android.hardware.camera2.CameraManager;
+import android.os.Build.VERSION_CODES;
+import android.util.Range;
+import android.util.Rational;
+import android.util.Size;
+import androidx.annotation.RequiresApi;
+
+/** An interface allowing access to the different characteristics of the device's camera. */
+public interface CameraProperties {
+
+  /**
+   * Returns the name (or identifier) of the camera device.
+   *
+   * @return String The name of the camera device.
+   */
+  String getCameraName();
+
+  /**
+   * Returns the list of frame rate ranges for @see android.control.aeTargetFpsRange supported by
+   * this camera device.
+   *
+   * <p>By default maps to the @see
+   * android.hardware.camera2.CameraCharacteristics#CONTROL_AE_TARGET_FPS_RANGE key.
+   *
+   * @return android.util.Range<Integer>[] List of frame rate ranges supported by this camera
+   *     device.
+   */
+  Range<Integer>[] getControlAutoExposureAvailableTargetFpsRanges();
+
+  /**
+   * Returns the maximum and minimum exposure compensation values for @see
+   * android.control.aeExposureCompensation, in counts of @see android.control.aeCompensationStep,
+   * that are supported by this camera device.
+   *
+   * <p>By default maps to the @see
+   * android.hardware.camera2.CameraCharacteristics#CONTROL_AE_COMPENSATION_RANGE key.
+   *
+   * @return android.util.Range<Integer> Maximum and minimum exposure compensation supported by this
+   *     camera device.
+   */
+  Range<Integer> getControlAutoExposureCompensationRange();
+
+  /**
+   * Returns the smallest step by which the exposure compensation can be changed.
+   *
+   * <p>By default maps to the @see
+   * android.hardware.camera2.CameraCharacteristics#CONTROL_AE_COMPENSATION_STEP key.
+   *
+   * @return double Smallest step by which the exposure compensation can be changed.
+   */
+  double getControlAutoExposureCompensationStep();
+
+  /**
+   * Returns a list of auto-focus modes for @see android.control.afMode that are supported by this
+   * camera device.
+   *
+   * <p>By default maps to the @see
+   * android.hardware.camera2.CameraCharacteristics#CONTROL_AF_AVAILABLE_MODES key.
+   *
+   * @return int[] List of auto-focus modes supported by this camera device.
+   */
+  int[] getControlAutoFocusAvailableModes();
+
+  /**
+   * Returns the maximum number of metering regions that can be used by the auto-exposure routine.
+   *
+   * <p>By default maps to the @see
+   * android.hardware.camera2.CameraCharacteristics#CONTROL_MAX_REGIONS_AE key.
+   *
+   * @return Integer Maximum number of metering regions that can be used by the auto-exposure
+   *     routine.
+   */
+  Integer getControlMaxRegionsAutoExposure();
+
+  /**
+   * Returns the maximum number of metering regions that can be used by the auto-focus routine.
+   *
+   * <p>By default maps to the @see
+   * android.hardware.camera2.CameraCharacteristics#CONTROL_MAX_REGIONS_AF key.
+   *
+   * @return Integer Maximum number of metering regions that can be used by the auto-focus routine.
+   */
+  Integer getControlMaxRegionsAutoFocus();
+
+  /**
+   * Returns a list of distortion correction modes for @see android.distortionCorrection.mode that
+   * are supported by this camera device.
+   *
+   * <p>By default maps to the @see
+   * android.hardware.camera2.CameraCharacteristics#DISTORTION_CORRECTION_AVAILABLE_MODES key.
+   *
+   * @return int[] List of distortion correction modes supported by this camera device.
+   */
+  @RequiresApi(api = VERSION_CODES.P)
+  int[] getDistortionCorrectionAvailableModes();
+
+  /**
+   * Returns whether this camera device has a flash unit.
+   *
+   * <p>By default maps to the @see
+   * android.hardware.camera2.CameraCharacteristics#FLASH_INFO_AVAILABLE key.
+   *
+   * @return Boolean Whether this camera device has a flash unit.
+   */
+  Boolean getFlashInfoAvailable();
+
+  /**
+   * Returns the direction the camera faces relative to device screen.
+   *
+   * <p><string>Possible values:</string>
+   *
+   * <ul>
+   *   <li>@see android.hardware.camera2.CameraMetadata.LENS_FACING_FRONT
+   *   <li>@see android.hardware.camera2.CameraMetadata.LENS_FACING_BACK
+   *   <li>@see android.hardware.camera2.CameraMetadata.LENS_FACING_EXTERNAL
+   * </ul>
+   *
+   * By default maps to the @see android.hardware.camera2.CameraCharacteristics.LENS_FACING key.
+   *
+   * @return int Direction the camera faces relative to device screen.
+   */
+  int getLensFacing();
+
+  /**
+   * Returns the shortest distance from front most surface of the lens that can be brought into
+   * sharp focus.
+   *
+   * <p>By default maps to the @see
+   * android.hardware.camera2.CameraCharacteristics#LENS_INFO_MINIMUM_FOCUS_DISTANCE key.
+   *
+   * @return Float Shortest distance from front most surface of the lens that can be brought into
+   *     sharp focus.
+   */
+  Float getLensInfoMinimumFocusDistance();
+
+  /**
+   * Returns the maximum ratio between both active area width and crop region width, and active area
+   * height and crop region height, for @see android.scaler.cropRegion.
+   *
+   * <p>By default maps to the @see
+   * android.hardware.camera2.CameraCharacteristics#SCALER_AVAILABLE_MAX_DIGITAL_ZOOM key.
+   *
+   * @return Float Maximum ratio between both active area width and crop region width, and active
+   *     area height and crop region height
+   */
+  Float getScalerAvailableMaxDigitalZoom();
+
+  /**
+   * Returns the area of the image sensor which corresponds to active pixels after any geometric
+   * distortion correction has been applied.
+   *
+   * <p>By default maps to the @see
+   * android.hardware.camera2.CameraCharacteristics#SENSOR_INFO_ACTIVE_ARRAY_SIZE key.
+   *
+   * @return android.graphics.Rect area of the image sensor which corresponds to active pixels after
+   *     any geometric distortion correction has been applied.
+   */
+  Rect getSensorInfoActiveArraySize();
+
+  /**
+   * Returns the dimensions of the full pixel array, possibly including black calibration pixels.
+   *
+   * <p>By default maps to the @see
+   * android.hardware.camera2.CameraCharacteristics#SENSOR_INFO_PIXEL_ARRAY_SIZE key.
+   *
+   * @return android.util.Size Dimensions of the full pixel array, possibly including black
+   *     calibration pixels.
+   */
+  Size getSensorInfoPixelArraySize();
+
+  /**
+   * Returns the area of the image sensor which corresponds to active pixels prior to the
+   * application of any geometric distortion correction.
+   *
+   * <p>By default maps to the @see
+   * android.hardware.camera2.CameraCharacteristics#SENSOR_INFO_PRE_CORRECTION_ACTIVE_ARRAY_SIZE
+   * key.
+   *
+   * @return android.graphics.Rect Area of the image sensor which corresponds to active pixels prior
+   *     to the application of any geometric distortion correction.
+   */
+  @RequiresApi(api = VERSION_CODES.M)
+  Rect getSensorInfoPreCorrectionActiveArraySize();
+
+  /**
+   * Returns the clockwise angle through which the output image needs to be rotated to be upright on
+   * the device screen in its native orientation.
+   *
+   * <p>By default maps to the @see
+   * android.hardware.camera2.CameraCharacteristics#SENSOR_ORIENTATION key.
+   *
+   * @return int Clockwise angle through which the output image needs to be rotated to be upright on
+   *     the device screen in its native orientation.
+   */
+  int getSensorOrientation();
+
+  /**
+   * Returns a level which generally classifies the overall set of the camera device functionality.
+   *
+   * <p><strong>Possible values:</strong>
+   *
+   * <ul>
+   *   <li>@see android.hardware.camera2.CameraMetadata.INFO_SUPPORTED_HARDWARE_LEVEL_LEGACY
+   *   <li>@see android.hardware.camera2.CameraMetadata.INFO_SUPPORTED_HARDWARE_LEVEL_LIMITED
+   *   <li>@see android.hardware.camera2.CameraMetadata.INFO_SUPPORTED_HARDWARE_LEVEL_FULL
+   *   <li>@see android.hardware.camera2.CameraMetadata.INFO_SUPPORTED_HARDWARE_LEVEL_LEVEL_3
+   *   <li>@see android.hardware.camera2.CameraMetadata.INFO_SUPPORTED_HARDWARE_LEVEL_EXTERNAL
+   * </ul>
+   *
+   * By default maps to the @see
+   * android.hardware.camera2.CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL key.
+   *
+   * @return int Level which generally classifies the overall set of the camera device
+   *     functionality.
+   */
+  int getHardwareLevel();
+
+  /**
+   * Returns a list of noise reduction modes for @see android.noiseReduction.mode that are supported
+   * by this camera device.
+   *
+   * <p>By default maps to the @see
+   * android.hardware.camera2.CameraCharacteristics#NOISE_REDUCTION_AVAILABLE_NOISE_REDUCTION_MODES
+   * key.
+   *
+   * @return int[] List of noise reduction modes that are supported by this camera device.
+   */
+  int[] getAvailableNoiseReductionModes();
+}
+
+/**
+ * Implementation of the @see CameraProperties interface using the @see
+ * android.hardware.camera2.CameraCharacteristics class to access the different characteristics.
+ */
+class CameraPropertiesImpl implements CameraProperties {
+  private final CameraCharacteristics cameraCharacteristics;
+  private final String cameraName;
+
+  public CameraPropertiesImpl(String cameraName, CameraManager cameraManager)
+      throws CameraAccessException {
+    this.cameraName = cameraName;
+    this.cameraCharacteristics = cameraManager.getCameraCharacteristics(cameraName);
+  }
+
+  @Override
+  public String getCameraName() {
+    return cameraName;
+  }
+
+  @Override
+  public Range<Integer>[] getControlAutoExposureAvailableTargetFpsRanges() {
+    return cameraCharacteristics.get(CameraCharacteristics.CONTROL_AE_AVAILABLE_TARGET_FPS_RANGES);
+  }
+
+  @Override
+  public Range<Integer> getControlAutoExposureCompensationRange() {
+    return cameraCharacteristics.get(CameraCharacteristics.CONTROL_AE_COMPENSATION_RANGE);
+  }
+
+  @Override
+  public double getControlAutoExposureCompensationStep() {
+    Rational rational =
+        cameraCharacteristics.get(CameraCharacteristics.CONTROL_AE_COMPENSATION_STEP);
+
+    return rational == null ? 0.0 : rational.doubleValue();
+  }
+
+  @Override
+  public int[] getControlAutoFocusAvailableModes() {
+    return cameraCharacteristics.get(CameraCharacteristics.CONTROL_AF_AVAILABLE_MODES);
+  }
+
+  @Override
+  public Integer getControlMaxRegionsAutoExposure() {
+    return cameraCharacteristics.get(CameraCharacteristics.CONTROL_MAX_REGIONS_AE);
+  }
+
+  @Override
+  public Integer getControlMaxRegionsAutoFocus() {
+    return cameraCharacteristics.get(CameraCharacteristics.CONTROL_MAX_REGIONS_AF);
+  }
+
+  @RequiresApi(api = VERSION_CODES.P)
+  @Override
+  public int[] getDistortionCorrectionAvailableModes() {
+    return cameraCharacteristics.get(CameraCharacteristics.DISTORTION_CORRECTION_AVAILABLE_MODES);
+  }
+
+  @Override
+  public Boolean getFlashInfoAvailable() {
+    return cameraCharacteristics.get(CameraCharacteristics.FLASH_INFO_AVAILABLE);
+  }
+
+  @Override
+  public int getLensFacing() {
+    return cameraCharacteristics.get(CameraCharacteristics.LENS_FACING);
+  }
+
+  @Override
+  public Float getLensInfoMinimumFocusDistance() {
+    return cameraCharacteristics.get(CameraCharacteristics.LENS_INFO_MINIMUM_FOCUS_DISTANCE);
+  }
+
+  @Override
+  public Float getScalerAvailableMaxDigitalZoom() {
+    return cameraCharacteristics.get(CameraCharacteristics.SCALER_AVAILABLE_MAX_DIGITAL_ZOOM);
+  }
+
+  @Override
+  public Rect getSensorInfoActiveArraySize() {
+    return cameraCharacteristics.get(CameraCharacteristics.SENSOR_INFO_ACTIVE_ARRAY_SIZE);
+  }
+
+  @Override
+  public Size getSensorInfoPixelArraySize() {
+    return cameraCharacteristics.get(CameraCharacteristics.SENSOR_INFO_PIXEL_ARRAY_SIZE);
+  }
+
+  @RequiresApi(api = VERSION_CODES.M)
+  @Override
+  public Rect getSensorInfoPreCorrectionActiveArraySize() {
+    return cameraCharacteristics.get(
+        CameraCharacteristics.SENSOR_INFO_PRE_CORRECTION_ACTIVE_ARRAY_SIZE);
+  }
+
+  @Override
+  public int getSensorOrientation() {
+    return cameraCharacteristics.get(CameraCharacteristics.SENSOR_ORIENTATION);
+  }
+
+  @Override
+  public int getHardwareLevel() {
+    return cameraCharacteristics.get(CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL);
+  }
+
+  @Override
+  public int[] getAvailableNoiseReductionModes() {
+    return cameraCharacteristics.get(
+        CameraCharacteristics.NOISE_REDUCTION_AVAILABLE_NOISE_REDUCTION_MODES);
+  }
+}