content: /*
   * Copyright (C) 2014 The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package com.android.ex.camera2.portability;
  
  import android.graphics.Matrix;
  import android.graphics.RectF;
  
  import com.android.ex.camera2.portability.debug.Log;
  
  /**
   * The device info for all attached cameras.
   */
  public interface CameraDeviceInfo {
  
      static final int NO_DEVICE = -1;
  
      /**
       * @param cameraId Which device to interrogate.
       * @return The static characteristics of the specified device, or {@code null} on error.
       */
      Characteristics getCharacteristics(int cameraId);
  
      /**
       * @return The total number of the available camera devices.
       */
      int getNumberOfCameras();
  
      /**
       * @return The first (lowest) ID of the back cameras or {@code NO_DEVICE}
       *         if not available.
       */
      int getFirstBackCameraId();
  
      /**
       * @return The first (lowest) ID of the front cameras or {@code NO_DEVICE}
       *         if not available.
       */
      int getFirstFrontCameraId();
  
      /**
       * Device characteristics for a single camera.
       */
      public abstract class Characteristics {
          private static final Log.Tag TAG = new Log.Tag("CamDvcInfChar");
  
          /**
           * @return Whether the camera faces the back of the device.
           */
          public abstract boolean isFacingBack();
  
          /**
           * @return Whether the camera faces the device's screen.
           */
          public abstract boolean isFacingFront();
  
          /**
           * @return The camera sensor orientation, or the counterclockwise angle
           *          from its natural position that the device must be held at
           *          for the sensor to be right side up (in degrees, always a
           *          multiple of 90, and between 0 and 270, inclusive).
           */
          public abstract int getSensorOrientation();
  
          /**
           * @param currentDisplayOrientation
           *          The current display orientation, measured counterclockwise
           *          from to the device's natural orientation (in degrees, always
           *          a multiple of 90, and between 0 and 270, inclusive).
           * @return
           *          The relative preview image orientation, or the clockwise
           *          rotation angle that must be applied to display preview
           *          frames in the matching orientation, accounting for implicit
           *          mirroring, if applicable (in degrees, always a multiple of
           *          90, and between 0 and 270, inclusive).
           */
          public int getPreviewOrientation(int currentDisplayOrientation) {
              // Drivers tend to mirror the image during front camera preview.
              return getRelativeImageOrientation(currentDisplayOrientation, true);
          }
  
          /**
           * @param currentDisplayOrientation
           *          The current display orientation, measured counterclockwise
           *          from to the device's natural orientation (in degrees, always
           *          a multiple of 90, and between 0 and 270, inclusive).
           * @return
           *          The relative capture image orientation, or the clockwise
           *          rotation angle that must be applied to display these frames
           *          in the matching orientation (in degrees, always a multiple
           *          of 90, and between 0 and 270, inclusive).
           */
          public int getJpegOrientation(int currentDisplayOrientation) {
              // Don't mirror during capture!
              return getRelativeImageOrientation(currentDisplayOrientation, false);
          }
  
          /**
           * @param currentDisplayOrientaiton
           *          {@link #getPreviewOrientation}, {@link #getJpegOrientation}
           * @param compensateForMirroring
           *          Whether to account for mirroring in the case of front-facing
           *          cameras, which is necessary iff the OS/driver is
           *          automatically reflecting the image.
           * @return
           *          {@link #getPreviewOrientation}, {@link #getJpegOrientation}
           *
           * @see android.hardware.Camera.setDisplayOrientation
           */
          protected int getRelativeImageOrientation(int currentDisplayOrientation,
                                                    boolean compensateForMirroring) {
              if (!orientationIsValid(currentDisplayOrientation)) {
                  return 0;
              }
  
              int result = 0;
              if (isFacingFront()) {
                  result = (getSensorOrientation() + currentDisplayOrientation) % 360;
                  if (compensateForMirroring) {
                      result = (360 - result) % 360;
                  }
              } else if (isFacingBack()) {
                  result = (getSensorOrientation() - currentDisplayOrientation + 360) % 360;
              } else {
                  Log.e(TAG, "Camera is facing unhandled direction");
              }
              return result;
          }
  
          /**
           * @param currentDisplayOrientation
           *          The current display orientation, measured counterclockwise
           *          from to the device's natural orientation (in degrees, always
           *          a multiple of 90, and between 0 and 270, inclusive).
           * @param surfaceDimensions
           *          The dimensions of the {@link android.view.Surface} on which
           *          the preview image is being rendered. It usually only makes
           *          sense for the upper-left corner to be at the origin.
           * @return
           *          The transform matrix that should be applied to the
           *          {@link android.view.Surface} in order for the image to
           *          display properly in the device's current orientation.
           */
          public Matrix getPreviewTransform(int currentDisplayOrientation, RectF surfaceDimensions) {
              return getPreviewTransform(currentDisplayOrientation, surfaceDimensions,
                      new RectF(surfaceDimensions));
          }
  
          /**
           * @param currentDisplayOrientation
           *          The current display orientation, measured counterclockwise
           *          from to the device's natural orientation (in degrees, always
           *          a multiple of 90, and between 0 and 270, inclusive).
           * @param surfaceDimensions
           *          The dimensions of the {@link android.view.Surface} on which
           *          the preview image is being rendered. It usually only makes
           *          sense for the upper-left corner to be at the origin.
           * @param desiredBounds
           *          The boundaries within the {@link android.view.Surface} where
           *          the final image should appear. These can be used to
           *          translate and scale the output, but note that the image will
           *          be stretched to fit, possibly changing its aspect ratio.
           * @return
           *          The transform matrix that should be applied to the
           *          {@link android.view.Surface} in order for the image to
           *          display properly in the device's current orientation.
           */
          public Matrix getPreviewTransform(int currentDisplayOrientation, RectF surfaceDimensions,
                                            RectF desiredBounds) {
              if (!orientationIsValid(currentDisplayOrientation) ||
                      surfaceDimensions.equals(desiredBounds)) {
                  return new Matrix();
              }
  
              Matrix transform = new Matrix();
              transform.setRectToRect(surfaceDimensions, desiredBounds, Matrix.ScaleToFit.FILL);
              return transform;
          }
  
          /**
           * @return Whether the shutter sound can be disabled.
           */
          public abstract boolean canDisableShutterSound();
  
          protected static boolean orientationIsValid(int angle) {
              if (angle % 90 != 0) {
                  Log.e(TAG, "Provided display orientation is not divisible by 90");
                  return false;
              }
              if (angle < 0 || angle > 270) {
                  Log.e(TAG, "Provided display orientation is outside expected range");
                  return false;
              }
              return true;
          }
      }
  }
  