content: /*
   * Copyright (C) 2018 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.server.wm.utils;
  
  import static android.view.DisplayCutout.BOUNDS_POSITION_LENGTH;
  import static android.view.Surface.ROTATION_0;
  import static android.view.Surface.ROTATION_180;
  import static android.view.Surface.ROTATION_270;
  import static android.view.Surface.ROTATION_90;
  
  import static com.android.server.wm.utils.CoordinateTransforms.transformPhysicalToLogicalCoordinates;
  
  import android.graphics.Matrix;
  import android.graphics.Rect;
  import android.graphics.RectF;
  
  import com.android.internal.annotations.VisibleForTesting;
  
  /**
   * Utility to compute bounds after rotating the screen.
   */
  public class DisplayRotationUtil {
      private final Matrix mTmpMatrix = new Matrix();
  
      private static int getRotationToBoundsOffset(int rotation) {
          switch (rotation) {
              case ROTATION_0:
                  return 0;
              case ROTATION_90:
                  return -1;
              case ROTATION_180:
                  return 2;
              case ROTATION_270:
                  return 1;
              default:
                  // should not happen
                  return 0;
          }
      }
  
      @VisibleForTesting
      static int getBoundIndexFromRotation(int i, int rotation) {
          return Math.floorMod(i + getRotationToBoundsOffset(rotation),
                  BOUNDS_POSITION_LENGTH);
      }
  
      /**
       * Compute bounds after rotating teh screen.
       *
       * @param bounds Bounds before the rotation. The array must contain exactly 4 non-null elements.
       * @param rotation rotation constant defined in android.view.Surface.
       * @param initialDisplayWidth width of the display before the rotation.
       * @param initialDisplayHeight height of the display before the rotation.
       * @return Bounds after the rotation.
       *
       * @hide
       */
      public Rect[] getRotatedBounds(
              Rect[] bounds, int rotation, int initialDisplayWidth, int initialDisplayHeight) {
          if (bounds.length != BOUNDS_POSITION_LENGTH) {
              throw new IllegalArgumentException(
                      "bounds must have exactly 4 elements: bounds=" + bounds);
          }
          if (rotation == ROTATION_0) {
              return bounds;
          }
          transformPhysicalToLogicalCoordinates(rotation, initialDisplayWidth, initialDisplayHeight,
                  mTmpMatrix);
          Rect[] newBounds = new Rect[BOUNDS_POSITION_LENGTH];
          for (int i = 0; i < bounds.length; i++) {
  
              final Rect rect = bounds[i];
              if (!rect.isEmpty()) {
                  final RectF rectF = new RectF(rect);
                  mTmpMatrix.mapRect(rectF);
                  rectF.round(rect);
              }
              newBounds[getBoundIndexFromRotation(i, rotation)] = rect;
          }
          return newBounds;
      }
  }
  