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 android.graphics.Rect;
  import android.util.Size;
  import android.view.DisplayCutout;
  import android.view.Gravity;
  
  import java.util.List;
  import java.util.Objects;
  
  /**
   * Wrapper for DisplayCutout that also tracks the display size and using this allows (re)calculating
   * safe insets.
   */
  public class WmDisplayCutout {
  
      public static final WmDisplayCutout NO_CUTOUT = new WmDisplayCutout(DisplayCutout.NO_CUTOUT,
              null);
  
      private final DisplayCutout mInner;
      private final Size mFrameSize;
  
      public WmDisplayCutout(DisplayCutout inner, Size frameSize) {
          mInner = inner;
          mFrameSize = frameSize;
      }
  
      public static WmDisplayCutout computeSafeInsets(DisplayCutout inner,
              int displayWidth, int displayHeight) {
          if (inner == DisplayCutout.NO_CUTOUT || inner.isBoundsEmpty()) {
              return NO_CUTOUT;
          }
  
          final Size displaySize = new Size(displayWidth, displayHeight);
          final Rect safeInsets = computeSafeInsets(displaySize, inner);
          return new WmDisplayCutout(inner.replaceSafeInsets(safeInsets), displaySize);
      }
  
      /**
       * Insets the reference frame of the cutout in the given directions.
       *
       * @return a copy of this instance which has been inset
       * @hide
       */
      public WmDisplayCutout inset(int insetLeft, int insetTop, int insetRight, int insetBottom) {
          DisplayCutout newInner = mInner.inset(insetLeft, insetTop, insetRight, insetBottom);
  
          if (mInner == newInner) {
              return this;
          }
  
          Size frame = mFrameSize == null ? null : new Size(
                  mFrameSize.getWidth() - insetLeft - insetRight,
                  mFrameSize.getHeight() - insetTop - insetBottom);
  
          return new WmDisplayCutout(newInner, frame);
      }
  
      /**
       * Recalculates the cutout relative to the given reference frame.
       *
       * The safe insets must already have been computed, e.g. with {@link #computeSafeInsets}.
       *
       * @return a copy of this instance with the safe insets recalculated
       * @hide
       */
      public WmDisplayCutout calculateRelativeTo(Rect frame) {
          if (mFrameSize == null) {
              return this;
          }
          final int insetRight = mFrameSize.getWidth() - frame.right;
          final int insetBottom = mFrameSize.getHeight() - frame.bottom;
          if (frame.left == 0 && frame.top == 0 && insetRight == 0 && insetBottom == 0) {
              return this;
          }
          if (frame.left >= mInner.getSafeInsetLeft()
                  && frame.top >= mInner.getSafeInsetTop()
                  && insetRight >= mInner.getSafeInsetRight()
                  && insetBottom >= mInner.getSafeInsetBottom()) {
              return NO_CUTOUT;
          }
          if (mInner.isEmpty()) {
              return this;
          }
          return inset(frame.left, frame.top, insetRight, insetBottom);
      }
  
      /**
       * Calculates the safe insets relative to the given display size.
       *
       * @return a copy of this instance with the safe insets calculated
       * @hide
       */
      public WmDisplayCutout computeSafeInsets(int width, int height) {
          return computeSafeInsets(mInner, width, height);
      }
  
      private static Rect computeSafeInsets(Size displaySize, DisplayCutout cutout) {
          if (displaySize.getWidth() < displaySize.getHeight()) {
              final List<Rect> boundingRects = cutout.replaceSafeInsets(
                      new Rect(0, displaySize.getHeight() / 2, 0, displaySize.getHeight() / 2))
                      .getBoundingRects();
              int topInset = findInsetForSide(displaySize, boundingRects, Gravity.TOP);
              int bottomInset = findInsetForSide(displaySize, boundingRects, Gravity.BOTTOM);
              return new Rect(0, topInset, 0, bottomInset);
          } else if (displaySize.getWidth() > displaySize.getHeight()) {
              final List<Rect> boundingRects = cutout.replaceSafeInsets(
                      new Rect(displaySize.getWidth() / 2, 0, displaySize.getWidth() / 2, 0))
                      .getBoundingRects();
              int leftInset = findInsetForSide(displaySize, boundingRects, Gravity.LEFT);
              int right = findInsetForSide(displaySize, boundingRects, Gravity.RIGHT);
              return new Rect(leftInset, 0, right, 0);
          } else {
              throw new UnsupportedOperationException("not implemented: display=" + displaySize +
                      " cutout=" + cutout);
          }
      }
  
      private static int findInsetForSide(Size display, List<Rect> boundingRects, int gravity) {
          int inset = 0;
          final int size = boundingRects.size();
          for (int i = 0; i < size; i++) {
              Rect boundingRect = boundingRects.get(i);
              switch (gravity) {
                  case Gravity.TOP:
                      if (boundingRect.top == 0) {
                          inset = Math.max(inset, boundingRect.bottom);
                      }
                      break;
                  case Gravity.BOTTOM:
                      if (boundingRect.bottom == display.getHeight()) {
                          inset = Math.max(inset, display.getHeight() - boundingRect.top);
                      }
                      break;
                  case Gravity.LEFT:
                      if (boundingRect.left == 0) {
                          inset = Math.max(inset, boundingRect.right);
                      }
                      break;
                  case Gravity.RIGHT:
                      if (boundingRect.right == display.getWidth()) {
                          inset = Math.max(inset, display.getWidth() - boundingRect.left);
                      }
                      break;
                  default:
                      throw new IllegalArgumentException("unknown gravity: " + gravity);
              }
          }
          return inset;
      }
  
      public DisplayCutout getDisplayCutout() {
          return mInner;
      }
  
      @Override
      public boolean equals(Object o) {
          if (!(o instanceof WmDisplayCutout)) {
              return false;
          }
          WmDisplayCutout that = (WmDisplayCutout) o;
          return Objects.equals(mInner, that.mInner) &&
                  Objects.equals(mFrameSize, that.mFrameSize);
      }
  
      @Override
      public int hashCode() {
          return Objects.hash(mInner, mFrameSize);
      }
  
      @Override
      public String toString() {
          return "WmDisplayCutout{" + mInner + ", mFrameSize=" + mFrameSize + '}';
      }
  }
  