content: /*
   * Copyright (C) 2019 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;
  
  import android.util.ArraySet;
  import android.view.Display.Mode;
  import android.view.DisplayInfo;
  
  /**
   * Policy to select a lower refresh rate for the display if applicable.
   */
  class RefreshRatePolicy {
  
      private final int mLowRefreshRateId;
      private final ArraySet<String> mNonHighRefreshRatePackages = new ArraySet<>();
      private final HighRefreshRateBlacklist mHighRefreshRateBlacklist;
      private final WindowManagerService mWmService;
  
      RefreshRatePolicy(WindowManagerService wmService, DisplayInfo displayInfo,
              HighRefreshRateBlacklist blacklist) {
          mLowRefreshRateId = findLowRefreshRateModeId(displayInfo);
          mHighRefreshRateBlacklist = blacklist;
          mWmService = wmService;
      }
  
      /**
       * Finds the mode id with the lowest refresh rate which is >= 60hz and same resolution as the
       * default mode.
       */
      private int findLowRefreshRateModeId(DisplayInfo displayInfo) {
          Mode mode = displayInfo.getDefaultMode();
          float[] refreshRates = displayInfo.getDefaultRefreshRates();
          float bestRefreshRate = mode.getRefreshRate();
          for (int i = refreshRates.length - 1; i >= 0; i--) {
              if (refreshRates[i] >= 60f && refreshRates[i] < bestRefreshRate) {
                  bestRefreshRate = refreshRates[i];
              }
          }
          return displayInfo.findDefaultModeByRefreshRate(bestRefreshRate);
      }
  
      void addNonHighRefreshRatePackage(String packageName) {
          mNonHighRefreshRatePackages.add(packageName);
          mWmService.requestTraversal();
      }
  
      void removeNonHighRefreshRatePackage(String packageName) {
          mNonHighRefreshRatePackages.remove(packageName);
          mWmService.requestTraversal();
      }
  
      int getPreferredModeId(WindowState w) {
  
          // If app is animating, it's not able to control refresh rate because we want the animation
          // to run in default refresh rate.
          if (w.isAnimating()) {
              return 0;
          }
  
          // If app requests a certain refresh rate or mode, don't override it.
          if (w.mAttrs.preferredRefreshRate != 0 || w.mAttrs.preferredDisplayModeId != 0) {
              return w.mAttrs.preferredDisplayModeId;
          }
  
          final String packageName = w.getOwningPackage();
  
          // If app is using Camera, force it to default (lower) refresh rate.
          if (mNonHighRefreshRatePackages.contains(packageName)) {
              return mLowRefreshRateId;
          }
  
          // If app is blacklisted using higher refresh rate, return default (lower) refresh rate
          if (mHighRefreshRateBlacklist.isBlacklisted(packageName)) {
              return mLowRefreshRateId;
          }
          return 0;
      }
  }
  