content: /*
   * Copyright (C) 2017 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.launcher3.util;
  
  import android.view.View;
  import android.view.Window;
  
  import com.android.launcher3.Utilities;
  
  /**
   * Utility class to manage various window flags to control system UI.
   */
  public class SystemUiController {
  
      // Various UI states in increasing order of priority
      public static final int UI_STATE_BASE_WINDOW = 0;
      public static final int UI_STATE_ALL_APPS = 1;
      public static final int UI_STATE_WIDGET_BOTTOM_SHEET = 2;
      public static final int UI_STATE_ROOT_VIEW = 3;
  
      public static final int FLAG_LIGHT_NAV = 1 << 0;
      public static final int FLAG_DARK_NAV = 1 << 1;
      public static final int FLAG_LIGHT_STATUS = 1 << 2;
      public static final int FLAG_DARK_STATUS = 1 << 3;
  
      private final Window mWindow;
      private final int[] mStates = new int[4];
  
      public SystemUiController(Window window) {
          mWindow = window;
      }
  
      public void updateUiState(int uiState, boolean isLight) {
          updateUiState(uiState, isLight
                  ? (FLAG_LIGHT_NAV | FLAG_LIGHT_STATUS) : (FLAG_DARK_NAV | FLAG_DARK_STATUS));
      }
  
      public void updateUiState(int uiState, int flags) {
          if (mStates[uiState] == flags) {
              return;
          }
          mStates[uiState] = flags;
  
          int oldFlags = mWindow.getDecorView().getSystemUiVisibility();
          // Apply the state flags in priority order
          int newFlags = oldFlags;
          for (int stateFlag : mStates) {
              if (Utilities.ATLEAST_OREO) {
                  if ((stateFlag & FLAG_LIGHT_NAV) != 0) {
                      newFlags |= View.SYSTEM_UI_FLAG_LIGHT_NAVIGATION_BAR;
                  } else if ((stateFlag & FLAG_DARK_NAV) != 0) {
                      newFlags &= ~(View.SYSTEM_UI_FLAG_LIGHT_NAVIGATION_BAR);
                  }
              }
  
              if ((stateFlag & FLAG_LIGHT_STATUS) != 0) {
                  newFlags |= View.SYSTEM_UI_FLAG_LIGHT_STATUS_BAR;
              } else if ((stateFlag & FLAG_DARK_STATUS) != 0) {
                  newFlags &= ~(View.SYSTEM_UI_FLAG_LIGHT_STATUS_BAR);
              }
          }
          if (newFlags != oldFlags) {
              mWindow.getDecorView().setSystemUiVisibility(newFlags);
          }
      }
  }
  