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 android.attention;
  
  /**
   * Attention manager local system server interface.
   *
   * @hide Only for use within the system server.
   */
  public abstract class AttentionManagerInternal {
      /**
       * Returns {@code true} if attention service is supported on this device.
       */
      public abstract boolean isAttentionServiceSupported();
  
      /**
       * Checks whether user attention is at the screen and calls in the provided callback.
       *
       * @param timeoutMillis a budget for the attention check; if it takes longer - {@link
       *                      AttentionCallbackInternal#onFailure} would be called with the {@link
       *                      android.service.attention.AttentionService#ATTENTION_FAILURE_TIMED_OUT}
       *                      code
       * @param callback      a callback for when the attention check has completed
       * @return {@code true} if the attention check should succeed.
       */
      public abstract boolean checkAttention(long timeoutMillis, AttentionCallbackInternal callback);
  
      /**
       * Cancels the specified attention check in case it's no longer needed.
       *
       * @param callback a callback that was used in {@link #checkAttention}
       */
      public abstract void cancelAttentionCheck(AttentionCallbackInternal callback);
  
      /** Internal interface for attention callback. */
      public abstract static class AttentionCallbackInternal {
          /**
           * Provides the result of the attention check, if the check was successful.
           *
           * @param result      an int with the result of the check
           * @param timestamp   a {@code SystemClock.uptimeMillis()} timestamp associated with the
           *                    attention check
           */
          public abstract void onSuccess(int result, long timestamp);
  
          /**
           * Provides the explanation for why the attention check had failed.
           *
           * @param error       an int with the reason for failure
           */
          public abstract void onFailure(int error);
      }
  }
  