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 android.content.res;
  
  import android.annotation.AnyRes;
  
  /**
   * Provides a set of utility methods for dealing with Resource IDs.
   * @hide
   */
  public final class ResourceId {
      /**
       * Checks whether the integer {@code id} is a valid resource ID, as generated by AAPT.
       * <p>Note that a negative integer is not necessarily an invalid resource ID, and custom
       * validations that compare the {@code id} against {@code 0} are incorrect.</p>
       * @param id The integer to validate.
       * @return {@code true} if the integer is a valid resource ID.
       */
      public static boolean isValid(@AnyRes int id) {
          // With the introduction of packages with IDs > 0x7f, resource IDs can be negative when
          // represented as a signed Java int. Some legacy code assumes -1 is an invalid resource ID,
          // despite the existing documentation.
          return id != -1 && (id & 0xff000000) != 0 && (id & 0x00ff0000) != 0;
      }
  }
  