content: /*
   * Copyright (C) 2016 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.text;
  
  import android.annotation.NonNull;
  
  import java.text.CharacterIterator;
  
  /**
   * An implementation of {@link java.text.CharacterIterator} that iterates over a given CharSequence.
   * {@hide}
   */
  public class CharSequenceCharacterIterator implements CharacterIterator {
      private final int mBeginIndex, mEndIndex;
      private int mIndex;
      private final CharSequence mCharSeq;
  
      /**
       * Constructs the iterator given a CharSequence and a range. The position of the iterator index
       * is set to the beginning of the range.
       */
      public CharSequenceCharacterIterator(@NonNull CharSequence text, int start, int end) {
          mCharSeq = text;
          mBeginIndex = mIndex = start;
          mEndIndex = end;
      }
  
      public char first() {
          mIndex = mBeginIndex;
          return current();
      }
  
      public char last() {
          if (mBeginIndex == mEndIndex) {
              mIndex = mEndIndex;
              return DONE;
          } else {
              mIndex = mEndIndex - 1;
              return mCharSeq.charAt(mIndex);
          }
      }
  
      public char current() {
          return (mIndex == mEndIndex) ? DONE : mCharSeq.charAt(mIndex);
      }
  
      public char next() {
          mIndex++;
          if (mIndex >= mEndIndex) {
              mIndex = mEndIndex;
              return DONE;
          } else {
              return mCharSeq.charAt(mIndex);
          }
      }
  
      public char previous() {
          if (mIndex <= mBeginIndex) {
              return DONE;
          } else {
              mIndex--;
              return mCharSeq.charAt(mIndex);
          }
      }
  
      public char setIndex(int position) {
          if (mBeginIndex <= position && position <= mEndIndex) {
              mIndex = position;
              return current();
          } else {
              throw new IllegalArgumentException("invalid position");
          }
      }
  
      public int getBeginIndex() {
          return mBeginIndex;
      }
  
      public int getEndIndex() {
          return mEndIndex;
      }
  
      public int getIndex() {
          return mIndex;
      }
  
      public Object clone() {
          try {
              return super.clone();
          } catch (CloneNotSupportedException e) {
              throw new InternalError();
          }
      }
  }
  