| /* |
| * 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(); |
| } |
| } |
| } |