SettableBBreakIterator.java

class SettableBreakIterator extends BreakIterator {

  private final BreakIterator delegate;
  private int currentCache;

  public SettableBreakIterator(BreakIterator delegate) {
    this.delegate = delegate;
    currentCache = delegate.current();
  }

  public void setPosition(int position) {
    this.currentCache = position;
  }

  @Override
  public int current() {
    return currentCache;
  }

  @Override
  public int next() {
    if (currentCache == current()) {
      return currentCache = delegate.next();
    } else {
      return currentCache = delegate.next(currentCache);
    }
  }

  @Override
  public int previous() {
    if (currentCache == current()) {
      return currentCache = delegate.previous();
    } else {
      return currentCache = delegate.preceding(currentCache);
    }
  }

  @Override
  public int first() {
    return currentCache = delegate.first();
  }

  @Override
  public int last() {
    return currentCache = delegate.last();
  }

  @Override
  public int next(int n) {
    this.next(); // sets currentCache
    if (n > 1) {
      currentCache = delegate.next(n - 1);
    }
    return currentCache;
  }

  @Override
  public int following(int offset) {
    return currentCache = delegate.following(offset);
  }

  @Override
  public int preceding(int offset) {
    return currentCache = delegate.preceding(offset);
  }

  @Override
  public boolean isBoundary(int offset) {
    return delegate.isBoundary(offset);
  }

  @Override
  public CharacterIterator getText() {
    return delegate.getText();
  }

  @Override
  public void setText(String newText) {
    delegate.setText(newText);
    currentCache = delegate.current();
  }

  @Override
  public void setText(CharacterIterator newText) {
    delegate.setText(newText);
    currentCache = delegate.current();
  }
}