/*
 * Copyright (C) 2012 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 com.android.contacts.common.database;

import android.database.AbstractCursor;
import android.database.CursorIndexOutOfBoundsException;

/**
 * A cursor that is empty.
 *
 * <p>If you want an empty cursor, this class is better than a MatrixCursor because it has less
 * overhead.
 */
public final class EmptyCursor extends AbstractCursor {

  private String[] mColumns;

  public EmptyCursor(String[] columns) {
    this.mColumns = columns;
  }

  @Override
  public int getCount() {
    return 0;
  }

  @Override
  public String[] getColumnNames() {
    return mColumns;
  }

  @Override
  public String getString(int column) {
    throw cursorException();
  }

  @Override
  public short getShort(int column) {
    throw cursorException();
  }

  @Override
  public int getInt(int column) {
    throw cursorException();
  }

  @Override
  public long getLong(int column) {
    throw cursorException();
  }

  @Override
  public float getFloat(int column) {
    throw cursorException();
  }

  @Override
  public double getDouble(int column) {
    throw cursorException();
  }

  @Override
  public boolean isNull(int column) {
    throw cursorException();
  }

  private CursorIndexOutOfBoundsException cursorException() {
    return new CursorIndexOutOfBoundsException("Operation not permitted on an empty cursor.");
  }
}