content: /*
   *  Copyright 2011 Yuri Kanivets
   *
   *  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.zhongou.adapter;
  
  import android.database.DataSetObserver;
  import android.view.View;
  import android.view.ViewGroup;
  
  /**
   * Wheel items adapter interface
   */
  public interface WheelViewAdapter {
  	/**
  	 * Gets items count
  	 *
  	 * @return the count of wheel items
  	 */
  	public int getItemsCount();
  
  	/**
  	 * Get a View that displays the data at the specified position in the data
  	 * set
  	 *
  	 * @param index
  	 *            the item index
  	 * @param convertView
  	 *            the old view to reuse if possible
  	 * @param parent
  	 *            the parent that this view will eventually be attached to
  	 * @return the wheel item View
  	 */
  	public View getItem(int index, View convertView, ViewGroup parent);
  
  	/**
  	 * Get a View that displays an empty wheel item placed before the first or
  	 * after the last wheel item.
  	 *
  	 * @param convertView
  	 *            the old view to reuse if possible
  	 * @param parent
  	 *            the parent that this view will eventually be attached to
  	 * @return the empty item View
  	 */
  	public View getEmptyItem(View convertView, ViewGroup parent);
  
  	/**
  	 * Register an observer that is called when changes happen to the data used
  	 * by this adapter.
  	 *
  	 * @param observer
  	 *            the observer to be registered
  	 */
  	public void registerDataSetObserver(DataSetObserver observer);
  
  	/**
  	 * Unregister an observer that has previously been registered
  	 *
  	 * @param observer
  	 *            the observer to be unregistered
  	 */
  	void unregisterDataSetObserver(DataSetObserver observer);
  }
  