AdapterBase.java

package edu.hebtu.movingcampus.adapter.base;

import java.util.LinkedList;
import java.util.List;

import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;

public abstract class AdapterBase<T> extends BaseAdapter {

	protected List<T> mList =null;

	/**
	 * list == null, not save adater data state, list!=null, save it's state util next shown
	 * @param list
	 */
	public AdapterBase(List<T> list ){
		super();
		if(list==null)
			mList=new LinkedList<T>();
		else this.mList=list;
	}

	public List<T> getList() {
		return mList;
	}

	/*
	 * 往后加
	 */
	public void appendToList(List<T> list) {
		if (list == null) {
			return;
		}
		mList.addAll(list);
		notifyDataSetChanged();
	}

	/*
	 * 往前加
	 */
	public void appendToTopList(List<T> list) {
		if (list == null) {
			return;
		}
		mList.addAll(0, list);
		notifyDataSetChanged();
	}

	public void clear() {
		mList.clear();
		notifyDataSetChanged();
	}

	@Override
	public int getCount() {
		return mList==null?0:mList.size();
	}

	@Override
	public Object getItem(int position) {
		// TODO Auto-generated method stub
		if (position > mList.size() - 1) {
			return null;
		}
		return mList.get(position);
	}

	@Override
	public long getItemId(int position) {
		// TODO Auto-generated method stub
		return position;
	}

	@Override
	public View getView(int position, View convertView, ViewGroup parent) {
		// TODO Auto-generated method stub
		if (position == getCount() - 1) {
			onReachBottom();
		}
		return getNextView(position, convertView, parent);
	}

	protected abstract View getNextView(int position, View convertView,
			ViewGroup parent);

	protected abstract void onReachBottom();

}