LuckyHu Blog

/**
 * used to display a grid view that can show a loadmore footerview.
 * 
 * @author huji
 * 
 */
public class FooterableGridView extends RelativeLayout {

	public static final int COUNT_PER_PAGE = 20;

	private ViewGroup loadMoreLayout;
	private GridView mGridView;

	private TextView loadMoreTextView;

	private TextView text;

	private ProgressBar moreProgressBar;

	private OnClickListener mLoadMoreClickListener;

	public FooterableGridView(Context context, AttributeSet attrs) {
		super(context, attrs);
		init();
	}

	public FooterableGridView(Context context) {
		super(context);
		init();
	}

	private void init() {

		mGridView = new GridView(getContext());

		loadMoreLayout = (ViewGroup) LayoutInflater.from(getContext()).inflate(R.layout.course_load_more_layout, null);

		loadMoreTextView = (TextView) loadMoreLayout.findViewById(R.id.load_more_textview);
		moreProgressBar = (ProgressBar) loadMoreLayout.findViewById(R.id.load_more_progressbar);

		loadMoreLayout.setOnClickListener(clickListener);
		LayoutParams lp = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
		lp.addRule(CENTER_HORIZONTAL);
		lp.addRule(ALIGN_PARENT_BOTTOM);
		loadMoreLayout.setLayoutParams(lp);
		loadMoreLayout.setBackgroundResource(R.drawable.titlebackaground);

		mGridView.setOnScrollListener(footerViewListener);

		text = new TextView(getContext());
		text.setText("加载中...");
		LayoutParams lpt = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
		lpt.addRule(CENTER_IN_PARENT);
		text.setLayoutParams(lpt);

		addView(mGridView);
		addView(loadMoreLayout);
		addView(text);
		
	}

	public void setAdapter(ListAdapter adapter) {
		mGridView.setAdapter(adapter);
	}

	public void setOnItemClickListener(OnItemClickListener itemclick) {
		mGridView.setOnItemClickListener(itemclick);
	}

	public void setNumColumns(int num) {
		mGridView.setNumColumns(num);
	}

	public GridView getGridView() {
		return mGridView;
	}

	/**
	 * called this method after load data from the internet compkete. has more
	 * means if has more data to load.
	 * 
	 * @param hasmore
	 */
	public void loadComplete(boolean hasmore) {
		loadMoreTextView.setVisibility(View.VISIBLE);
		moreProgressBar.setVisibility(View.GONE);

		if (text.getVisibility() == VISIBLE) {
			text.setVisibility(View.GONE);
			
			TextView empty=new TextView(getContext());
			empty.setText("暂无数据");
			mGridView.setEmptyView(empty);
		}

		if (!hasmore) {
			loadMoreLayout.setVisibility(View.GONE);
			mGridView.setOnScrollListener(null);
		}
	}

	public void setLoadMoreClickListener(OnClickListener listener) {
		mLoadMoreClickListener = listener;
	}

	private OnScrollListener footerViewListener = new OnScrollListener() {

		@Override
		public void onScrollStateChanged(AbsListView view, int scrollState) {
			// TODO Auto-generated method stub

		}

		@Override
		public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
			if (firstVisibleItem == 0 && visibleItemCount == 0 && totalItemCount == 0) {
				return;
			}

			if (firstVisibleItem + visibleItemCount == totalItemCount) {
				if (loadMoreLayout.getVisibility() == View.GONE) {
					loadMoreLayout.setVisibility(View.VISIBLE);
				}
			} else {
				if (loadMoreLayout.getVisibility() == View.VISIBLE) {
					loadMoreLayout.setVisibility(View.GONE);
				}
			}
		}
	};

	private OnClickListener clickListener = new OnClickListener() {

		@Override
		public void onClick(View v) {
			if (v.getVisibility() == INVISIBLE) {
				return;
			}

			loadMoreTextView.setVisibility(View.GONE);
			moreProgressBar.setVisibility(View.VISIBLE);

			if (mLoadMoreClickListener != null) {
				mLoadMoreClickListener.onClick(v);
			}
		}
	};
}

<relativelayout android:layout_width="match_parent" android:visibility="gone" xmlns:android="http://schemas.android.com/apk/res/android" android:padding="15dp" android:gravity="center" android:layout_height="match_parent">

    <textview android:layout_width="wrap_content" android:id="@+id/load_more_textview" android:layout_centerinparent="true" android:layout_height="wrap_content" android:textsize="23sp" android:text="点击加载更多"></textview>

    <progressbar android:layout_width="wrap_content" android:id="@+id/load_more_progressbar" android:layout_height="wrap_content" android:layout_centerinparent="true"></progressbar>

</relativelayout>