LoadMoreListView.java

package com.costum.android.widget;

import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.ProgressBar;
import android.widget.RelativeLayout;

import com.daifan.R;

/*
 * Copyright (C) 2012 Fabian Leon Ortega <http://orleonsoft.blogspot.com/,
 *  http://yelamablog.blogspot.com/>
 *
 * 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.
 */

public class LoadMoreListView extends ListView implements OnScrollListener {

    private static final String TAG = "LoadMoreListView";

    /**
     * Listener that will receive notifications every time the list scrolls.
     */
    private OnScrollListener mOnScrollListener;
    private LayoutInflater mInflater;

    // footer view
    private RelativeLayout mFooterView;
    // private TextView mLabLoadMore;
    private ProgressBar mProgressBarLoadMore;

    // Listener to process load more items when user reaches the end of the list
    private OnLoadMoreListener mOnLoadMoreListener;
    // To know if the list is loading more items
    private boolean mIsLoadingMore = false;
    private int mCurrentScrollState;

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

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

    public LoadMoreListView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init(context);
    }

    private void init(Context context) {

        mInflater = (LayoutInflater) context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        // footer
        mFooterView = (RelativeLayout) mInflater.inflate(
                R.layout.new_load_more_footer, this, false);
        /*
         * mLabLoadMore = (TextView) mFooterView
		 * .findViewById(R.id.load_more_lab_view);
		 */
        mProgressBarLoadMore = (ProgressBar) mFooterView
                .findViewById(R.id.load_more_progressBar);

        addFooterView(mFooterView);

        super.setOnScrollListener(this);
    }

    @Override
    public void setAdapter(ListAdapter adapter) {
        super.setAdapter(adapter);
    }

    /**
     * Set the listener that will receive notifications every time the list
     * scrolls.
     *
     * @param l The scroll listener.
     */
    @Override
    public void setOnScrollListener(OnScrollListener l) {
        mOnScrollListener = l;
    }

    /**
     * Register a callback to be invoked when this list reaches the end (last
     * item be visible)
     *
     * @param onLoadMoreListener The callback to run.
     */

    public void setOnLoadMoreListener(OnLoadMoreListener onLoadMoreListener) {
        mOnLoadMoreListener = onLoadMoreListener;
    }

    public void onScroll(AbsListView view, int firstVisibleItem,
                         int visibleItemCount, int totalItemCount) {

        if (mOnScrollListener != null) {
            mOnScrollListener.onScroll(view, firstVisibleItem,
                    visibleItemCount, totalItemCount);
        }

        if (mOnLoadMoreListener != null) {

            if (visibleItemCount == totalItemCount) {
                mProgressBarLoadMore.setVisibility(View.GONE);
                // mLabLoadMore.setVisibility(View.GONE);
                return;
            }

            boolean loadMore = firstVisibleItem + visibleItemCount >= totalItemCount;

            if (!mIsLoadingMore && loadMore
                    && mCurrentScrollState != SCROLL_STATE_IDLE) {
                mProgressBarLoadMore.setVisibility(View.VISIBLE);
                // mLabLoadMore.setVisibility(View.VISIBLE);
                mIsLoadingMore = true;
                onLoadMore();
            }

        }

    }

    public void onScrollStateChanged(AbsListView view, int scrollState) {
        mCurrentScrollState = scrollState;

        if (mOnScrollListener != null) {
            mOnScrollListener.onScrollStateChanged(view, scrollState);
        }

    }

    public void onLoadMore() {
        Log.d(TAG, "onLoadMore");
        if (mOnLoadMoreListener != null) {
            mOnLoadMoreListener.onLoadMore();
        }
    }

    /**
     * Notify the loading more operation has finished
     */
    public void onLoadMoreComplete() {
        mIsLoadingMore = false;
        mProgressBarLoadMore.setVisibility(View.GONE);
    }

    /**
     * Interface definition for a callback to be invoked when list reaches the
     * last item (the user load more items in the list)
     */
    public interface OnLoadMoreListener {
        /**
         * Called when the list reaches the last item (the last item is visible
         * to the user)
         */
        public void onLoadMore();
    }

}