xlistview的（java）

package com.bwie.xlistviews;

import java.text.SimpleDateFormat;
import java.util.Date;

import com.bwie.test.R;

import android.annotation.SuppressLint;
import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewTreeObserver.OnGlobalLayoutListener;
import android.view.animation.DecelerateInterpolator;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.RelativeLayout;
import android.widget.Scroller;
import android.widget.TextView;
public class XListView extends ListView implements OnScrollListener {
    private float mLastY = -1; // save event y
    private Scroller mScroller; // 用于回滚
    private OnScrollListener mScrollListener; // 回滚监听
    // 触发刷新和加载更多接口.
    private IXListViewListener mListViewListener;
    // -- 头部的View
    private XListViewHeader mHeaderView;
    // 查看头部的内容，用它计算头部高度，和隐藏它
    // 当禁用的时候刷新
    private RelativeLayout mHeaderViewContent;
    private TextView mHeaderTimeView;
    private int mHeaderViewHeight; // 头部View的高
    private boolean mEnablePullRefresh = true;
    private boolean mPullRefreshing = false; // 是否刷新.
    // -- 底部的View
    private XListViewFooter mFooterView;
    private boolean mEnablePullLoad;
    private boolean mPullLoading;
    private boolean mIsFooterReady = false;
    // 总列表项，用于检测列表视图的底部
    private int mTotalItemCount;

// for mScroller, 滚动页眉或者页脚
    private int mScrollBack;
    private final static int SCROLLBACK_HEADER = 0;// 顶部
    private final static int SCROLLBACK_FOOTER = 1;// 下部

private final static int SCROLL_DURATION = 400; // 滚动回时间
    private final static int PULL_LOAD_MORE_DELTA = 50; // 当大于50PX的时候，加载更多

private final static float OFFSET_RADIO = 1.8f; // support iOS like pull
                                                    // feature.

/**
     * @param context
     */
    public XListView(Context context) {
        super(context);
        initWithContext(context);
    }

public XListView(Context context, AttributeSet attrs) {
        super(context, attrs);
        initWithContext(context);
    }

public XListView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        initWithContext(context);
    }

private void initWithContext(Context context) {
        mScroller = new Scroller(context, new DecelerateInterpolator());
        // XListView need the scroll event, and it will dispatch the event to
        // user's listener (as a proxy).
        super.setOnScrollListener(this);

// 初始化头部View
        mHeaderView = new XListViewHeader(context);
        mHeaderViewContent = (RelativeLayout) mHeaderView
                .findViewById(R.id.xlistview_header_content);
        mHeaderTimeView = (TextView) mHeaderView
                .findViewById(R.id.xlistview_header_time);
        addHeaderView(mHeaderView);// 把头部这个视图添加进去

// 初始化底部的View
        mFooterView = new XListViewFooter(context);

// 初始化头部高度,通过全局布局改变事件的监听
        mHeaderView.getViewTreeObserver().addOnGlobalLayoutListener(
                new OnGlobalLayoutListener() {
                    @Override
                    public void onGlobalLayout() {
                        
                        mHeaderViewHeight = mHeaderViewContent.getHeight();
                        getViewTreeObserver()
                                .removeGlobalOnLayoutListener(this);
                    }
                });
    }

@Override
    public void setAdapter(ListAdapter adapter) {
        // 确定XListViewFooter是最后底部的View, 并且只有一次
        if (mIsFooterReady == false) {
            mIsFooterReady = true;
            addFooterView(mFooterView);
        }
        super.setAdapter(adapter);
    }

/**
     * 启用或禁用下拉刷新功能.
     *
     * @param enable
     */
    public void setPullRefreshEnable(boolean enable) {
        mEnablePullRefresh = enable;
        if (!mEnablePullRefresh) { // 禁用,隐藏内容
            mHeaderViewContent.setVisibility(View.INVISIBLE);// 如果为false则隐藏下拉刷新功能
        } else {
            mHeaderViewContent.setVisibility(View.VISIBLE);// 否则就显示下拉刷新功能
        }
    }

/**
     * 启用或禁用加载更多的功能.
     *
     * @param enable
     */
    public void setPullLoadEnable(boolean enable) {
        mEnablePullLoad = enable;
        if (!mEnablePullLoad) {
            mFooterView.hide();// 隐藏
            mFooterView.setOnClickListener(null);
        } else {
            mPullLoading = false;
            mFooterView.show();// 显示
            mFooterView.setState(XListViewFooter.STATE_NORMAL);
            // both "上拉" 和 "点击" 将调用加载更多.
            mFooterView.setOnClickListener(new OnClickListener() {
                @Override
                public void onClick(View v) {
                    startLoadMore();
                }
            });
        }
    }

/**
     * 停止刷新, 重置头视图.
     */
    public void stopRefresh() {
        if (mPullRefreshing == true) {
            mPullRefreshing = false;
            resetHeaderHeight();
        }
    }

/**
     * stop load more, reset footer view.
     */
    public void stopLoadMore() {
        if (mPullLoading == true) {
            mPullLoading = false;
            mFooterView.setState(XListViewFooter.STATE_NORMAL);
        }
    }

/**
     * 設置最後一次刷新時間
     *
     * @param time
     */
    @SuppressLint("SimpleDateFormat")
    public void setRefreshTime(String time) {        
         SimpleDateFormat   formatter   =   new   SimpleDateFormat   ("yyyy年MM月dd日   HH:mm:ss     ");    
         Date   curDate   =   new   Date(System.currentTimeMillis());
         //获取当前时间   
         String   str   =   formatter.format(curDate);  
        mHeaderTimeView.setText(str);
    }

private void invokeOnScrolling() {
        if (mScrollListener instanceof OnXScrollListener) {
            OnXScrollListener l = (OnXScrollListener) mScrollListener;
            l.onXScrolling(this);
        }
    }

private void updateHeaderHeight(float delta) {
        mHeaderView.setVisiableHeight((int) delta+ mHeaderView.getVisiableHeight());
        if (mEnablePullRefresh && !mPullRefreshing) { // 未处于刷新状态，更新箭头
            if (mHeaderView.getVisiableHeight() > mHeaderViewHeight) {
                mHeaderView.setState(XListViewHeader.STATE_READY);
            } else {
                mHeaderView.setState(XListViewHeader.STATE_NORMAL);
            }
        }
        setSelection(0); // scroll to top each time
    }

/**
     * 重置头视图的高度
     */
    private void resetHeaderHeight() {
        int height = mHeaderView.getVisiableHeight();
        if (height == 0) // 不显示.
            return;
        // 不显示刷新和标题的时候，什么都不显示
        if (mPullRefreshing && height <= mHeaderViewHeight) {
            return;
        }
        int finalHeight = 0; // 默认：滚动回头.
        // 当滚动回显示所有头标题时候，刷新
        if (mPullRefreshing && height > mHeaderViewHeight) {
            finalHeight = mHeaderViewHeight;
        }
        mScrollBack = SCROLLBACK_HEADER;
        mScroller.startScroll(0, height, 0, finalHeight - height,
                SCROLL_DURATION);
        // 触发刷新
        invalidate();
    }

// 改变底部视图高度
    private void updateFooterHeight(float delta) {
        int height = mFooterView.getBottomMargin() + (int) delta;
        if (mEnablePullLoad && !mPullLoading) {
            if (height > PULL_LOAD_MORE_DELTA) { // 高度足以调用加载更多
                mFooterView.setState(XListViewFooter.STATE_READY);
            } else {
                mFooterView.setState(XListViewFooter.STATE_NORMAL);
            }
        }
        mFooterView.setBottomMargin(height);

// setSelection(mTotalItemCount - 1); // scroll to bottom
    }

private void resetFooterHeight() {
        int bottomMargin = mFooterView.getBottomMargin();
        if (bottomMargin > 0) {
            mScrollBack = SCROLLBACK_FOOTER;
            mScroller.startScroll(0, bottomMargin, 0, -bottomMargin,
                    SCROLL_DURATION);
            invalidate();
        }
    }

// 开始加载更多
    private void startLoadMore() {
        mPullLoading = true;
        mFooterView.setState(XListViewFooter.STATE_LOADING);
        if (mListViewListener != null) {
            mListViewListener.onLoadMore();
        }
    }

// 触发事件
    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        if (mLastY == -1) {
            mLastY = ev.getRawY();
        }

switch (ev.getAction()) {
        case MotionEvent.ACTION_DOWN:
            mLastY = ev.getRawY();
            break;
        case MotionEvent.ACTION_MOVE:
            final float deltaY = ev.getRawY() - mLastY;
            mLastY = ev.getRawY();
            System.out.println("数据监测：" + getFirstVisiblePosition() + "---->"
                    + getLastVisiblePosition());
            if (getFirstVisiblePosition() == 0
                    && (mHeaderView.getVisiableHeight() > 0 || deltaY > 0)) {
                // 第一项显示,标题显示或拉下来.
                updateHeaderHeight(deltaY / OFFSET_RADIO);
                invokeOnScrolling();
            } else if (getLastVisiblePosition() == mTotalItemCount - 1
                    && (mFooterView.getBottomMargin() > 0 || deltaY < 0)) {
                // 最后一页，已停止或者想拉起
                updateFooterHeight(-deltaY / OFFSET_RADIO);
            }
            break;
        default:
            mLastY = -1; // 重置
            if (getFirstVisiblePosition() == 0) {
                // 调用刷新,如果头部视图高度大于设定高度。
                if (mEnablePullRefresh
                        && mHeaderView.getVisiableHeight() > mHeaderViewHeight) {
                    mPullRefreshing = true;// 那么刷新
                    mHeaderView.setState(XListViewHeader.STATE_REFRESHING);
                    if (mListViewListener != null) {
                        mListViewListener.onRefresh();
                    }
                }
                resetHeaderHeight();// 刷新完毕，重置头部高度，也就是返回上不
            }
            if (getLastVisiblePosition() == mTotalItemCount - 1) {
                // 调用加载更多.
                if (mEnablePullLoad
                        && mFooterView.getBottomMargin() > PULL_LOAD_MORE_DELTA) {
                    startLoadMore();// 如果底部视图高度大于可以加载高度，那么就开始加载
                }
                resetFooterHeight();// 重置加载更多视图高度
            }
            break;
        }
        return super.onTouchEvent(ev);
    }

@Override
    public void computeScroll() {
        if (mScroller.computeScrollOffset()) {
            if (mScrollBack == SCROLLBACK_HEADER) {
                mHeaderView.setVisiableHeight(mScroller.getCurrY());
            } else {
                mFooterView.setBottomMargin(mScroller.getCurrY());
            }
            postInvalidate();
            invokeOnScrolling();
        }
        super.computeScroll();
    }

@Override
    public void setOnScrollListener(OnScrollListener l) {
        mScrollListener = l;
    }

@Override
    public void onScrollStateChanged(AbsListView view, int scrollState) {
        if (mScrollListener != null) {
            mScrollListener.onScrollStateChanged(view, scrollState);
        }
    }

@Override
    public void onScroll(AbsListView view, int firstVisibleItem,
            int visibleItemCount, int totalItemCount) {
        // 发送到用户的监听器
        mTotalItemCount = totalItemCount;
        if (mScrollListener != null) {
            mScrollListener.onScroll(view, firstVisibleItem, visibleItemCount,
                    totalItemCount);
        }
    }

public void setXListViewListener(IXListViewListener l) {
        mListViewListener = l;
    }

/**
     * 你可以监听到列表视图，OnScrollListener 或者这个. 他将会被调用 , 当头部或底部触发的时候
     */
    public interface OnXScrollListener extends OnScrollListener {
        public void onXScrolling(View view);
    }

/**
     * 实现这个接口来刷新/负载更多的事件
     */
    public interface IXListViewListener {
        public void onRefresh();

public void onLoadMore();
    }
}