listview 最简单也最困难3

源文件

android中listView下拉刷新  链接在 http://www.cnblogs.com/xiaoran1129/archive/2012/07/04/2576221.html

package com.tianxia.lib.baseworld.widget;

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

import android.content.Context;
import android.os.Handler;
import android.os.Message;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.ProgressBar;
import android.widget.TextView;

import com.tianxia.lib.baseworld.R;

/**
 * 下拉刷新，底部更多
 *
 */
public class RefreshListView extends ListView implements OnScrollListener{

    private float mDownY;
    private float mMoveY;

    private int mHeaderHeight;

    private int mCurrentScrollState;

    private final static int NONE_PULL_REFRESH = 0;    //正常状态
    private final static int ENTER_PULL_REFRESH = 1;   //进入下拉刷新状态
    private final static int OVER_PULL_REFRESH = 2;    //进入松手刷新状态
    private final static int EXIT_PULL_REFRESH = 3;    //松手后反弹和加载状态
    private int mPullRefreshState = 0;                 //记录刷新状态

    private final static int REFRESH_BACKING = 0;      //反弹中
    private final static int REFRESH_BACED = 1;        //达到刷新界限，反弹结束后
    private final static int REFRESH_RETURN = 2;       //没有达到刷新界限，返回
    private final static int REFRESH_DONE = 3;         //加载数据结束

    private LinearLayout mHeaderLinearLayout = null;
    private LinearLayout mFooterLinearLayout = null;
    private TextView mHeaderTextView = null;
    private TextView mHeaderUpdateText = null;
    private ImageView mHeaderPullDownImageView = null;
    private ImageView mHeaderReleaseDownImageView = null;
    private ProgressBar mHeaderProgressBar = null;
    private TextView mFooterTextView = null;
    private ProgressBar mFooterProgressBar = null;

    private SimpleDateFormat mSimpleDateFormat;

    private Object mRefreshObject = null;
    private RefreshListener mRefreshListener = null;
    public void setOnRefreshListener(RefreshListener refreshListener) {
        this.mRefreshListener = refreshListener;
    }

    public RefreshListView(Context context) {
        this(context, null);
    }

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

    void init(final Context context) {
        mHeaderLinearLayout = (LinearLayout) LayoutInflater.from(context).inflate(R.layout.refresh_list_header, null);
        addHeaderView(mHeaderLinearLayout);
        mHeaderTextView = (TextView) findViewById(R.id.refresh_list_header_text);
        mHeaderUpdateText = (TextView) findViewById(R.id.refresh_list_header_last_update);
        mHeaderPullDownImageView = (ImageView) findViewById(R.id.refresh_list_header_pull_down);
        mHeaderReleaseDownImageView = (ImageView) findViewById(R.id.refresh_list_header_release_up);
        mHeaderProgressBar = (ProgressBar) findViewById(R.id.refresh_list_header_progressbar);

        mFooterLinearLayout = (LinearLayout) LayoutInflater.from(context).inflate(R.layout.refresh_list_footer, null);
        addFooterView(mFooterLinearLayout);
        mFooterProgressBar = (ProgressBar) findViewById(R.id.refresh_list_footer_progressbar);
        mFooterTextView = (TextView) mFooterLinearLayout.findViewById(R.id.refresh_list_footer_text);
        mFooterLinearLayout.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                if (context.getString(R.string.app_list_footer_more).equals(mFooterTextView.getText())) {
                    mFooterTextView.setText(R.string.app_list_footer_loading);
                    mFooterProgressBar.setVisibility(View.VISIBLE);
                    if (mRefreshListener != null) {
                        mRefreshListener.more();
                    }
                }
            }
        });

        setSelection(1);
        setOnScrollListener(this);
        measureView(mHeaderLinearLayout);
        mHeaderHeight = mHeaderLinearLayout.getMeasuredHeight();

        mSimpleDateFormat = new SimpleDateFormat("yyyy-MM-dd hh:mm");
        mHeaderUpdateText.setText(context.getString(R.string.app_list_header_refresh_last_update, mSimpleDateFormat.format(new Date())));
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        switch (ev.getAction()) {
            case MotionEvent.ACTION_DOWN:
                mDownY = ev.getY();
                break;
            case MotionEvent.ACTION_MOVE:
                mMoveY = ev.getY();
                if (mPullRefreshState == OVER_PULL_REFRESH) {
                    mHeaderLinearLayout.setPadding(mHeaderLinearLayout.getPaddingLeft(),
                            (int)((mMoveY - mDownY)/3),
                            mHeaderLinearLayout.getPaddingRight(),
                            mHeaderLinearLayout.getPaddingBottom());
                }
                break;
            case MotionEvent.ACTION_UP:
                //when you action up, it will do these:
                //1. roll back util header topPadding is 0
                //2. hide the header by setSelection(1)
                if (mPullRefreshState == OVER_PULL_REFRESH || mPullRefreshState == ENTER_PULL_REFRESH) {
                    new Thread() {
                        public void run() {
                            Message msg;
                            while(mHeaderLinearLayout.getPaddingTop() > 1) {
                                msg = mHandler.obtainMessage();
                                msg.what = REFRESH_BACKING;
                                mHandler.sendMessage(msg);
                                try {
                                    sleep(5);
                                } catch (InterruptedException e) {
                                    e.printStackTrace();
                                }
                            }
                            msg = mHandler.obtainMessage();
                            if (mPullRefreshState == OVER_PULL_REFRESH) {
                                msg.what = REFRESH_BACED;
                            } else {
                                msg.what = REFRESH_RETURN;
                            }
                            mHandler.sendMessage(msg);
                        };
                    }.start();
                }
                break;
        }
        return super.onTouchEvent(ev);
    }

    @Override
    public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
        if (mCurrentScrollState == SCROLL_STATE_TOUCH_SCROLL
                && firstVisibleItem == 0
                && (mHeaderLinearLayout.getBottom() >= 0 && mHeaderLinearLayout.getBottom() < mHeaderHeight)) {
            //进入且仅进入下拉刷新状态
            if (mPullRefreshState == NONE_PULL_REFRESH) {
                mPullRefreshState = ENTER_PULL_REFRESH;
            }
        } else if (mCurrentScrollState == SCROLL_STATE_TOUCH_SCROLL
                && firstVisibleItem == 0
                && (mHeaderLinearLayout.getBottom() >= mHeaderHeight)) {
            //下拉达到界限，进入松手刷新状态
            if (mPullRefreshState == ENTER_PULL_REFRESH || mPullRefreshState == NONE_PULL_REFRESH) {
                mPullRefreshState = OVER_PULL_REFRESH;
                mDownY = mMoveY; //为下拉1/3折扣效果记录开始位置
                mHeaderTextView.setText("松手刷新");//显示松手刷新
                mHeaderPullDownImageView.setVisibility(View.GONE);//隐藏"下拉刷新"
                mHeaderReleaseDownImageView.setVisibility(View.VISIBLE);//显示向上的箭头
            }
        } else if (mCurrentScrollState == SCROLL_STATE_TOUCH_SCROLL && firstVisibleItem != 0) {
            //不刷新了
            if (mPullRefreshState == ENTER_PULL_REFRESH) {
                mPullRefreshState = NONE_PULL_REFRESH;
            }
        } else if (mCurrentScrollState == SCROLL_STATE_FLING && firstVisibleItem == 0) {
            //飞滑状态，不能显示出header，也不能影响正常的飞滑
            //只在正常情况下才纠正位置
            if (mPullRefreshState == NONE_PULL_REFRESH) {
                setSelection(1);
            }
        }
    }

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

    @Override
    public void setAdapter(ListAdapter adapter) {
        super.setAdapter(adapter);
        setSelection(1);
    }

    private void measureView(View child) {
        ViewGroup.LayoutParams p = child.getLayoutParams();
        if (p == null) {
            p = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT,
                    ViewGroup.LayoutParams.WRAP_CONTENT);
        }

        int childWidthSpec = ViewGroup.getChildMeasureSpec(0, 0 + 0, p.width);
        int lpHeight = p.height;
        int childHeightSpec;
        if (lpHeight > 0) {
            childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight,
                    MeasureSpec.EXACTLY);
        } else {
            childHeightSpec = MeasureSpec.makeMeasureSpec(0,
                    MeasureSpec.UNSPECIFIED);
        }
        child.measure(childWidthSpec, childHeightSpec);
    }

    private Handler mHandler = new Handler(){
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
            case REFRESH_BACKING:
                mHeaderLinearLayout.setPadding(mHeaderLinearLayout.getPaddingLeft(),
                        (int) (mHeaderLinearLayout.getPaddingTop()*0.75f),
                        mHeaderLinearLayout.getPaddingRight(),
                        mHeaderLinearLayout.getPaddingBottom());
                break;
            case REFRESH_BACED:
                mHeaderTextView.setText("正在加载...");
                mHeaderProgressBar.setVisibility(View.VISIBLE);
                mHeaderPullDownImageView.setVisibility(View.GONE);
                mHeaderReleaseDownImageView.setVisibility(View.GONE);
                mPullRefreshState = EXIT_PULL_REFRESH;
                new Thread() {
                    public void run() {
                        if (mRefreshListener != null) {
                            mRefreshObject = mRefreshListener.refreshing();
                        }
                        Message msg = mHandler.obtainMessage();
                        msg.what = REFRESH_DONE;
                        mHandler.sendMessage(msg);
                    };
                }.start();
                break;
            case REFRESH_RETURN:
                mHeaderTextView.setText("下拉刷新");
                mHeaderProgressBar.setVisibility(View.INVISIBLE);
                mHeaderPullDownImageView.setVisibility(View.VISIBLE);
                mHeaderReleaseDownImageView.setVisibility(View.GONE);
                mHeaderLinearLayout.setPadding(mHeaderLinearLayout.getPaddingLeft(),
                        0,
                        mHeaderLinearLayout.getPaddingRight(),
                        mHeaderLinearLayout.getPaddingBottom());
                mPullRefreshState = NONE_PULL_REFRESH;
                setSelection(1);
                break;
            case REFRESH_DONE:
                mHeaderTextView.setText("下拉刷新");
                mHeaderProgressBar.setVisibility(View.INVISIBLE);
                mHeaderPullDownImageView.setVisibility(View.VISIBLE);
                mHeaderReleaseDownImageView.setVisibility(View.GONE);
                mHeaderUpdateText.setText(getContext().getString(R.string.app_list_header_refresh_last_update,
                        mSimpleDateFormat.format(new Date())));
                mHeaderLinearLayout.setPadding(mHeaderLinearLayout.getPaddingLeft(),
                        0,
                        mHeaderLinearLayout.getPaddingRight(),
                        mHeaderLinearLayout.getPaddingBottom());
                mPullRefreshState = NONE_PULL_REFRESH;
                setSelection(1);
                if (mRefreshListener != null) {
                    mRefreshListener.refreshed(mRefreshObject);
                }
                break;
            default:
                break;
            }
        }
    };
    public interface RefreshListener {
        Object refreshing();
        void refreshed(Object obj);
        void more();
    }

    public void finishFootView() {
        mFooterProgressBar.setVisibility(View.GONE);
        mFooterTextView.setText(R.string.app_list_footer_more);
    }

    public void addFootView() {
        if (getFooterViewsCount() == 0) {
            addFooterView(mFooterLinearLayout);
        }
    }

    public void removeFootView() {
        removeFooterView(mFooterLinearLayout);
    }
}