android listview 下拉回弹刷新效果

package com.markupartist.android.widget; import com.markupartist.android.example.pulltorefresh.R; import android.content.Context; import android.util.AttributeSet; import android.util.Log; import android.view.LayoutInflater; import android.view.MotionEvent; import android.view.View; import android.view.ViewGroup; import android.view.animation.LinearInterpolator; import android.view.animation.RotateAnimation; import android.widget.AbsListView; import android.widget.ImageView; import android.widget.ListAdapter; import android.widget.ListView; import android.widget.ProgressBar; import android.widget.RelativeLayout; import android.widget.TextView; import android.widget.AbsListView.OnScrollListener; public class PullToRefreshListView extends ListView implements OnScrollListener { private static final int TAP_TO_REFRESH = 1; // 初始状态 private static final int PULL_TO_REFRESH = 2; //拉动刷新 private static final int RELEASE_TO_REFRESH = 3; //释放刷新 private static final int REFRESHING = 4; //正在刷新 private static final String TAG = "PullToRefreshListView"; //刷新接口 private OnRefreshListener mOnRefreshListener; //箭头图片 private static int REFRESHICON = R.drawable.goicon; /** * listview 滚动监听器 */ private OnScrollListener mOnScrollListener; //视图索引器 private LayoutInflater mInflater; /** * 头部视图 内容 -- start */ private RelativeLayout mRefreshView; private TextView mRefreshViewText; private ImageView mRefreshViewImage; private ProgressBar mRefreshViewProgress; private TextView mRefreshViewLastUpdated; /** * 头部视图 内容 -- end */ //当前listivew 的滚动状态 private int mCurrentScrollState; //当前listview 的刷新状态 private int mRefreshState; //动画效果 //变为向下的箭头 private RotateAnimation mFlipAnimation; //变为逆向的箭头 private RotateAnimation mReverseFlipAnimation; //头视图的高度 private int mRefreshViewHeight; //头视图 原始的 top padding 属性值 private int mRefreshOriginalTopPadding; // private int mLastMotionY; //是否反弹 private boolean mBounceHack; public PullToRefreshListView(Context context) { super(context); init(context); } public PullToRefreshListView(Context context, AttributeSet attrs) { super(context, attrs); init(context); } public PullToRefreshListView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); init(context); } private void init(Context context) { // Load all of the animations we need in code rather than through XML //初始化动画 // mFlipAnimation = new RotateAnimation(0, -180, RotateAnimation.RELATIVE_TO_SELF, 0.5f, RotateAnimation.RELATIVE_TO_SELF, 0.5f); mFlipAnimation.setInterpolator(new LinearInterpolator()); mFlipAnimation.setDuration(250); mFlipAnimation.setFillAfter(true); mReverseFlipAnimation = new RotateAnimation(-180, 0, RotateAnimation.RELATIVE_TO_SELF, 0.5f, RotateAnimation.RELATIVE_TO_SELF, 0.5f); mReverseFlipAnimation.setInterpolator(new LinearInterpolator()); mReverseFlipAnimation.setDuration(250); mReverseFlipAnimation.setFillAfter(true); mInflater = (LayoutInflater) context.getSystemService( Context.LAYOUT_INFLATER_SERVICE); mRefreshView = (RelativeLayout) mInflater.inflate(R.layout.pull_to_refresh_header, this, false);//(R.layout.pull_to_refresh_header, null); mRefreshViewText = (TextView) mRefreshView.findViewById(R.id.pull_to_refresh_text); mRefreshViewImage = (ImageView) mRefreshView.findViewById(R.id.pull_to_refresh_image); mRefreshViewProgress = (ProgressBar) mRefreshView.findViewById(R.id.pull_to_refresh_progress); mRefreshViewLastUpdated = (TextView) mRefreshView.findViewById(R.id.pull_to_refresh_updated_at); mRefreshViewImage.setMinimumHeight(50); mRefreshView.setOnClickListener(new OnClickRefreshListener()); mRefreshOriginalTopPadding = mRefreshView.getPaddingTop(); mRefreshState = TAP_TO_REFRESH; addHeaderView(mRefreshView); super.setOnScrollListener(this); measureView(mRefreshView); mRefreshViewHeight = mRefreshView.getMeasuredHeight(); //获取头文件的测量高度 } @Override protected void onAttachedToWindow() { setSelection(1); } @Override public void setAdapter(ListAdapter adapter) { super.setAdapter(adapter); setSelection(1); } /** * Set the listener that will receive notifications every time the list * scrolls. * * @param l The scroll listener. */ @Override public void setOnScrollListener(AbsListView.OnScrollListener l) { mOnScrollListener = l; } /** * Register a callback to be invoked when this list should be refreshed. * * @param onRefreshListener The callback to run. */ public void setOnRefreshListener(OnRefreshListener onRefreshListener) { mOnRefreshListener = onRefreshListener; } /** * Set a text to represent when the list was last updated. * @param lastUpdated Last updated at. */ public void setLastUpdated(CharSequence lastUpdated) { if (lastUpdated != null) { mRefreshViewLastUpdated.setVisibility(View.VISIBLE); mRefreshViewLastUpdated.setText(lastUpdated); } else { mRefreshViewLastUpdated.setVisibility(View.GONE); } } @Override public boolean onTouchEvent(MotionEvent event) { //当前手指的Y值 final int y = (int) event.getY(); //Log.i(TAG, "触屏的Y值"+y); mBounceHack = false; //不反弹 switch (event.getAction()) { case MotionEvent.ACTION_UP: //将垂直滚动条设置为可用状态 if (!isVerticalScrollBarEnabled()) { setVerticalScrollBarEnabled(true); } //如果头部刷新条出现，并且不是正在刷新状态 if (getFirstVisiblePosition() == 0 && mRefreshState != REFRESHING) { if ((mRefreshView.getBottom() >= mRefreshViewHeight || mRefreshView.getTop() >= 0) && mRefreshState == RELEASE_TO_REFRESH) { //如果头部视图处于拉离顶部的情况 // Initiate the refresh mRefreshState = REFRESHING; //将标量设置为，正在刷新 prepareForRefresh(); //准备刷新 onRefresh(); //刷新 } else if (mRefreshView.getBottom() < mRefreshViewHeight || mRefreshView.getTop() <= 0) { // Abort refresh and scroll down below the refresh view // 停止刷新，并且滚动到头部刷新视图的下一个视图 resetHeader(); setSelection(1); //定位在第二个列表项 } } break; case MotionEvent.ACTION_DOWN: mLastMotionY = y; //跟踪手指的Y值 break; case MotionEvent.ACTION_MOVE: //更行头视图的toppadding 属性 applyHeaderPadding(event); break; } return super.onTouchEvent(event); } /**** * 不断的头部的top padding 属性 * @param ev */ private