package com.ccxt.whl.widget;
import java.util.Date;
import com.ccxt.whl.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.BaseAdapter;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.ProgressBar;
import android.widget.TextView;
/**
*
* 自定义MsgListView，继承了ListView，
* 但填充了listview的头部，即下拉刷新样式，并实现其功能
* @author yanbo
*
*/
public class MsgListView extends ListView implements OnScrollListener {
private final static int RELEASE_To_REFRESH = 0;
private final static int PULL_To_REFRESH = 1;
private final static int REFRESHING = 2;
private final static int DONE = 3;
private LayoutInflater inflater;
private LinearLayout headView; // 头部
private TextView tipsTextview;//下拉刷新
private TextView lastUpdatedTextView;//最新更新
private ImageView arrowImageView;//箭头
private ProgressBar progressBar;//刷新进度条
private RotateAnimation animation;//旋转特效 刷新中箭头翻转 向下变向上
private RotateAnimation reverseAnimation;
// 用于保证startY的值在一个完整的touch事件中只被记录一次
private boolean isRecored;
private int headContentWidth;//头部宽度
private int headContentHeight;//头部高度
private int startY;//高度起始位置，用来记录与头部距离
private int firstItemIndex;//列表中首行索引，用来记录其与头部距离
private int state;//下拉刷新中、松开刷新中、正在刷新中、完成刷新
private boolean isBack;
public OnRefreshListener refreshListener;//刷新监听
private final static String TAG = "abc";
public MsgListView(Context context, AttributeSet attrs) {
super(context, attrs);
init(context);
}
private void init(Context context) {
inflater = LayoutInflater.from(context);
headView = (LinearLayout) inflater.inflate(R.layout.head, null);//listview拼接headview
arrowImageView = (ImageView) headView
.findViewById(R.id.head_arrowImageView);//headview中各view
arrowImageView.setMinimumWidth(50);
arrowImageView.setMinimumHeight(50);
progressBar = (ProgressBar) headView
.findViewById(R.id.head_progressBar);//headview中各view
tipsTextview = (TextView) headView.findViewById(R.id.head_tipsTextView);//headview中各view
lastUpdatedTextView = (TextView) headView
.findViewById(R.id.head_lastUpdatedTextView);//headview中各view
measureView(headView);
headContentHeight = headView.getMeasuredHeight();//头部高度
headContentWidth = headView.getMeasuredWidth();//头部宽度
headView.setPadding(0, -1 * headContentHeight, 0, 0);//setPadding(int left, int top, int right, int bottom)
headView.invalidate();//Invalidate the whole view
Log.v("size", "width:" + headContentWidth + " height:"
+ headContentHeight);
addHeaderView(headView);//添加进headview
setOnScrollListener(this);//滚动监听
animation = new RotateAnimation(0, -180,
RotateAnimation.RELATIVE_TO_SELF, 0.5f,
RotateAnimation.RELATIVE_TO_SELF, 0.5f);
animation.setInterpolator(new LinearInterpolator());
animation.setDuration(250);
animation.setFillAfter(true);//特效animation设置
reverseAnimation = new RotateAnimation(-180, 0,
RotateAnimation.RELATIVE_TO_SELF, 0.5f,
RotateAnimation.RELATIVE_TO_SELF, 0.5f);
reverseAnimation.setInterpolator(new LinearInterpolator());
reverseAnimation.setDuration(250);
reverseAnimation.setFillAfter(true);//特效reverseAnimation设置
}
public void onScroll(AbsListView arg0, int firstVisiableItem, int arg2,//滚动事件
int arg3) {
firstItemIndex = firstVisiableItem;//得到首item索引
}
public void onScrollStateChanged(AbsListView arg0, int arg1) {
}
public boolean onTouchEvent(MotionEvent event) {//触摸事件
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN://手按下 对应下拉刷新状态
if (firstItemIndex == 0 && !isRecored) {//如果首item索引为0，且尚未记录startY,则在下拉时记录之，并执行isRecored = true;
startY = (int) event.getY();
isRecored = true;
Log.v(TAG, "在down时候记录当前位置‘");
}
break;
case MotionEvent.ACTION_UP://手松开 对应松开刷新状态
if (state != REFRESHING) {//手松开有4个状态：下拉刷新、松开刷新、正在刷新、完成刷新。如果当前不是正在刷新
if (state == DONE) {//如果当前是完成刷新，什么都不做
}
if (state == PULL_To_REFRESH) {//如果当前是下拉刷新，状态设为完成刷新（意即下拉刷新中就松开了，实际未完成刷新），执行changeHeaderViewByState()
state = DONE;
changeHeaderViewByState();
Log.v(TAG, "由下拉刷新状态，到done状态");
}
if (state == RELEASE_To_REFRESH) {//如果当前是松开刷新，状态设为正在刷新（意即松开刷新中松开手，才是真正地刷新），执行changeHeaderViewByState()
state = REFRESHING;
changeHeaderViewByState();
onRefresh();//真正刷新，所以执行onrefresh，执行后状态设为完成刷新
Log.v(TAG, "由松开刷新状态，到done状态");
}
}
isRecored = false;//手松开，则无论怎样，可以重新记录startY,因为只要手松开就认为一次刷新已完成
isBack = false;
break;
case MotionEvent.ACTION_MOVE://手拖动，拖动过程中不断地实时记录当前位置
int tempY = (int) event.getY();
if (!isRecored && firstItemIndex == 0) {//如果首item索引为0，且尚未记录startY,则在拖动时记录之，并执行isRecored = true;
Log.v(TAG, "在move时候记录下位置");
isRecored = true;
startY = tempY;
}
if (state != REFRESHING && isRecored) {//如果状态不是正在刷新，且已记录startY：tempY为拖动过程中一直在变的高度，startY为拖动起始高度
// 可以松手去刷新了
if (state == RELEASE_To_REFRESH) {//如果状态是松开刷新
// 往上推了，推到了屏幕足够掩盖head的程度，但是还没有推到全部掩盖的地步
if ((tempY - startY < headContentHeight)//如果实时高度大于起始高度，且两者之差小于头部高度，则状态设为下拉刷新
&& (tempY - startY) > 0) {
state = PULL_To_REFRESH;
changeHeaderViewByState();
Log.v(TAG, "由松开刷新状态转变到下拉刷新状态");
}
// 一下子推到顶了
else if (tempY - startY <= 0) {//如果实时高度小于等于起始高度了，则说明到顶了，状态设为完成刷新
state = DONE;
changeHeaderViewByState();
Log.v(TAG, "由松开刷新状态转变到done状态");
}
// 往下拉了，或者还没有上推到屏幕顶部掩盖head的地步
else {//如果当前拖动过程中既没有到下拉刷新的地步，也没有到完成刷新（到顶）的地步，则保持松开刷新状态
// 不用进行特别的操作，只用更新paddingTop的值就行了
}
}
// 还没有到达显示松开刷新的时候,DONE或者是PULL_To_REFRESH状态
if (state == PULL_To_REFRESH) {//如果状态是下拉刷新
// 下拉到可以进入RELEASE_TO_REFRESH的状态
if (tempY - startY >= headContentHeight) {//如果实时高度与起始高度之差大于等于头部高度，则状态设为松开刷新
state = RELEASE_To_REFRESH;
isBack = true;
changeHeaderViewByState();
Log.v(TAG, "由done或者下拉刷新状态转变到松开刷新");
}
// 上推到顶了
else if (tempY - startY <= 0) {//如果实时高度小于等于起始高度了，则说明到顶了，状态设为完成刷新
state = DONE;
changeHeaderViewByState();
Log.v(TAG, "由DOne或者下拉刷新状态转变到done状态");
}
}
// done状态下
if (state == DONE) {//如果状态是完成刷新
if (tempY - startY > 0) {//如果实时高度大于起始高度了，则状态设为下拉刷新
state = PULL_To_REFRESH;
changeHeaderViewByState();
}
}
// 更新headView的size
if (state == PULL_To_REFRESH) {//如果状态是下拉刷新，更新headview的size ?
headView.setPadding(0, -1 * headContentHeight
+ (tempY - startY), 0, 0);
headView.invalidate();
}
// 更新headView的paddingTop
if (state == RELEASE_To_REFRESH) {//如果状态是松开刷新，更新 headview的paddingtop ?
headView.setPadding(0, tempY - startY - headContentHeight,
0, 0);
headView.invalidate();
}
}
break;
}
return super.onTouchEvent(event);
}
// 当状态改变时候，调用该方法，以更新界面
private void changeHeaderViewByState() {
switch (state) {
case RELEASE_To_REFRESH:
arrowImageView.setVisibility(View.VISIBLE);
progressBar.setVisibility(View.GONE);
tipsTextview.setVisibility(View.VISIBLE);
lastUpdatedTextView.setVisibility(View.VISIBLE);
arrowImageView.clearAnimation();
arrowImageView.startAnimation(animation);
tipsTextview.setText("松开刷新");
Log.v(TAG, "当前状态，松开刷新");
break;
case PULL_To_REFRESH:
progressBar.setVisibility(View.GONE);
tipsTextview.setVisibility(View.VISIBLE);
lastUpdatedTextView.setVisibility(View.VISIBLE);
arrowImageView.clearAnimation();
arrowImageView.setVisibility(View.VISIBLE);
// 是由RELEASE_To_REFRESH状态转变来的
if (isBack) {
isBack = false;
arrowImageView.clearAnimation();
arrowImageView.startAnimation(reverseAnimation);
tipsTextview.setText("下拉刷新");
} else {
tipsTextview.setText("下拉刷新");
}
Log.v(TAG, "当前状态，下拉刷新");
break;
case REFRESHING:
headView.setPadding(0, 0, 0, 0);
headView.invalidate();
progressBar.setVisibility(View.VISIBLE);
arrowImageView.clearAnimation();
arrowImageView.setVisibility(View.GONE);
tipsTextview.setText("正在刷新...");
lastUpdatedTextView.setVisibility(View.VISIBLE);
Log.v(TAG, "当前状态,正在刷新...");
break;
case DONE:
headView.setPadding(0, -1 * headContentHeight, 0, 0);
headView.invalidate();
progressBar.setVisibility(View.GONE);
arrowImageView.clearAnimation();
arrowImageView
.setImageResource(R.drawable.ic_pulltorefresh_arrow);
tipsTextview.setText("下拉刷新");
lastUpdatedTextView.setVisibility(View.VISIBLE);
Log.v(TAG, "当前状态，done");
break;
}
}
public void setonRefreshListener(OnRefreshListener refreshListener) {
this.refreshListener = refreshListener;
}
public interface OnRefreshListener {
public void onRefresh();
}
public void onRefreshComplete() {
state = DONE;
lastUpdatedTextView.setText("最近更新:" + new Date().toLocaleString());//刷新完成时，头部提醒的刷新日期
changeHeaderViewByState();
}
private void onRefresh() {
if (refreshListener != null) {
refreshListener.onRefresh();
}
}
//此方法直接照搬自网络上的一个下拉刷新的demo，此处是“估计”headView的width以及height
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);
}
}