package com.example.administrator.cookman.ui.component.twinklingrefreshlayout;
import android.os.Handler;
import android.os.Message;
import android.support.v7.widget.RecyclerView;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.VelocityTracker;
import android.view.View;
import android.view.ViewConfiguration;
import android.view.ViewGroup;
import android.webkit.WebView;
import android.widget.AbsListView;
import com.example.administrator.cookman.ui.component.twinklingrefreshlayout.utils.ScrollingUtil;
/**
* Created by lcodecore on 2016/11/26.
*/
public class OverScrollProcessor {
private TwinklingRefreshLayout.CoProcessor cp;
//满足越界的手势的最低速度(默认3000)
protected int OVER_SCROLL_MIN_VX = 3000;
public OverScrollProcessor(TwinklingRefreshLayout.CoProcessor coProcessor) {
this.cp = coProcessor;
mTouchSlop = cp.getTouchSlop();
}
private VelocityTracker moveTracker;
private int mPointerId;
private float vy;
public void init() {
final View mChildView = cp.getContent();
final GestureDetector gestureDetector = new GestureDetector(cp.getContext(), new GestureDetector.SimpleOnGestureListener() {
@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
if (cp.isRefreshVisible() && distanceY >= mTouchSlop && !cp.isOpenFloatRefresh()) {
cp.setRefreshing(false);
cp.getAnimProcessor().animHeadHideByVy((int) vy);
}
if (cp.isLoadingVisible() && distanceY <= -mTouchSlop) {
cp.setLoadingMore(false);
cp.getAnimProcessor().animBottomHideByVy((int) vy);
}
return super.onScroll(e1, e2, distanceX, distanceY);
}
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
if (!cp.enableOverScroll()) return false;
mVelocityY = velocityY;
// if (!(mChildView instanceof AbsListView || mChildView instanceof RecyclerView)) {
//既不是AbsListView也不是RecyclerView,由于这些没有实现OnScrollListener接口,无法回调状态,只能采用延时策略
if (Math.abs(mVelocityY) >= OVER_SCROLL_MIN_VX) {
mHandler.sendEmptyMessage(MSG_START_COMPUTE_SCROLL);
} else {
mVelocityY = 0;
cur_delay_times = ALL_DELAY_TIMES;
}
// }
return false;
}
});
mChildView.setOnTouchListener(new View.OnTouchListener() {
int mMaxVelocity = ViewConfiguration.get(cp.getContext()).getScaledMaximumFlingVelocity();
@Override
public boolean onTouch(View v, MotionEvent event) {
//手势监听的两个任务：1.监听fling动作，获取速度 2.监听滚动状态变化
obtainTracker(event);
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
mPointerId = event.getPointerId(0);
break;
case MotionEvent.ACTION_UP:
moveTracker.computeCurrentVelocity(1000, mMaxVelocity);
vy = moveTracker.getYVelocity(mPointerId);
releaseTracker();
break;
case MotionEvent.ACTION_CANCEL:
releaseTracker();
break;
}
return gestureDetector.onTouchEvent(event);
}
});
if (!cp.enableOverScroll()) return;
if (mChildView instanceof AbsListView) {
((AbsListView) mChildView).setOnScrollListener(new AbsListView.OnScrollListener() {
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
if (cp.allowOverScroll() && firstVisibleItem == 0 || ((AbsListView) mChildView).getLastVisiblePosition() == totalItemCount - 1) {
if (mVelocityY >= OVER_SCROLL_MIN_VX && ScrollingUtil.isAbsListViewToTop((AbsListView) mChildView)) {
cp.getAnimProcessor().animOverScrollTop(mVelocityY, cur_delay_times);
mVelocityY = 0;
cur_delay_times = ALL_DELAY_TIMES;
}
if (mVelocityY <= -OVER_SCROLL_MIN_VX && ScrollingUtil.isAbsListViewToBottom((AbsListView) mChildView)) {
cp.getAnimProcessor().animOverScrollBottom(mVelocityY, cur_delay_times);
mVelocityY = 0;
cur_delay_times = ALL_DELAY_TIMES;
}
}
}
});
} else if (mChildView instanceof RecyclerView) {
((RecyclerView) mChildView).addOnScrollListener(new RecyclerView.OnScrollListener() {
@Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
if (cp.allowOverScroll() && newState == RecyclerView.SCROLL_STATE_IDLE) {
if (mVelocityY >= OVER_SCROLL_MIN_VX && ScrollingUtil.isRecyclerViewToTop((RecyclerView) mChildView)) {
cp.getAnimProcessor().animOverScrollTop(mVelocityY, cur_delay_times);
mVelocityY = 0;
cur_delay_times = ALL_DELAY_TIMES;
}
if (mVelocityY <= -OVER_SCROLL_MIN_VX && ScrollingUtil.isRecyclerViewToBottom((RecyclerView) mChildView)) {
cp.getAnimProcessor().animOverScrollBottom(mVelocityY, cur_delay_times);
mVelocityY = 0;
cur_delay_times = ALL_DELAY_TIMES;
}
}
super.onScrollStateChanged(recyclerView, newState);
}
});
}
}
private void obtainTracker(MotionEvent event) {
if (null == moveTracker) {
moveTracker = VelocityTracker.obtain();
}
moveTracker.addMovement(event);
}
private void releaseTracker() {
if (null != moveTracker) {
moveTracker.clear();
moveTracker.recycle();
moveTracker = null;
}
}
//主要为了监测Fling的动作,实现越界回弹
private float mVelocityY;
//针对部分没有OnScrollListener的View的延时策略
private static final int MSG_START_COMPUTE_SCROLL = 0; //开始计算
private static final int MSG_CONTINUE_COMPUTE_SCROLL = 1;//继续计算
private static final int MSG_STOP_COMPUTE_SCROLL = 2; //停止计算
private int cur_delay_times = 0; //当前计算次数
private static final int ALL_DELAY_TIMES = 60; //10ms计算一次,总共计算20次
private int mTouchSlop;
private Handler mHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case MSG_START_COMPUTE_SCROLL:
cur_delay_times = -1; //这里没有break,写作-1方便计数
case MSG_CONTINUE_COMPUTE_SCROLL:
cur_delay_times++;
View mChildView = cp.getContent();
if (!(mChildView instanceof AbsListView || mChildView instanceof RecyclerView)) {
if (cp.allowOverScroll() && mVelocityY >= OVER_SCROLL_MIN_VX && (mChildView != null && Math.abs(mChildView.getScrollY()) <= 2 * mTouchSlop)) {
cp.getAnimProcessor().animOverScrollTop(mVelocityY, cur_delay_times);
mVelocityY = 0;
cur_delay_times = ALL_DELAY_TIMES;
}
if (cp.allowOverScroll() && mVelocityY <= -OVER_SCROLL_MIN_VX && mChildView != null) {
if (mChildView instanceof WebView) {
WebView webview = (WebView) (mChildView);
if (Math.abs(webview.getContentHeight() * webview.getScale() - (webview.getHeight() + webview.getScrollY())) <= 2 * mTouchSlop) {
cp.getAnimProcessor().animOverScrollBottom(mVelocityY, cur_delay_times);
mVelocityY = 0;
cur_delay_times = ALL_DELAY_TIMES;
}
} else if (mChildView instanceof ViewGroup) {
View subChildView = ((ViewGroup) mChildView).getChildAt(0);
if (subChildView != null && subChildView.getMeasuredHeight() <= mChildView.getScrollY() + mChildView.getHeight()) {
//滚动到了底部
cp.getAnimProcessor().animOverScrollBottom(mVelocityY, cur_delay_times);
mVelocityY = 0;
cur_delay_times = ALL_DELAY_TIMES;
}
} else if (mChildView.getScrollY() >= mChildView.getHeight()) {
cp.getAnimProcessor().animOverScrollBottom(mVelocityY, cur_delay_times);
mVelocityY = 0;
cur_delay_times = ALL_DELAY_TIMES;
}
}
}
if (cur_delay_times < ALL_DELAY_TIMES)
mHandler.sendEmptyMessageDelayed(MSG_CONTINUE_COMPUTE_SCROLL, 10);
break;
case MSG_STOP_COMPUTE_SCROLL:
cur_delay_times = ALL_DELAY_TIMES;
break;
}
}
};
}