package com.amlogic.tzr.charismatic_yichang.view;
import android.content.Context;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.app.FragmentStatePagerAdapter;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.VelocityTracker;
import android.view.View;
import android.view.ViewConfiguration;
import android.view.ViewGroup;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.OverScroller;
import android.widget.ScrollView;
import com.amlogic.tzr.charismatic_yichang.R;
public class StickyNavLayout extends LinearLayout
{
private View mTop;
private View mNav;
private ViewPager mViewPager;
private int mTopViewHeight;
private ViewGroup mInnerScrollView;
private boolean isTopHidden = false;
private OverScroller mScroller;
private VelocityTracker mVelocityTracker;
private int mTouchSlop;
private int mMaximumVelocity, mMinimumVelocity;
private float mLastY;
private boolean mDragging;
public StickyNavLayout(Context context, AttributeSet attrs)
{
super(context, attrs);
setOrientation(LinearLayout.VERTICAL);
mScroller = new OverScroller(context);
mVelocityTracker = VelocityTracker.obtain();
mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
mMaximumVelocity = ViewConfiguration.get(context)
.getScaledMaximumFlingVelocity();
mMinimumVelocity = ViewConfiguration.get(context)
.getScaledMinimumFlingVelocity();
}
@Override
protected void onFinishInflate()
{
super.onFinishInflate();
mTop = findViewById(R.id.id_stickynavlayout_topview);
mNav = findViewById(R.id.id_stickynavlayout_indicator);
View view = findViewById(R.id.id_stickynavlayout_viewpager);
if (!(view instanceof ViewPager))
{
throw new RuntimeException(
"id_stickynavlayout_viewpager show used by ViewPager !");
}
mViewPager = (ViewPager) view;
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
{
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
ViewGroup.LayoutParams params = mViewPager.getLayoutParams();
params.height = getMeasuredHeight() - mNav.getMeasuredHeight();
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh)
{
super.onSizeChanged(w, h, oldw, oldh);
mTopViewHeight = mTop.getMeasuredHeight();
}
@Override
public boolean onInterceptTouchEvent(MotionEvent ev)
{
int action = ev.getAction();
float y = ev.getY();
switch (action)
{
case MotionEvent.ACTION_DOWN:
mLastY = y;
break;
case MotionEvent.ACTION_MOVE:
float dy = y - mLastY;
getCurrentScrollView();
if (Math.abs(dy) > mTouchSlop)
{
mDragging = true;
if(mInnerScrollView instanceof ScrollView)
{
if (!isTopHidden
|| (mInnerScrollView.getScrollY() == 0 && isTopHidden && dy > 0))
{
return true;
}
}else if(mInnerScrollView instanceof ListView)
{
ListView lv = (ListView) mInnerScrollView;
View c = lv.getChildAt(lv.getFirstVisiblePosition());
if (!isTopHidden
|| ( c!= null && c.getTop() == 0 && isTopHidden && dy > 0))
{
return true;
}
}
}
break;
}
return super.onInterceptTouchEvent(ev);
}
private void getCurrentScrollView()
{
int currentItem = mViewPager.getCurrentItem();
PagerAdapter a = mViewPager.getAdapter();
if (a instanceof FragmentPagerAdapter)
{
FragmentPagerAdapter fadapter = (FragmentPagerAdapter) a;
Fragment item = fadapter.getItem(currentItem);
mInnerScrollView = (ViewGroup) (item.getView()
.findViewById(R.id.id_stickynavlayout_innerscrollview));
} else if (a instanceof FragmentStatePagerAdapter)
{
FragmentStatePagerAdapter fsAdapter = (FragmentStatePagerAdapter) a;
Fragment item = fsAdapter.getItem(currentItem);
mInnerScrollView = (ViewGroup) (item.getView()
.findViewById(R.id.id_stickynavlayout_innerscrollview));
}
}
@Override
public boolean onTouchEvent(MotionEvent event)
{
mVelocityTracker.addMovement(event);
int action = event.getAction();
float y = event.getY();
switch (action)
{
case MotionEvent.ACTION_DOWN:
if (!mScroller.isFinished())
mScroller.abortAnimation();
mVelocityTracker.clear();
mVelocityTracker.addMovement(event);
mLastY = y;
return true;
case MotionEvent.ACTION_MOVE:
float dy = y - mLastY;
if (!mDragging && Math.abs(dy) > mTouchSlop)
{
mDragging = true;
}
if (mDragging)
{
scrollBy(0, (int) -dy);
mLastY = y;
}
break;
case MotionEvent.ACTION_CANCEL:
mDragging = false;
if (!mScroller.isFinished())
{
mScroller.abortAnimation();
}
break;
case MotionEvent.ACTION_UP:
mDragging = false;
mVelocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
int velocityY = (int) mVelocityTracker.getYVelocity();
if (Math.abs(velocityY) > mMinimumVelocity)
{
fling(-velocityY);
}
mVelocityTracker.clear();
break;
}
return super.onTouchEvent(event);
}
public void fling(int velocityY)
{
mScroller.fling(0, getScrollY(), 0, velocityY, 0, 0, 0, mTopViewHeight);
invalidate();
}
@Override
public void scrollTo(int x, int y)
{
if (y < 0)
{
y = 0;
}
if (y > mTopViewHeight)
{
y = mTopViewHeight;
}
if (y != getScrollY())
{
super.scrollTo(x, y);
}
isTopHidden = getScrollY() == mTopViewHeight;
}
@Override
public void computeScroll()
{
if (mScroller.computeScrollOffset())
{
scrollTo(0, mScroller.getCurrY());
invalidate();
}
}
}