public void OnScrollChanged(Android.Widget.ScrollView who, int l, int t, int oldl, int oldt)
{
if (OnScrollChangedListener != null)
{
OnScrollChangedListener.OnScrollChanged(who, l, t, oldl, oldt);
}
var isSignificantDelta = Math.Abs(t - lastScrollY) > ScrollThreshold;
if (isSignificantDelta)
{
if (t > lastScrollY)
{
OnScrollUp();
}
else
{
OnScrollDown();
}
}
lastScrollY = t;
}
private bool CanScrollUp(Android.Views.View view)
{
if (!RefreshView.IsPullToRefreshEnabled)
{
return(true);
}
else
{
ViewGroup viewGroup = view as ViewGroup;
if (viewGroup == null)
{
return(base.CanChildScrollUp());
}
int sdk = (int)global::Android.OS.Build.VERSION.SdkInt;
if (sdk >= 16)
{
//
//is a scroll container such as listview, scroll view, gridview
//
if (viewGroup.IsScrollContainer)
{
return(base.CanChildScrollUp());
}
}
//
//if you have something custom and you can't scroll up you might need to enable this
//for instance on a custom recycler view where the code above isn't working!
//
for (int i = 0; i < viewGroup.ChildCount; i++)
{
var child = viewGroup.GetChildAt(i);
if (child is Android.Widget.AbsListView)
{
Android.Widget.AbsListView list = child as Android.Widget.AbsListView;
if (list != null)
{
if (list.FirstVisiblePosition == 0)
{
Android.Views.View subChild = list.GetChildAt(0);
return(subChild != null && subChild.Top != 0);
}
//
//if children are in list and we are scrolled a bit... sure you can scroll up
//
return(true);
}
}
else if (child is Android.Widget.ScrollView)
{
Android.Widget.ScrollView scrollview = child as Android.Widget.ScrollView;
return(scrollview.ScrollY <= 0.0);
}
else if (child is Android.Webkit.WebView)
{
Android.Webkit.WebView webView = child as Android.Webkit.WebView;
return(webView.ScrollY > 0.0);
}
else if (child is Android.Support.V4.Widget.SwipeRefreshLayout)
{
return(CanScrollUp(child as ViewGroup));
}
//
//else if something else like a recycler view?
//
}
return(false);
}
}
