public override bool Fling(int velocityX, int velocityY)
{
if (ItemCount < 1)
{
return(true);
}
FlingEventArgs flingEventArgs;
if (velocityX > 0)
{
flingEventArgs = new FlingEventArgs(FlingDirection.Right, CurrentItem);
if (CurrentItem == ItemCount - 1)
{
return(true);
}
}
else
{
flingEventArgs = new FlingEventArgs(FlingDirection.Left, CurrentItem);
}
if (BeforeFling != null)
{
BeforeFling(this, flingEventArgs);
}
LinearLayoutManager linearLayoutManager = (LinearLayoutManager)GetLayoutManager();
//these four variables identify the views you see on screen.
int lastVisibleView = linearLayoutManager.FindLastVisibleItemPosition();
int firstVisibleView = linearLayoutManager.FindFirstVisibleItemPosition();
View firstView = linearLayoutManager.FindViewByPosition(firstVisibleView);
View lastView = linearLayoutManager.FindViewByPosition(lastVisibleView);
//these variables get the distance you need to scroll in order to center your views.
//my views have variable sizes, so I need to calculate side margins separately.
//note the subtle difference in how right and left margins are calculated, as well as
//the resulting scroll distances.
int leftMargin = (screenWidth - lastView.Width) / 2;
int rightMargin = (screenWidth - firstView.Width) / 2 + firstView.Width;
int leftEdge = lastView.Left;
int rightEdge = firstView.Right;
int scrollDistanceLeft = leftEdge - leftMargin;
int scrollDistanceRight = rightMargin - rightEdge;
//if(user swipes to the left)
if (velocityX > 0)
{
CurrentItem = lastVisibleView - 1;
SmoothScrollBy(scrollDistanceLeft, 0);
}
else
{
CurrentItem = firstVisibleView - 1;
SmoothScrollBy(-scrollDistanceRight, 0);
}
if (OnFling != null)
{
OnFling(this, flingEventArgs);
}
return(true);
}
private void OnRecyclerViewFling(object sender, FlingEventArgs e)
{
}