internal double GetItemHeight()
{
if (UseHorizontalLayout)
{
return(ItemAspectRatio.GetHeight(GetItemWidth()));
}
else
{
return(viewport.Height / (Rows + marginOffset));
}
}
internal void UpdateScrollInfo(Size availableSize)
{
if (availableSize != viewport)
{
viewport = availableSize;
ScrollOwner?.InvalidateScrollInfo();
}
if (UseHorizontalLayout)
{
itemHeight = GetItemHeight();
if (itemHeight > viewport.Height)
{
itemHeight = viewport.Height;
itemWidth = ItemAspectRatio.GetWidth(itemHeight);
}
else
{
itemWidth = GetItemWidth();
}
computedRows = (int)Math.Floor(viewport.Height / itemHeight);
}
else
{
itemWidth = GetItemWidth();
if (itemWidth > viewport.Width)
{
itemWidth = viewport.Width;
itemHeight = ItemAspectRatio.GetHeight(itemWidth);
}
else
{
itemHeight = GetItemHeight();
}
computedColumns = (int)Math.Floor(viewport.Width / itemWidth);
}
centerMargin = GetCenterMargin();
var newExtent = GetExtent();
if (extent != newExtent)
{
extent = newExtent;
ScrollOwner?.InvalidateScrollInfo();
}
if (offset.Y > extent.Height)
{
offset.Y = 0;
trans.Y = 0;
ScrollOwner?.InvalidateScrollInfo();
}
if (offset.X > extent.Width)
{
offset.X = 0;
trans.X = 0;
ScrollOwner?.InvalidateScrollInfo();
}
}