/// <summary>
/// Scrolls if mouse is pressed and over scroll border.
/// </summary>
/// <param name="position">Mouse position relative to treeView control.</param>
/// <returns>Returns true if over scroll border, otherwise false.</returns>
internal bool TryScroll(Point position)
{
if (!IsLeftButtonDown)
{
return(false);
}
double scrollDelta;
if ((position.Y < AutoScroller.ScrollBorderSize) && _AutoScroller.CanScrollUp)
{
//scroll down
scrollDelta = -AutoScroller.ScrollDelta;
}
else if (((TreeView.RenderSize.Height - position.Y) < AutoScroller.ScrollBorderSize) && _AutoScroller.CanScrollDown)
{
//scroll up
scrollDelta = AutoScroller.ScrollDelta;
}
else
{
_StopWatch = null;
return(false);
}
if (_StopWatch == null || _StopWatch.ElapsedMilliseconds > AutoScroller.ScrollDelay)
{
_AutoScroller.Scroll(scrollDelta);
_StopWatch = new Stopwatch();
_StopWatch.Start();
}
return(true);
}
