MetroFramework.Controls.MetroScrollBar.ProgressThumb C# (CSharp) Method

        private void ProgressThumb(bool enableTimer)
        {
            int scrollOldValue = curValue;
            var type = ScrollEventType.First;
            int thumbSize, thumbPos;

            if (Orientation == MetroScrollOrientation.Vertical)
            {
                thumbPos = thumbRectangle.Y;
                thumbSize = thumbRectangle.Height;
            }
            else
            {
                thumbPos = thumbRectangle.X;
                thumbSize = thumbRectangle.Width;
            }

            if ((bottomBarClicked && (thumbPos + thumbSize) < trackPosition))
            {
                type = ScrollEventType.LargeIncrement;

                curValue = GetValue(false, false);

                if (curValue == maximum)
                {
                    ChangeThumbPosition(thumbBottomLimitTop);

                    type = ScrollEventType.Last;
                }
                else
                {
                    ChangeThumbPosition(Math.Min(thumbBottomLimitTop, GetThumbPosition()));
                }
            }
            else if ((topBarClicked && thumbPos > trackPosition))
            {
                type = ScrollEventType.LargeDecrement;

                curValue = GetValue(false, true);

                if (curValue == minimum)
                {
                    ChangeThumbPosition(thumbTopLimit);

                    type = ScrollEventType.First;
                }
                else
                {
                    ChangeThumbPosition(Math.Max(thumbTopLimit, GetThumbPosition()));
                }
            }

            if (scrollOldValue != curValue)
            {
                OnScroll(type, scrollOldValue, curValue, scrollOrientation);

                Invalidate();

                if (enableTimer)
                {
                    EnableTimer();
                }
            }
        }