DX
Size of the thumb in the horizontal scrollbar, in any unit.
Value
Any floating-point value greater than zero and smaller than the difference between XMAX and XMIN.
Default:: "0.1".
Notes
LINEX, XMAX and XMIN are only updated in the scrollbar when DX is updated.
When the canvas is visible, a change in DX can generate a redraw in the horizontal scrollbar on the screen. But it may generate a RESIZE_CB callback event if XAUTOHIDE=YES.
A change in these values can affect the attribute POSX.