The default setting. Indicates that the scrollbar's slider is not moved.
1
GTK_SCROLL_STEP_BACKWARD
Sets the scrollbar's slider back one step increment from its current
position. The value of the step increment is taken from the underlying
GtkAdjustment in the scrollbar.
2
GTK_SCROLL_STEP_FORWARD
Sets the scrollbar's slider forward one step increment from its current
position. The value of the step increment is taken from the underlying
GtkAdjustment in the scrollbar.
3
GTK_SCROLL_PAGE_BACKWARD
Sets the scrollbar's slider back one page increment from its current
position. The value of the page increment is taken from the underlying
GtkAdjustment in the scrollbar.
4
GTK_SCROLL_PAGE_FORWARD
Sets the scrollbar's slider forward one page increment from its current
position. The value of the page increment is taken from the underlying
GtkAdjustment in the scrollbar.
5
GTK_SCROLL_JUMP
Sets the scrollbar's slider to the position described in the accompanying
float parameter. The range of values are 0 to
1, with the halfway point being 0.5.