%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%          examplescroll v1.0
%
%     Date: January 17, 1990
%     Authors:
%             David G. Zawada
%             EAIS-VIS
%             Argonne National Laboratory
%             zawada@athens.ees.anl.gov
%
%             David C. Mak
%             EAIS-VIS
%             Argonne National Laboratory
%             mak@athens.ees.anl.gov
%
%	DualScrollBar.ps is the definition for a new subclass of
%	the SimpleScrollbar item.  New features include
%	
%	--> Dual Scrolling is available, meaning that Up and Down
%		scrolling are both possible from either end of
%		the ScrollBar.
%
%	--> Continuous Scrolling is possible by keeping any MouseButton
%		 depressed within one of the ScrollButtons.
%
%	--> Colorization is available via the /sethue method.
%
%	--> Adjustable Thumb sizes are available via the /setrange
%		and /reshape methods.  Through the use of these
%		methods, the size of the Thumb can reflect
%		what fraction of the scrolling list is currently
%		visible to the user.  For examples of this 
%		concept, look at applications which use scrollbars
%		and run under the SunView or NeXT environments.
%
%	--> Scrollbar width can be adjustable.  The smallest
%		width that aesthetically pleasing is 18.
%
%  A simple example:
%

systemdict /DualScrollBar known not
	{ (/DualScrollBar.ps) append run } if  %Adjust path as necessary

/win framebuffer /new DefaultWindow send def
{
	100 dup 400 dup reshape

	/items
	[
		[ 1 0 0.1 0.5 0.1] 0 {} ClientCanvas
		/new DualScrollBar send
			dup /BarVertical? true put
			{
				0.1 sethue
				10 20 dup 300 reshape
			} 1 index send

		[ 1 0 0.1 0.5 0.5] 0 {} ClientCanvas
		/new DualScrollBar send
			dup /BarVertical? false put
			{
				0.7 sethue
				60 20 300 34 reshape
			} 1 index send
	] def

	items forkitems pop

	/PaintClient { items paintitems } def

	totop
	map
} win send