                          Zoomler
                           v 1.1

                  (c) Alexander Rublinetsky
                      rublin@iname.com

OVERVIEW

Zoomler is a scrollbar-like component that can be used for
scrolling and zooming any continuous objects: charts, images
etc. All its position properties are of Double type -- it is
convenient for charts, and one can always call Round() if
the object has integer coordinates. Zoomler can be horizontal
and vertical. It is not a windowed control so it cannot receive
focus, thus it has mouse interface only. Zoomler has seven
mouse-sensitive areas:
 * two arrow buttons : for scrolling by 1;
 * two zooming points (on both sides of the thumb): for zooming
 * two areas on either side of the thumb : for large one-step scrolling
 * middle thumb area : for scrolling
Zoomler is inherited from TGraphicControl. It was designed and tested
under Delphi-3 but I cannot see any problems with other versions of Delphi.

PROPERTIES

 * DblClkEnable : if TRUE then if double-clicked it is fully zoomed,
   i.e. Start:=Min; Finish:=Max; 
 * Min,
 * Max : minimum and maximum possible values
 * Start,
 * Finish : current minimum and maximum position of the thumb. These
   values are changed by user's mouse activities
 * Orientation : Horizontal or Vertical -- the way Zoomler draws
   itself
Other properties are inherited and self-explanatory.

METHODS

  Constructor and destructor.

EVENTS

 * OnChanged : this event is triggered when user releases the mouse
   button
 * OnScrolling,
 * OnZooming : these events are triggered while user is scrolling or
   zooming.
If the scrolled/zoomed object's painting is not consuming much time it is
advised to repaint it in OnScrolling and OnZooming events. But in the case
of complicated drawing this will cause poor responsiveness and, possibly,
flickering. Then object's Invalidate method have to be called in OnChanged
event.

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Zoomler component is freeware and includes full sources. If someone will
improve it, I will appreciate if he or she will send me the changed
source code. Component is released on the "AS IS" basis and AUTHOR HELDS
NO RESPONSIBILITY IN ANY CASE. YOU ARE USING ZOOMLER AT YOUR OWN RISK!
***************************************************************************

Feedback can be sent to rublin@iname.com.
