Shareware delay box by Paul Jones for Atari Computing. Feel free to 
add this code to your own programs if you have the need. However, if 
you do add this code to your own program, you must announce this in 
the program's documentation.

(c) Paul Jones and Renegade Publishing Ltd

Shareware dialogs... what's tha' then?
--------------------------------------

You'd be forgiving for asking such a question, some people have never 
seen one before since or if they have, call it by another name, or 
nothing at all!

A shareware delay bar is just what it sounds like. It's a bar in a 
dialog box which progresses to show how much time you've waited. Since 
it's shareware, indicating the author wishes you to pay money to 
"register" the software, he/she encourages you to do so by adding this. 
While the bar is display, you can't click on anything, in effect, your 
computer is frozen until the time is up... even on multitasking 
systems. 

The code in the file SHAREWAR.BAS is an example of such a bar, with 
source code and executable. The above is to be included in PDO (Print 
Documents Out) to encourage people to register.

How does it work?
-----------------

It's quite simple really. First you design a normal form dialog, with 
two exceptions: 1) It doesn't have any exit buttons 2) It has a 
SLIDERBAR.

A sliderbar is an object which can have it's size (width, height, x 
and y co-ordinates etc) edited within a program. These are usually 
boxes. There are actually two bars in a slide box, they are called the 
background and the foreground. The background one isn't edited at all, 
but used to find out the maximum size of the foreground sliderbar 
(this is the white bar in our example). The foreground one is the bar 
that moves (the blue one in our example).

Once the RSC has been loaded into memory, we have to find the maximum 
width of the background bar since the foreground bar has it's width 
set to a small width (this is so we can actually click on the thing in 
the RSC editor, and also have access to the background bar too).

Using the system clock we can increment this bar whenever we like (I 
use 100 milliseconds, which equals 0.1 second bursts). Instead of the 
usuall form handling routines, we don't ask for any button selections, 
so we come out of displaying the dialog instantly. We can then update 
the dialog whenever it changes.

BASICally, it goes like this...
-------------------------------

Here is how the most important routines work in the program:

SUB form_show (dial)
STATIC junk,tree&,x,y,w,h,but,type_tree,treeno,tree&

junk=FNrsrc_gaddr(0,dial,tree&)
form_center tree&,x,y,w,h
form_dial FMD_START,0,0,0,0,x,y,w,h
junk=FNobjc_draw(tree&,0,10,x,y,w,h)
END SUB

This routine will first display the dialog box. It's a different model 
of our normal dialog box displayer, because we don't ask GEM to wait 
for a button to be pressed.

SUB form_show_part (dial, object)
STATIC junk,tree&,x,y,w,h,but,type_tree,treeno,tree&
STATIC x2,y2,w2,h2

junk=FNrsrc_gaddr(0,dial,tree&)
form_center tree&,x,y,w,h
SelectTree dial

form_dial FMD_START,0,0,0,0,x,y,w,h

junk=FNobjc_draw(tree&,object,0,x,y,w,h)

END SUB

This sub-routine can redraw parts of the dialog box for us. Notice the 
objc_draw () which actually displays the sliderbar on the screen.

SUB GetSetObjects
SHARED wwidth,swidth,spart

SelectTree sharedial
wwidth=FNgetob_width (whiteback)

setob_width slidebar, 0
swidth=0

spart=wwidth/100

END SUB

This is quite an important routine. It first finds out the width of 
our background bar, then sets the foreground sliders width to 0. It 
then calculates how much to add to the sliderbar each time the below 
routine is called:

SUB do_timer
SHARED swidth,wwidth,spart
SHARED finished

swidth=swidth+spart
IF swidth>wwidth THEN
	finished=-1
ELSE
	setob_width slidebar,swidth
	form_show_part sharedial, slidebar
END IF

END SUB

This part is called every 100 milliseconds. It adds on part of the 
slidebar to what already exists so gives the impression it's moving. 
If the new width is over the size of the orginall, then the program 
quits, otherwise the new size is implemented into the dialog and 
redrawn.

DIM mess(16)
StartProgram "SHAREWAR.RSC"
GetSetObjects

	form_show (sharedial)

DO
	e=FNevnt_multi(MU_TIMER,0,0,0,0,0,0,0,0,0,0,0,0,0,_
					VARPTR(mess(0)),100,0,0,0,0,k,0)

	IF e AND MU_TIMER THEN CALL do_timer

IF finished=-1 THEN CALL StopProgram

LOOP

The main loop. First it loads up the dialogs into memory (notice this 
is different verion of StartProgram which we're used to). Then we set 
the objects size.

The main evnt_multi contains another difference - instead of checking 
for GEM messages and keyboard clicks, we're just looking for 
MU_TIMERs. GEM will give us a signal whenever a certain amount of time 
in milliseconds passes (notice the 100 in the parameters list?).