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Text File | 2004-01-01 | 8.3 KB | 379 lines

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          DotBASIC Tutorial
           by Dave Moorman


    DotBASIC is a fantastic way to
quickly develop software. Visual
Design lets you see what your main
screen is going to look like -- and
lets you define buttons or Event Areas
and assign each to a certain line
number in your DotBASIC program.
Object Oriented Programming features
make writing the code a cinch. Your
project is finished in no time!

    This tutorial will take you
through the whole process of designing
a Quiz game. The questions with up to
four answers each are in a quiz file.
So the task is to allow the user to:

    Pick a quiz
    Take the quiz
    Exit the program.

    The first step in DotBASIC is to
move the DotBASIC files to your work
disk:

    B.DOT
    DOT.DOT
    DOT.ML

    You also will need B.VDOT in order
to design the screen. For this
tutorial, we will assume all four
program files are on your work disk
(on drive 8).

[NOTE:] All four programs are on this
disk. Unfortunately, we could not
include our Copy It feature on this
side of the 1541 disks -- so you will
need to use your own copy program to
make the transfer.


LOAD"B.VDOT",8:<Shift-RUN>

(If you are using VICE, use WARP
speed whenever in Mouse Mode with
VDOT. It just makes things faster and
smoother.)

    Press <F3> and point to the
Reverse Space on the Font window and
click. Then press <F5>, and click on
White on the Color Palette. Now, press
<F3> (toggles off font window) and
<F1> (toggles off menu bar).

    Press <Ctrl-E> to open the Edit
Menu. Click on Box. Move the square to
the upper-left corner of the screen
and click. Then move down and right
until the whole screen is bracketed --
and click. Press <F3>, move the White
"bucket" to the left edge of the
window and click. This makes the
border white.

    Now you have a nice, white screen,
in reverse with a black background.

    Press <Shift-RETURN> to toggle
into Text Mode. (VICE users will want
to toggle off Warp.) A shimmering
square is your cursor. You edit the
screen almost exactly like using the
C-64s own text editor. Cursor up to
row 0, column 1. Type <Ctrl-9>
<Ctrl-2> (reverse white), then

 Quiz    Exit

(separated by four spaces).

    Press <Shift-RETURN> to toggle
back to mouse mode. If the Color
Palette is not visible, press <F3> and
<F5> until it is. Press <UP ARROW> to
move the Palette to the bottom of the
screen.

    Point the bucket to Yellow and
click, then point at the word Quiz,
hold down the left mouse button, and
"paint" all of row 0 yellow.

    Choose the color Cyan from the
Palette and paint a 40 column wide, 7
column tall box (for your quiz
questions). Below it, paint four
40-column, two-row boxes (for the
answers). You can add shadows if you
want.

 NOW TO DEFINE EVENT REGIONS

    Event Regions are areas on the
screen that can change color when the
mouse arrow rolls over, and when
clicked will call Event Handling
routines in your DotBASIC program.

    Press <F1> until you see the menu
bar (Files Edit, etc). Click Edit,
Box. Place the square to the left of
the word Quiz, and click. Then move
right until Quiz is bracketed, and
click. The Edit menu will reappear.
Click Add Region. A dialog box will
appear. Press the indicated <keys>:

Line Number 1000 <RETURN>
Hot Key <q><RETURN>
Right Clk (Y/N) <n>
Unhighlighted Color <7><RETURN>
Reverse (Y/N) <y>
Highlighted Color <8><RETURN>
Reverse (Y/N) <y>
Is This Right? (Y/N) <y>

    Region 1 is now added. Click Edit,
Box again, put the little box to left
of Edit, click, bracket Exit, click,
and click Add Region.

Line Number 2000 <RETURN>
Hot Key <e>
(repeat as above for Region 2).

(If you are wondering why we did not
make the answer boxes into Event
Areas -- we will discuss it later.
Event Driven programming has its
limitations at this point.)

    You have now defined and assigned
two Event Regions. You are ready to
save your screen. Click File, Save,
MeddleScreen MED. Type in the name you
are going to call your program. In
this case, quiz and press <RETURN>.
Click OK.

    Your screen is ready. If you need
to edit it later, you can Load it
(File, Load, "quiz.med"). When you
resave, you have to click OK twice.

    Now -- on to the real fun! Reset
your computer and

LOAD"B.DOT",8

LIST 60008

  60008 N$="DOT"

    Change the name DOT to QUIZ. Press
<RETURN>, then type

GOTO60000<RETURN>

Your boot is ready. RUN it.

    You will soon see the title, then
a list of lines:

1000 return:rl1
2000 return:rl2

?undef'd statement  error in 90
ready.


Move your cursor up and press
<RETURN> on each line. Move to the
bottom of the screen and type

GOTO60000<RETURN>

LOAD"B.QUIZ",8:<Shift-RUN>

    And -- Lo and Behold! There is
your screen. Notice how Quiz and Exit
change color when you roll over with
the mouse arrow. Nothing works when
you click, because you have not
written the Event Handling routines.
Press <BACK ARROW> to escape.

NOTE: It you happen to press STOP or
the mouse arrow is still visible,
type

.OF<RETURN>

to turn off the Event and Mouse
Drivers. This is important: If these
are not off, you may get a corrupted
program.


LIST 100-199


100 .do:.ee:.wb:.un e%
101 .of:end

    These few commands create a loop
that operates while the Event Driver
is working. Note that DotCommands all
begin with a period (dot) and have two
characters. Here is a quick
run-through of line 100:

.DO  Begins a DO-LOOP, one of the
most powerful features of DotBASIC.
See .UN below.

.EE  Event Enable. When you started
your program, the assigned line
numbers were all found and internal
GOSUBs were calculated. While line
100 loops around, the Event Driver
watches for roll-overs and clicks on
Event Regions. A click is an Event.
The Event Driver is disabled (because
we don't need an event to happen
while one is being handled). The
Event Handling Routine at the
assigned line number is called. When
RETURN is encountered, the program
comes back to the loop at line 100.
The .EE command re-enables the Event
Driver.

.WB  Watch Backarrow. This command
watches the <BACK ARROW> key, and
when pressed, the variable E% (which
is normally 0) becomes -1.

.UN E%  This is the end of the
DO-LOOP, and will loop back to the
.DO command UNtil E% is not zero.

.OF  Off. Turns off DotBASIC.

And the program ENDs.

    Now it is time to do the Event
Handling Routine for Exit, which
begins with line 2000.

2000 .RU,216,215
2002 E%=I%
2004 .ER:RETURN

.RU is short for "Are You Sure," an
automatic dialog box that asks, of
all things, "Are You Sure?" The two
numbers indicate the color of the box
(plus 208) and the color of the
selected response (also plus 208).

E%=I%

The result of the Are You Sure dialog
is returned in I% -- 0 for No, -1 for
Yes. We put the result in E%

.ER  Event Screen Restore -- which
removes the Are Your Sure Dialog box.

RETURN  Returns to line 100. If we
have put Not Zero into E%, the loop
will end. Note: You can use different
values in E% to signal different
things, and sort them out in line
101.

To save your work, type:

GOTO60000<RETURN>

NOTE: Be sure to save early and often.
With DotBASIC, saving the current code
is always the same: GOTO60000.

    Then RUN the program. You can
point and click Exit, or press <E> to
bring up the Are You Sure box. Try
clicking No, pressing <N>, clicking
Yes, and (after running again),
pressing <Y>.

    See how easy that was? DotBASIC
does a lot for you!

    We will now need to make a couple
of test quizzes for our program to
use. Be sure to save your program with
GOTO60000. Then reset your computer
and boot MR.EDSTAR or EDSTAR.

The first line of the file is the
Quiz Name. Then follows 5 lines of
question, then, for each answer, a
line with the value for the answer
and two lines of the answer. Here is
our example:

----------------- <top of text
Quiz One
Question 1: What is
the size of
the
Grand
Canyon?

Smaller than
a Breadbox
10
Really, Really
BIG (you will get 10 points)
-5
This answer will cost
you five points

This answer is wrong, but
you will not be penalized.
<ENGLISH POUND SIGN>
Question 2
Line 2
Line 3
Line 4
Line 5

Wrong
.................

Wrong Again
..................

Wronger Yet
................
1
Right
You get one point with this answer.
<ENGLISH POUND SIGN>
end quiz

       -----------------------

    The layout is self-explanatory.
Save the file to "q.quiz 1". Save it
again to "q.another quiz", and a third
time as "q.busy".

    You are ready to do some serious
coding -- the easy DotBASIC way -- in
Part 2.

 DMM