C++ Allegro 5 Made Easy Tutorial 3 - Native Message Boxes Video Lecture | Allegro: A Complete Guide - Game Development

hello everybody and welcome to your next
Allegro 5 tutorial in this tutorial
we're going to be learning about the
Allegro native message box that you
could use to actually display error
messages or other certain messages to
the people that are playing your game or
application so if you haven't had an
error using that Allegro library yet
then you probably have not seen the
Allegro message box and action so let's
do some code and I'll show you how to
utilize the message box and you can see
it in action so below the display so if
display is created then we wanted to
create a message box a sample one just
to show you some difference that you can
do with it so we're going to do unjust
al underscore show underscore native
underscore message underscore box now
look I know that's a bit hard to
memorize but just um you're gonna have
to get used to it sorry but I mean the
first parameter asked for our arm
display you can put not on the
parameters but if you put a null then it
will appear behind the game window and
generally if you have an error or a
message box you want it to appear above
the window so if you want to pair it if
you want it to appear above the window
and not as a part of the game window if
you want it to sort of like be a part of
the game window then you will actually
put the game windows name right there so
on our next one that asks for a title
now every window and your operating
system should have a title right-hand
visual studio the title is YouTube
Allegro five series - Microsoft Visual
Studio right so every single
um thing has a title so um it's always
good to general generally state the
title of your message box and you can
always put this as null but I'm going to
put message box title two for you to
better understand what its function does
the next one is the heading now this is
what you want to what you're going to be
talking about so normally we use message
boxes for errors so I'm going to put the
having this error and then our message
I'm going to put arm display window all
could not be shown even though this this
isn't true we're just doing this to test
it out for buttons we'll leave this as
null and for flags we'll need leave this
is no and I'll get to those in a second
if you run this program we get a box
that will pop up on the screen and the
title is message box title we see our
heading error and the phrase we wrote
display window cannot be shown and we
see the symbol right here
well sometimes you want to have special
symbols to signify what you're talking
about
so this is a default symbol and if
you'll notice when the window popped up
you might have heard a certain sound it
made when the window popped up different
imputed or operating systems might make
different sounds or depending on the
flags that you specify right here will
determine the sounds what sounds alike
when the windows when the pop-up window
occurs if that even matters to or not so
Allegro has um five built-in flags and I
think you can create your own using the
buttons I've tried it and it did not
work properly so I will not be teaching
about um buttons you can search a pop-up
about it on the Allegro manual and if
you want you can inbox me on how to do
it properly and I'll teach the rest of
the viewers how to do it but I haven't
really figured out how to work that yet
but
I'll get into that in the future if I
figure it out anyways so for the flags
the first one since is the error message
we're going to put a leg roll underscore
message box make sure it's all in caps
sorry underscore message box underscore
error and if we run this program we're
going to see how it differs
differentiates from the first one so it
made a different sound effect for me I'm
not sure about you as a symbol has
changed to an error symbol defaults to
your actual operating system depending
on your operating system this symbol
should be different okay um so I believe
that if you right-click here I'm not
sure and we go to go to declaration or
yeah if we go to declaration then we can
see arm we can see the five functions
that we can use the five different items
that we can use that have different
functions right here now these stuff are
for arm different things that we'll be
learning in the future and stuff like
that but these five are the different
options that you can put in the flags so
you can put one bigger put ever okay
under square cancel yes under square no
or question notice that all of them
start with a letter or underscore
message box so only the endings are
different so now let's get back to a
program so we've seen what error does so
let's put one this time and let's
compile this
and when it pops up we get a different
symbol and a different sound effect for
me I don't know about you oh yeah and we
get the symbol here now let's put in
question this time and when we run it we
should be getting a question mark right
about now yes we should get a question
mark right here saying that we maybe ask
you a question now um as you can see the
only button that we saw was okay well
say you want to ask um you want to have
an okay option and the cancel option we
can always do that with okay on our
square cancel so we can choose between
okay and cancel either one and last but
not least we can put yes sorry we could
put yes or yes I'm just gonna for the
yes or no option so for you visual
learners that I want to see what happens
um you can select yes or no okay simple
enough now you may be asking um what if
I want to have an error message along
with the or say I have I want to have a
question the question symbol along with
yes or no well it's possible to use
different flags all at once the one rule
is that you can't use okay um okay
unscrew cancel with yes and no and you
can't use one question or um error all
together at once so you could do
something like this go do a little
message box underscore error or another
question
and then what you do is put this symbol
right here the straight-line symbol
there to separate the two so we're we're
doing it so you only can have one symbol
and then um one user-defined option you
can have two user options or two symbols
at once you're going to only have one
you could only have one of each so if we
display a question like this
um do did you visit coding made easy GA
or let's name the header question then
it should have been did you visit the
community yeah you guys should all join
the community but anyways so did you
guys visit coding made easy eh we have
the option that we could choose yes or
no right now you might be asking you
guys are like okay I could choose yes or
no but like how do I know when the user
has selected yes or no well that is a
very good question if you were wondering
well on the AL native message box
returns an integer value so what we
could do is create an integer variable
to find out the return value so what I
mean by that is this so let's put int
and let's name it value okay so um we
want to find so at the end of this
program if you select either yes/no ok
or cancel or whatever it will return the
value now on default Allegra manual it
will say that if you click yes or okay
it will return a value of 1 and if you
click no or cancel and will return a
value of 2 and if you close the window
any other way it will turn the value of
0 it with my experimentation if you
click no or cancel it will return a
value of zero rather than a value of 2
so you might be different on your
operating system or your computer but
I'm pretty sure we return the value of
zero
so I have included iostream here and
we're going to use the iostream to see
our return value so I'm going to put STD
C out and we're going to put value and
we're going to end the line and I
another cool function and allegro is el
underscore rest it allows us the
positive program for a set number of
seconds or if you put or a certain
amount of milliseconds or anything you
want to do whatever you need to do so in
this case we're going to pause it for
three seconds okay and say I want to for
half a second then I'll put 0.5 etc etc
so let us run this program
so if I press yes then value is going to
be equal to one right let me run this
one more time
so I press you know it returns the value
of zero right so then you can say from
that so then you can if you ask them a
question I believe is according maybe
CCA then you can put if value is equal
to one then just you could be like you
can put an option on the screen saying
you are a great person or whatever or
you could say thank you or whatever and
you can put else you need to check out
the website and you're going to be
working on graphics so don't worry about
the console window I'm just showing you
different options you can work with so
let's test this out to see if it works
so if you click yes it says you are a
great person and wait for it to close
and let's try it one more time
if you click no you need to check out
the website so that's how you determine
what the user has pressed in the program
now I believe there's one more thing I
should let you know now the Allegro
message box and stuff is an enum and if
you look at it you can see the value is
equal to 16 if you look at it there's a
leg Roman underscore message box
under question is equal to 16 answers
equal to 8 so I never tested this out
before but I'm pretty sure this should
work um because if you look at it when
you're creating um a message box so al
underscore show underscore native
underscore message box if you look at it
it says int flags so you can indeed put
integer values into there so let's see
so if we replace this with 16 and 8
let's see if this will work so 16/8 and
let's see if this actually works yes it
still works you can still select the
option yes or no and the program still
runs fluently so that is it for this
tutorial I'll hope you enjoyed it and
thanks for watching and bye