Java Programming Tutorial - 67 - JRadioButton Final Program Video Lecture | Java Programming Fundamentals: For Beginners - Back-End Programming

what's going on everyone welcome to 67th
java tutorial and in this tutorial we're
gonna be finishing this program
demonstrating je radio buttons so where
we left off on the last tutorial we
pretty much made four different kinds of
fonts and now what we need to do is
pretty much take that text field and we
need to set it equal to a font by
default and we just need to set it equal
to a font by default so in the program
runs for the first time and knows what
font to use so I'm gonna set equal to
plain font because I'm just a plain old
guy
you can set equal to different fun if
you want but I ain't gonna so now what
we need to do is pretty much create an
add item listener for each button so we
can take that plain button first and add
item listener just like that fun fun fun
fun there we go got clear on my throat
and the parameter this add item listener
takes is gonna be this get out of my way
new handler class and for the
constructor we're gonna pass in the
plain font now what happens is this an
add item listener pretty much shows
there and waits for something to happen
to that item which is in this case the
plain button now whenever it does happen
what do we want the object because this
is object in here and what do we want it
to do whoa for the handler class is
gonna be handling it or it's pretty much
the code that's gonna happen if this
button is clicked we need to pass in
plain font to the constructor and let me
go ahead and add a comment so this wait
for event to happen and this what this
doesn't pass and font object to
constructor and we didn't even create a
class or constructor yet so this might
be confusing but I spoke constructor run
see this this thing if I click it it's
not only
a platform but it also is a spellchecker
so since I spoke constructor on it
corrected it for me how cool is that
compiler and a spell checker double
banger so now let's go ahead and add
this for well the rest of them copy this
and put that's for a bold button italic
button and bold and italic button so
bold 1c italic button is IB and bold and
italic button of course we need to
change these to bold font and I said
italic font was ITF and the bold and
italic font was that so now we pretty
much got our constructor of our main
class built now we can go ahead and
we're giving this error message because
handler class is not a class yet so
let's change that right now let's go
ahead and make a handed request and
we're gonna put this inside the other
class so let's go ahead and make private
class hand or lower a little alert class
right there no my sound didn't mess up I
actually just said that implements item
listener and you guys know what
implements means from the last tutorials
so inside my handler class the first
thing I'm gonna want to do is create a
variable since uh you know we're just
gonna need one it's gonna be a font
variable and it set it equal to the name
of font because I mean makes sense right
the next thing I'm going to want to do
is create that constructor that we used
up here now as you can see that
constructor takes a font object as its
argument so we got to make sure we have
a foreign objects as argument when it
created it so let's go ahead and make
public and alert class and let's go
ahead and put like font and just name it
F or something
so now plus I'm lucky TF so now in our
constructor for this and make sure yep
looks right to me let's go ahead and
just add font and set equal to F
now let's see what error I'm getting oh
I must inherit the abstract method item
listener items state changed so since we
use item listener it has a method in it
cut item state change that we need to
use so let me add a comment to here and
what this does is the font object gets
variable fun this is pretty much just
changing the object we pass in to the
variable font so now that we implemented
from item listener we need to use that
method called item state change so let's
go ahead and make a new method called
public boy doesn't return anything item
state changed and if I spelled that
right we should be good so now this
argument takes the item event in which
name it events and for this in the body
let's just go ahead and have something
like text font and we'll set it equal to
set font for that font so now if I do
this my error should go away but they're
not so I'm gonna positive figure out
what's wrong okay guys I found my error
and it was really embarrassing actually
he's worth constructor of handler class
up a handler class and I spelled it
wrong so you definitely need to put
handler class and spoil your
constructors right pretty embarrassing
if he asked me so you know not gonna let
it happen again I promise
so now that we got all that changed
let's go ahead and well I'll pretty much
oh I had a comment for this for ease of
reading I will put sits the font to the
font object that was passed in looks
good so well I'm gonna go ahead and run
this then I'll talk you guys through it
so I'm just gonna use my seen object
from last oriole if you didn't watch my
less sorrow then pause the video right
now and copy that and I'm just gonna go
ahead and run this and hopefully it
works so now we got Bucky is awesome as
huh uh-huh
thank you and it's plain by default like
we said before and now you can see these
radio buttons since they're part of a
group
then whenever we click one then the rest
uncheck and that is because they are
part of a group and they're able to see
each other or know each other is doing
and that's some built-in um methods that
allow you to do that so that's pretty
cool right there so let me talk you guys
one last time through how we did this
well let's see let's just get to the
hard stuff we made variables we added a
we added all the stuff this screen right
here BAM here's the confusing stuff
aside from adding all the stuff to the
screen here's what we did we pretty much
need to add add item listener to each
button so that something can sit on
those buttons and wait for it to be
click or unclick now add item listener
this built-in method it takes this
handler class object as a parameter so
what this is is pretty much saying
alright we're gonna be waiting for
something happen and as soon as it
clicks then I'm gonna call this class
right here and that's the code that's
going to happen when this event happens
so now that we told it all right we want
you to wait for something to happen and
when it happens do this we said all
right what do we want to do well we
created a new handler class and the
constructor for that class is called an
alert class of course and it takes a fog
object so let's go ahead and look at
that constructor right now the
constructor all it does is it gets that
font which was plain font and sets it
equal to the name font or the variable
font and why do we need to set it equal
to this variable so we can use it later
on to set the font so pretty much we
took that font set it equal to the word
font and then in the item state change
which pretty much is the event that
happens when it's clicked it takes that
font and sets it equal to plain font
bold fonts out font or plain and bold
font or simply bold and italic font so
now that we have a constructor in our
item state changed we're good to go
and we were able to run the program
so that's your real quick tutorial of
radio buttons and the last thing that
you guys don't want to forget don't
forget to group your buttons right here
set equal to new button group objects in
this group allows your buttons to be one
big family and allows them to see what
each other is doing and this lets them
know when each other's is selected or
deselected so that's that for this
tutorial hope you guys learned a little
something not too much of course so
thank you guys for watching don't forget
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my contests and I will see you next time