Java Programming Tutorial - 84 - Drawing Graphics Video Lecture - Java

what is going on guys it's Bucky and
welcome to your 84th Jeff tutorial and
this story I'm going to be going over
graphics because well my ultimate goal
of these tutorials is pretty much make
computer games and we can't make a
computer game without sweet graphics so
I'm finally getting into graphics I
decided to abandon flowlayout and stuff
for now because you know this is just
much more exciting if we need any other
layouts we'll go back to them but for
now I want to start making some sweet
graphics on the screen so let's go ahead
and do that as you can see I made a new
class called peach because well it'll be
quite honest just because I like peaches
and it needs to extend jpanel because
we're going to be using that so don't
forget to have all your imports now
let's go ahead and get started with
making graphics on the screen now in
order to make graphics on the screen we
need a method called paint component and
this paint component method is used to
draw graphics on the screen so let's go
ahead and put public void paint
component and for a parameter it takes
an object from the graphics class so
graphics and I'll just name a G you can
name it whatever variable you want in
this parameter right here this G this is
going to be used to like set the color
and we manipulate this object depending
on what we want to draw but don't forget
that you need this method called paint
component this is built-in method um
that's inherited and this is the method
used to create all graphics on the
screen so now that we have this method
we can automatically start creating
graphics so let's go ahead and get to it
the first thing we need to do is just
one other housekeeping thing we need to
put super paint component in just fill
in G right there and what this is going
to do is it's going to call the super
classes remember this is how you call
super classes methods we want to call
the super classes pink component method
and you just need to do this because
there's stuff in the superclass that we
need to use just for housekeeping stuff
and pass
in your parameter or whatever it was
here and that's the only kind of
confusing thing that might not be
self-explanatory so don't forget that so
now let's go ahead and get started
the first thing we want to do is set the
background color for our screen so go
ahead and write this which means this
object set background and bam look at
that now is a parameter for your
background color you just take a color
now Java already has built-in constants
of colors which is pretty much all your
basic colors but for now in order to get
constant just put color dot white
because we just want a plain white
background so now we pretty much have on
our screen a white background not very
exciting but we're going to change that
soon in order to draw objects on the
screen you first need to tell your
object or your graphic object what color
you want to use to draw with so let's go
ahead and put G set color and is our
parameter just like set background it
takes a color constant now let's go
ahead and set our color to color blue
and make sure blue is in all caps and
that means constant in Java so now that
we have a color for our graphics object
we can begin drawing a rectangle on our
screen so the first thing I'm going to
tell you guys is how to draw a rectangle
and to do that it's fill ret and what
this is going to do is it's going to
give you four parameters and this is
going to draw a rectangle a solid
rectangle on the screen so the first
parameter it takes is the X parameter
and Y now this top left corner of your
window is zero zero in from left to
right this is the X from left to right
and Y is up and down so let's go ahead
and make the coordinates x and y and you
should know this if you ever took a math
class in your life so at 25 25 which
would be somewhere around here 25 over
and 25 down that is where we want the
top-left of the rectangle to be now how
why do we want the rectangle to be let's
just go ahead and put
100 pixels wide by 30 pixels high so now
we got our color and our coordinates of
our rectangle right here so now we just
have a blue rectangle chillin on our
screen if I want to tell you guys
something else you can do next we can go
ahead and put set color and we can set
the color again or pretty much reset the
color and if we want to have a custom
color that's not a constant like our own
RGB values and RGB means red green and
blue just go ahead and put new color and
as our parameters you type in the RGB
value you want so let's put like 190
commas 81 comma 215 make sure none of
these values go above 255 and this
pretty much means all right how much red
do we want it 190 red 81 green and 215
blue what color this is
I'm not sure but I know that it's going
to be some weird color but again if you
want custom colors then that's how you
create it what I usually do is I go in
Photoshop and mess around with the RGB
value but you know that's not important
right now
so now let's go ahead and put this
rectangle or draw rectangle Shoji fill
repped and again we have to fill in all
our parameters so where do we want to we
can't have it start in the same place so
let's have it like start at 25 over but
we'll have this one go 65 down since
this one ends at 55 again this is the Y
and this is the height so this will give
us 10 pixels of padding and you can mess
around with this on your own and we'll
make it the same width and height for
you no it's just nice to be constant get
it constant I just made it up and it's
not even a joke really but anyways now
we have two rectangles chilling on the
screen so the last thing I want to show
you guys is that not only rectangles but
you can actually draw text on the screen
so let's go ahead and change our color
one more time just because we don't want
everything the same color on the screen
it's going to be boring set color
we'll just change this color to like red
or something using color dot red is our
constant and now let's just go ahead and
this is how you draw strings or text on
the screen G draw string how easy is
that
now your iterator is pretty much what do
you want the string to say and this is
some text and make sure you spell text
wrong or else it won't work I'm just
kidding and now where do you want to
appear well let's make a x.25 and let's
see 120 that should be below everything
so now we have a rectangle right here a
rectangle under it and some text under
that so now I already did this all I
forgot I did this all but pretty much
make a new frame with your title set the
close operation don't forget to do that
and then make object of your class
whatever you name to add a peach class
so I named P add it to the frame set the
size of your window and make sure you
set the visible to true so it actually
appears and now if we go ahead and run
this program
you see that we created two rectangles
that were filled in because we use the
method foe rectangle and again if I do
this you can see that the coordinates
for the first one the blue one were 25
over 25 down this is a hundred wide and
30 pixels tall and next we set the color
again and we give it our custom color
evidently this is some kind of purple
color and this has RGB value of 190 81
215 and this is 25 over 65 down and
that's your top left point right there
100 wide and 30 tall and next we just
pretty much made some text on the screen
and this text started at 25 over and 128
pixels down that's where your text
started and then you pretty much just
draw drew a string on the screen using
the current color of your G object so
that is pretty much the basics of how do
you make simple rectangles of course
there's more stuff we can do but for now
just sticking with the basics in the
next story I'm going to show you guys
how to draw some sweet graphics
and uh well they're not gonna be that
sweet but they're going to be a little
better in this one so thank you guys for
watching now don't you subscribe and
hopefully I'll see you next tutorial