Android Application Development Tutorial - 42 - Using BitmapFactory

what's up guys welcome to 40 second
Android tutorial for the new boss in
again with me Travis
we're going to do in this tutorial is
basically break through or talk through
our application for the most part gives
you guys a little more comfortable with
what we're doing and also fix one of the
errors that we're having so basically
one of the areas that we're having is if
we try and set the wallpaper right when
our application starts it's going to
give us an error in crash or program so
what we're going to do to fix that is
basically set our bitmap up to equal
something at the beginning before
application starts so there if they
actually hit the set wall it's just
going to set it to our default icon that
shows in our image view but quickly
that's just break through or talk
through how to keep saying break through
we're going to talk through their
application get you guys again hopefully
familiar with what we're doing or doing
is set in the content view set them some
variables so we can use it within
different methods and then we're using
this initialize method that just kind of
sets all the references and sets are on
click listeners for our two buttons once
one of those buttons are pressed it's
going to go to this on click method it's
good going to determine which button was
pressed by the switching case it's going
to get the ID of the button that was
pressed if it's button set will do this
if it's button set picture or take
picture I'll do this method within this
case now if it is the set picture or
take picture button our image view
button it's going to start a new intent
again the intent action name of the
camera application that comes with your
phone and then it's going to start that
activity for result giving some data
back and then once once we get done
using that activity our camera activity
it's going to come back give us some
data through this on activity result
method
just give us some stuff that we can work
with we're going to check if you know it
worked if it's successful if we got a
picture we got some data back for the
most part by using this result code
which is our second parameter that's
that gets passed in if that's okay we're
going to get the bundle or get extras
from that activity and then we're gonna
set up a bitmap based on that activity
then we're going to set the image view
based off of our bit
so it's kind of confusing especially
like you're like okay I don't really
understand these two lines for sure
that's okay guys for the most part right
now don't worry too much about that
again we're just kind of learning Java
and some of the methods and some of the
stuff that we can do with Android so
what we're going to do to fix our first
error this bitmap error that we're
getting if we try to set you know the
wallpaper right as our application
starts basically our bitmap is not set
to anything so that's what it's
referencing when we say set wallpaper
it's going to say set the wallpaper to
basically our bitmap right here so what
we need to do is define this bitmap at
the beginning and how we're going to do
that is we're going to define it a
different way than we did right here
you're like dang it man what are you
doing I don't even understand this I'm
sorry guys but you will in time trust me
I promise you guys so what we're going
to do is we're going to do it a
different way setting up the bitmap by
input stream and we're going to set it
up that way now it's basically kind of
confusing but for the most part of the
input stream is going to get us some
input from our you know our resource
folder so our drawable folder here and
just basically set it to the default
image we're going to say it to the icon
for the most part so we're going to set
up our bitmap within the oncreate method
after everything gets initialized we're
variables get set up so we're going to
say bitmap actually let's do this way
we're gonna say input stream and we're
going to say I is for input stream
equals how's that blue import that and
we're going to set this equal to
something a method called get resources
because again our image or icon PNG is
within a resource folder so we're going
to say get resources and that's just
going to be method that kind of relates
to our resources for the most part
against method so it has parentheses and
we're going to say dot we're going to
say open raw raw resources you guys are
probably thinking it's referring to this
raw folder for the most part it's not
just still think of that as accessing a
resource folder we're going to click
that and then we're going to say what
ever image we want to set up our dot
drops our dot drawable dot and then we
can pick an image that we want basically
set as the background if the person
doesn't take the picture and just use
that set button I set wallpaper so we're
going to set their background as the
icon which is pretty lame they'll teach
them not to take a picture and set their
background that way
so basically we set up an input stream
and now we need to decode this input
stream as we set up our bitmap so we're
going to say bitmap basically our bitmap
variable and we're going to set it equal
to basically this input stream but we
have to decode an input stream for the
most part I know this is kind of
confusing as well but just to get our
application working and we'll get into
more detail as well as we go through the
series promise guys and we're going to
refer to the class bitmap factory we
need to import this class it's not
allowing us to do so yet so we just hit
bitmap factory decode stream or decode
what is this input stream now decode
stream I believe and then there we go
and get an input import the bitmap
factory for the most part you guys will
pro have to do that I might have done
that already when I was just messing
around make sure this works and now what
we're going to do is we're going to
decode the stream basically our input
stream that were set up here called is
so that's going to basically set up our
bitmap to equal something our resources
and how we do that is the bitmap factory
decode a stream and then we throw in
whatever stream we want it to decode
which is getting our resources for the
most part that's what these two things
will do and this is our actual bitmap
that we want to decode for the most part
so hopefully that kind of makes sense
guys I'll get rid of one of our errors
and then in the next tutorial we'll get
rid of the other air as our emulator
turns on its side so I know it's kind of
confusing guys please stick with the
series and I will catch you guys in the
next tutorial have a good one