Android Application Development Tutorial - 139 - ItemizedOverlay to draw on our Map Video Lecture | Android Application Development (Mobile App) - Software Development

up guys welcome to your hundred in 39th
Android tutorial for the new Boston what
we're gonna do in this tutorial is we're
actually going to start setting up our
first button which is going to be
placing a pin point and how we're going
to do that is we're going to create a
new class that's going to kind of be
passed in the drawable item that we're
actually going to draw to our map or a
pin point you can think of it as and
handle it within that class so we're
gonna create new class and we're gonna
call this custom pin point or something
of the sort whatever you guys want to
call this hit enter and what this is
gonna extends is something called an
itemized overlay because again we're
drawing some kind of item itemized
object or a drawable to our overlay so
it's gonna be itemized overlay and it's
gonna be of the type overlay item so
we're gonna say overlay item and we're
just gonna hit command shift I to add or
sorry command shift o to add our imports
and as you can see your custom pinpoint
class getting some errors because we
need a constructor so we're gonna just
say add constructor and we're also gonna
hover over and add the unimplemented
methods overlay item create item and the
size so now what this first constructor
is what we want it to do is basically
Center our our drawable we're gonna draw
like a target or something like that and
we want the center of our bitmap or a
drawable item that's being passed in to
align to where we actually want to place
the pin point so what we're gonna do is
on the super method we're gonna say
bound Center and then we're gonna add a
parenthesis here and again around our
default item that's being passed in
which is a drawable so again all that's
going to do is take our drawable item
find the center of that drawable and
bound it to the center of our you know
found the point to the center of our
drawable and that's where it's going to
kind of pinpoint on our map
now well now what we want to do is we
want to add some items that we can refer
to or instance of classes that we can
refer to within this class so what we
want to do is we want to say private
array array list of the type overlay
item we're gonna call this map items
whoops
or pinpoints and we're gonna set this
equal to new ArrayList of the type
overlay and then open parentheses close
parentheses and we're done again we just
hit control shift oh and oh I'm sorry
and this is supposed to be overlay items
or overlay item I should say and there
we go we have our and we have an import
set up and and we aren't obviously this
isn't set to anything it's just a new
ArrayList and what we're also gonna add
is a context so private context can't
spell and we're just gonna call this C
maybe something like that again we just
have to import context now what we want
to do is we want to create a constructor
again that is going to refer to a
drawable and a context so we can pass in
the context work with the class that
we're getting and setting that I'm gonna
hit ctrl C to copy and then just paste
below again this is just another
constructor this time what we're gonna
do is we're just going to refer to this
as drawable m4 marker and also a context
we're gonna call that C as well or
whatever you guys want to refer to that
as and what we want this constructor to
do is basically create this context
equal to the context that's being passed
in it's basically now we just have to
relate our drawable and our context so
what we're going to do is just say this
we're going to call this within the
parentheses M
which again is our drawable item that's
being passed in and then what we also
want to do is we want to relate this
context that we set up here to the
context that's being passed in so I
changed I don't know I kind of clipped
the video but I this was see just change
it to context so it's a little bit more
simple to work with down here and we're
all we're gonna do is set our C which is
our variable for this class a private
variable we're gonna set that equal to
the context that's being passed in which
we called context so that's all that
that constructor is doing now we can
relate to this and it's still the same
context that's being passed in through
this constructor so that's pretty much
it for this tutorial guys in the next
tutorial we'll finish this class called
custom pinpoint because again we have
this ArrayList that it's basically not
set to equal to anything there's no way
that we can insert into this ArrayList
so we're gonna create a method that's
going to insert we're also going to
change some of these return methods in
that tutorial so we're basically to get
that finished up again all we created
was a custom pinpoint class that uses
itemized overlay that we're going to
refer to our drawable that's being
passed in and then we're going to draw
that to an overlay and we have two
constructors again one that just handles
a drawable being pass in all that's
gonna do is bound the center of the
drawable item so we're gonna pin point
through the center on the place that we
touch on our map and that's how it's
gonna align for the most part right in
the center of our drawable item then we
also have a constructor that handles our
drawable item and a context so just the
you know marker is gonna be the same and
our context we're gonna set equal to the
context that's being passed in so we
don't really have to worry about getting
mixed up and using the context of this
class and all that good stuff so that's
basically our constructors in the setup
of this class see you guys in the next
one have a good