Code Cuts - Creating an Android Live Wallpaper, Part 1

In this episode, I teach you the basics behind how to create an Android Live Wallpaper. We look at the manifest file and write some barebones code necessary to get a LWP up and running!

Note: This ends abruptly because there is another video after this which picks up right where I leave off in this episode.

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Closed Caption:

welcome to the code cuts episode three
today I'm going to go over how to make a
live wallpaper from start to finish we
probably won't finish it but we will
definitely get started making a
framework that you guys can hopefully
use future production code make actual
live wallpapers with so that'll be
really fun right now what I'm looking at
is a completely blank project and
specifically I've gone into the manifest
file for my blank project now before we
do anything here let's go over to our
package Explorer and go to the resources
folder and then inside the layout folder
let's right-click that layout folder and
create a new android xml file this
android xml file when we do that it will
bring up this creation screen and we're
going to put filename we're going to
make it lay out dot XML and will click
finish as soon as it starts isn't it
creates the layout file let's go down to
the very bottom of the screen and we'll
click layout XML so we can actually see
the code that's back there now we are
going to delete the linear layout that
was automatically generated for us we'll
leave the top xml definition and instead
we're going to put a wallpaper tag here
wallpaper so we start with an open
bracket then we take wallpaper then we
go xmlns colon android equals quotation
marks
HTTP colon forward slash forward slash
schemas that android com /ap cave sure
as for / android close comments are
closed quotation mark
and then drop down the line will go
android and actually sorry that's it
then we'll just put a closing bracket
and now we've got a wallpaper tag and
that's good we'll use this later on to
define things like the thumbnail and in
these settings pages that we may add
later on so once we've created that
layout XML file we can jump back over to
the manifest folder file now one of the
first things we're going to do is go
right underneath the uses sdk tag and
create a new tag will go open back it
uses dash feature and we'll go android
colon name equals quotation mark android
dot software live underscored wallpaper
closed quotation mark close tag and what
that does is it basically marks our
application as being a live wallpaper so
the next thing we're going to do is
we're actually going to delete our
activity so if you look a little bit
further down you see that in activity
was automatically created for us
well we don't want that because we're
not really making an application like
that we're making a live wallpaper so
instead we go delete activity and
replace it with bracket service the
service tag declares an android app
doubt service class so this is telling
it that we're using something that's
special like a live wallpaper and we'll
go android colon name equals and you're
going to want to use your package name
here
initially but at the end of it you'll
put on dot mainactivity something like
that
ok that's a bad example huh main service
how about that ok then we'll drop down
the line and we'll go android coin label
equals and then we'll give it a name for
whatever we want a combine demo live
wallpaper i know not very original then
we'll drop down the line and we'll go
android colon permission equals android
dot permission dot bind underscore
wallpaper closed quotation mark close
service bracket are closed bracket put
service tag and now that we've created
the service we're going to put another
tag inside of it
we're going to put an intent filter
intent so we'll go open bracket intense
dash filter close bracket and inside
this intent filter will go open back at
action android colon name equals android
got service dog wallpaper wallpaper
service closed quotation mark close
bracket
ok now let's drop down from the intent
filter but will still be inside the
service tag and we're going to add
another one last thing we'll go open
bracket made a dash data android colon
name equals android dot service
wallpaper and then we'll go android
colon resource equals @ symbol layout
colon layout
xml sorry don't put the dot XML hand and
then you can close bracket that and
that's all there is to the manifest file
so what we've done is we told it that
we're creating a live wallpaper
requested the specific wallpaper
permissions set up a service entry point
give it a name set up an intent filter
and pointed it to our layout file
ok now let's go take a look let's leave
the the manifest file let's go to source
and inside source will go to live
wallpaper demo activity java or whatever
the java file is that was automatically
generated so a few things to note if you
remember we deleted sir or we we deleted
the activity code in the manifest and we
replaced it with a service so what we're
going to do inside this demo activity
wallpaper file we're going to delete the
oncreate method that is automatically
generated and if you notice it says
extends activity up there
well we don't want it to extend activity
we wanted to extend service and
specifically wallpaper surface and
you'll notice that it gets angry at you
so what you can do is you can go control
shift oh and that will automatically
resolve the the namespace package that's
missing and then it will get angry at
you in a different way so we'll mouse
over the red squiggly that's above the
class name or below the class name and
will click Add unimplemented methods and
then it just puts in one constructor for
oncreate engine
Stubbs in one method so what we've just
done is we created the basics behind a
wallpaper now if you were to run this
you could actually run this right now
and it would crash but that's okay
because we're almost to the point where
we have a working live wallpaper