Android Homework Silicon Valley Young Coders Club

1. Homework
for
July
12th
2015
Starting
Android
Development
Shivaum
Kumar
and
Aditya
Aggarwal
wrote
the
following
tutorial
for
the
Saratoga
Young
Coders
Club.

2. Introduction
• In
this
tutorial,
you
will
learn
how
to
program
apps
for
Android
devices.
• Android
devices
are
phones,
tablets,
and
even
watches
that
run
the
Android
software.
• The
Android
software
is
also
called
the
Android
Operating
System.
• 84%
of
the
world’s
devices
run
the
Android
Operating
System
(OS);
therefore,
if
you
know
how
to
code
for
the
Android
OS,
you
can
make
apps
for
many
people.
At
the
end
of
the
tutorial,
you
will
make
this:
Android
apps
are
coded
in
JAVA
and
XML
and
are
created
using
the
computer
program,
Android
Studio.
Before
I
describe
what
each
language
does
and
how
to
use
Android
Studio,
you
have
to
set
up
your
computer
to
use
them.
The
setup
is
what
much
of
this
tutorial
will
be
about.

3. STEP
1:
JDK
7
First,
you
have
to
make
sure
JDK
7
(Java
Version
7)
is
installed.
__________________________________________________________________________________
Mac
Users
Search
for
the
application
TERMINAL
on
your
computer.
Next
in
the
terminal
app
type
in
java
-­‐version.
If
you
don’t
have
the
JDK
7
installed
terminal
will
tell
you
command
not
found.
__________________________________________________________________________________

4. ___________________________________________________________________________________
Windows
Users
For
newer
versions
of
Windows
or
if
you
already
have
JDK
7,
these
may
not
be
the
right
instructions.
Meet
me
10
minutes
before
the
workshop,
if
you
cannot
install
JDK
7.
1. Go
to
the
Control
Panel
2. Click
the
Programs
Icon
3. Click
the
Java
Icon
4. Click
the
About
Icon
The
version
should
be
listed
here.
If
the
Version
number
is
7
or
greater
(ignore
the
other
information)
you
already
have
JDK
7.
Here
are
further
instructions:
https://wiki.csuchico.edu/confluence/display/help/How+to+check+yo
ur+Java+Version+in+Windows+7
___________________________________________________________________________________
Here
is
the
link
to
download
JDK
7
if
you
do
not
have
it:
http://www.oracle.com/technetwork/java/javase/downloads/index.ht
ml

5. STEP
2:
Download
Android
Studio
Go
to
this
link.
https://developer.android.com/sdk/index.html
Click
the
Download
button.
Accept
the
terms
and
conditions.
After
done
downloading,
if
any
update
is
there
it
will
prompt
you
to
update.
Always
choose
the
update
and
restart
option.

6.
STEP
3:
Using
SDK
(Software
Development
Kit)
Manager
When
at
the
screen
below
click
Configure.
Next
click
SDK
Manager
to
update
all
the
folders
and
tools
in
the
SDK
Manager
so
the
application
won’t
get
any
errors
because
of
missing
updates.

7. A
window
looking
like
the
picture
on
the
bottom
left
should
open
up.
Now
click
the
Install
Packages
to
update
all
the
folders
in
the
SDK
Manager.
Now
click
accept
license
for
each
package.
And
the
download
should
take
10-­‐20
minutes
depending
on
how
many
packages
should
be
installed.

8. STEP
4:
Creating
a
Project
Part
1
Click
Start
a
new
Android
Studio
App.
Name
the
Application
My
First
App.
Company
Domain
can
be
anything
you
want
to
name
it
(it
is
used
to
give
a
unique
name
to
apps
once
they
are
sent
to
the
app
store
called
Google
Play
(because
multiple
people
might
make
My
First
App)).
Project
Location
can
be
changed
to
anywhere
on
your
computer.

9. Part
2
Click
Next.
Check
mark
“Phone
and
Tablet”
because
we
are
making
This
part
is
where
you
choose
the
lowest
android
version
that
is
compatible
with
the
app.
Select
the
API
8
Android
2.2(Froyo)
which
will
let
the
app
work
on
all
Android
devices.
(Higher
Minimum
SDKs
will
allow
for
more
features
but
will
exclude
devices
that
run
older
Android
versions).

10.
Part
3
Click
Next.
You
should
come
to
a
screen
like
the
one
below
Select
Blank
Activity.
You
are
choosing
a
template
for
your
app
to
run
on.

11. Part
4
Click
Next.
Android
includes
dynamic
language,
language
that
causes
actions
(for
example
the
screen
changing
when
you
click
on
a
button)
and
static
language,
the
graphics
or
picture
layout
of
the
screen.
You
will
be
asked
to
enter
in
the
Activity
Name
in
the
next
part.
The
activity
contains
the
dynamic
language
of
a
screen/page.
The
Layout
Name
is
the
name
of
the
graphics
file
that
is
used
for
a
screen.
For
this
program
we
will
use
the
default
names
that
are
given
to
create
the
screen
we
need
for
the
app.
Now
click
Finish.

12.
STEP
5:
Running
on
Emulator
To
run
an
Android
Emulator
on
your
computer,
click
the
AVD
Manager
(blue
in
pic
to
the
right)
on
the
top
of
the
screen,
and
select
CREATE
VIRTUAL
DEVICE.
Select
the
NEXUS
S.
Select
the
one
with
API
level
22,
x86,
and
the
target
is
Google
APIs.
Now
click
Finish
and
you
now
have
created
a
virtual
device.
Now
click
Run,
which
looks
like
the
play
icon
(red
on
pic
to
the
right).
There
may
be
a
little
bit
of
a
wait
after
selecting
Run.
Another
window
will
appear
asking
to
choose
a
device.
Choose
the
device
shown
to
the
right
and
press
OK.
Wait
for
1
to
2
minutes
for
the
emulator
to
launch.
And
now
your
Hello
World
App
should
be
displayed
on
the
emulator.
Congratulations
you
have
made
your
first
app!

13.
The
reason
this
worked
without
programming
anything
is
that
Android
Studio
by
default
creates
a
hello
world
app
so
it
worked
without
any
manual
work
in
the
program.

14. STEP
6:
Getting
Familiar
with
an
Android
Studio
Project
Part
1
(Project
Explorer)
I
will
call
this
window
in
the
right
of
your
Android
Studio
the
Project
Explorer.
The
Project
Explorer
shows
the
file
structure
of
your
project.

15. Step
2
(Manifests)
Go
into
the
manifests
folder
in
the
Project
Explorer
and
click
on
the
AndroidManifest.xml
file.
Your
Android
Studio
should
look
something
like
the
picture
below.
The
manifest
file
is
the
definition
file
of
your
project.
Just
like
you
have
to
know
the
definition
of
words
in
order
to
make
a
sentence,
a
computer
has
to
know
the
definition
of
each
part
of
the
app
(for
example
an
activity)
in
order
to
make
the
app.
Don’t
worry
about
the
syntax
(the
code)
of
the
manifest
for
now.
Manifests
are
coded
in
a
language
called
XML.

16. Part
3
(Activity)
Next,
go
into
the
java
folder
of
your
app.
There
should
be
two
folders
inside
with
your
company
domain.
Go
into
the
one
without
“androidTest”
and
inside
should
be
MainActivity.
Double
click
on
MainActivity.
The
window
to
the
left
of
your
Project
Explorer
called
the
editor
should
look
like
this.
The
activity
contains
all
the
dynamic
code
of
a
screen.
Dynamic
code
for
Android
is
written
in
JAVA.
MainActivity
is
the
dynamic
code
for
the
only
screen
currently
in
our
app.
Don’t
worry
about
the
syntax
for
now.

17. Part
4
(resources:
drawables,
layouts,
and
values)
Next
go
into
the
res
folder
of
your
app.
Res
contains
all
the
static
resources,
things
(like
graphics
and
images)
that
don’t
change
in
the
app.
Code
for
static
resources
is
done
in
XML.
Drawable
Go
into
the
drawable
folder.
Double
click
on
ic_launcher.png.
The
drawable
folder
contains
the
pure,
non
code
generated
graphics
of
your
app
(pictures).
Your
app
uses
ic_launcher.png
for
an
app
icon
on
the
home
page
of
your
android
device.
There
are
many
different
ic_launcher
files
because
the
app
needs
differently
sized
images
for
differently
sized
screens
of
Android
devices.

18. Layout
Next
enter
the
layout
folder
below
the
drawable
folder
in
your
Project
Explorer.
Double
click
on
activity_main.xml.
Your
Android
Studio
should
like
this.
The
layout
folder
contains
the
files
that
define
the
graphics
for
screens
(how
pictures,
buttons,
text
boxes,
etc.
are
arranged
on
the
touch
screen).
Activity_main.xml
contains
this
information
for
the
only
screen
in
our
app.
Enter
into
the
menu
folder.
This
folder
contains
the
layout
for
the
bar
at
the
top
of
your
app
(called
the
ActionBar).

19. Values
Enter
into
the
values
folder.
Values
are
static
resources
that
do
not
fall
into
the
categories
of
drawable
and
layout.
An
example
would
be
constant
strings,
a
series
of
letters
that
will
not
need
to
be
changed
in
the
app.
Click
on
strings.xml.
Your
Android
Studio
should
look
like
this
below.
As
you
may
guess
from
the
other
files,
styles
(colors
and
patterns)
and
dimensions
can
also
be
defined
as
values.

20. Part
5
(Gradle
Scripts)
Next
go
into
gradle
scripts.
Click
on
build.gradle
(Module:
app).
Your
Android
Studio
should
look
like
the
picture
below.
Gradle
Scripts
are
files
that
allow
the
computer
to
convert
the
code
into
an
app;
they
are
usually
auto
generated.
An
understanding
of
them
is
only
needed
for
more
advanced
programming
and
configurations.

21. PART
6:
Experimenting
with
the
App
Now
time
to
experiment
with
this
project.
Go
into
the
folder
on
the
left
called
res
then
drop
down
the
folders
and
find
values
and
finally
double
click
on
the
.xml
file
strings.xml.
This
.xml
file
has
all
the
constant
strings
you
can
display
on
the
app.
Where
it
says
“hello_world”>Hello
World!</string>.
Change
it
to
anything
you
want.
I
am
a
big
Warriors
fan
so
I
changed
it
to
“hello_world”>Go
Warriors!</string>.And
now
on
the
screen
it
should
display
that.

22.
Possible
Errors
and
Solutions
Once
I
opened
the
app
I
got
an
error
that
said
A
quick
way
to
fix
this
if
you
come
across
this
problem
would
be
by
clicking
on
the
MyFirstApp
folder,
then
the
app
folder.
When
in
the
app
folder
click
the
build.gradle
file.
Now
you
should
be
at
a
screen
like
this
below:
One
small
change
that
is
needed
is
to
change
the
buildToolsVersion
“23.0.0
rc1”
to
buildToolsVersion
“23.0.0
rc2”.
It
is
the
second
line
on
that
page.
This
should
fix
the
problem.

23.
Also,
you
are
not
allowed
to
insert
apostrophes
in
the
string.
Such
as
This
will
cause
an
error
that
apostrophes
cannot
be
insert
in
the
string.
If
you
see
an
error
like
this
in
your
app,
ignore
it
and
continue
on
in
the
tutorial:

24.
Further
Resources
and
Links
Here
are
resources
that
may
help
you
in
this
tutorial:
How
to
create
an
Android
Studio
Project.
http://developer.android.com/training/basics/firstapp/index.html
How
to
run
your
app.
http://developer.android.com/training/basics/firstapp/running-­‐
app.html
The
conceptual
fundamentals
of
Android
Development
http://developer.android.com/guide/index.html