Introduction to Android Platform Development. Contains architecture, design and development principles and code examples

1. Mobile application
development
Android introduction
Alberto Rubalcaba
Oracle Certified Professional, Java SE Programmer

2. ¿What is Android?
 Open source, open platform for mobile development
 All the SDK, API and platform source is available
 No need for licence or app review
 You can replace any system app with your own
 Official development site: developer.android.com

3. How it works?
Components architecture model
Every component provides his interface
Java programming

4. Useful programming tips
Avoid creating objects
Use native functions
Prefer static
Avoid internal getter o setter
Declare constants final
Avoid floats and enums

5. Android Architecture

6. Project architecture

7. Design principles
Delight me in surprising
Real objects are more fun than buttons and menus
Let me make it mine
Get to know me
Keep it brief
Pictures are faster than words
Decide for me, but let me have the final say
http://developer.android.com/design/get-started/principles.html

8. App components
Activities
Services
Content providers
Broadcast receivers

9. Activity life cycle

10. Services
Perform long operations on background
Runs trough applications
A component can bind to a service to interact with and perform
interprocess communication (IPC)
Service states
Started
Bound
http://developer.android.com/guide/components/services.html

11. Content providers
Manages access to structured set of data
Provide mechanisms for defining data security
Connects data in one process with code running in another process
http://developer.android.com/guide/topics/providers/content-
providers.html

12. Broadcast receivers
Send broadcasts across applications
Registered by the context of the application dynamically
Registered statically in the android manifest
http://developer.android.com/reference/android/content/BroadcastRe
ceiver.html

13. Intents
Abstract description of an operation to be performed
Can be used to start activities, send broadcasts, start or bind services
Intent structure
Action. The general action to be performed
Data. The data to operate on, such a record on contacts, as a URI
Category. Gives additional information about the action to execute
Type. Specifies an explicit type (MIME types) of the intent data
Extras. This is a Bundle of additional information
http://developer.android.com/reference/android/content/Intent.html

14. Application Context
Interface to global information about an application environment
Abstract class whose implementation is provided by Android system
Allows access to application-specific resources and classes
Calls for application-level operations such as launching activities,
broadcasting and receiving intents
http://developer.android.com/reference/android/content/Context.htm
l

15. Bundle
Mapping to String values to various Parcelable types (Serializable)
Has methods to put <key,value>’s to the map
Has methods to get <key,value>’s from the map
Has a method to clear() the whole map
http://developer.android.com/reference/android/os/Bundle.html

16. Manifest
All applications must have a manifest in the root directory
Presents essential information the system must have before running
the app
It names the java package for the application
It describes the components of the application
It determines which processes will host application components
Declares permissions to access protected parts of the API
http://developer.android.com/guide/topics/manifest/manifest-
intro.html

17. User interface
Built using View and ViewGroup objects
A View is an object that draws something on the screen to interact
with
A ViewGroup is an object that holds other View’s and ViewGroup’s
objects in order to define the layout of the app
http://developer.android.com/guide/topics/ui/index.html

18. User interface layout

19. User interface layout
The effective way to define your layout is via XML
The name of the XML element is respective to the Android class it
represents
http://developer.android.com/guide/topics/ui/declaring-layout.html

20. Example

21. Layouts
Defines the visual structure for a user interface
After declaring a layout in XML, it should be saved in the res/layout
project directory
When you compile your app, each layout is compiled into a View
resource
The layout should be loaded in the Activity.onCreate(Bundle b)
method
Call setContentView(R.layout.my_view)

22. Common Layouts
Linear layout
Relative layout
Web view
List view
Grid view

23. Input controls
Interactive components in your UI
Just add the control to the xml
http://developer.android.com/guide/topics/ui/controls.html

24. Common controls

25. Event listeners

26. Event listener example

27. Menus
Common UI component
Appears when the user touch the menu soft/hard button
Types of menus
Options menu and action bar
Context menu and contextual action menu
Pop up menu
http://developer.android.com/guide/topics/ui/menus.html

28. Defining a menu in XML
Defined in res/menu
Inflate the menu in the onCreate(Bundle b) method
Easier to visualize the menu structure in XML
Separates the content of the menu from the behavioral code
Allows to create alternative menu configurations
Allows to create submenus

29. Menu example

30. Handling menu events

31. Dialogs
AlertDialog
DatePickerDialog
TimePickerDialog
CustomDialogs
http://developer.android.com/guide/topics/ui/dialogs.html

32. Dialogs (1)
Dialogs content
Title
Optional, should be used only when the content area is occupied by a detailed message,
list or custom layout
Content area
This can display a message, a list or a custom layout
Action buttons
There should be no more than 3 action buttons in a dialog

33. Dialogs (2)
The alertDialog.Builder class provides API’s that allow you to create
an AlertDialog with the kinds of contents, including custom layouts

34. Dialogs (3)
To add action buttons call the setPositiveButton() and
setNegativeButton() methods

35. Dialogs (4)
Traditional single-choice list
Persistent single-choice list (radio buttons)
Persistent multiple-choice list (check boxes)

36. Toasts
Provides a simple feedback about an operation in a small popup
Fills the amount of space required for the message
http://developer.android.com/guide/topics/ui/notifiers/toasts.html

37. Toasts (1)
Instantiate a Toast object with one of the makeToast() methods
This method takes three parameters
Application context
String message
Toast duration (millis)

38. Custom Toasts
 You can create customized layout for your toast notification
 Define a view XML layout
 Pass the root view object to the setView(View) method

39. Custom Toasts
You must use the ID of your custom layout to inflate it from the XML

40. Sensors

41. Sensors (1)
Sensor framwork
SensorManager
Sensor
SensorEvent
SensorEventListener
http://developer.android.com/guide/topics/sensors/index.html

42. Sensors (2)
Identifying sensors
Get the sensor service
Get the sensor that you are looking for

43. Sensors (3)
• Monitoring events

44. Let’s code 