Android App Development (Basics)
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This document is an introduction to mobile application development on the Android platform, discussing its open-source nature, architecture, and essential components such as activities, services, content providers, and broadcast receivers. It provides guidelines for user interface design, including layout definitions, input controls, menus, and dialogs, alongside programming tips and resource management. Additionally, it covers the use of intents, application context, and toasts for notifications, along with an overview of the sensor framework.
Android App Development (Basics)
- 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
- 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
- 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
- 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
- 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
- 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
- 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