Android: Short Summary

The main component in Android Application
- Activity (UI components)
- Services (background code)
- Broadcast receivers (handler that responds to broadcast events)
- Content Providers (expose a data API to other application)

Addional compoent
- Views (UI elements)
- Layouts (View hierarchies that control screen appearance)
- Intents (Messages wiring components together) 
- Resources (External data such as strings and drawables)
- Manifest (Configuration for applications)

Views
- SurfaceView (basic type that provides a direct drawing surface)
- ViewGroup (View that contain other Views)
- Widget (the classic UI components, e.g. Test input boxes, buttons)

Lifecycle
- onCreate
- onRestart
- onStart
- onResume
- onPause
- onStop
- onDestory
- onLowMemory
- onTerminate
- onConfigurationChanged

Process status
- Foreground
- Visible
- Service
- Background
- Empty

Layout
- FrameLayout
- RelativeLayout
- LinearLayout
- TableLayout
- AbsoluteLayout

Adapter
When you have to feed data from a data source to a view, you’ll use an Adapter
.
Intents and IntentFilters
IntentFilter - The Android platform keeps track of all the IntentFilter declarations that the current running system is capable of handling, and then resolves intents as they come in to the most suitable component dynamically, on the fly, at runtime.
Intents - provides in communicating between components, and sharing data between them.
        Intent intent = new Intent(Name);
        startActivity(intent);

        Intent intent = this.getIntent();

        Intent intent = new Intent(Intent.ACTION_VIEW);
        intent.setData(Uri.parse("http://www.google.com/"));
        startActivity(intent);

        Intent intent = new Intent(Intent.ACTION_WEB_SEARCH);
        intent.setData(Uri.parse("http://www.google.com/"));
        startActivity(intent);

        Intent intent = new Intent(Intent.ACTION_DIAL);
        activity.startActivity(intent);

        Intent intent = new Intent(Intent.ACTION_CALL);
        intent.setData(Uri.parse("tel:987-654-321"));
       startActivity(intent);



Container -

Thread -

Theme - Styles

Dialog -

Toast - Small rectanglar pop-up notification

Status bar -

Sliding drawer -

Notification bar -

Build-in Providers -

Directory structure
src/ - Java source code
gen/ - auto gen file (R.java)
asset/ - hold other static files
bin/ - compiled files
libs/ - holding third party Java JARs
res/ - resource such as icon, GUI layout,
AndroidManifest.xml

Size
5px is 5 pixels, 5dip is 5 density-independent pixels, or 5mm is 5 millimeter

Color
"#rgb", "#argb", "#rrggbb", or "#aarrggbb".