//very helpful src of how adapter is refreshed:

http://stackoverflow.com/questions/12229817/android-how-does-notifydatasetchanged-method-and-listviews-work

//src: http://developer.android.com/guide/topics/ui/declaring-layout.html#AdapterViews

Use if: content for layout is dynamic or not pre-determined.

Want to populate the layout with views at runtime.

Need a layout that subclasses the AdapterView class

>> Use an Adapter to bind data to its layout.

Layout examples:

ListView, GridView

To populate:

bind AdapterView instance to an Adapter (which retrieves ata from external source. creates a View for each data entry)

Popular Adapters:

ArrayAdapter (works for Strings only)

for array data sources.

view is created by callign toString() on each.

>> contents placed into a TextView

Override options:

[1] IF want object appearance to change, override MyObject.toString()

[2] To create a view other than a TextView (maybe want ImageView), extend ArrayDapter class and override getView() to retun the type of view you want for each item

SimpleCursorAdapter (works if data comes form a Cursor)

+ Must specify layout to use for each row in Cursor

+ Must specify which columns in Cursor can be inserted into which views of the layout

eg) create list of people's name + phone

String[] fromColumns = {ContactsContract.Data.DISPLAY_NAME,

ContactsContract.CommonDataKinds.Phone.NUMBER};

int[] toViews = {R.id.display_name, R.id.phone_number};

When instantiating SimpleCursorAdapter, choose what layout to use for each result, what Cursor to draw results from, and the from[] and to[] arrays

SimpleCursorAdapter adapter = new SimpleCursorAdapter(this,

R.layout.person_name_and_number, cursor, fromColumns, toViews, 0);

ListView listView = getListView();

listView.setAdapter(adapter);

eg) ListView for string array

/**

* @param context (this in this case)

* @param layout that contains a TextView for each MyObject in array

* @param MyObjectClassArray

*/

ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, myStringArray);

ListView listView = (ListView) findViewById(R.id.listview);

listView.setAdapter(adapter);

If data pool changed, call notifyDataSetChanged()

>> notifies view that data changed

>> view should refresh itself

Handling Click Events for each item in AdapterView

+ Must implement AdapterView.OnItemClickListener interface

// Create a message handling object as an anonymous class.

private OnItemClickListener mMessageClickedHandler = new OnItemClickListener() {

public void onItemClick(AdapterView parent, View v, int position, long id) {

// Do something in response to the click

}

};

listView.setOnItemClickListener(mMessageClickedHandler);

eg) Big example involving ListFragment and its adapter

public class BDArrayAdapter extends ArrayAdapter<BluetoothDevice> {

private final Context context;

private List<BluetoothDevice> items;

public BDArrayAdapter(Context context, List<BluetoothDevice> objects){

super(context, R.layout.rows_peers, objects);

this.context = context;

this.items = objects;

}

public View getView(int position, View convertView, ViewGroup parent){

LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

View rowView = inflater.inflate(R.layout.rows_peers, parent, false);

//do stuff to rowView's views

TextView device_info = (TextView) rowView.findViewById(R.id.people_name_address);

BluetoothDevice device = items.get(position);

device_info.setText(device.getName() + "\n" + device.getAddress());

return rowView;

}

}

public class ListPeers extends ListFragment {

List<BluetoothDevice> pairedDevices = new ArrayList<BluetoothDevice>();

public ListPeers() {

// Required empty public constructor

}

@Override

public void onActivityCreated(Bundle savedInstanceState){

super.onActivityCreated(savedInstanceState);

this.setListAdapter(new BDArrayAdapter(getActivity(), pairedDevices));

}

@Override

public View onCreateView(LayoutInflater inflater, ViewGroup container,

Bundle savedInstanceState) {

// Inflate the layout for this fragment

return inflater.inflate(R.layout.fragment_list_peers, container, false);

}

}

public class BlueToothActivity extends Activity {

...

Set<BluetoothDevice> pairedDevices;

public void onDiscoverOtherDevices(){

if (mReceiver == null){

mReceiver = new BroadcastReceiver() {

@Override

public void onReceive(Context context, Intent intent) {

String action = intent.getAction();

//If found device

if (BluetoothDevice.ACTION_FOUND.equals(action)){

//Add device info

BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);

if (pairedDevices.add(device)){

};

}

}

};

}

registerReceiver(mReceiver, filter);

}

}