am edb7a442: Merge "docs: Wear DataItem listener improvements" into lmp-docs

</ol>

<p>

However, instead of working with raw bytes using <a href="{@docRoot}reference/com/google/android/gms/wearable/PutDataRequest.html#setData(byte[])">setData()</a>,

However, instead of working with raw bytes using <a href="{@docRoot}reference/com/google/android/gms/wearable/PutDataRequest.html#setData(byte[])"><code>setData()</code></a>,

we recommend you <a href="#SyncData">use a data map</a>, which exposes

a data item in an easy-to-use {@link android.os.Bundle}-like interface.

</p>

  </li>

</ol>

<p>The following example shows how to create a data map and put data on it:</p>

<p>The <code>increaseCounter()</code> method in the following example shows how to create a

data map and put data in it:</p>

<pre>

PutDataMapRequest dataMap = PutDataMapRequest.create("/count");

dataMap.getDataMap().putInt(COUNT_KEY, count++);

PutDataRequest request = dataMap.asPutDataRequest();

PendingResult<DataApi.DataItemResult> pendingResult = Wearable.DataApi

        .putDataItem(mGoogleApiClient, request);

public class MainActivity extends Activity implements

        DataApi.DataListener,

        GoogleApiClient.ConnectionCallbacks,

        GoogleApiClient.OnConnectionFailedListener {

    private static final String COUNT_KEY = "com.example.key.count";

    private GoogleApiClient mGoogleApiClient;

    private int count = 0;

    ...

    // Create a data map and put data in it

    private void <strong>increaseCounter</strong>() {

        PutDataMapRequest putDataMapReq = PutDataMapRequest.create("/count");

        putDataMapReq.getDataMap().putInt(COUNT_KEY, count++);

        PutDataRequest putDataReq = putDataMapReq.asPutDataRequest();

        PendingResult<DataApi.DataItemResult> pendingResult =

                Wearable.DataApi.putDataItem(mGoogleApiClient, putDataReq);

    }

    ...

}

</pre>

<p>For more information about handling the

<a href="{@docRoot}reference/com/google/android/gms/common/api/PendingResult.html">

<code>PendingResult</code></a> object, see

<a href="{@docRoot}training/wearables/data-layer/events.html#Wait">Wait for the Status of Data

Layer Calls</a>.</p>

<h2 id="ListenEvents">Listen for Data Item Events</h2>

If one side of the data layer connection changes a data item, you probably want

<p>If one side of the data layer connection changes a data item, you probably want

to be notified of any changes on the other side of the connection.

You can do this by implementing a listener for data item events.

You can do this by implementing a listener for data item events.</p>

<p>For example, here's what a typical callback looks like to carry out certain actions

when data changes:</p>

<p>The code snippet in the following example notifies your app when the value of the

counter defined in the previous example changes:</p>

<pre>

public class MainActivity extends Activity implements

        DataApi.DataListener,

        GoogleApiClient.ConnectionCallbacks,

        GoogleApiClient.OnConnectionFailedListener {

    private static final String COUNT_KEY = "com.example.key.count";

    private GoogleApiClient mGoogleApiClient;

    private int count = 0;

    @Override

public void onDataChanged(DataEventBuffer dataEvents) {

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        mGoogleApiClient = new GoogleApiClient.Builder(this)

                .addApi(Wearable.API)

                .addConnectionCallbacks(this)

                .addOnConnectionFailedListener(this)

                .build();

    }

    @Override

    protected void onResume() {

        super.onStart();

        mGoogleApiClient.connect();

    }

    @Override

    public void onConnected(Bundle bundle) {

        <strong>Wearable.DataApi.addListener</strong>(mGoogleApiClient, this);

    }

    @Override

    protected void onPause() {

        super.onPause();

        <strong>Wearable.DataApi.removeListener</strong>(mGoogleApiClient, this);

        mGoogleApiClient.disconnect();

    }

    @Override

    public void <strong>onDataChanged</strong>(DataEventBuffer dataEvents) {

        for (DataEvent event : dataEvents) {

        if (event.getType() == DataEvent.TYPE_DELETED) {

            Log.d(TAG, "DataItem deleted: " + event.getDataItem().getUri());

        } else if (event.getType() == DataEvent.TYPE_CHANGED) {

             Log.d(TAG, "DataItem changed: " + event.getDataItem().getUri());

            if (event.getType() == DataEvent.TYPE_CHANGED) {

                // DataItem changed

                DataItem item = event.getDataItem();

                if (item.getUri().getPath().compareTo("/count") == 0) {

                    DataMap dataMap = DataMapItem.fromDataItem(item).getDataMap();

                    updateCount(dataMap.getInt(COUNT_KEY));

                }

            } else if (event.getType() == DataEvent.TYPE_DELETED) {

                // DataItem deleted

            }

        }

    }

    // Our method to update the count

    private void updateCount(int c) { ... }

    ...

}

</pre>

<p>

This is just a snippet that requires more implementation details. Learn about

how to implement a full listener service or activity in

<p>This activity implements the

<a href="{@docRoot}reference/com/google/android/gms/wearable/DataApi.DataListener.html">

<code>DataItem.DataListener</code></a> interface. This activity adds itself as a listener

for data item events inside the <code>onConnected()</code> method and removes the listener

in the <code>onPause()</code> method.</p>

<p>You can also implement the listener as a service. For more information, see

<a href="{@docRoot}training/wearables/data-layer/events.html#Listen">Listen for Data Layer

Events</a>.

</p>

 No newline at end of file

Events</a>.</p>

public class MainActivity extends Activity implements

        DataApi.DataListener, ConnectionCallbacks, OnConnectionFailedListener {

    private GoogleApiClient mGoogleApiClient;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

            }

        }

    }

}

</pre>