From c2be8a6da0c193a0592586cfc8bdfdb7903cc055 Mon Sep 17 00:00:00 2001 From: Ricardo Cervera Date: Tue, 20 Jan 2015 13:41:56 -0800 Subject: [PATCH] docs: Wear DataItem listener improvements Change-Id: I07bf2ab063556dd4f6e42a5835f73dd5b326d26e --- .../wearables/data-layer/data-items.jd | 138 ++++++++++++++---- .../training/wearables/data-layer/events.jd | 3 + 2 files changed, 113 insertions(+), 28 deletions(-) diff --git a/docs/html/training/wearables/data-layer/data-items.jd b/docs/html/training/wearables/data-layer/data-items.jd index 12babbfa40822..49a8d32f97927 100644 --- a/docs/html/training/wearables/data-layer/data-items.jd +++ b/docs/html/training/wearables/data-layer/data-items.jd @@ -46,7 +46,7 @@ directly. Instead, you:

-However, instead of working with raw bytes using setData(), +However, instead of working with raw bytes using setData(), we recommend you use a data map, which exposes a data item in an easy-to-use {@link android.os.Bundle}-like interface.

@@ -88,39 +88,121 @@ app, you should create a path scheme that matches the structure of the data. -

The following example shows how to create a data map and put data on it:

+

The increaseCounter() method in the following example shows how to create a +data map and put data in it:

-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 { -

Listen for Data Item Events

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

For example, here's what a typical callback looks like to carry out certain actions -when data changes:

+ private GoogleApiClient mGoogleApiClient; + private int count = 0; -
-@Override
-public void onDataChanged(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());
-        }
+    ...
+
+    // Create a data map and put data in it
+    private void increaseCounter() {
+        PutDataMapRequest putDataMapReq = PutDataMapRequest.create("/count");
+        putDataMapReq.getDataMap().putInt(COUNT_KEY, count++);
+        PutDataRequest putDataReq = putDataMapReq.asPutDataRequest();
+        PendingResult<DataApi.DataItemResult> pendingResult =
+                Wearable.DataApi.putDataItem(mGoogleApiClient, putDataReq);
     }
+
+    ...
 }
-

-This is just a snippet that requires more implementation details. Learn about -how to implement a full listener service or activity in + +

For more information about handling the + +PendingResult object, see +Wait for the Status of Data +Layer Calls.

+ + +

Listen for Data Item Events

+ +

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.

+ +

The code snippet in the following example notifies your app when the value of the +counter defined in the previous example changes:

+ +
+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
+    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) {
+        Wearable.DataApi.addListener(mGoogleApiClient, this);
+    }
+
+    @Override
+    protected void onPause() {
+        super.onPause();
+        Wearable.DataApi.removeListener(mGoogleApiClient, this);
+        mGoogleApiClient.disconnect();
+    }
+
+    @Override
+    public void onDataChanged(DataEventBuffer dataEvents) {
+        for (DataEvent event : dataEvents) {
+            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) { ... }
+
+    ...
+}
+
+ +

This activity implements the + +DataItem.DataListener interface. This activity adds itself as a listener +for data item events inside the onConnected() method and removes the listener +in the onPause() method.

+ +

You can also implement the listener as a service. For more information, see Listen for Data Layer -Events. -

\ No newline at end of file +Events.

diff --git a/docs/html/training/wearables/data-layer/events.jd b/docs/html/training/wearables/data-layer/events.jd index 6a3949a6fc241..c797f6882fffe 100644 --- a/docs/html/training/wearables/data-layer/events.jd +++ b/docs/html/training/wearables/data-layer/events.jd @@ -267,6 +267,8 @@ or