MyActivity.java

package de.peterfriese.notificationwithopenactivityonwearableaction;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;

import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.wearable.PutDataMapRequest;
import com.google.android.gms.wearable.PutDataRequest;
import com.google.android.gms.wearable.Wearable;

import java.text.DateFormat;
import java.util.Date;

import de.peterfriese.notificationwithopenactivityonwearableaction.common.Constants;

public class MyActivity extends Activity {

    private static final String TAG = "PhoneActivity";
    private GoogleApiClient mGoogleApiClient;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_my);

        mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addConnectionCallbacks(new GoogleApiClient.ConnectionCallbacks() {
                    @Override
                    public void onConnected(Bundle connectionHint) {
                        Log.d(TAG, "onConnected: " + connectionHint);
                    }
                    @Override
                    public void onConnectionSuspended(int cause) {
                        Log.d(TAG, "onConnectionSuspended: " + cause);
                    }
                })
                .addOnConnectionFailedListener(new GoogleApiClient.OnConnectionFailedListener() {
                    @Override
                    public void onConnectionFailed(ConnectionResult result) {
                        Log.d(TAG, "onConnectionFailed: " + result);
                    }
                })
                .addApi(Wearable.API)
                .build();

        Button button = (Button) findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                sendNotification();
            }
        });
    }

    @Override
    protected void onStart() {
        super.onStart();
        mGoogleApiClient.connect();
    }

    @Override
    protected void onStop() {
        super.onStop();
        mGoogleApiClient.disconnect();
    }

    private String now() {
        DateFormat dateFormat = android.text.format.DateFormat.getTimeFormat(this);
        return dateFormat.format(new Date());
    }

    private void sendNotification() {
        if (mGoogleApiClient.isConnected()) {
            PutDataMapRequest dataMapRequest = PutDataMapRequest.create(Constants.NOTIFICATION_PATH);
            // Make sure the data item is unique. Usually, this will not be required, as the payload
            // (in this case the title and the content of the notification) will be different for almost all
            // situations. However, in this example, the text and the content are always the same, so we need
            // to disambiguate the data item by adding a field that contains teh current time in milliseconds.
            dataMapRequest.getDataMap().putDouble(Constants.NOTIFICATION_TIMESTAMP, System.currentTimeMillis());
            dataMapRequest.getDataMap().putString(Constants.NOTIFICATION_TITLE, "This is the title");
            dataMapRequest.getDataMap().putString(Constants.NOTIFICATION_CONTENT, "This is a notification with some text.");
            PutDataRequest putDataRequest = dataMapRequest.asPutDataRequest();
            Wearable.DataApi.putDataItem(mGoogleApiClient, putDataRequest);
        }
        else {
            Log.e(TAG, "No connection to wearable available!");
        }
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.my, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
}