samples/WiFiDirectServiceDiscovery/src/com/example/android/wifidirect/discovery/WiFiServiceDiscoveryActivity.java

package com.example.android.wifidirect.discovery;

import android.Manifest;
import android.app.Activity;
import android.app.Fragment;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.IntentFilter;
import android.content.pm.PackageManager;
import android.net.wifi.WpsInfo;
import android.net.wifi.WifiManager;
import android.net.wifi.p2p.WifiP2pConfig;
import android.net.wifi.p2p.WifiP2pDevice;
import android.net.wifi.p2p.WifiP2pInfo;
import android.net.wifi.p2p.WifiP2pManager;
import android.net.wifi.p2p.WifiP2pManager.ActionListener;
import android.net.wifi.p2p.WifiP2pManager.Channel;
import android.net.wifi.p2p.WifiP2pManager.ConnectionInfoListener;
import android.net.wifi.p2p.WifiP2pManager.DnsSdServiceResponseListener;
import android.net.wifi.p2p.WifiP2pManager.DnsSdTxtRecordListener;
import android.net.wifi.p2p.nsd.WifiP2pDnsSdServiceInfo;
import android.net.wifi.p2p.nsd.WifiP2pDnsSdServiceRequest;
import android.os.Build;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.View;
import android.widget.TextView;

import com.example.android.wifidirect.discovery.WiFiChatFragment.MessageTarget;
import com.example.android.wifidirect.discovery.WiFiDirectServicesList.DeviceClickListener;
import com.example.android.wifidirect.discovery.WiFiDirectServicesList.WiFiDevicesAdapter;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

/**
 * The main activity for the sample. This activity registers a local service and
 * perform discovery over Wi-Fi p2p network. It also hosts a couple of fragments
 * to manage chat operations. When the app is launched, the device publishes a
 * chat service and also tries to discover services published by other peers. On
 * selecting a peer published service, the app initiates a Wi-Fi P2P (Direct)
 * connection with the peer. On successful connection with a peer advertising
 * the same service, the app opens up sockets to initiate a chat.
 * {@code WiFiChatFragment} is then added to the the main activity which manages
 * the interface and messaging needs for a chat session.
 */
public class WiFiServiceDiscoveryActivity extends Activity implements
        DeviceClickListener, Handler.Callback, MessageTarget,
        ConnectionInfoListener {

    public static final String TAG = "wifidirectdemo";

    // TXT RECORD properties
    public static final String TXTRECORD_PROP_AVAILABLE = "available";
    public static final String SERVICE_INSTANCE = "_wifidemotest";
    public static final String SERVICE_REG_TYPE = "_presence._tcp";

    public static final int MESSAGE_READ = 0x400 + 1;
    public static final int MY_HANDLE = 0x400 + 2;

    private static final int PERMISSIONS_REQUEST_CODE = 1001;

    private WifiP2pManager manager;

    static final int SERVER_PORT = 4545;

    private final IntentFilter intentFilter = new IntentFilter();
    private Channel channel;
    private BroadcastReceiver receiver = null;
    private WifiP2pDnsSdServiceRequest serviceRequest;

    private Handler handler = new Handler(this);
    private WiFiChatFragment chatFragment;
    private WiFiDirectServicesList servicesList;

    private TextView statusTxtView;

    public Handler getHandler() {
        return handler;
    }

    public void setHandler(Handler handler) {
        this.handler = handler;
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, String[] permissions,
            int[] grantResults) {
        switch (requestCode) {
        case PERMISSIONS_REQUEST_CODE:
            if  (grantResults[0] != PackageManager.PERMISSION_GRANTED) {
                Log.e(TAG, "Fine location permission is not granted!");
                finish();
            } else {
                startRegistrationAndDiscovery();
            }
            break;
        }
    }

    private boolean initP2p() {
        // Device capability definition check
        if (!getPackageManager().hasSystemFeature(PackageManager.FEATURE_WIFI_DIRECT)) {
            Log.e(TAG, "Wi-Fi Direct is not supported by this device.");
            return false;
        }

        // Hardware capability check
        WifiManager wifiManager = (WifiManager) getSystemService(Context.WIFI_SERVICE);
        if (wifiManager == null) {
            Log.e(TAG, "Cannot get Wi-Fi system service.");
            return false;
        }

        if (!wifiManager.isP2pSupported()) {
            Log.e(TAG, "Wi-Fi Direct is not supported by the hardware or Wi-Fi is off.");
            return false;
        }

        manager = (WifiP2pManager) getSystemService(Context.WIFI_P2P_SERVICE);
        if (manager == null) {
            Log.e(TAG, "Cannot get Wi-Fi Direct system service.");
            return false;
        }

        channel = manager.initialize(this, getMainLooper(), null);
        if (channel == null) {
            Log.e(TAG, "Cannot initialize Wi-Fi Direct.");
            return false;
        }

        return true;
    }

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        statusTxtView = (TextView) findViewById(R.id.status_text);

        intentFilter.addAction(WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION);
        intentFilter.addAction(WifiP2pManager.WIFI_P2P_PEERS_CHANGED_ACTION);
        intentFilter
                .addAction(WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION);
        intentFilter
                .addAction(WifiP2pManager.WIFI_P2P_THIS_DEVICE_CHANGED_ACTION);

        if (!initP2p()) {
            finish();
        }

        servicesList = new WiFiDirectServicesList();
        getFragmentManager().beginTransaction()
                .add(R.id.container_root, servicesList, "services").commit();

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M
                    && checkSelfPermission(Manifest.permission.ACCESS_FINE_LOCATION)
                    != PackageManager.PERMISSION_GRANTED) {
            requestPermissions(new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
                    PERMISSIONS_REQUEST_CODE);
            // After this point you wait for callback in
            // onRequestPermissionsResult(int, String[], int[]) overridden method
        } else {
            startRegistrationAndDiscovery();
        }

    }

    @Override
    protected void onRestart() {
        Fragment frag = getFragmentManager().findFragmentByTag("services");
        if (frag != null) {
            getFragmentManager().beginTransaction().remove(frag).commit();
        }
        super.onRestart();
    }

    @Override
    protected void onStop() {
        if (manager != null && channel != null) {
            manager.removeGroup(channel, new ActionListener() {

                @Override
                public void onFailure(int reasonCode) {
                    Log.d(TAG, "Disconnect failed. Reason :" + reasonCode);
                }

                @Override
                public void onSuccess() {
                }

            });
        }
        super.onStop();
    }

    /**
     * Registers a local service and then initiates a service discovery
     */
    private void startRegistrationAndDiscovery() {
        Map<String, String> record = new HashMap<String, String>();
        record.put(TXTRECORD_PROP_AVAILABLE, "visible");

        WifiP2pDnsSdServiceInfo service = WifiP2pDnsSdServiceInfo.newInstance(
                SERVICE_INSTANCE, SERVICE_REG_TYPE, record);
        manager.addLocalService(channel, service, new ActionListener() {

            @Override
            public void onSuccess() {
                appendStatus("Added Local Service");
            }

            @Override
            public void onFailure(int error) {
                appendStatus("Failed to add a service");
            }
        });

        discoverService();

    }

    private void discoverService() {

        /*
         * Register listeners for DNS-SD services. These are callbacks invoked
         * by the system when a service is actually discovered.
         */

        manager.setDnsSdResponseListeners(channel,
                new DnsSdServiceResponseListener() {

                    @Override
                    public void onDnsSdServiceAvailable(String instanceName,
                            String registrationType, WifiP2pDevice srcDevice) {

                        // A service has been discovered. Is this our app?

                        if (instanceName.equalsIgnoreCase(SERVICE_INSTANCE)) {

                            // update the UI and add the item the discovered
                            // device.
                            WiFiDirectServicesList fragment = (WiFiDirectServicesList) getFragmentManager()
                                    .findFragmentByTag("services");
                            if (fragment != null) {
                                WiFiDevicesAdapter adapter = ((WiFiDevicesAdapter) fragment
                                        .getListAdapter());
                                WiFiP2pService service = new WiFiP2pService();
                                service.device = srcDevice;
                                service.instanceName = instanceName;
                                service.serviceRegistrationType = registrationType;
                                adapter.add(service);
                                adapter.notifyDataSetChanged();
                                Log.d(TAG, "onBonjourServiceAvailable "
                                        + instanceName);
                            }
                        }

                    }
                }, new DnsSdTxtRecordListener() {

                    /**
                     * A new TXT record is available. Pick up the advertised
                     * buddy name.
                     */
                    @Override
                    public void onDnsSdTxtRecordAvailable(
                            String fullDomainName, Map<String, String> record,
                            WifiP2pDevice device) {
                        Log.d(TAG,
                                device.deviceName + " is "
                                        + record.get(TXTRECORD_PROP_AVAILABLE));
                    }
                });

        // After attaching listeners, create a service request and initiate
        // discovery.
        serviceRequest = WifiP2pDnsSdServiceRequest.newInstance();
        manager.addServiceRequest(channel, serviceRequest,
                new ActionListener() {

                    @Override
                    public void onSuccess() {
                        appendStatus("Added service discovery request");
                    }

                    @Override
                    public void onFailure(int arg0) {
                        appendStatus("Failed adding service discovery request");
                    }
                });
        manager.discoverServices(channel, new ActionListener() {

            @Override
            public void onSuccess() {
                appendStatus("Service discovery initiated");
            }

            @Override
            public void onFailure(int arg0) {
                appendStatus("Service discovery failed");

            }
        });
    }

    @Override
    public void connectP2p(WiFiP2pService service) {
        WifiP2pConfig config = new WifiP2pConfig();
        config.deviceAddress = service.device.deviceAddress;
        config.wps.setup = WpsInfo.PBC;
        if (serviceRequest != null)
            manager.removeServiceRequest(channel, serviceRequest,
                    new ActionListener() {

                        @Override
                        public void onSuccess() {
                        }

                        @Override
                        public void onFailure(int arg0) {
                        }
                    });

        manager.connect(channel, config, new ActionListener() {

            @Override
            public void onSuccess() {
                appendStatus("Connecting to service");
            }

            @Override
            public void onFailure(int errorCode) {
                appendStatus("Failed connecting to service");
            }
        });
    }

    @Override
    public boolean handleMessage(Message msg) {
        switch (msg.what) {
            case MESSAGE_READ:
                byte[] readBuf = (byte[]) msg.obj;
                // construct a string from the valid bytes in the buffer
                String readMessage = new String(readBuf, 0, msg.arg1);
                Log.d(TAG, readMessage);
                (chatFragment).pushMessage("Buddy: " + readMessage);
                break;

            case MY_HANDLE:
                Object obj = msg.obj;
                (chatFragment).setChatManager((ChatManager) obj);

        }
        return true;
    }

    @Override
    public void onResume() {
        super.onResume();
        receiver = new WiFiDirectBroadcastReceiver(manager, channel, this);
        registerReceiver(receiver, intentFilter);
    }

    @Override
    public void onPause() {
        super.onPause();
        unregisterReceiver(receiver);
    }

    @Override
    public void onConnectionInfoAvailable(WifiP2pInfo p2pInfo) {
        Thread handler = null;
        /*
         * The group owner accepts connections using a server socket and then spawns a
         * client socket for every client. This is handled by {@code
         * GroupOwnerSocketHandler}
         */

        if (p2pInfo.isGroupOwner) {
            Log.d(TAG, "Connected as group owner");
            try {
                handler = new GroupOwnerSocketHandler(
                        ((MessageTarget) this).getHandler());
                handler.start();
            } catch (IOException e) {
                Log.d(TAG,
                        "Failed to create a server thread - " + e.getMessage());
                return;
            }
        } else {
            Log.d(TAG, "Connected as peer");
            handler = new ClientSocketHandler(
                    ((MessageTarget) this).getHandler(),
                    p2pInfo.groupOwnerAddress);
            handler.start();
        }
        chatFragment = new WiFiChatFragment();
        getFragmentManager().beginTransaction()
                .replace(R.id.container_root, chatFragment).commit();
        statusTxtView.setVisibility(View.GONE);
    }

    public void appendStatus(String status) {
        String current = statusTxtView.getText().toString();
        statusTxtView.setText(current + "\n" + status);
    }
}