Added WiFi Communication to project

app/src/main/AndroidManifest.xml

 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.example.greenwatch">
 
+    <uses-permission android:name="android.permission.INTERNET" />
+
     <application
         android:allowBackup="true"
         android:icon="@mipmap/ic_launcher"
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/Theme.GreenWatch">
-        <activity
-            android:name=".ConnectionActivity"
-            android:exported="false" />
         <activity
             android:name=".VideodetectionAndAccelerometerActivity"
             android:exported="false" />

app/src/main/java/com/example/greenwatch/ConnectionActivity.java

-package com.example.greenwatch;
-
-import androidx.appcompat.app.AppCompatActivity;
-
-import android.os.Bundle;
-import android.view.View;
-import android.widget.Button;
-
-public class ConnectionActivity extends AppCompatActivity {
-
-    private Button backToMainActivity;
-
-    @Override
-    protected void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        setContentView(R.layout.activity_connection);
-
-        backToMainActivity = (Button) findViewById(R.id.connectionBackToMainActivity);
-
-        backToMainActivity.setOnClickListener(new View.OnClickListener() {
-            @Override
-            public void onClick(View v) {
-                finish();
-            }
-        });
-    }
-}

app/src/main/java/com/example/greenwatch/MainActivity.java

 import androidx.appcompat.app.AppCompatActivity;
 import androidx.lifecycle.Observer;
 import androidx.lifecycle.ViewModelProvider;
+import androidx.recyclerview.widget.LinearLayoutManager;
+import androidx.recyclerview.widget.RecyclerView;
 
 import android.content.Intent;
 import android.os.Bundle;
 import android.widget.TextView;
 import android.widget.Toast;
 
+import com.example.greenwatch.adapters.DeviceListAdapter;
 import com.example.greenwatch.models.Device;
 import com.example.greenwatch.viewmodels.MainActivityViewModel;
 
         mMainActivityViewModel.getConnectedDeviceList().observe(this, new Observer<List<Device>>() {
             @Override
             public void onChanged(List<Device> devices) {
+                deviceListAdapter.setDevices(devices);
                 StringBuilder sb = new StringBuilder();
                 sb.append("Time Stamp: ");
                 sb.append(mMainActivityViewModel.getTimeStamp(mMainActivityViewModel.getLocalDeviceUUID()));
         startActivity(intent);
     }
     public void openVideodetectionAndAccelerometerActivity(){
-        Intent intent = new Intent(this, VideodetectionAndAccelerometerActivity.class);
-        startActivity(intent);
+        //Intent intent = new Intent(this, VideodetectionAndAccelerometerActivity.class);
+        //startActivity(intent);
+        mMainActivityViewModel.setDevice(mMainActivityViewModel.getLocalDeviceUUID(), "24:00",  false, "Video", 0);
     }
     public void openConnectionActivity(){
-        Intent intent = new Intent(this, ConnectionActivity.class);
-        startActivity(intent);
+        //Intent intent = new Intent(this, ConnectionActivity.class);
+        //startActivity(intent);
+        mMainActivityViewModel.setDevice(mMainActivityViewModel.getLocalDeviceUUID(), "10:51",  true, "Audio", 10);
     }
 
 }

app/src/main/java/com/example/greenwatch/communication/WiFiCommunication.java

+package com.example.greenwatch.communication;
+
+import com.example.greenwatch.repositories.DeviceRepository;
+
+import java.io.IOException;
+import java.net.DatagramPacket;
+import java.net.DatagramSocket;
+import java.net.Inet4Address;
+import java.net.InetAddress;
+import java.net.NetworkInterface;
+import java.net.SocketException;
+import java.net.UnknownHostException;
+import java.util.Enumeration;
+
+public class WiFiCommunication {
+
+    private final InetAddress address;
+    private final DatagramSocket socket;
+    private final int port;
+    private String rxString;
+    private String sendMessage;
+    //private String sendMsg = "default";
+    private boolean isNewMessage;
+    volatile private boolean running;
+    private static WiFiCommunication wifiCommunicationInstance;
+    private DeviceRepository mDeviceRepository;
+
+    private WiFiCommunication() {
+        port = 1234;
+        try {
+            socket = new DatagramSocket(port);
+            socket.setBroadcast(true);
+            address = InetAddress.getByName("255.255.255.255");
+            running = true;
+            isNewMessage = false;
+            new ReceiveThread().start();
+            new SendThread().start();
+        } catch (SocketException | UnknownHostException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    public static synchronized WiFiCommunication getInstance() {
+        if (wifiCommunicationInstance == null){
+            wifiCommunicationInstance = new WiFiCommunication();
+        }
+        return wifiCommunicationInstance;
+    }
+
+    public void setDeviceRepository(DeviceRepository deviceRepository) {
+        this.mDeviceRepository = deviceRepository;
+    }
+
+    public void setNewMessage(String newMessage, boolean isNewMessage){
+        this.sendMessage = newMessage;
+        this.isNewMessage = isNewMessage;
+    }
+
+    public static String getLocalIpAddress() {
+        try {
+            for (Enumeration<NetworkInterface> en = NetworkInterface.getNetworkInterfaces(); en.hasMoreElements();) {
+                NetworkInterface networkInterface = (NetworkInterface) ((Enumeration<?>) en).nextElement();
+                for (Enumeration<InetAddress> addresses = networkInterface.getInetAddresses(); addresses.hasMoreElements();) {
+                    InetAddress inetAddress = addresses.nextElement();
+                    if (!inetAddress.isLoopbackAddress() && inetAddress instanceof Inet4Address) {
+                        return inetAddress.getHostAddress();
+                    }
+                }
+            }
+        } catch (SocketException ex) {
+            ex.printStackTrace();
+        }
+        return null;
+    }
+
+    public void stopCommunication() {
+        running = false;
+        socket.close();
+    }
+
+    private class SendThread extends Thread {
+        private int tmpCnt = 0;
+        @Override
+        public void run() {
+            try {
+                do {
+
+                    if(isNewMessage)
+                    {
+                        isNewMessage = false;
+                        //todo: adapt send String
+                        String txString = getLocalIpAddress() + " sends. #" + tmpCnt++ + sendMessage;
+                        byte[] txBuffer = txString.getBytes();
+
+                        DatagramPacket txPacket = new DatagramPacket(txBuffer, txBuffer.length, address, port);
+
+                        for(int i = 0; i < 20; i++) {
+                            socket.send(txPacket);
+                        }
+                    }
+                } while (running);
+            } catch (IOException e) {
+                e.printStackTrace();
+            }
+        }
+    }
+
+    private class ReceiveThread extends Thread {
+        private String rxString = "";
+        private String previousRxString = "";
+        @Override
+        public void run() {
+            try {
+                do {
+                    byte[] rxBuffer = new byte[1024];
+                    DatagramPacket packet = new DatagramPacket(rxBuffer, rxBuffer.length);
+                    socket.receive(packet);
+                    rxString = new String(packet.getData(), 0, packet.getLength());
+
+                    if(!previousRxString.equals(rxString)){
+                        mDeviceRepository.getNewReceivedMessage(rxString);
+
+                    }
+                    previousRxString = rxString;
+
+                } while (running);
+            }
+            catch (IOException e) {
+                e.printStackTrace();
+            }
+        }
+    }
+}

app/src/main/java/com/example/greenwatch/repositories/DeviceRepository.java

 import androidx.lifecycle.MutableLiveData;
 
 import com.example.greenwatch.models.Device;
+import com.example.greenwatch.communication.WiFiCommunication;
 
 import java.util.ArrayList;
 import java.util.HashMap;
 
 public class DeviceRepository {
 
-    private String delimiter = ", ";
-    private String deviceUUID;
+    private final String delimiter = ", ";
+    private final String SensorStatusKey = "An";
+    private String localDeviceUUID;
     private static DeviceRepository deviceRepositoryInstance;
+    private WiFiCommunication mWiFiCommunication;
     private MutableLiveData<List<Device>> deviceList = new MutableLiveData<>();
     private HashMap<String, Device> connectedDevicesList = new HashMap<>();
     private HashMap<String, String> deviceIDMapper = new HashMap<>();
 
+    private DeviceRepository() {
+        setLocalDeviceUUID();
+    }
+
     public static synchronized DeviceRepository getInstance() {
         if (deviceRepositoryInstance == null){
             deviceRepositoryInstance = new DeviceRepository();
-            deviceRepositoryInstance.setDeviceUUID();
         }
         return deviceRepositoryInstance;
     }
 
+    public void setWiFiCommunication(WiFiCommunication wiFiCommunication) {
+        this.mWiFiCommunication = wiFiCommunication;
+    }
+
     public MutableLiveData<List<Device>> getConnectedDeviceList() {
         setMutableLiveDataValue();
         return deviceList;
 
     public void createNewDevice(String timeStamp, String deviceID, boolean sensorStatus, String sensorType, int sensorMassage){
         Device newDevice = new Device(timeStamp, deviceID, sensorStatus, sensorType, sensorMassage);
+        setDeviceIDMapper(deviceID);
         addToConnectedDeviceList(newDevice.getDeviceID(), newDevice);
         setMutableLiveDataValue();
     }
 
-    public void createNewRemoteDevice(String message) {
-        String[] messageString = messageStringSplitter(message);
-        String timeStamp = messageString[0];
-        String deviceID = messageString[1];
-        boolean sensorStatus = Boolean.valueOf(messageString[1]);
-        String sensorType = messageString[3];
-        int sensorMassage = Integer.valueOf(messageString[4]);
-
-        if(!connectedDevicesList.containsKey(deviceID)) {
-            createNewDevice(timeStamp, deviceID, sensorStatus, sensorType, sensorMassage);
-        }
-    }
-
-    public String messageStringBuilder(String deviceID) {
+    private String messageStringBuilder(String deviceID) {
         StringBuilder message = new StringBuilder();
         Device device = connectedDevicesList.get(deviceID);
         if(device != null) {
                     .append(device.getSensorMassage());
             return message.toString();
         }
-        return message.toString();
+        else {
+            message.append("")
+                    .append(delimiter)
+                    .append("")
+                    .append(delimiter)
+                    .append("")
+                    .append(delimiter)
+                    .append("")
+                    .append(delimiter)
+                    .append("");
+            return message.toString();
+        }
     }
 
     public String getLocalDeviceUUID() {
-        return deviceUUID;
+        return localDeviceUUID;
     }
 
-    public void setDevice(String deviceID, String timeStamp, boolean sensorStatus, String sensorType, int sensorMassage) {
+    public void updateDevice(String deviceID, String timeStamp, boolean sensorStatus, String sensorType, int sensorMassage) {
         String checkedDeviceID = checkDeviceID(deviceID);
         Device device = connectedDevicesList.get(checkedDeviceID);
         if(device != null) {
 
     private void addToConnectedDeviceList(String key, Device device) {
         connectedDevicesList.put(key, device);
+        if (key.equals(checkDeviceID(localDeviceUUID))) {
+            mWiFiCommunication.setNewMessage(messageStringBuilder(device.getDeviceID()),true);
+        }
     }
 
     private String checkDeviceID(String deviceID) {
-        if(!deviceIDMapper.isEmpty() && deviceID.equals(deviceUUID)) {
+        if(!deviceIDMapper.isEmpty() && deviceID.equals(localDeviceUUID)) {
             return deviceIDMapper.get(deviceID);
         }
         return deviceID;
     }
 
     private void setDeviceIDMapper(String deviceID) {
-        deviceIDMapper.put(deviceUUID, deviceID);
+        deviceIDMapper.put(localDeviceUUID, deviceID);
     }
 
-    private void setDeviceUUID(){
-        this.deviceUUID = UUID.randomUUID().toString();
+    private void setLocalDeviceUUID(){
+        this.localDeviceUUID = UUID.randomUUID().toString();
     }
 
     private String[] messageStringSplitter(String message) {
         return message.split(delimiter);
     }
+
+    public void getNewReceivedMessage(String newMessage) {
+        String[] messageString = messageStringSplitter(newMessage);
+        String timeStamp = messageString[0];
+        String deviceID = messageString[1];
+        boolean sensorStatus = convertSensorStatus(messageString[2]);
+        String sensorType = messageString[3];
+        int sensorMassage = Integer.valueOf(messageString[4]);
+
+        if (deviceID.equals(checkDeviceID(localDeviceUUID))) {
+            return;
+        }
+
+        if(!connectedDevicesList.containsKey(deviceID)) {
+            createNewDevice(timeStamp, deviceID, sensorStatus, sensorType, sensorMassage);
+        }
+        else {
+            updateDevice(deviceID, timeStamp, sensorStatus, sensorType, sensorMassage);
+        }
+    }
+
+    private boolean convertSensorStatus(String status) {
+        return status.equals(SensorStatusKey);
+    }
 }

app/src/main/java/com/example/greenwatch/viewmodels/AccelerometerViewModel.java

     }
 
     public void setDevice(String deviceID, String timeStamp, boolean sensorStatus, String sensorType, int sensorMassage) {
-        mDeviceRepository.setDevice(deviceID, timeStamp, sensorStatus, sensorType, sensorMassage);
+        mDeviceRepository.updateDevice(deviceID, timeStamp, sensorStatus, sensorType, sensorMassage);
     }
 
     public void setTimeStamp(String deviceID, String timeStamp) {

app/src/main/java/com/example/greenwatch/viewmodels/MainActivityViewModel.java

 import androidx.lifecycle.MutableLiveData;
 import androidx.lifecycle.ViewModel;
 
+import com.example.greenwatch.communication.WiFiCommunication;
 import com.example.greenwatch.models.Device;
 import com.example.greenwatch.repositories.DeviceRepository;
 
     private MutableLiveData<List<Device>> mDeviceList;
     private DeviceRepository mDeviceRepository;
 
+
     public void init() {
+        WiFiCommunication mWiFiCommunication;
         if(mDeviceList != null) {
             return;
         }
+        //todo: check if WiFi instanz can be hold only by the repository
         mDeviceRepository = DeviceRepository.getInstance();
-        mDeviceRepository.createNewDevice("", mDeviceRepository.getLocalDeviceUUID(), false, "", 0);
+        mWiFiCommunication = WiFiCommunication.getInstance();
+        mDeviceRepository.setWiFiCommunication(mWiFiCommunication);
+        mWiFiCommunication.setDeviceRepository(mDeviceRepository);
+        mDeviceRepository.createNewDevice("", mDeviceRepository.getLocalDeviceUUID(), false, "No Sensor selected", 0);
         mDeviceList = mDeviceRepository.getConnectedDeviceList();
     }
 
     }
 
     public void setDevice(String deviceID, String timeStamp, boolean sensorStatus, String sensorType, int sensorMassage) {
-        mDeviceRepository.setDevice(deviceID, timeStamp, sensorStatus, sensorType, sensorMassage);
+        mDeviceRepository.updateDevice(deviceID, timeStamp, sensorStatus, sensorType, sensorMassage);
     }
 
     public void setTimeStamp(String deviceID, String timeStamp) {

app/src/main/res/layout/activity_connection.xml

-<?xml version="1.0" encoding="utf-8"?>
-<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:app="http://schemas.android.com/apk/res-auto"
-    xmlns:tools="http://schemas.android.com/tools"
-    android:layout_width="match_parent"
-    android:layout_height="match_parent"
-    android:orientation="vertical"
-    android:padding="10dp"
-    tools:context=".ConnectionActivity">
-
-    <TextView
-        android:id="@+id/tvConnectionStatusmessage"
-        android:layout_width="match_parent"
-        android:layout_height="wrap_content"
-        android:text="Connection Activity">
-    </TextView>
-
-    <Button
-        android:id="@+id/connectionBackToMainActivity"
-        android:layout_width="match_parent"
-        android:layout_height="wrap_content"
-        android:text="Back to MainActivity">
-    </Button>
-
-</LinearLayout>