Added Gson for JSON parsing, added Exercise retriever

code/src/Fitbot/app/build.gradle

@@ -35,7 +35,11 @@ dependencies {
     implementation 'com.android.support:cardview-v7:28.0.0'
     implementation 'com.android.support:design:28.0.0'
     implementation 'org.joml:joml:1.10.5'
+    implementation 'com.google.code.gson:gson:2.8.6'
     testImplementation 'junit:junit:4.13.2'
+    testImplementation 'org.junit.jupiter:junit-jupiter'
+    testImplementation 'org.junit.jupiter:junit-jupiter'
+    testImplementation 'org.junit.jupiter:junit-jupiter'
     androidTestImplementation 'com.android.support.test:runner:1.0.2'
     androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
 	implementation 'com.aldebaran:qisdk:1.7.5'

code/src/Fitbot/app/src/main/AndroidManifest.xml

@@ -15,8 +15,9 @@
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/Theme.Fitbot" >
+        <!--android:name=".ui.activities.MainActivity"-->
         <activity
-            android:name=".ui.activities.MainActivity"
+            android:name=".ui.activities.FitnessActivity"
             android:exported="true" >
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />

code/src/Fitbot/app/src/main/java/com/example/fitbot/exercise/AbstractExercise.java

@@ -10,8 +10,7 @@ import java.util.Objects;
 
 public abstract class AbstractExercise implements IWebSocketHandler {
 
-    private EMuscleGroup[] muscleGroups;
+    private EMuscleGroup muscleGroup;
-    private EExerciseType exerciseType;
     private GesturePath path;
 
     // Static fields.
@@ -22,13 +21,11 @@ public abstract class AbstractExercise implements IWebSocketHandler {
     /**
      * Constructor for the AbstractExercise class.
      *
-     * @param muscleGroups  The muscle group of the exercise.
+     * @param muscleGroup  The muscle group of the exercise.
-     * @param exerciseType The type of exercise.
      * @param path         The path of the exercise.
      */
-    public AbstractExercise(EMuscleGroup[] muscleGroups, EExerciseType exerciseType, GesturePath path) {
+    public AbstractExercise(EMuscleGroup muscleGroup,  GesturePath path) {
-        this.muscleGroups = muscleGroups;
+        this.muscleGroup = muscleGroup;
-        this.exerciseType = exerciseType;
         this.path = path;
     }
 
@@ -82,19 +79,8 @@ public abstract class AbstractExercise implements IWebSocketHandler {
             webSocket = null;
         }
         currentExercise = null;
-        this.onStopExercise();
     }
 
-    /**
-     * Method for checking whether the activity is finished.
-     */
-    public abstract boolean isActivityFinished();
-
-    /**
-     * Method for stopping this exercise.
-     */
-    public abstract void onStopExercise();
-
     /**
      * Check if the current exercise is the current activity.
      */
@@ -105,15 +91,8 @@ public abstract class AbstractExercise implements IWebSocketHandler {
     /**
      * Get the muscle group of the exercise.
      */
-    public EMuscleGroup[] getMuscleGroup() {
+    public EMuscleGroup getMuscleGroup() {
-        return muscleGroups;
+        return muscleGroup;
-    }
-
-    /**
-     * Get the exercise type.
-     */
-    public EExerciseType getExerciseType() {
-        return exerciseType;
     }
 
     /**

code/src/Fitbot/app/src/main/java/com/example/fitbot/exercise/EExerciseType.java

@@ -1,18 +0,0 @@
-package com.example.fitbot.exercise;
-
-public enum EExerciseType {
-
-    FITNESS("Fitness"),
-    POWER("Krachttrening");
-
-    private final String name;
-
-    EExerciseType(String name) {
-        this.name = name;
-    }
-
-    public String getName() {
-        return name;
-    }
-
-}

code/src/Fitbot/app/src/main/java/com/example/fitbot/exercise/EMuscleGroup.java

@@ -18,4 +18,13 @@ public enum EMuscleGroup {
         return this.muscleGroupIdentifier;
     }
 
+    public static EMuscleGroup parse(int identifier) {
+        for (EMuscleGroup muscleGroup : EMuscleGroup.values()) {
+            if (muscleGroup.getIdentifier() == identifier) {
+                return muscleGroup;
+            }
+        }
+        return null;
+    }
+
 }

code/src/Fitbot/app/src/main/java/com/example/fitbot/exercise/FitnessManager.java

@@ -1,11 +1,16 @@
 package com.example.fitbot.exercise;
 
 import com.example.fitbot.util.path.GesturePath;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParser;
+
+import org.joml.Vector3f;
 
 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
+import java.lang.reflect.Constructor;
 import java.net.URL;
 import java.net.URLConnection;
 
@@ -13,6 +18,11 @@ public class FitnessManager {
 
     private static final String HOST_ADDRESS = "http://145.92.8.132";
 
+    private static final String PROPERTY_DESC = "description";
+    private static final String PROPERTY_VECTORS = "vector_data";
+    private static final String PROPERTY_NAME = "name";
+    private static final String PROPERTY_MUSCLE_GROUP = "muscle_group";
+
     private static String sendHTTP(String url, String method, String contentType, String body) {
         try {
             URLConnection connection = new URL(url).openConnection();
@@ -34,15 +44,70 @@ public class FitnessManager {
         return null;
     }
 
-    public static GesturePath acquirePath(String uniqueIdentifier) {
+    /**
+     * Function for retrieving an exercise from the Raspberry Pi Database.
+     *
+     * @param uniqueIdentifier The unique identifier of the exercise
+     * @return The exercise, if it exists on the server. Otherwise null.
+     */
+    public static <T extends AbstractExercise> AbstractExercise acquireExercise(String uniqueIdentifier, Class<T> referenceClass) {
         String response = sendHTTP(
                 HOST_ADDRESS + "/acquire", "GET", "application/json", "{\"kind\":\"" + uniqueIdentifier + "\"}"
         );
         // Validate the response
         if (response != null) {
-
+            try {
+                JsonObject content = JsonParser.parseString(response).getAsJsonObject();
+                Constructor<T> constructor = referenceClass.getConstructor(referenceClass);
+                T instance = null;
+                try {
+                    instance = constructor.newInstance(
+                            EMuscleGroup.parse(content.get(PROPERTY_MUSCLE_GROUP).getAsInt()),
+                            gesturePathFromString(content.get(PROPERTY_VECTORS).getAsString())
+                    );
+                } catch (Exception e) {
+                    e.printStackTrace();
+                }
+                return instance;
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
         }
         return null;
     }
 
+    /**
+     * Function for converting a string to a GesturePath object.
+     * The input string bytes will be directly converted into 3d vectors.
+     * Every coordinate is composed of 32 bits, so four characters per coordinate.
+     *
+     * @param input The string to convert
+     * @return The GesturePath object
+     */
+    private static GesturePath gesturePathFromString(String input) {
+        byte[] bytes = input.getBytes();
+
+        // Check if the input string contains a valid amount of bytes (12 bytes per vector)
+        if (input.length() % 12 != 0) {
+            throw new IllegalArgumentException("Invalid input string length");
+        }
+        GesturePath.Builder builder = new GesturePath.Builder();
+
+        float[] xyz = new float[3];
+        for (int i = 0; i < bytes.length; i += 12) {
+            for (int j = 0; j < 3; j++) {
+                xyz[j] = Float.intBitsToFloat(
+                                (bytes[i + j * 4] & 0xFF) << 24 |
+                                (bytes[i + j * 4 + 1] & 0xFF) << 16 |
+                                (bytes[i + j * 4 + 2] & 0xFF) << 8 |
+                                (bytes[i + j * 4 + 3] & 0xFF)
+                );
+            }
+            builder.addVector(new Vector3f(
+                    xyz[0], xyz[1], xyz[2]
+            ));
+        }
+        return builder.build();
+    }
+
 }

code/src/Fitbot/app/src/main/java/com/example/fitbot/exercise/exercises/BicepCurlExercise.java

@@ -1,45 +0,0 @@
-package com.example.fitbot.exercise.exercises;
-
-import com.example.fitbot.exercise.AbstractExercise;
-import com.example.fitbot.exercise.EExerciseType;
-import com.example.fitbot.exercise.EMuscleGroup;
-import com.example.fitbot.exercise.FitnessManager;
-import com.example.fitbot.util.server.WebSocket;
-
-import java.net.Socket;
-
-public class BicepCurlExercise extends AbstractExercise {
-
-    private static final String UNIQUE_ID = "bicep_curl";
-
-    /**
-     * Constructor for the BicepCurlExercise class.
-     */
-    public BicepCurlExercise() {
-        super(
-                new EMuscleGroup[] { EMuscleGroup.ARMS },
-                EExerciseType.POWER,
-                FitnessManager.acquirePath(UNIQUE_ID)
-        );
-    }
-
-    @Override
-    public boolean isActivityFinished() {
-        return false;
-    }
-
-    @Override
-    public void onStopExercise() {
-
-    }
-
-    @Override
-    public void onMessageReceived(WebSocket.Message message, WebSocket.MessageReply replier) {
-
-    }
-
-    @Override
-    public void onError(Socket socket, String error) {
-
-    }
-}