improved IFavorites and TestFavorites

APED/app/src/main/java/com/example/aped/utils/Favorites.java

@@ -1,21 +0,0 @@
-package com.example.aped.utils;
-
-import java.util.List;
-
-public class Favorites implements IFAVORITES{
-
-    @Override
-    public List<String> getFavorites() {
-        return null;
-    }
-
-    @Override
-    public String addFavorite(String deviceName) {
-        return null;
-    }
-
-    @Override
-    public String removeFavorite(String deviceName) {
-        return null;
-    }
-}

APED/app/src/main/java/com/example/aped/utils/IFAVORITES.java

@@ -2,8 +2,28 @@ package com.example.aped.utils;
 
 import java.util.List;
 
+/**
+ * Interface for managing the favorites.
+ */
 public interface IFAVORITES {
+
+    /**
+     * Returns the names of the favorite devices.
+     * @return list of strings
+     */
     List<String> getFavorites();
+
+    /**
+     * Adds a favorite to the list.
+     * @param deviceName the name of the device to be added
+     * @return the name of the device addition worked
+     */
     String addFavorite(String deviceName);
+
+    /**
+     * Removes a device from the favorite list.
+     * @param deviceName the name of the device to be removed
+     * @return the name of the device if the removal worked
+     */
     String removeFavorite(String deviceName);
 }

APED/app/src/main/java/com/example/aped/utils/TestFavorites.java

@@ -0,0 +1,30 @@
+package com.example.aped.utils;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class TestFavorites implements IFAVORITES{
+
+    private List<String> favorites = new ArrayList<>();
+
+    @Override
+    public List<String> getFavorites() {
+        return favorites;
+    }
+
+    @Override
+    public String addFavorite(String deviceName) {
+        if (!favorites.contains(deviceName)) {
+          favorites.add(deviceName);
+        }
+        return deviceName;
+    }
+
+    @Override
+    public String removeFavorite(String deviceName) {
+        if (favorites.contains(deviceName)) {
+           favorites.remove(deviceName);
+        }
+        return deviceName;
+    }
+}