Remove redundant code in checkboxes by using generics and interfaces

app/src/main/java/com/testapp/NavDrawerActivity.java

@@ -26,6 +26,7 @@ import com.google.gson.GsonBuilder;
 import com.testapp.entities.Cuisine;
 import com.testapp.entities.Dish;
 import com.testapp.entities.DishType;
+import com.testapp.entities.Filter;
 import com.testapp.entities.Location;
 import java.io.File;
 import java.io.IOException;
@@ -41,9 +42,7 @@ import retrofit2.Response;
 import retrofit2.Retrofit;
 import retrofit2.converter.gson.GsonConverterFactory;
 
-public class NavDrawerActivity extends AppCompatActivity
-        implements NavigationView.OnNavigationItemSelectedListener {
-
+public class NavDrawerActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener {
 
     private CanteeneoApiInterface service;
     private static Context c;
@@ -104,81 +103,35 @@ public class NavDrawerActivity extends AppCompatActivity
         String message = intent.getStringExtra(LoginActivity.EXTRA_MESSAGE);
         Toast.makeText(NavDrawerActivity.this, message, Toast.LENGTH_SHORT).show();
 
-        populateDishTypeFilters();
-        populateCuisineFilters();
-        populateLocationFilters();
+        populateFilter(service.getDishTypes(), R.id.type_checkboxes);
+        populateFilter(service.getCuisines(), R.id.cuisine_checkboxes);
+        populateFilter(service.getLocations(), R.id.location_checkboxes);
     }
 
-    public void populateDishTypeFilters() {
-        final LinearLayout type_checkboxes = (LinearLayout)findViewById(R.id.type_checkboxes);
-        type_checkboxes.removeAllViewsInLayout();
-
-        Call<List<DishType>> call = service.getDishTypes();
-        call.enqueue(new Callback<List<DishType>>() {
-            @Override
-            public void onResponse(Call<List<DishType>> call, Response<List<DishType>> response) {
-                List<DishType> types = response.body();
-                LayoutInflater checkboxInflater = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
-                for(DishType t: types) {
-                    CheckBox checkbox = (CheckBox)checkboxInflater.inflate(R.layout.search_checkbox, null);
-                    checkbox.setId(t.getId());
-                    checkbox.setText(t.getName());
-                    type_checkboxes.addView(checkbox);
-                }
-            }
+    public <T extends Filter> void populateFilter(Call<List<T>> call, int layout_id) {
+        final LinearLayout checkboxes = (LinearLayout)findViewById(layout_id);
+        checkboxes.removeAllViewsInLayout();
 
+        call.enqueue(new Callback<List<T>>() {
             @Override
-            public void onFailure(Call<List<DishType>> call, Throwable t) {
+            public void onResponse(Call<List<T>> call, Response<List<T>> response) {
+                List<T> filters = response.body();
+                LayoutInflater inflater = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
+                for(T filter: filters) {
+                    CheckBox checkbox = (CheckBox)inflater.inflate(R.layout.search_checkbox, null);
+                    checkbox.setId(filter.getId());
+                    checkbox.setText(filter.getName());
+                    checkbox.setChecked(true);
+                    checkboxes.addView(checkbox);
                 }
-        });
             }
 
-    public void populateCuisineFilters() {
-        final LinearLayout cuisine_checkboxes = (LinearLayout)findViewById(R.id.cuisine_checkboxes);
-        cuisine_checkboxes.removeAllViewsInLayout();
-
-        Call<List<Cuisine>> call = service.getCuisines();
-        call.enqueue(new Callback<List<Cuisine>>() {
             @Override
-            public void onResponse(Call<List<Cuisine>> call, Response<List<Cuisine>> response) {
-                List<Cuisine> cuisines = response.body();
-                LayoutInflater checkboxInflater = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
-                for(Cuisine c: cuisines) {
-                    CheckBox checkbox = (CheckBox)checkboxInflater.inflate(R.layout.search_checkbox, null);
-                    checkbox.setId(c.getId());
-                    checkbox.setText(c.getName());
-                    cuisine_checkboxes.addView(checkbox);
-                }
-            }
+            public void onFailure(Call<List<T>> call, Throwable t) {
 
-            @Override
-            public void onFailure(Call<List<Cuisine>> call, Throwable t) {
             }
         });
-    }
-
-    public void populateLocationFilters() {
-        final LinearLayout location_checkboxes = (LinearLayout)findViewById(R.id.location_checkboxes);
-        location_checkboxes.removeAllViewsInLayout();
 
-        Call<List<Location>> call = service.getLocations();
-        call.enqueue(new Callback<List<Location>>() {
-            @Override
-            public void onResponse(Call<List<Location>> call, Response<List<Location>> response) {
-                List<Location> locations = response.body();
-                LayoutInflater checkboxInflater = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
-                for(Location l: locations) {
-                    CheckBox checkbox = (CheckBox)checkboxInflater.inflate(R.layout.search_checkbox, null);
-                    checkbox.setId(l.getId());
-                    checkbox.setText(l.getName());
-                    location_checkboxes.addView(checkbox);
-                }
-            }
-
-            @Override
-            public void onFailure(Call<List<Location>> call, Throwable t) {
-            }
-        });
     }
 
 

app/src/main/java/com/testapp/entities/Cuisine.java

 package com.testapp.entities;
 
-public class Cuisine {
+public class Cuisine implements Filter {
 
     int id;
     String name;

app/src/main/java/com/testapp/entities/DishType.java

 package com.testapp.entities;
 
-public class DishType {
+public class DishType implements Filter {
 
     int id;
     String name;

app/src/main/java/com/testapp/entities/Filter.java

+package com.testapp.entities;
+
+public interface Filter {
+    int getId();
+    void setId(int id);
+    String getName();
+    void setName(String name);
+}

app/src/main/java/com/testapp/entities/Location.java

 package com.testapp.entities;
 
-public class Location {
+public class Location implements Filter {
 
     int id;
     String name;

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

@@ -85,7 +85,6 @@
                     android:layout_width="match_parent"
                     android:layout_height="match_parent">
 
-
                 </LinearLayout>
 
                 <TextView

app/src/main/res/values/strings.xml

@@ -26,9 +26,6 @@
     <string name="drawer_5_2">  JSEC</string>
     <string name="drawer_5_3">  Zekaf</string>
     <string name="drawer_6">Cuisine</string>
-    <string name="drawer_6_1">  American</string>
-    <string name="drawer_6_2">  Japanese</string>
-    <string name="drawer_6_3">  Chinese</string>
     <string name="hint_search">Search</string>
 
     <string name="navigation_drawer_open">Open navigation drawer</string>