Adding some dependencies to use sqlite database librairies

.idea/gradle.xml

@@ -5,6 +5,7 @@
     <option name="linkedExternalProjectsSettings">
       <GradleProjectSettings>
         <option name="testRunner" value="PLATFORM" />
+        <option name="disableWrapperSourceDistributionNotification" value="true" />
         <option name="distributionType" value="DEFAULT_WRAPPED" />
         <option name="externalProjectPath" value="$PROJECT_DIR$" />
         <option name="gradleJvm" value="1.8" />

app/build.gradle

@@ -38,4 +38,6 @@ dependencies {
     testImplementation 'junit:junit:4.+'
     androidTestImplementation 'androidx.test.ext:junit:1.1.1'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
+    implementation "androidx.room:room-runtime:2.2.5"
+    annotationProcessor "androidx.room:room-compiler:2.2.5"
 }

app/src/main/AndroidManifest.xml

@@ -9,7 +9,8 @@
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/Theme.MyWeather">
-        <!-- Adding an attribute to remove the app bar only in the activity that allows the user to add a city-->
+        <!-- Adding an attribute to remove the app bar (.NoActionBar) only in the activity that allows the user to add a city, also declaring
+        the mainActivity as a parent of AddCity activity in order to go back to the mainActivity screen-->
         <activity android:name=".AddCity"
             android:parentActivityName=".MainActivity"
             android:theme="@style/Theme.MyWeather.NoActionBar">
@@ -17,7 +18,6 @@
         <activity android:name=".MainActivity">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
-
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>

app/src/main/java/fr/romanet/vj/apps/myweather/AddCity.java

@@ -2,41 +2,55 @@ package fr.romanet.vj.apps.myweather;
 
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.appcompat.widget.Toolbar;
-
 import android.os.Bundle;
 import android.view.View;
 import android.widget.Button;
 import android.widget.EditText;
-
+import fr.romanet.vj.apps.myweather.bo.City;
-import com.google.android.material.floatingactionbutton.FloatingActionButton;
+import fr.romanet.vj.apps.myweather.repository.CityRepository;
 
 public class AddCity extends AppCompatActivity {
 
+    private EditText cityName;
+
     @Override
     protected void onCreate(Bundle savedInstanceState)
     {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.add_city_page);
+
         Toolbar toolbarAddCity = (Toolbar) findViewById(R.id.toolbarAddCity);
         setSupportActionBar(toolbarAddCity);
+
         getSupportActionBar().setDisplayHomeAsUpEnabled(true);
         getSupportActionBar().setDisplayShowHomeEnabled(true);
+
         Button button = (Button) findViewById(R.id.btnSaveCity);
-        button.setOnClickListener(new View.OnClickListener() {
+        button.setOnClickListener(new View.OnClickListener()
-            public void onClick(View v) {
-                EditText editTextnewCity =  (EditText) findViewById(R.id.editTextNewCity);
-                String newCity = (String) editTextnewCity.getText().toString();
-                if(editTextnewCity.length() == 0)
         {
-                    editTextnewCity.setError("Please, enter a city name");
+            public void onClick(View v)
+            {
+                cityName =  (EditText) findViewById(R.id.editTextNewCity);
+                final String newCityString = cityName.getEditableText().toString();
+                if(newCityString.length() == 0)
+                {
+                    cityName.setError("Please, enter a city name");
                 }
                 else
-                    System.out.println(newCity);
+                    saveCity(newCityString);
-                    //Ajoute la ville a une base de données
+                    resetForm();
-                //Prélève le texte avec le get
-                    //S'il est vide on l'alert et on fais rien
-                        //Sinon écran d'accueil qui change
             }
         });
     }
+
+    private void resetForm()
+    {
+        cityName.setText(null);
+    }
+
+    private void saveCity(String cityName)
+    {
+        CityRepository.getInstance(this).addCity(new City(cityName));
+    }
+
 }

app/src/main/java/fr/romanet/vj/apps/myweather/ICityService.java

@@ -0,0 +1,32 @@
+package fr.romanet.vj.apps.myweather;
+
+import java.util.List;
+import fr.romanet.vj.apps.myweather.bo.City;
+
+//Interface used in order to implement correctly the repository pattern
+public interface ICityService
+{
+    /**
+     * Get all the city
+     * @return {@link List}
+     */
+    List<City> getCity();
+
+    /**
+     * Deletes a city
+     * @param cityToDelete
+     */
+    void deleteCity(City cityToDelete);
+
+    /**
+     * Add a city
+     * @param cityToAdd
+     */
+    void addCity(City cityToAdd);
+
+    /**
+     * Get all cities sorted by name
+     * @return {@link List}
+     */
+    List<City> sortCityByName();
+}

app/src/main/java/fr/romanet/vj/apps/myweather/MainActivity.java

@@ -2,11 +2,8 @@ package fr.romanet.vj.apps.myweather;
 
 import android.content.*;
 import androidx.appcompat.app.AppCompatActivity;
-import androidx.appcompat.widget.Toolbar;
-
 import android.os.Bundle;
 import android.view.View;
-
 import com.google.android.material.floatingactionbutton.FloatingActionButton;
 
 public class MainActivity extends AppCompatActivity {

app/src/main/java/fr/romanet/vj/apps/myweather/bo/City.java

@@ -0,0 +1,82 @@
+package fr.romanet.vj.apps.myweather.bo;
+
+import androidx.annotation.NonNull;
+import androidx.room.Entity;
+import androidx.room.PrimaryKey;
+import java.io.Serializable;
+import java.util.Comparator;
+import java.util.Objects;
+
+//This class is used in order to represent a city
+@Entity
+final public class City implements Serializable
+{
+    //Class CityComparator that implements Comparator interface in order to compare two cities
+    public static final class CityComparator implements Comparator<City>
+    {
+        /**
+         * Compare function that compare two city by their name
+         * @param o1 The first city to compare
+         * @param o2 Second city to compare with the first
+         * @return
+         */
+        @Override
+        public int compare(City o1, City o2)
+        {
+            return o1.nameCity.compareTo(o2.nameCity);
+        }
+
+    }
+
+    /**
+     * The primary key of the city in our datbase which is automatically incremented
+     */
+    @PrimaryKey(autoGenerate = true)
+    public int id;
+
+    /**
+     * The name of the city
+     */
+    @NonNull
+    public String nameCity;
+
+    /**
+     * Constructor of the city class
+     * @param nameCity The name of the new city
+     */
+    public City(@NonNull String nameCity)
+    {
+        id = 0;
+        this.nameCity = nameCity;
+    }
+
+    /**
+     * Equals function that return true or false weither both name are same and both object belongs to City class
+     * @param o The object to compare
+     * @return true or false
+     */
+    @Override
+    public boolean equals(Object o) {
+        if (this == o)
+        {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass())
+        {
+            return false;
+        }
+        City city1 = (City) o;
+
+        return nameCity.equals(city1.nameCity);
+    }
+
+    /**
+     * hashCode function
+     * @return Clé de hashage (int)
+     */
+    @Override
+    public int hashCode()
+    {
+        return Objects.hash(nameCity);
+    }
+}

app/src/main/java/fr/romanet/vj/apps/myweather/dao/CityDao.java

@@ -0,0 +1,30 @@
+package fr.romanet.vj.apps.myweather.dao;
+
+import androidx.room.Dao;
+import androidx.room.Delete;
+import androidx.room.Insert;
+import androidx.room.OnConflictStrategy;
+import androidx.room.Query;
+import fr.romanet.vj.apps.myweather.ICityService;
+import fr.romanet.vj.apps.myweather.bo.City;
+import java.util.List;
+
+@Dao
+public interface CityDao extends ICityService
+{
+    @Override
+    @Query("SELECT * FROM City")
+    List<City> getCity();
+
+    @Override
+    @Delete
+    void deleteCity(City cityToDelete);
+
+    @Override
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    void addCity(City cityToAdd);
+
+    @Override
+    @Query("SELECT * FROM City ORDER BY nameCity DESC")
+    List<City> sortCityByName();
+}

app/src/main/java/fr/romanet/vj/apps/myweather/database/CityDatabase.java

@@ -0,0 +1,13 @@
+package fr.romanet.vj.apps.myweather.database;
+
+import androidx.room.Database;
+import androidx.room.RoomDatabase;
+
+import fr.romanet.vj.apps.myweather.bo.City;
+import fr.romanet.vj.apps.myweather.dao.CityDao;
+
+@Database(entities = { City.class }, version = 1)
+public abstract class CityDatabase extends RoomDatabase
+{
+    public abstract CityDao cityDao();
+}

app/src/main/java/fr/romanet/vj/apps/myweather/repository/CityRepository.java

@@ -0,0 +1,56 @@
+package fr.romanet.vj.apps.myweather.repository;
+
+import android.content.Context;
+import androidx.room.Room;
+import java.util.List;
+import fr.romanet.vj.apps.myweather.bo.City;
+import fr.romanet.vj.apps.myweather.database.CityDatabase;
+
+public final class CityRepository
+{
+    private static volatile CityRepository instance;
+
+    // We accept the "out-of-order writes" case
+    public static CityRepository getInstance(Context context)
+    {
+        if (instance == null)
+        {
+            synchronized (CityRepository.class)
+            {
+                if (instance == null)
+                {
+                    instance = new CityRepository(context);
+                }
+            }
+        }
+        return instance;
+    }
+
+    private final CityDatabase cityDatabase;
+
+    private CityRepository(Context context)
+    {
+        cityDatabase = Room.databaseBuilder(context, CityDatabase.class, "city-database").allowMainThreadQueries().build();
+    }
+
+    public List<City> getCity()
+    {
+        return cityDatabase.cityDao().getCity();
+    }
+
+    public void deleteCity(City cityToDelete)
+    {
+        cityDatabase.cityDao().deleteCity(cityToDelete);
+    }
+
+    public void addCity(City cityToAdd)
+    {
+        cityDatabase.cityDao().addCity(cityToAdd);
+    }
+
+    public List<City> sortCityByName()
+    {
+        return cityDatabase.cityDao().sortCityByName();
+    }
+
+}