Modyfing the id of our components

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

@@ -4,6 +4,11 @@ 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 com.google.android.material.floatingactionbutton.FloatingActionButton;
 
 public class AddCity extends AppCompatActivity {
 
@@ -16,5 +21,22 @@ public class AddCity extends AppCompatActivity {
         setSupportActionBar(toolbarAddCity);
         getSupportActionBar().setDisplayHomeAsUpEnabled(true);
         getSupportActionBar().setDisplayShowHomeEnabled(true);
+        Button button = (Button) findViewById(R.id.btnSaveCity);
+        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");
+                }
+                else
+                    System.out.println(newCity);
+                    //Ajoute la ville a une base de données
+                //Prélève le texte avec le get
+                    //S'il est vide on l'alert et on fais rien
+                        //Sinon écran d'accueil qui change
+            }
+        });
     }
 }

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

@@ -16,8 +16,8 @@ public class MainActivity extends AppCompatActivity {
     {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
-        FloatingActionButton buttonAddCity = (FloatingActionButton) findViewById(R.id.fab);
-        buttonAddCity.setOnClickListener(new View.OnClickListener() {
+        FloatingActionButton buttonPlus = (FloatingActionButton) findViewById(R.id.plusButton);
+        buttonPlus.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View view)
             {

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

@@ -30,11 +30,11 @@
         android:gravity="center"
         android:text="@string/firstAction"
         android:textSize="20sp"
-        app:layout_constraintBottom_toTopOf="@+id/fab"
+        app:layout_constraintBottom_toTopOf="@+id/plusButton"
         tools:layout_editor_absoluteX="89dp" />
 
     <com.google.android.material.floatingactionbutton.FloatingActionButton
-        android:id="@+id/fab"
+        android:id="@+id/plusButton"
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintEnd_toEndOf="parent"
         android:layout_width="wrap_content"

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

@@ -45,7 +45,7 @@
         android:layout_height="100dp" />
 
     <EditText
-        android:id="@+id/editText"
+        android:id="@+id/editTextNewCity"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:layout_marginLeft="10dp"
@@ -58,7 +58,7 @@
         android:layout_height="90dp" />
 
     <Button
-        android:id="@+id/btnSave"
+        android:id="@+id/btnSaveCity"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:layout_marginLeft="10dp"