MainActivity class : make the connection between first and second screen for the moment

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

@@ -1,14 +1,33 @@
 package fr.romanet.vj.apps.myweather;
 
+import android.widget.Button;
+import android.content.*;
 import androidx.appcompat.app.AppCompatActivity;
-
 import android.os.Bundle;
+import android.view.View;
 
 public class MainActivity extends AppCompatActivity {
 
+    private Button buttonAddCity;
+
     @Override
-    protected void onCreate(Bundle savedInstanceState) {
+    protected void onCreate(Bundle savedInstanceState)
+    {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
+
+        buttonAddCity = (Button) findViewById(R.id.fab);
+        buttonAddCity.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View view) {
+                openAddCityPage();
+            }
+        });
+    }
+
+    public void openAddCityPage()
+    {
+        Intent intent = new Intent(this, AddCity.class);
+        startActivity(intent);
     }
 }