Add SharedPreferences to handle global behaviour. First use is "Hiding umbrella ImageView when new city is added into the DB"

.idea/render.experimental.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="RenderSettings">
+    <option name="showDecorations" value="true" />
+  </component>
+</project>

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

@@ -2,6 +2,9 @@ package fr.romanet.vj.apps.myweather;
 
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.appcompat.widget.Toolbar;
+
+import android.content.Context;
+import android.content.SharedPreferences;
 import android.os.Bundle;
 import android.view.View;
 import android.widget.Button;
@@ -13,6 +16,10 @@ public class AddCity extends AppCompatActivity {
 
     private EditText cityName;
 
+    // - Define shared preferences var -
+    SharedPreferences sharedPreferences;
+
+
     @Override
     protected void onCreate(Bundle savedInstanceState)
     {
@@ -37,8 +44,21 @@ public class AddCity extends AppCompatActivity {
                     cityName.setError("Please, enter a city name");
                 }
                 else
+
+                    // - Load Shared Preferences (named 'prefs') -
+                    sharedPreferences = getSharedPreferences("prefs", Context.MODE_PRIVATE);
+
+                    // - Now the ImageView has to be hidden, so write it into the shared preferences -
+                    // - Put value '0' into the preference 'umbrella_visible' of the shared preference book called 'prefs'
+                    SharedPreferences.Editor editor = sharedPreferences.edit();
+                    editor.putInt("umbrella_visible", 0);
+                    editor.apply();
+
                     saveCity(newCityString);
                     resetForm();
+
+
+
             }
         });
     }

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

@@ -3,11 +3,24 @@ package fr.romanet.vj.apps.myweather;
 import android.content.*;
 import androidx.appcompat.app.AppCompatActivity;
 import android.os.Bundle;
+import android.util.Log;
 import android.view.View;
+import android.widget.ImageView;
+
 import com.google.android.material.floatingactionbutton.FloatingActionButton;
 
 public class MainActivity extends AppCompatActivity {
 
+    // - Umbrella ImageView
+    public static ImageView imgPara;
+
+    // - Is used to store the shared preference value of umbrella visibility
+    public int umbrella_visible;
+
+    // - Define shared preferences var -
+    SharedPreferences sharedPreferences;
+
+
     @Override
     protected void onCreate(Bundle savedInstanceState)
     {
@@ -21,6 +34,46 @@ public class MainActivity extends AppCompatActivity {
                 openAddCityPage();
             }
         });
+
+        // - Assign Activity ImageView to var -
+        imgPara = (ImageView) findViewById(R.id.imageView);
+
+        // - Load Shared Preferences (named 'prefs') -
+        sharedPreferences = getSharedPreferences("prefs", Context.MODE_PRIVATE);
+
+        // - Try to retrieve 'umbrella_visible', if not set return 3 -
+        umbrella_visible = sharedPreferences.getInt("umbrella_visible", 3);
+
+        // - If preference not yet defined, set value to 1 (visible) -
+        if (umbrella_visible == 3){
+
+            // - Put value '1' into the preference 'umbrella_visible' of the shared preference book called 'prefs'
+            SharedPreferences.Editor editor = sharedPreferences.edit();
+            editor.putInt("umbrella_visible", 1);
+            editor.apply();
+        }
+
+        Log.d("DEBUG1 -> create", Integer.toString(umbrella_visible));
+
+    }
+
+    @Override
+    protected void onResume() {
+        super.onResume();
+
+        // - Load Shared Preferences (named 'prefs') -
+        sharedPreferences = getSharedPreferences("prefs", Context.MODE_PRIVATE);
+
+        // - Try to retrieve 'umbrella_visible', if not set return 3 -
+        umbrella_visible = sharedPreferences.getInt("umbrella_visible", 3);
+        Log.d("DEBUG1 -> resume", Integer.toString(umbrella_visible));
+
+        // - If 'umbrella_visible' is equal to '0', we have to hide the ImageView -
+        if(umbrella_visible == 0){
+
+            // - Hide ImageView -
+            imgPara.setVisibility(View.GONE);
+        }
     }
 
     public void openAddCityPage()