Add mock settings activity.

NucuHub.Android/app/build.gradle

@@ -51,6 +51,7 @@ dependencies {
     implementation 'androidx.navigation:navigation-fragment:2.1.0'
     implementation 'androidx.navigation:navigation-ui:2.1.0'
     implementation 'androidx.lifecycle:lifecycle-extensions:2.1.0'
+    implementation 'androidx.preference:preference:1.1.0'
     testImplementation 'junit:junit:4.12'
     androidTestImplementation 'androidx.test.ext:junit:1.1.1'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'

NucuHub.Android/app/src/main/AndroidManifest.xml

@@ -2,15 +2,21 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
           package="dev.nuculabs.nucuhub">
 
-    <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.INTERNET"/>
 
     <application
             android:allowBackup="true"
+            android:fullBackupContent="@xml/backup_rules"
             android:icon="@mipmap/ic_launcher"
             android:label="@string/app_name"
             android:roundIcon="@mipmap/ic_launcher_round"
             android:supportsRtl="true"
             android:theme="@style/AppTheme">
+        <activity
+                android:name=".SettingsActivity"
+                android:label="@string/title_activity_settings"
+                android:theme="@style/AppTheme.NoActionBar">
+        </activity>
         <activity
                 android:name=".MainActivity"
                 android:label="@string/app_name"

NucuHub.Android/app/src/main/java/dev/nuculabs/nucuhub/MainActivity.java

@@ -1,7 +1,10 @@
 package dev.nuculabs.nucuhub;
 
+import android.content.Intent;
 import android.os.Bundle;
 import android.view.Menu;
+import android.view.MenuItem;
+import android.view.View;
 import com.google.android.material.navigation.NavigationView;
 import androidx.navigation.NavController;
 import androidx.navigation.Navigation;
@@ -44,10 +47,25 @@ public class MainActivity extends AppCompatActivity {
         return true;
     }
 
+    @Override
+    public boolean onOptionsItemSelected(MenuItem item) {
+        // Handle item selection
+        if (item.getItemId() == R.id.action_settings) {
+            startSettingsActivity();
+            return true;
+        }
+        return super.onOptionsItemSelected(item);
+    }
+
     @Override
     public boolean onSupportNavigateUp() {
         NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment);
         return NavigationUI.navigateUp(navController, mAppBarConfiguration)
                 || super.onSupportNavigateUp();
     }
+
+    private void startSettingsActivity() {
+        Intent intent = new Intent(this, SettingsActivity.class);
+        startActivity(intent);
+    }
 }

NucuHub.Android/app/src/main/java/dev/nuculabs/nucuhub/SettingsActivity.java

@@ -0,0 +1,47 @@
+package dev.nuculabs.nucuhub;
+
+import android.os.Bundle;
+import android.view.MenuItem;
+import androidx.appcompat.app.ActionBar;
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.appcompat.widget.Toolbar;
+import androidx.preference.PreferenceFragmentCompat;
+
+public class SettingsActivity extends AppCompatActivity {
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.settings_activity);
+        getSupportFragmentManager()
+                .beginTransaction()
+                .replace(R.id.settings, new SettingsFragment())
+                .commit();
+
+        // This activity has a no toolbar style. We've duplicate code in order to implement our own Toolbar.
+        Toolbar toolbar = findViewById(R.id.toolbar);
+        setSupportActionBar(toolbar);
+
+        ActionBar actionBar = getSupportActionBar();
+        if (actionBar != null) {
+            actionBar.setDisplayHomeAsUpEnabled(true);
+        }
+    }
+
+    @Override
+    public boolean onOptionsItemSelected(MenuItem item) {
+        if (item.getItemId()==android.R.id.home) {
+            finish();
+            return true;
+        }
+
+        return super.onOptionsItemSelected(item);
+    }
+
+    public static class SettingsFragment extends PreferenceFragmentCompat {
+        @Override
+        public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
+            setPreferencesFromResource(R.xml.root_preferences, rootKey);
+        }
+    }
+}

NucuHub.Android/app/src/main/res/layout/settings_activity.xml

@@ -0,0 +1,34 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.coordinatorlayout.widget.CoordinatorLayout
+        xmlns:android="http://schemas.android.com/apk/res/android"
+        xmlns:app="http://schemas.android.com/apk/res-auto"
+        xmlns:tools="http://schemas.android.com/tools"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        tools:context=".MainActivity">
+
+    <com.google.android.material.appbar.AppBarLayout
+            android:layout_height="wrap_content"
+            android:layout_width="match_parent"
+            android:theme="@style/AppTheme.AppBarOverlay">
+
+        <androidx.appcompat.widget.Toolbar
+                android:id="@+id/toolbar"
+                android:layout_width="match_parent"
+                android:layout_height="?attr/actionBarSize"
+                android:background="?attr/colorPrimary"
+                app:popupTheme="@style/AppTheme.PopupOverlay"/>
+
+    </com.google.android.material.appbar.AppBarLayout>
+
+    <LinearLayout
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            android:orientation="vertical">
+
+        <FrameLayout
+                android:id="@+id/settings"
+                android:layout_width="match_parent"
+                android:layout_height="match_parent"/>
+    </LinearLayout>
+</androidx.coordinatorlayout.widget.CoordinatorLayout>

NucuHub.Android/app/src/main/res/values/arrays.xml

@@ -0,0 +1,12 @@
+<resources>
+    <!-- Reply Preference -->
+    <string-array name="reply_entries">
+        <item>Reply</item>
+        <item>Reply to all</item>
+    </string-array>
+
+    <string-array name="reply_values">
+        <item>reply</item>
+        <item>reply_all</item>
+    </string-array>
+</resources>

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

@@ -7,10 +7,11 @@
     <string name="nav_header_subtitle">denis@nuculabs.dev</string>
     <string name="nav_header_desc">Navigation header</string>
     <string name="action_settings">Settings</string>
-
-    <string name="menu_environment_sensor">Environment Sensor</string>
     <string name="menu_gallery">Gallery</string>
     <string name="menu_slideshow">Slideshow</string>
+
+    <!-- Environment Sensor Data -->
+    <string name="menu_environment_sensor">Environment Sensor</string>
     <string name="humidity_icon_desc">humidity image</string>
     <string name="temperature_icon_desc">temperature icon</string>
     <string name="barometer_icon_desc">barometer icon</string>
@@ -19,4 +20,19 @@
     <string name="temp_sensor_unit">Celsius</string>
     <string name="pressure_unit_desc">hPa</string>
     <string name="gasvoc_sensor_unit_descriptio">VOC kΩ</string>
+    <string name="title_activity_settings">SettingsActivity</string>
+
+    <!-- Preference Titles -->
+    <string name="messages_header">Messages</string>
+    <string name="sync_header">Sync</string>
+
+    <!-- Messages Preferences -->
+    <string name="signature_title">Your signature</string>
+    <string name="reply_title">Default reply action</string>
+
+    <!-- Sync Preferences -->
+    <string name="sync_title">Sync email periodically</string>
+    <string name="attachment_title">Download incoming attachments</string>
+    <string name="attachment_summary_on">Automatically download attachments for incoming emails</string>
+    <string name="attachment_summary_off">Only download attachments when manually requested</string>
 </resources>

NucuHub.Android/app/src/main/res/values/styles.xml

@@ -5,12 +5,12 @@
         <item name="colorPrimary">@color/colorPrimary</item>
         <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
         <item name="colorAccent">@color/colorAccent</item>
+
     </style>
     <style name="AppTheme.NoActionBar">
         <item name="windowActionBar">false</item>
         <item name="windowNoTitle">true</item>
     </style>
-    <style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar"/>
+    <style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark"/>
-    <style name="AppTheme.PopupOverlay" parent="ThemeOverlay.AppCompat.Light"/>
+    <style name="AppTheme.PopupOverlay" parent="ThemeOverlay.AppCompat.Dark"/>
-
 </resources>

NucuHub.Android/app/src/main/res/xml/backup_rules.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- https://developer.android.com/guide/topics/data/autobackup-->
+<full-backup-content>
+    <include domain="sharedpref" path="." requireFlags="clientSideEncryption" />
+</full-backup-content>

NucuHub.Android/app/src/main/res/xml/root_preferences.xml

@@ -0,0 +1,38 @@
+<PreferenceScreen
+        xmlns:app="http://schemas.android.com/apk/res-auto">
+
+    <PreferenceCategory
+            app:title="@string/messages_header">
+
+        <EditTextPreference
+                app:key="signature"
+                app:title="@string/signature_title"
+                app:useSimpleSummaryProvider="true"/>
+
+        <ListPreference
+                app:key="reply"
+                app:title="@string/reply_title"
+                app:entries="@array/reply_entries"
+                app:entryValues="@array/reply_values"
+                app:defaultValue="reply"
+                app:useSimpleSummaryProvider="true"/>
+
+    </PreferenceCategory>
+
+    <PreferenceCategory
+            app:title="@string/sync_header">
+
+        <SwitchPreferenceCompat
+                app:key="sync"
+                app:title="@string/sync_title"/>
+
+        <SwitchPreferenceCompat
+                app:key="attachment"
+                app:title="@string/attachment_title"
+                app:summaryOn="@string/attachment_summary_on"
+                app:summaryOff="@string/attachment_summary_off"
+                app:dependency="sync"/>
+
+    </PreferenceCategory>
+
+</PreferenceScreen>