Add welcome screen for first-time users

Show a welcome screen on first launch and add a GSettings key to track
first boot. Integrate WelcomeScreen into application startup flow.

Author: lainsce

data/io.github.lainsce.Notejot.gschema.xml

@@ -9,5 +9,10 @@
             <summary>Active map source</summary>
             <description>The type of the map last used</description>
         </key>
+        <key type="b" name="is-first-boot">
+            <default>true</default>
+            <summary>First run indicator</summary>
+            <description>Whether to show the welcome screen on startup</description>
+        </key>
 	</schema>
 </schemalist>

meson.build

@@ -41,6 +41,7 @@ sources = [
   'src/ReminderService.vala',
   'src/SettingsWindow.vala',
   'src/SettingsManager.vala',
+  'src/WelcomeScreen.vala',
 ]
 
 dependencies = [

src/Application.vala

@@ -7,8 +7,11 @@ namespace Notejot {
             { "quit", quit },
         };
 
+        // Hold a strong reference so the welcome window isn't GC'ed
+        private WelcomeScreen? welcome_screen = null;
+
         public NotejotApp () {
-            Object (application_id: "io.github.lainsce.Notejot");
+            Object (application_id : "io.github.lainsce.Notejot");
         }
 
         static construct {
@@ -21,7 +24,40 @@ namespace Notejot {
         }
 
         public override void activate () {
-            this.active_window?.present ();
+            var window = this.active_window;
+            if (window == null) {
+                window = new Window (this);
+            }
+            window.present ();
+
+            if (WelcomeScreen.should_show (settings)) {
+                this.welcome_screen = new WelcomeScreen (window);
+
+                // Make the Gtk.Application own the welcome window as well
+                this.add_window (this.welcome_screen);
+
+                GLib.Idle.add (() => {
+                    // It may have been closed quickly; guard against null
+                    if (this.welcome_screen != null) {
+                        this.welcome_screen.present ();
+                    }
+                    return false;
+                });
+
+                this.welcome_screen.finished.connect (() => {
+                    this.welcome_screen.mark_completed ();
+
+                    // Close the welcome window and drop our reference
+                    this.welcome_screen.close ();
+                    this.welcome_screen = null;
+
+                    this.reminder_service = new ReminderService ();
+                    this.reminder_service.start ();
+                });
+            } else {
+                this.reminder_service = new ReminderService ();
+                this.reminder_service.start ();
+            }
         }
 
         public override void startup () {
@@ -44,19 +80,16 @@ namespace Notejot {
             base.startup ();
 
             add_action_entries (APP_ENTRIES, this);
+            new Window (this);
 
             // React to dark-mode changes
             this.app_css_provider = new Gtk.CssProvider ();
-            var settings = Gtk.Settings.get_default ();
-            if (settings != null) {
-                settings.notify["gtk-application-prefer-dark-theme"].connect (() => {
+            var gsettings = Gtk.Settings.get_default ();
+            if (gsettings != null) {
+                gsettings.notify["gtk-application-prefer-dark-theme"].connect (() => {
                     load_theme_css ();
                 });
             }
-
-            new Window (this);
-            this.reminder_service = new ReminderService ();
-            this.reminder_service.start ();
         }
 
         private void load_theme_css () {

src/WelcomeScreen.vala

@@ -0,0 +1,38 @@
+namespace Notejot {
+    public class WelcomeScreen : He.WelcomeScreen {
+        public signal void finished ();
+
+        public WelcomeScreen (Gtk.Window parent) {
+            Object (parent: parent);
+
+            this.app_name = "Notejot";
+
+            this.add_row (new He.WelcomeRow ("list-add-symbolic",
+                                             _("Create Entries"),
+                                             _("Capture your thoughts quickly with a simple, focused editor."),
+                                             He.Colors.ORANGE));
+
+            this.add_row (new He.WelcomeRow ("tag-symbolic",
+                                             _("Organize with Tags"),
+                                             _("Group related notes with colorful tags and icons."),
+                                             He.Colors.PURPLE));
+
+            this.add_row (new He.WelcomeRow ("alarm-symbolic",
+                                             _("Keep Your Streak"),
+                                             _("Enable reminders to build a daily writing habit."),
+                                             He.Colors.GREEN));
+
+            this.get_start_button ().clicked.connect (() => {
+                this.finished ();
+            });
+        }
+
+        public static bool should_show (GLib.Settings settings) {
+            return settings.get_boolean ("is-first-boot");
+        }
+
+        public void mark_completed () {
+            NotejotApp.settings.set_boolean ("is-first-boot", false);
+        }
+    }
+}