Expose system document font in Preferences dialog

src/Application.vala

@@ -28,7 +28,8 @@ namespace Scratch {
 
     public class Application : Gtk.Application {
         public string data_home_folder_unsaved { get { return _data_home_folder_unsaved; } }
-        public string default_font { get; set; }
+        public string system_monospace_font { get; set; }
+        public string system_document_font { get; set; }
         public bool is_running_in_flatpak { get; construct; }
 
         private static string _data_home_folder_unsaved;
@@ -66,11 +67,13 @@ namespace Scratch {
             add_main_option_entries (ENTRIES);
 
             // Init settings
-            default_font = new GLib.Settings ("org.gnome.desktop.interface").get_string ("monospace-font-name");
             saved_state = new GLib.Settings (Constants.PROJECT_NAME + ".saved-state");
             settings = new GLib.Settings (Constants.PROJECT_NAME + ".settings");
             service_settings = new GLib.Settings (Constants.PROJECT_NAME + ".services");
             privacy_settings = new GLib.Settings ("org.gnome.desktop.privacy");
+            var desktop_interface_settings = new GLib.Settings ("org.gnome.desktop.interface");
+            desktop_interface_settings.bind ("document-font-name", this, "system-document-font", GET);
+            desktop_interface_settings.bind ("monospace-font-name", this, "system-monospace-font", GET);
 
             location_jump_manager = new LocationJumpManager ();
             Environment.set_variable ("GTK_USE_PORTAL", "1", true);

src/Dialogs/PreferencesDialog.vala

@@ -117,13 +117,21 @@ public class Scratch.Dialogs.Preferences : Granite.Dialog {
         editor_box.add (new SettingSwitch (_("Line width guide"), "show-right-margin"));
         editor_box.add (right_margin_position);
 
+
+        var application = ((Scratch.Application) (GLib.Application.get_default ()));
+        var font_switch = new SettingSwitch (
+            _("Use system font (%s)").printf (application.system_document_font),
+            "use-system-font"
+        );
+        // We assume the system font will not change while dialog open
+
         var select_font = new Gtk.FontButton ();
         Scratch.settings.bind ("font", select_font, "font-name", DEFAULT);
         Scratch.settings.bind ("use-system-font", select_font, "sensitive", INVERT_BOOLEAN);
 
         var font_box = new Gtk.Box (VERTICAL, 12);
         font_box.add (new Granite.HeaderLabel (_("Font")));
-        font_box.add (new SettingSwitch (_("Use system font"), "use-system-font"));
+        font_box.add (font_switch);
         font_box.add (select_font);
 
         var interface_box = new Gtk.Box (VERTICAL, 24);
@@ -191,7 +199,6 @@ public class Scratch.Dialogs.Preferences : Granite.Dialog {
                 hexpand = true,
                 mnemonic_widget = switch_widget
             };
-
             column_spacing = 12;
             attach (label_widget, 0, 0);
             attach (switch_widget, 1, 0, 1, 2);

src/MainWindow.vala

@@ -930,13 +930,13 @@ namespace Scratch {
         }
 
         public string get_default_font () {
-            string font = app.default_font;
+            string font = app.system_document_font;
             string font_family = font.substring (0, font.last_index_of (" "));
             return font_family;
         }
 
         public double get_default_font_size () {
-            string font = app.default_font;
+            string font = app.system_document_font;
             string font_size = font.substring (font.last_index_of (" ") + 1);
             return double.parse (font_size);
         }

src/Widgets/SourceView.vala

@@ -43,6 +43,8 @@ namespace Scratch.Widgets {
         private double total_delta = 0;
         private const double SCROLL_THRESHOLD = 1.0;
 
+        protected static Scratch.Application application;
+
         public signal void style_changed (Gtk.SourceStyleScheme style);
         // "selection_changed" signal now only emitted when the selected text changes (position ignored).
         // Listened to by searchbar and highlight word selection plugin
@@ -84,6 +86,7 @@ namespace Scratch.Widgets {
         }
 
         construct {
+            application = (Scratch.Application) (GLib.Application.get_default ());
             space_drawer.enable_matrix = true;
 
             expand = true;
@@ -201,6 +204,12 @@ namespace Scratch.Widgets {
                     });
                 }
             });
+
+            application.notify["system-document-font"].connect (() => {
+                if (Scratch.settings.get_boolean ("use-system-font")) {
+                    update_font ();
+                }
+            });
         }
 
         private bool get_current_line (out Gtk.TextIter start, out Gtk.TextIter end) {
@@ -278,8 +287,27 @@ namespace Scratch.Widgets {
                 set_wrap_mode (Gtk.WrapMode.NONE);
             }
 
+            update_font ();
+
+            if (settings.get_boolean ("follow-system-style")) {
+                var system_prefers_dark = Granite.Settings.get_default ().prefers_color_scheme == Granite.Settings.ColorScheme.DARK;
+                if (system_prefers_dark) {
+                    source_buffer.style_scheme = style_scheme_manager.get_scheme ("elementary-dark");
+                } else {
+                    source_buffer.style_scheme = style_scheme_manager.get_scheme ("elementary-light");
+                }
+            } else {
+                var scheme = style_scheme_manager.get_scheme (Scratch.settings.get_string ("style-scheme"));
+                source_buffer.style_scheme = scheme ?? style_scheme_manager.get_scheme ("classic");
+            }
+
+            git_diff_gutter_renderer.set_style_scheme (source_buffer.style_scheme);
+            style_changed (source_buffer.style_scheme);
+        }
+
+        private void update_font () {
             if (Scratch.settings.get_boolean ("use-system-font")) {
-                font = ((Scratch.Application) GLib.Application.get_default ()).default_font;
+                font = application.system_document_font;
             } else {
                 font = Scratch.settings.get_string ("font");
             }
@@ -296,21 +324,6 @@ namespace Scratch.Widgets {
             } catch (Error e) {
                 critical (e.message);
             }
-
-            if (settings.get_boolean ("follow-system-style")) {
-                var system_prefers_dark = Granite.Settings.get_default ().prefers_color_scheme == Granite.Settings.ColorScheme.DARK;
-                if (system_prefers_dark) {
-                    source_buffer.style_scheme = style_scheme_manager.get_scheme ("elementary-dark");
-                } else {
-                    source_buffer.style_scheme = style_scheme_manager.get_scheme ("elementary-light");
-                }
-            } else {
-                var scheme = style_scheme_manager.get_scheme (Scratch.settings.get_string ("style-scheme"));
-                source_buffer.style_scheme = scheme ?? style_scheme_manager.get_scheme ("elementary-highcontrast-light");
-            }
-
-            git_diff_gutter_renderer.set_style_scheme (source_buffer.style_scheme);
-            style_changed (source_buffer.style_scheme);
         }
 
         public void go_to_line (int line, int offset = 0) {
@@ -631,7 +644,7 @@ namespace Scratch.Widgets {
             // Use a default size of 10pt
             double px_per_line = 10 * PT_TO_PX;
 
-            var last_window = ((Scratch.Application) GLib.Application.get_default ()).get_last_window ();
+            var last_window = application.get_last_window ();
             if (last_window != null) {
                 // Get the actual font size
                 px_per_line = last_window.get_current_font_size () * PT_TO_PX;

src/Widgets/Terminal.vala

@@ -22,7 +22,6 @@ public class Code.Terminal : Gtk.Box {
     private const string TERMINAL_FOREGROUND_KEY = "foreground";
     private const string TERMINAL_BACKGROUND_KEY = "background";
     private const string TERMINAL_PALETTE_KEY = "palette";
-    private const string GNOME_FONT_KEY = "monospace-font-name";
     private const string GNOME_BELL_KEY = "audible-bell";
 
     public Vte.Terminal terminal { get; construct; }
@@ -37,7 +36,10 @@ public class Code.Terminal : Gtk.Box {
     private GLib.Pid child_pid;
     private Gtk.Clipboard current_clipboard;
 
+    private Scratch.Application application;
+
     construct {
+        application = (Scratch.Application) (GLib.Application.get_default ());
         terminal = new Vte.Terminal () {
             hexpand = true,
             vexpand = true,
@@ -95,20 +97,11 @@ public class Code.Terminal : Gtk.Box {
             // "org.gnome.desktop.interface.color-scheme"
         }
 
-        // Always monitor changes in default font as that is what Terminal usually follows
-        var gnome_interface_settings_schema = schema_source.lookup (GNOME_DESKTOP_INTERFACE_SCHEMA, true);
-        if (gnome_interface_settings_schema != null) {
-            gnome_interface_settings = new Settings.full (gnome_interface_settings_schema, null, null);
-            gnome_interface_settings.changed.connect ((key) => {
-                switch (key) {
-                    case GNOME_FONT_KEY:
-                        update_font ();
-                        break;
-                    default:
-                        break;
-                }
-            });
-        }
+        // Always monitor changes in systen font as that is what Terminal usually follows
+        // The terminal font key is by default "" and can only be changed by editing the settings externally
+        application.notify["system-monospace-font"].connect (() => {
+            update_font ();
+        });
 
         update_font ();
         update_audible_bell ();
@@ -224,8 +217,8 @@ public class Code.Terminal : Gtk.Box {
             font_name = terminal_settings.get_string (TERMINAL_FONT_KEY);
         }
 
-        if (font_name == "" && gnome_interface_settings != null) {
-            font_name = gnome_interface_settings.get_string (GNOME_FONT_KEY);
+        if (font_name == "" ) {
+            font_name = application.system_monospace_font;
         }
 
         var fd = Pango.FontDescription.from_string (font_name);