[gnome-2048] Create Preferences dialog on the fly.

[Arnaud B. <arnaudb src gnome org>]

commit f53fcb0311eede4611348e369c5abe68ffb52b7f
Author: Arnaud Bonatti <arnaud bonatti gmail com>
Date:   Thu Jan 24 17:10:47 2019 +0100

    Create Preferences dialog on the fly.
    
    No need to create it all the time,
    it should not be opened regularly.

 data/mainwindow.ui   |   4 +-
 src/application.vala | 120 ++++++++++++++++++++++++++-------------------------
 2 files changed, 63 insertions(+), 61 deletions(-)
---
diff --git a/data/mainwindow.ui b/data/mainwindow.ui
index 060489f..623b12e 100644
--- a/data/mainwindow.ui
+++ b/data/mainwindow.ui
@@ -32,7 +32,7 @@
         <property name="title" translatable="yes">GNOME 2048</property>
         <property name="show-close-button">True</property>
         <child>
-          <object class="GtkButton" id="undo-button">
+          <object class="GtkButton">
             <property name="visible">True</property>
             <property name="can-focus">True</property>
             <property name="receives-default">True</property>
@@ -57,7 +57,7 @@
           </packing>
         </child>
         <child>
-          <object class="GtkButton" id="new-game-button">
+          <object class="GtkButton">
             <!-- Translators: button in the headerbar -->
             <property name="label" translatable="yes">_New Game</property>
             <property name="visible">True</property>
diff --git a/src/application.vala b/src/application.vala
index 36acea8..ded407b 100644
--- a/src/application.vala
+++ b/src/application.vala
@@ -35,13 +35,9 @@ public class Application : Gtk.Application
     /* private widgets */
     private Window _window;
     private HeaderBar _header_bar;
-    private Button _undo_button;
-    private Button _new_game_button;
-    private Dialog _preferences_dialog;
     private Dialog _congrats_dialog;
     private Label _congrats_message;
     private Label _score;
-    private ComboBoxText _grid_size_combo;
     private MenuButton _hamburger_button;
 
     private GtkClutter.Embed embed;
@@ -133,7 +129,6 @@ public class Application : Gtk.Application
 
         Builder builder = new Builder ();
         _create_window (builder);
-        _create_preferences_dialog (builder);
         _create_congrats_dialog (builder);
 
         _create_scores ();
@@ -250,11 +245,8 @@ public class Application : Gtk.Application
 
         _score = (Label) builder.get_object ("score");
 
-        _undo_button = (Button) builder.get_object ("undo-button");
         ((SimpleAction) lookup_action ("undo")).set_enabled (false);
 
-        _new_game_button = (Button) builder.get_object ("new-game-button");
-
         _hamburger_button = (MenuButton) builder.get_object ("hamburger-button");
         _hamburger_button.notify ["active"].connect (() => {
                 if (!_hamburger_button.active)
@@ -270,47 +262,6 @@ public class Application : Gtk.Application
         _game.view = embed.get_stage ();
     }
 
-    private void _create_preferences_dialog (Builder builder)
-    {
-        try {
-            builder.add_from_resource ("/org/gnome/gnome-2048/data/preferences.ui");
-        } catch (GLib.Error e) {
-            stderr.printf ("%s\n", e.message);
-        }
-
-        _preferences_dialog = (Dialog) builder.get_object ("preferencesdialog");
-        _preferences_dialog.set_transient_for (_window);
-
-        _grid_size_combo = (ComboBoxText) builder.get_object ("gridsizecombo");
-
-        _preferences_dialog.response.connect ((response_id) => {
-                _preferences_dialog.hide_on_delete ();
-            });
-        _preferences_dialog.delete_event.connect ((response_id) => {
-                int grid_size;
-                int rows, cols;
-                bool settings_changed;
-
-                grid_size = _grid_size_combo.get_active ();
-                if (grid_size == 0)
-                    rows = cols = 4;
-                else
-                    rows = cols = 5;
-
-                _settings.set_int ("rows", rows);
-                _settings.set_int ("cols", cols);
-
-                settings_changed = _game.reload_settings ();
-                if (settings_changed)
-                    new_game_cb ();
-                return _preferences_dialog.hide_on_delete ();
-            });
-
-        _settings.bind ("do-congrat", builder.get_object ("congratswitch"), "active", 
GLib.SettingsBindFlags.DEFAULT);
-        _settings.bind ("animations-speed", builder.get_object ("animationsspeed"), "value", 
GLib.SettingsBindFlags.DEFAULT);
-        _settings.bind ("allow-undo", builder.get_object ("undoswitch"), "active", 
GLib.SettingsBindFlags.DEFAULT);
-    }
-
     private void _create_congrats_dialog (Builder builder)
     {
         try {
@@ -382,16 +333,6 @@ public class Application : Gtk.Application
         _scores_ctx.run_dialog ();
     }
 
-    private void preferences_cb ()
-    {
-        if (_settings.get_int ("rows") == 4)
-            _grid_size_combo.set_active (0);
-        else
-            _grid_size_combo.set_active (1);
-
-        _preferences_dialog.present ();
-    }
-
 /*    private void help_cb ()
     {
         try {
@@ -459,4 +400,65 @@ public class Application : Gtk.Application
 
         return false;
     }
+
+    /*\
+    * * preferences dialog
+    \*/
+
+    private Dialog          _preferences_dialog;
+    private ComboBoxText    _grid_size_combo;
+
+    private bool _should_create_preferences_dialog = true;
+    private inline void _create_preferences_dialog ()
+    {
+        Builder builder = new Builder.from_resource ("/org/gnome/gnome-2048/data/preferences.ui");
+
+        _preferences_dialog = (Dialog) builder.get_object ("preferencesdialog");
+        _preferences_dialog.set_transient_for (_window);
+
+        _grid_size_combo = (ComboBoxText) builder.get_object ("gridsizecombo");
+
+        _preferences_dialog.response.connect ((response_id) => {
+                _preferences_dialog.hide_on_delete ();
+            });
+        _preferences_dialog.delete_event.connect ((response_id) => {
+                int grid_size;
+                int rows, cols;
+                bool settings_changed;
+
+                grid_size = _grid_size_combo.get_active ();
+                if (grid_size == 0)
+                    rows = cols = 4;
+                else
+                    rows = cols = 5;
+
+                _settings.set_int ("rows", rows);
+                _settings.set_int ("cols", cols);
+
+                settings_changed = _game.reload_settings ();
+                if (settings_changed)
+                    new_game_cb ();
+                return _preferences_dialog.hide_on_delete ();
+            });
+
+        _settings.bind ("do-congrat", builder.get_object ("congratswitch"), "active", 
GLib.SettingsBindFlags.DEFAULT);
+        _settings.bind ("animations-speed", builder.get_object ("animationsspeed"), "value", 
GLib.SettingsBindFlags.DEFAULT);
+        _settings.bind ("allow-undo", builder.get_object ("undoswitch"), "active", 
GLib.SettingsBindFlags.DEFAULT);
+    }
+
+    private inline void preferences_cb (/* SimpleAction action, Variant? variant */)
+    {
+        if (_should_create_preferences_dialog)
+        {
+            _create_preferences_dialog ();
+            _should_create_preferences_dialog = false;
+        }
+
+        if (_settings.get_int ("rows") == 4)
+            _grid_size_combo.set_active (0);
+        else
+            _grid_size_combo.set_active (1);
+
+        _preferences_dialog.present ();
+    }
 }