[gnome-games/wip/exalm/preferences] ui: Simplify preferences page subpages

[Alexander Mikhaylenko <alexm src gnome org>]

commit e36638c0d8ff26d9739eb8e8ca776958d4d1e627
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Wed Jun 3 17:07:18 2020 +0500

    ui: Simplify preferences page subpages
    
    Pass the window reference to the pages and allow them to open subpage by
    just calling a method instead of setting a property that's bound to the
    window for the current page.

 data/ui/preferences-window.ui            |  9 ++--
 src/ui/preferences-page-controllers.vala | 15 +-----
 src/ui/preferences-page.vala             |  2 +-
 src/ui/preferences-subpage-gamepad.vala  |  2 -
 src/ui/preferences-subpage-keyboard.vala |  2 -
 src/ui/preferences-subpage.vala          |  2 +
 src/ui/preferences-window.vala           | 83 ++++++++------------------------
 7 files changed, 31 insertions(+), 84 deletions(-)
---
diff --git a/data/ui/preferences-window.ui b/data/ui/preferences-window.ui
index 413c11ac..bdf06c20 100644
--- a/data/ui/preferences-window.ui
+++ b/data/ui/preferences-window.ui
@@ -9,8 +9,8 @@
     <child>
       <object class="HdyDeck" id="deck">
         <property name="visible">True</property>
-        <signal name="notify::transition-running" handler="subpage_transition_finished"/>
-        <signal name="notify::visible-child" handler="on_visible_child_changed"/>
+        <signal name="notify::transition-running" handler="try_remove_subpage"/>
+        <signal name="notify::visible-child" handler="try_remove_subpage"/>
         <child>
           <object class="GtkBox" id="main_box">
             <property name="visible">True</property>
@@ -38,10 +38,10 @@
                 <property name="visible-child">video_page</property>
                 <property name="transition-type">crossfade</property>
                 <property name="width-request">300</property>
-                <signal name="notify::visible-child" handler="update_ui"/>
                 <child>
                   <object class="GamesPreferencesPageVideo" id="video_page">
                     <property name="visible">True</property>
+                    <property name="window">GamesPreferencesWindow</property>
                   </object>
                   <packing>
                     <property name="title" translatable="yes">Video</property>
@@ -51,6 +51,7 @@
                 <child>
                   <object class="GamesPreferencesPageControllers" id="controllers_page">
                     <property name="visible">True</property>
+                    <property name="window">GamesPreferencesWindow</property>
                   </object>
                   <packing>
                     <property name="title" translatable="yes">Controllers</property>
@@ -60,6 +61,7 @@
                 <child>
                   <object class="GamesPreferencesPagePlatforms" id="platforms_page">
                     <property name="visible">True</property>
+                    <property name="window">GamesPreferencesWindow</property>
                   </object>
                   <packing>
                     <property name="title" translatable="yes">Platforms</property>
@@ -69,6 +71,7 @@
                 <child>
                   <object class="GamesPreferencesPageImportExport" id="import_export_page">
                     <property name="visible">True</property>
+                    <property name="window">GamesPreferencesWindow</property>
                   </object>
                   <packing>
                     <property name="title" translatable="yes">Import &amp; Export</property>
diff --git a/src/ui/preferences-page-controllers.vala b/src/ui/preferences-page-controllers.vala
index 7bbdcb19..208301fd 100644
--- a/src/ui/preferences-page-controllers.vala
+++ b/src/ui/preferences-page-controllers.vala
@@ -9,8 +9,6 @@ private class Games.PreferencesPageControllers : PreferencesPage {
 
        private Manette.Monitor monitor;
 
-       private ulong back_handler_id;
-
        construct {
                monitor = new Manette.Monitor ();
                monitor.device_connected.connect (rebuild_gamepad_list);
@@ -41,9 +39,7 @@ private class Games.PreferencesPageControllers : PreferencesPage {
                        var this_device = device;
 
                        row.activated.connect (() => {
-                               var subpage_gamepad = new PreferencesSubpageGamepad (this_device);
-                               back_handler_id = subpage_gamepad.back.connect (on_back);
-                               subpage = subpage_gamepad;
+                               window.open_subpage (new PreferencesSubpageGamepad (this_device));
                        });
 
                        row.show_all ();
@@ -66,17 +62,10 @@ private class Games.PreferencesPageControllers : PreferencesPage {
                row.activatable = true;
 
                row.activated.connect (() => {
-                       var subpage_keyboard = new PreferencesSubpageKeyboard ();
-                       back_handler_id = subpage_keyboard.back.connect (on_back);
-                       subpage = subpage_keyboard;
+                       window.open_subpage (new PreferencesSubpageKeyboard ());
                });
 
                row.show_all ();
                keyboard_group.add (row);
        }
-
-       private void on_back () {
-               subpage.disconnect (back_handler_id);
-               subpage = null;
-       }
 }
diff --git a/src/ui/preferences-page.vala b/src/ui/preferences-page.vala
index 911996fe..98c1d0c9 100644
--- a/src/ui/preferences-page.vala
+++ b/src/ui/preferences-page.vala
@@ -2,7 +2,7 @@
 
 [GtkTemplate (ui = "/org/gnome/Games/ui/preferences-page.ui")]
 private class Games.PreferencesPage : Gtk.Bin, Gtk.Buildable {
-       public PreferencesSubpage subpage { get; set; }
+       public PreferencesWindow window { get; construct; }
 
        [GtkChild]
        private Gtk.Label error_label;
diff --git a/src/ui/preferences-subpage-gamepad.vala b/src/ui/preferences-subpage-gamepad.vala
index 36b1019c..ecfe5bf8 100644
--- a/src/ui/preferences-subpage-gamepad.vala
+++ b/src/ui/preferences-subpage-gamepad.vala
@@ -31,8 +31,6 @@ private class Games.PreferencesSubpageGamepad : Gtk.Bin, PreferencesSubpage {
                CONFIGURE,
        }
 
-       public signal void back ();
-
        private State _state;
        private State state {
                set {
diff --git a/src/ui/preferences-subpage-keyboard.vala b/src/ui/preferences-subpage-keyboard.vala
index b2b6951c..e0857fd7 100644
--- a/src/ui/preferences-subpage-keyboard.vala
+++ b/src/ui/preferences-subpage-keyboard.vala
@@ -26,8 +26,6 @@ private class Games.PreferencesSubpageKeyboard : Gtk.Bin, PreferencesSubpage {
                CONFIGURE,
        }
 
-       public signal void back ();
-
        private State _state;
        private State state {
                get { return _state; }
diff --git a/src/ui/preferences-subpage.vala b/src/ui/preferences-subpage.vala
index 17cf3baf..e81b00e2 100644
--- a/src/ui/preferences-subpage.vala
+++ b/src/ui/preferences-subpage.vala
@@ -1,5 +1,7 @@
 // This file is part of GNOME Games. License: GPL-3.0+.
 
 private interface Games.PreferencesSubpage : Gtk.Widget {
+       public signal void back ();
+
        public abstract bool allow_back { get; set; }
 }
diff --git a/src/ui/preferences-window.vala b/src/ui/preferences-window.vala
index 0db7b341..04c78bac 100644
--- a/src/ui/preferences-window.vala
+++ b/src/ui/preferences-window.vala
@@ -8,82 +8,39 @@ private class Games.PreferencesWindow : Hdy.Window {
        private Gtk.Box main_box;
        [GtkChild]
        private Gtk.Box subpage_box;
-       [GtkChild]
-       private Gtk.Stack stack;
-
-       private PreferencesSubpage _subpage;
-       public PreferencesSubpage subpage {
-               get { return _subpage; }
-               set {
-                       if (subpage == value)
-                               return;
-
-                       if (subpage != null) {
-                               deck.navigate (Hdy.NavigationDirection.BACK);
-                               swipe_back_binding.unbind ();
-                       }
-
-                       if (value != null) {
-                               subpage_box.add (value);
-
-                               swipe_back_binding = value.bind_property ("allow-back", deck,
-                                                                         "can-swipe-back",
-                                                                         BindingFlags.SYNC_CREATE);
-
-                               deck.navigate (Hdy.NavigationDirection.FORWARD);
-                       }
 
-                       _subpage = value;
-               }
-       }
-
-       private Binding subpage_binding;
+       private PreferencesSubpage subpage;
        private Binding swipe_back_binding;
 
-       construct {
-               update_ui ();
-       }
-
        [GtkCallback]
-       private void update_ui () {
-               var page = stack.visible_child as PreferencesPage;
-
-               if (subpage_binding != null) {
-                       subpage_binding.unbind ();
-                       subpage_binding = null;
-               }
-
-               if (page == null) {
-                       subpage = null;
-
+       public void try_remove_subpage () {
+               if (deck.transition_running ||
+                   deck.visible_child != main_box ||
+                   subpage == null)
                        return;
-               }
-
-               subpage_binding = page.bind_property ("subpage", this, "subpage",
-                                                     BindingFlags.SYNC_CREATE | BindingFlags.BIDIRECTIONAL);
-       }
 
-       private void remove_subpage () {
-               foreach (var child in subpage_box.get_children ())
-                       subpage_box.remove (child);
+               subpage_box.remove (subpage);
 
                subpage = null;
        }
 
-       [GtkCallback]
-       public void subpage_transition_finished () {
-               if (deck.transition_running ||
-                   deck.visible_child != main_box)
+       public void open_subpage (PreferencesSubpage subpage) {
+               if (this.subpage != null)
                        return;
 
-               remove_subpage ();
-       }
+               this.subpage = subpage;
 
-       [GtkCallback]
-       private void on_visible_child_changed () {
-               if (deck.transition_running || subpage == null)
-                       return;
+               swipe_back_binding = subpage.bind_property ("allow-back", deck,
+                                                           "can-swipe-back",
+                                                           BindingFlags.SYNC_CREATE);
+
+               subpage_box.add (subpage);
+
+               subpage.back.connect (() => {
+                       deck.navigate (Hdy.NavigationDirection.BACK);
+                       swipe_back_binding.unbind ();
+               });
 
-               remove_subpage ();
+               deck.navigate (Hdy.NavigationDirection.FORWARD);
        }
 }