[libhandy] preferences-window: Fix subpage removal with disabled animations

[Alexander Mikhaylenko <alexm src gnome org>]

commit 085a8c8f5b7f8c8b26a526a560fcb730a559cde4
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Wed Jul 29 14:02:09 2020 +0500

    preferences-window: Fix subpage removal with disabled animations
    
    The current HdyDeck API is weird and confusing and it's very easy to get it
    wrong. In particular, the transition-running property doesn't change its
    values if animations are disabled, so you need to also track visible-child
    changes.
    
    Signed-off-by: Alexander Mikhaylenko <alexm gnome org>

 src/hdy-preferences-window.c  | 15 ++++++++++++++-
 src/hdy-preferences-window.ui |  1 +
 2 files changed, 15 insertions(+), 1 deletion(-)
---
diff --git a/src/hdy-preferences-window.c b/src/hdy-preferences-window.c
index c5d73774..81bb7ba0 100644
--- a/src/hdy-preferences-window.c
+++ b/src/hdy-preferences-window.c
@@ -232,7 +232,7 @@ key_press_event_cb (GtkWidget            *sender,
 }
 
 static void
-subpages_deck_transition_running_cb (HdyPreferencesWindow *self)
+try_remove_subpages (HdyPreferencesWindow *self)
 {
   HdyPreferencesWindowPrivate *priv = hdy_preferences_window_get_instance_private (self);
 
@@ -249,6 +249,18 @@ subpages_deck_transition_running_cb (HdyPreferencesWindow *self)
     priv->subpage = NULL;
 }
 
+static void
+subpages_deck_transition_running_cb (HdyPreferencesWindow *self)
+{
+  try_remove_subpages (self);
+}
+
+static void
+subpages_deck_visible_child_cb (HdyPreferencesWindow *self)
+{
+  try_remove_subpages (self);
+}
+
 static void
 header_bar_size_allocate_cb (HdyPreferencesWindow *self,
                              GdkRectangle         *allocation)
@@ -500,6 +512,7 @@ hdy_preferences_window_class_init (HdyPreferencesWindowClass *klass)
   gtk_widget_class_bind_template_child_private (widget_class, HdyPreferencesWindow, view_switcher_bar);
   gtk_widget_class_bind_template_child_private (widget_class, HdyPreferencesWindow, view_switcher_title);
   gtk_widget_class_bind_template_callback (widget_class, subpages_deck_transition_running_cb);
+  gtk_widget_class_bind_template_callback (widget_class, subpages_deck_visible_child_cb);
   gtk_widget_class_bind_template_callback (widget_class, header_bar_size_allocate_cb);
   gtk_widget_class_bind_template_callback (widget_class, title_stack_notify_transition_running_cb);
   gtk_widget_class_bind_template_callback (widget_class, title_stack_notify_visible_child_cb);
diff --git a/src/hdy-preferences-window.ui b/src/hdy-preferences-window.ui
index 600ebbbe..ccc96fa0 100644
--- a/src/hdy-preferences-window.ui
+++ b/src/hdy-preferences-window.ui
@@ -14,6 +14,7 @@
         <property name="can-swipe-back" bind-source="HdyPreferencesWindow" bind-property="can-swipe-back" 
bind-flags="sync-create"/>
         <property name="visible">True</property>
         <signal name="notify::transition-running" handler="subpages_deck_transition_running_cb" 
swapped="yes"/>
+        <signal name="notify::visible-child" handler="subpages_deck_visible_child_cb" swapped="yes"/>
         <child>
           <object class="GtkBox" id="preferences">
             <property name="visible">True</property>