From 640488883bd2084715f8af5535c913c2c0b362af Mon Sep 17 00:00:00 2001
From: Federico Mena Quintero <federico@gnome.org>
Date: Tue, 25 Feb 2025 20:47:15 -0600
Subject: [PATCH] Introduce a WidgetState structure and compute it from
 GcalScheduleValues

You may think, yet more indirection!  But behold:

1. We take events from the widgets ("schedule type (all-day) changed") and turn
   them into actions (gcal_schedule_values_set_all_day()).

2. Those actions (e.g. that function) decide how to change the GcalScheduleValues.

3. We compute the desired state of the wigets, based on the new
   values.

4. We set the state of the widgets based on that.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-calendar/-/merge_requests/550>
---
 src/gui/event-editor/gcal-schedule-section.c | 51 ++++++++++++++++++--
 1 file changed, 46 insertions(+), 5 deletions(-)

diff --git a/src/gui/event-editor/gcal-schedule-section.c b/src/gui/event-editor/gcal-schedule-section.c
index 572bdaa3..422b2356 100644
--- a/src/gui/event-editor/gcal-schedule-section.c
+++ b/src/gui/event-editor/gcal-schedule-section.c
@@ -57,6 +57,22 @@ struct _GcalScheduleSection
   GcalEventEditorFlags flags;
 };
 
+/* Desired state of the widgets, computed from GcalScheduleValues.
+ *
+ * There is some subtle logic to decide how to update the widgets based on how
+ * each of them causes the GcalScheduleValues to be modified.  We encapsulate
+ * the desired state in this struct, so we can have tests for it.
+ */
+typedef struct
+{
+  gboolean date_widgets_visible;
+  gboolean date_time_widgets_visible;
+} WidgetState;
+
+static void widget_state_free (WidgetState *state);
+
+G_DEFINE_AUTOPTR_CLEANUP_FUNC (WidgetState, widget_state_free);
+
 static void          gcal_event_editor_section_iface_init        (GcalEventEditorSectionInterface *iface);
 
 G_DEFINE_TYPE_WITH_CODE (GcalScheduleSection, gcal_schedule_section, GTK_TYPE_BOX,
@@ -107,6 +123,23 @@ gcal_schedule_values_set_all_day (const GcalScheduleValues *values, gboolean all
   return copy;
 }
 
+static WidgetState *
+widget_state_from_values (const GcalScheduleValues *values)
+{
+  WidgetState *state = g_new0 (WidgetState, 1);
+
+  state->date_widgets_visible = values->all_day;
+  state->date_time_widgets_visible = !values->all_day;
+
+  return state;
+}
+
+static void
+widget_state_free (WidgetState *state)
+{
+  g_free (state);
+}
+
 /*
  * Auxiliary methods
  */
@@ -151,6 +184,15 @@ remove_recurrence_properties (GcalEvent *event)
   e_cal_component_commit_sequence (comp);
 }
 
+static void
+update_widgets (GcalScheduleSection *self,
+                WidgetState         *state)
+{
+  gtk_widget_set_visible (GTK_WIDGET (self->start_date_group), state->date_widgets_visible);
+  gtk_widget_set_visible (GTK_WIDGET (self->end_date_group), state->date_widgets_visible);
+  gtk_widget_set_visible (GTK_WIDGET (self->start_date_time_chooser), state->date_time_widgets_visible);
+  gtk_widget_set_visible (GTK_WIDGET (self->end_date_time_chooser), state->date_time_widgets_visible);
+}
 
 /*
  * Callbacks
@@ -162,14 +204,13 @@ on_schedule_type_changed_cb (GtkWidget           *widget,
                              GcalScheduleSection *self)
 {
   gboolean all_day = all_day_selected (self);
-
-  gtk_widget_set_visible (GTK_WIDGET (self->start_date_group), all_day);
-  gtk_widget_set_visible (GTK_WIDGET (self->end_date_group), all_day);
-  gtk_widget_set_visible (GTK_WIDGET (self->start_date_time_chooser), !all_day);
-  gtk_widget_set_visible (GTK_WIDGET (self->end_date_time_chooser), !all_day);
+  GcalScheduleValues *updated = gcal_schedule_values_set_all_day (self->values, all_day);
+  g_autoptr (WidgetState) state = widget_state_from_values (updated);
 
   block_date_signals (self);
 
+  update_widgets (self, state);
+
   if (all_day)
     {
       g_autoptr (GDateTime) start_local = NULL;