month-cell: Show month name on the 1st day

This helps differentiate when the month change happens.

src/gui/views/gcal-month-cell.c

@@ -36,6 +36,7 @@ struct _GcalMonthCell
 
   GtkLabel           *day_label;
   GtkWidget          *header_box;
+  GtkLabel           *month_name_label;
   GtkImage           *weather_icon;
   GtkLabel           *temp_label;
 
@@ -321,6 +322,7 @@ gcal_month_cell_class_init (GcalMonthCellClass *klass)
 
   gtk_widget_class_bind_template_child (widget_class, GcalMonthCell, day_label);
   gtk_widget_class_bind_template_child (widget_class, GcalMonthCell, header_box);
+  gtk_widget_class_bind_template_child (widget_class, GcalMonthCell, month_name_label);
   gtk_widget_class_bind_template_child (widget_class, GcalMonthCell, overflow_button);
   gtk_widget_class_bind_template_child (widget_class, GcalMonthCell, overflow_inscription);
   gtk_widget_class_bind_template_child (widget_class, GcalMonthCell, overlay);
@@ -365,6 +367,7 @@ gcal_month_cell_set_date (GcalMonthCell *self,
                           GDateTime     *date)
 {
   g_autofree gchar *text = NULL;
+  gint day_of_month;
 
   g_return_if_fail (GCAL_IS_MONTH_CELL (self));
 
@@ -379,6 +382,15 @@ gcal_month_cell_set_date (GcalMonthCell *self,
 
   gtk_label_set_text (self->day_label, text);
   update_style_flags (self);
+
+  /* Month name */
+  day_of_month = g_date_time_get_day_of_month (date);
+  gtk_widget_set_visible (GTK_WIDGET (self->month_name_label), day_of_month == 1);
+  if (g_date_time_get_day_of_month (date) == 1)
+    {
+      g_autofree gchar *month_name = g_date_time_format (date, "%b");
+      gtk_label_set_text (self->month_name_label, month_name);
+    }
 }
 
 /**

src/gui/views/gcal-month-cell.ui

@@ -24,6 +24,10 @@
               </object>
             </child>
 
+            <child>
+              <object class="GtkLabel" id="month_name_label" />
+            </child>
+
             <!-- Weather forecast -->
             <child>
               <object class="GtkImage" id="weather_icon">