month-view: preserve hovered cell on popover show

The hovered cell is the indicator to draw the background and the
coloring of the overflow indicator. Preserve its value as long as the
overflow is shown.

src/gcal-month-view.c

@@ -471,6 +471,16 @@ rebuild_popover_for_day (GcalMonthView *view,
   gtk_widget_set_size_request (child_widget, cell_width, -1);
 }
 
+static void
+overflow_popover_hide (GtkWidget *widget,
+                       gpointer   user_data)
+{
+  GcalMonthViewPrivate *priv;
+
+  priv = gcal_month_view_get_instance_private (GCAL_MONTH_VIEW (user_data));
+  priv->hovered_overflow_indicator = -1;
+
+  gtk_widget_queue_draw (GTK_WIDGET (user_data));
 }
 
 static void
@@ -541,6 +551,7 @@ gcal_month_view_init (GcalMonthView *self)
     priv->k = 1;
 
   priv->overflow_popover = gtk_popover_new (GTK_WIDGET (self));
+  g_signal_connect (priv->overflow_popover, "hide", G_CALLBACK (overflow_popover_hide), self);
 
   grid = gtk_grid_new ();
   g_object_set (grid, "margin", 6, "row-spacing", 6, "orientation", GTK_ORIENTATION_VERTICAL, NULL);
@@ -1385,6 +1396,8 @@ gcal_month_view_motion_notify_event (GtkWidget      *widget,
     {
       if (j > priv->days_delay && j <= days)
         {
+          if (priv->end_mark_cell != priv->start_mark_cell)
+            priv->hovered_overflow_indicator = -1;
           if (priv->end_mark_cell != new_end_cell)
             gtk_widget_queue_draw (widget);
 
@@ -1395,6 +1408,9 @@ gcal_month_view_motion_notify_event (GtkWidget      *widget,
     }
   else
     {
+      if (gtk_widget_is_visible (priv->overflow_popover))
+        return FALSE;
+
       if (hovered_indicator)
         new_hovered_cell = new_end_cell;
       else
@@ -1456,7 +1472,9 @@ gcal_month_view_button_release (GtkWidget      *widget,
 
   if (priv->pressed_overflow_indicator != -1 && priv->start_mark_cell == priv->end_mark_cell)
     {
-      rebuild_popover_for_cell (GCAL_MONTH_VIEW (widget));
+      priv->hovered_overflow_indicator = priv->pressed_overflow_indicator;
+
+      rebuild_popover_for_day (GCAL_MONTH_VIEW (widget), j - priv->days_delay);
       gtk_widget_show_all (priv->overflow_popover);
 
       priv->clicked_cell = -1;