[goffice] GOComboBox: improve css styling ability a bit

[Morten Welinder <mortenw src gnome org>]

commit 86dcb277297d26e5a215f280198f73e0c81a1824
Author: Morten Welinder <terra gnome org>
Date:   Thu Jan 20 20:45:50 2022 -0500

    GOComboBox: improve css styling ability a bit
    
    Also, make the arrow match that of GtkComboBox.

 goffice/gtk/go-combo-box.c     | 8 +++++++-
 goffice/gtk/go-combo-pixmaps.c | 1 +
 2 files changed, 8 insertions(+), 1 deletion(-)
---
diff --git a/goffice/gtk/go-combo-box.c b/goffice/gtk/go-combo-box.c
index e37b6538..fcc5ce61 100644
--- a/goffice/gtk/go-combo-box.c
+++ b/goffice/gtk/go-combo-box.c
@@ -336,6 +336,10 @@ go_combo_box_class_init (GObjectClass *object_class)
                                       G_PARAM_READABLE));
        widget_class->style_set = go_combo_box_style_set;
 
+#ifdef HAVE_GTK_WIDGET_CLASS_SET_CSS_NAME
+       gtk_widget_class_set_css_name (widget_class, "gocombobox");
+#endif
+
        go_combo_box_signals [POP_DOWN_DONE] = g_signal_new (
                "pop_down_done",
                G_OBJECT_CLASS_TYPE (object_class),
@@ -611,10 +615,12 @@ go_combo_box_init (GOComboBox *combo_box)
        combo_box->priv->show_arrow = TRUE;
 
        combo_box->priv->arrow_button = gtk_toggle_button_new ();
+       gtk_widget_set_name  (combo_box->priv->arrow_button, "arrow");
        gtk_button_set_relief (GTK_BUTTON (combo_box->priv->arrow_button), GTK_RELIEF_NONE);
        gtk_widget_set_can_focus (combo_box->priv->arrow_button, FALSE);
 
-       arrow = gtk_arrow_new (GTK_ARROW_DOWN, GTK_SHADOW_IN);
+       arrow = gtk_image_new_from_icon_name ("pan-down", GTK_ICON_SIZE_SMALL_TOOLBAR);
+       gtk_widget_set_name  (arrow, "arrow");
        gtk_container_add (GTK_CONTAINER (combo_box->priv->arrow_button), arrow);
        gtk_box_pack_end (GTK_BOX (combo_box), combo_box->priv->arrow_button, FALSE, FALSE, 0);
        g_signal_connect_swapped (combo_box->priv->arrow_button,
diff --git a/goffice/gtk/go-combo-pixmaps.c b/goffice/gtk/go-combo-pixmaps.c
index 60ee78e5..7aa6ed73 100644
--- a/goffice/gtk/go-combo-pixmaps.c
+++ b/goffice/gtk/go-combo-pixmaps.c
@@ -122,6 +122,7 @@ go_combo_pixmaps_init (GOComboPixmaps *combo)
        combo->grid = g_object_ref (gtk_grid_new ());
 
        combo->preview_button = gtk_toggle_button_new ();
+       gtk_widget_set_name  (combo->preview_button, "preview");
        combo->preview_image = gtk_image_new ();
        gtk_container_add (GTK_CONTAINER (combo->preview_button),
                           GTK_WIDGET (combo->preview_image));