[gtksourceview/wip/chergert/gsv-gtk4] lines: avoid use of style-updated

[Christian Hergert <chergert src gnome org>]

commit c5151aea08bba25b06609922ce9b6961f6d85bd6
Author: Christian Hergert <chergert redhat com>
Date:   Tue Mar 17 17:10:35 2020 -0700

    lines: avoid use of style-updated
    
    This API was removed in GTK 4, so we need to drop our use of it. Instead
    we will watch for CSS changes and apply that.
    
    Long term, this will work better as CSS is inhereted from parent widgets
    before 4.0 is released.

 gtksourceview/gtksourcegutterrendererlines.c | 18 +++++++-----------
 1 file changed, 7 insertions(+), 11 deletions(-)
---
diff --git a/gtksourceview/gtksourcegutterrendererlines.c b/gtksourceview/gtksourcegutterrendererlines.c
index 23cc5dfc..67072c49 100644
--- a/gtksourceview/gtksourcegutterrendererlines.c
+++ b/gtksourceview/gtksourcegutterrendererlines.c
@@ -141,9 +141,13 @@ gutter_renderer_change_buffer (GtkSourceGutterRenderer *renderer,
 }
 
 static void
-on_view_style_updated (GtkTextView                  *view,
-                       GtkSourceGutterRendererLines *renderer)
+gtk_source_gutter_renderer_lines_css_changed (GtkWidget         *widget,
+                                              GtkCssStyleChange *change)
 {
+       GtkSourceGutterRendererLines *renderer = GTK_SOURCE_GUTTER_RENDERER_LINES (widget);
+
+       GTK_WIDGET_CLASS (_gtk_source_gutter_renderer_lines_parent_class)->css_changed (widget, change);
+
        /* Force to recalculate the size. */
        renderer->num_line_digits = -1;
        recalculate_size (renderer);
@@ -165,9 +169,6 @@ gutter_renderer_change_view (GtkSourceGutterRenderer *renderer,
 
        if (old_view != NULL)
        {
-               g_signal_handlers_disconnect_by_func (old_view,
-                                                     on_view_style_updated,
-                                                     renderer);
                g_signal_handlers_disconnect_by_func (old_view,
                                                      on_view_notify_cursor_visible,
                                                      renderer);
@@ -177,12 +178,6 @@ gutter_renderer_change_view (GtkSourceGutterRenderer *renderer,
 
        if (new_view != NULL)
        {
-               g_signal_connect_object (new_view,
-                                        "style-updated",
-                                        G_CALLBACK (on_view_style_updated),
-                                        renderer,
-                                        0);
-
                g_signal_connect_object (new_view,
                                         "notify::cursor-visible",
                                         G_CALLBACK (on_view_notify_cursor_visible),
@@ -384,6 +379,7 @@ _gtk_source_gutter_renderer_lines_class_init (GtkSourceGutterRendererLinesClass
        GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
 
        widget_class->measure = gtk_source_gutter_renderer_lines_measure;
+       widget_class->css_changed = gtk_source_gutter_renderer_lines_css_changed;
 
        renderer_class->query_activatable = gutter_renderer_query_activatable;
        renderer_class->query_data = gtk_source_gutter_renderer_lines_query_data;