[gtksourceview] gutterrenderertext: use cached styling information

[Christian Hergert <chergert src gnome org>]

commit 388b3d11deab050984a1293fef51179945fad9e1
Author: Christian Hergert <chergert redhat com>
Date:   Tue Dec 21 23:18:16 2021 -0800

    gutterrenderertext: use cached styling information
    
    Instead of relying on CSS for this (which was broken anyway) we can
    directly set the values and avoid a lot of extra cost in CSS changes.

 gtksourceview/gtksourcegutterrenderertext.c | 66 ++++++++++++++++++++++++++---
 1 file changed, 59 insertions(+), 7 deletions(-)
---
diff --git a/gtksourceview/gtksourcegutterrenderertext.c b/gtksourceview/gtksourcegutterrenderertext.c
index 1329e91c..36faa151 100644
--- a/gtksourceview/gtksourcegutterrenderertext.c
+++ b/gtksourceview/gtksourcegutterrenderertext.c
@@ -20,6 +20,8 @@
 #include "config.h"
 
 #include "gtksourcegutterrenderertext.h"
+#include "gtksourcegutterlines.h"
+#include "gtksourceview-private.h"
 
 /**
  * GtkSourceGutterRendererText:
@@ -38,12 +40,13 @@ typedef struct
 
 typedef struct
 {
-       gchar       *text;
-       PangoLayout *cached_layout;
-       GdkRGBA      cached_color;
-       gsize        text_len;
-       Size         cached_sizes[5];
-       guint        is_markup : 1;
+       gchar          *text;
+       PangoLayout    *cached_layout;
+       PangoAttribute *current_line_bold;
+       PangoAttribute *current_line_color;
+       gsize           text_len;
+       Size            cached_sizes[5];
+       guint           is_markup : 1;
 } GtkSourceGutterRendererTextPrivate;
 
 G_DEFINE_TYPE_WITH_PRIVATE (GtkSourceGutterRendererText, gtk_source_gutter_renderer_text, 
GTK_SOURCE_TYPE_GUTTER_RENDERER)
@@ -102,12 +105,26 @@ gtk_source_gutter_renderer_text_begin (GtkSourceGutterRenderer *renderer,
 
        GtkSourceGutterRendererText *text = GTK_SOURCE_GUTTER_RENDERER_TEXT (renderer);
        GtkSourceGutterRendererTextPrivate *priv = gtk_source_gutter_renderer_text_get_instance_private 
(text);
+       GtkSourceView *view = gtk_source_gutter_renderer_get_view (GTK_SOURCE_GUTTER_RENDERER (renderer));
+       GdkRGBA current;
 
        GTK_SOURCE_GUTTER_RENDERER_CLASS (gtk_source_gutter_renderer_text_parent_class)->begin (renderer, 
lines);
 
        g_clear_object (&priv->cached_layout);
        priv->cached_layout = gtk_widget_create_pango_layout (GTK_WIDGET (renderer), NULL);
 
+       if (_gtk_source_view_get_current_line_number_color (view, &current))
+       {
+               priv->current_line_color = pango_attr_foreground_new (current.red * 255,
+                                                                     current.green * 255,
+                                                                     current.blue * 255);
+       }
+
+       if (_gtk_source_view_get_current_line_number_bold (view))
+       {
+               priv->current_line_bold = pango_attr_weight_new (PANGO_WEIGHT_BOLD);
+       }
+
        gtk_source_gutter_renderer_text_clear_cached_sizes (text);
 }
 
@@ -120,6 +137,7 @@ gtk_source_gutter_renderer_text_snapshot_line (GtkSourceGutterRenderer *renderer
        GtkSourceGutterRendererText *text = GTK_SOURCE_GUTTER_RENDERER_TEXT (renderer);
        GtkSourceGutterRendererTextPrivate *priv = gtk_source_gutter_renderer_text_get_instance_private 
(text);
        PangoLayout *layout;
+       gboolean clear_attributes;
        float x;
        float y;
        int width;
@@ -131,6 +149,7 @@ gtk_source_gutter_renderer_text_snapshot_line (GtkSourceGutterRenderer *renderer
        }
 
        layout = priv->cached_layout;
+       clear_attributes = priv->is_markup;
 
        if (priv->is_markup)
        {
@@ -145,6 +164,37 @@ gtk_source_gutter_renderer_text_snapshot_line (GtkSourceGutterRenderer *renderer
                                       priv->text_len);
        }
 
+       if (G_UNLIKELY (gtk_source_gutter_lines_is_cursor (lines, line)))
+       {
+               PangoAttrList *attrs = pango_layout_get_attributes (layout);
+
+               if (attrs == NULL)
+               {
+                       attrs = pango_attr_list_new ();
+                       pango_layout_set_attributes (layout, attrs);
+               }
+               else
+               {
+                       pango_attr_list_ref (attrs);
+               }
+
+               if (priv->current_line_color)
+               {
+                       pango_attr_list_insert_before (attrs,
+                                                      pango_attribute_copy (priv->current_line_color));
+                       clear_attributes = TRUE;
+               }
+
+               if (priv->current_line_bold)
+               {
+                       pango_attr_list_insert_before (attrs,
+                                                      pango_attribute_copy (priv->current_line_bold));
+                       clear_attributes = TRUE;
+               }
+
+               pango_attr_list_unref (attrs);
+       }
+
        gtk_source_gutter_renderer_text_get_size (priv, layout, priv->text_len, &width, &height);
        gtk_source_gutter_renderer_align_cell (renderer, line, width, height, &x, &y);
 
@@ -154,7 +204,7 @@ gtk_source_gutter_renderer_text_snapshot_line (GtkSourceGutterRenderer *renderer
                                    ceilf (y),
                                    layout);
 
-       if (priv->is_markup)
+       if (clear_attributes)
        {
                pango_layout_set_attributes (layout, NULL);
        }
@@ -169,6 +219,8 @@ gtk_source_gutter_renderer_text_end (GtkSourceGutterRenderer *renderer)
 
        GTK_SOURCE_GUTTER_RENDERER_CLASS (gtk_source_gutter_renderer_text_parent_class)->end (renderer);
 
+       g_clear_pointer (&priv->current_line_bold, pango_attribute_destroy);
+       g_clear_pointer (&priv->current_line_color, pango_attribute_destroy);
        g_clear_object (&priv->cached_layout);
 }