[gtksourceview/wip/chergert/gsv-gtk4] stylescheme: remove use of widget for caret styling

[Christian Hergert <chergert src gnome org>]

commit 91153b804e44b33a38dc6e020f64a9cf3f219315
Author: Christian Hergert <chergert redhat com>
Date:   Mon Mar 16 14:40:45 2020 -0700

    stylescheme: remove use of widget for caret styling
    
    We really want to avoid using the widget here because we no longer have
    information about the widget background. The backgrounds could be an image
    or paintable for example.

 gtksourceview/gtksourcestylescheme.c | 67 +++++++++++-------------------------
 1 file changed, 20 insertions(+), 47 deletions(-)
---
diff --git a/gtksourceview/gtksourcestylescheme.c b/gtksourceview/gtksourcestylescheme.c
index da1a826b..11d6a3e2 100644
--- a/gtksourceview/gtksourcestylescheme.c
+++ b/gtksourceview/gtksourcestylescheme.c
@@ -690,8 +690,7 @@ _gtk_source_style_scheme_get_background_pattern_color (GtkSourceStyleScheme *sch
 }
 
 static gchar *
-get_cursors_css_style (GtkSourceStyleScheme *scheme,
-                       GtkWidget            *widget)
+get_cursors_css_style (GtkSourceStyleScheme *scheme)
 {
        GtkSourceStyle *primary_style;
        GtkSourceStyle *secondary_style;
@@ -721,65 +720,43 @@ get_cursors_css_style (GtkSourceStyleScheme *scheme,
 
                primary_color_str = gdk_rgba_to_string (&primary_color);
                g_string_append_printf (css,
-                                       "\tcaret-color: %s;\n",
-                                       primary_color_str);
+                                       "\tcaret-color: %s;\n",
+                                       primary_color_str);
                g_free (primary_color_str);
        }
 
        if (!secondary_color_set)
        {
-               GtkStyleContext *context;
-               GdkRGBA *background_color;
-
-               g_assert (primary_color_set);
-
-               context = gtk_widget_get_style_context (widget);
-
-               gtk_style_context_save (context);
-               gtk_style_context_set_state (context, GTK_STATE_FLAG_NORMAL);
-
-               gtk_style_context_get (context,
-                                      "background-color", &background_color,
-                                      NULL);
-
-               gtk_style_context_restore (context);
-
-               /* Blend primary cursor color with background color. */
-               secondary_color.red = (primary_color.red + background_color->red) * 0.5;
-               secondary_color.green = (primary_color.green + background_color->green) * 0.5;
-               secondary_color.blue = (primary_color.blue + background_color->blue) * 0.5;
-               secondary_color.alpha = (primary_color.alpha + background_color->alpha) * 0.5;
-
-               gdk_rgba_free (background_color);
+               if (primary_color_set)
+               {
+                       secondary_color = primary_color;
+                       secondary_color.alpha *= .5;
+                       secondary_color_set = TRUE;
+               }
        }
 
-       secondary_color_str = gdk_rgba_to_string (&secondary_color);
-       g_string_append_printf (css,
-                               "\t-gtk-secondary-caret-color: %s;\n",
-                               secondary_color_str);
-       g_free (secondary_color_str);
+       if (secondary_color_set)
+       {
+               secondary_color_str = gdk_rgba_to_string (&secondary_color);
+               g_string_append_printf (css,
+                                       "\t-gtk-secondary-caret-color: %s;\n",
+                                       secondary_color_str);
+               g_free (secondary_color_str);
+       }
 
        g_string_append_printf (css, "}\n");
 
        return g_string_free (css, FALSE);
 }
 
-/* The CssProvider for the cursors depends only on @scheme, but it needs a
- * @widget to shade the background color in case the secondary cursor color
- * isn't defined. The background color is normally defined by @scheme, or if
- * it's not defined it is taken from the GTK+ theme. So ideally, if the GTK+
- * theme changes at runtime, we should regenerate the CssProvider for the
- * cursors, but it isn't done.
- */
 static GtkCssProvider *
-get_css_provider_cursors (GtkSourceStyleScheme *scheme,
-                          GtkWidget            *widget)
+get_css_provider_cursors (GtkSourceStyleScheme *scheme)
 {
        gchar *css;
        GtkCssProvider *provider;
        GError *error = NULL;
 
-       css = get_cursors_css_style (scheme, widget);
+       css = get_cursors_css_style (scheme);
 
        if (css == NULL)
        {
@@ -824,13 +801,9 @@ _gtk_source_style_scheme_apply (GtkSourceStyleScheme *scheme,
                                        GTK_STYLE_PROVIDER (scheme->css_provider),
                                        GTK_SOURCE_STYLE_PROVIDER_PRIORITY);
 
-       /* The CssProvider for the cursors needs that the first provider is
-        * applied, to get the background color.
-        */
        if (scheme->css_provider_cursors == NULL)
        {
-               scheme->css_provider_cursors = get_css_provider_cursors (scheme,
-                                                                        GTK_WIDGET (view));
+               scheme->css_provider_cursors = get_css_provider_cursors (scheme);
        }
 
        if (scheme->css_provider_cursors != NULL)