[gtksourceview] gutterrendererlines: avoid extra function calls in ::query_data()

[Christian Hergert <chergert src gnome org>]

commit c4008d3eab19bccd8b8e1a1e1bd8ac853ec250d8
Author: Christian Hergert <christian hergert me>
Date:   Wed Apr 20 18:55:59 2016 -0700

    gutterrendererlines: avoid extra function calls in ::query_data()
    
    We can remove the calls to check if the cursor is visible for every visible
    line by keeping track of when the property changes. This removes a
    gtk_text_view_get_cursor_visible() and gtk_text_gutter_render_get_view()
    for every line in the rendering process.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=765356

 gtksourceview/gtksourcegutterrendererlines.c |   23 ++++++++++++++++++++++-
 1 files changed, 22 insertions(+), 1 deletions(-)
---
diff --git a/gtksourceview/gtksourcegutterrendererlines.c b/gtksourceview/gtksourcegutterrendererlines.c
index 5a07102..a8f1fb2 100644
--- a/gtksourceview/gtksourcegutterrendererlines.c
+++ b/gtksourceview/gtksourcegutterrendererlines.c
@@ -30,6 +30,7 @@ struct _GtkSourceGutterRendererLinesPrivate
 {
        gint num_line_digits;
        gint prev_line_num;
+       guint cursor_visible : 1;
 };
 
 G_DEFINE_TYPE_WITH_PRIVATE (GtkSourceGutterRendererLines, gtk_source_gutter_renderer_lines, 
GTK_SOURCE_TYPE_GUTTER_RENDERER_TEXT)
@@ -159,6 +160,14 @@ on_view_style_updated (GtkTextView                  *view,
 }
 
 static void
+on_view_notify_cursor_visible (GtkTextView                  *view,
+                               GParamSpec                   *pspec,
+                               GtkSourceGutterRendererLines *renderer)
+{
+       renderer->priv->cursor_visible = gtk_text_view_get_cursor_visible (view);
+}
+
+static void
 gutter_renderer_change_view (GtkSourceGutterRenderer *renderer,
                             GtkTextView             *old_view)
 {
@@ -169,6 +178,9 @@ gutter_renderer_change_view (GtkSourceGutterRenderer *renderer,
                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);
        }
 
        new_view = gtk_source_gutter_renderer_get_view (renderer);
@@ -180,6 +192,14 @@ gutter_renderer_change_view (GtkSourceGutterRenderer *renderer,
                                         G_CALLBACK (on_view_style_updated),
                                         renderer,
                                         0);
+
+               g_signal_connect_object (new_view,
+                                        "notify::cursor-visible",
+                                        G_CALLBACK (on_view_notify_cursor_visible),
+                                        renderer,
+                                        0);
+
+               GTK_SOURCE_GUTTER_RENDERER_LINES (renderer)->priv->cursor_visible = 
gtk_text_view_get_cursor_visible (new_view);
        }
 
        if (GTK_SOURCE_GUTTER_RENDERER_CLASS (gtk_source_gutter_renderer_lines_parent_class)->change_view != 
NULL)
@@ -195,6 +215,7 @@ gutter_renderer_query_data (GtkSourceGutterRenderer      *renderer,
                             GtkTextIter                  *end,
                             GtkSourceGutterRendererState  state)
 {
+       GtkSourceGutterRendererLines *lines = GTK_SOURCE_GUTTER_RENDERER_LINES (renderer);
        gchar text[24];
        gint line;
        gint len;
@@ -203,7 +224,7 @@ gutter_renderer_query_data (GtkSourceGutterRenderer      *renderer,
        line = gtk_text_iter_get_line (start) + 1;
 
        current_line = (state & GTK_SOURCE_GUTTER_RENDERER_STATE_CURSOR) &&
-                      gtk_text_view_get_cursor_visible (gtk_source_gutter_renderer_get_view (renderer));
+                      lines->priv->cursor_visible;
 
        if (current_line)
        {