[gtksourceview] Move ensure highlighting to LAYER_BELOW_TEXT

[Paolo Borelli <pborelli src gnome org>]

commit 045e75440f90cb5a3385c691c81cf2f651e59e84
Author: Paolo Borelli <pborelli gnome org>
Date:   Sat Jan 30 10:45:44 2016 +0100

    Move ensure highlighting to LAYER_BELOW_TEXT
    
    The new gtk introduced two new drawing layers (BELOW_TEXT and
    ABOVE_TEXT) that replace the old BELOW and ABOVE layer. The new
    layers work in buffer coordinates and so are easier to use.
    This is the first commit in a series to move all our drawing to
    the new layers.

 gtksourceview/gtksourceview.c |   67 +++++++++++++++++++++--------------------
 1 files changed, 34 insertions(+), 33 deletions(-)
---
diff --git a/gtksourceview/gtksourceview.c b/gtksourceview/gtksourceview.c
index 0bc7f3a..8dec430 100644
--- a/gtksourceview/gtksourceview.c
+++ b/gtksourceview/gtksourceview.c
@@ -2046,6 +2046,35 @@ gtk_source_view_extend_selection (GtkTextView            *text_view,
                                                                                     end);
 }
 
+static void
+gtk_source_view_ensure_redrawn_rect_is_highlighted (GtkSourceView *view,
+                                                   cairo_t       *cr)
+{
+       GdkRectangle clip;
+       GtkTextIter iter1, iter2;
+
+       if (view->priv->source_buffer == NULL ||
+           !gdk_cairo_get_clip_rectangle (cr, &clip))
+       {
+               return;
+       }
+
+       gtk_text_view_get_line_at_y (GTK_TEXT_VIEW (view), &iter1, clip.y, NULL);
+       gtk_text_iter_backward_line (&iter1);
+       gtk_text_view_get_line_at_y (GTK_TEXT_VIEW (view), &iter2, clip.y + clip.height, NULL);
+       gtk_text_iter_forward_line (&iter2);
+
+       DEBUG ({
+               g_print ("    draw area: %d - %d\n", clip.y, clip.y + clip.height);
+               g_print ("    lines to update: %d - %d\n",
+                        gtk_text_iter_get_line (&iter1),
+                        gtk_text_iter_get_line (&iter2));
+       });
+
+       _gtk_source_buffer_update_highlight (view->priv->source_buffer,
+                                            &iter1, &iter2, FALSE);
+}
+
 /* This function is taken from gtk+/tests/testtext.c */
 static void
 gtk_source_view_get_lines (GtkTextView *text_view,
@@ -2986,40 +3015,12 @@ gtk_source_view_draw_layer (GtkTextView      *text_view,
 
        cairo_save (cr);
 
-       if (layer == GTK_TEXT_VIEW_LAYER_BELOW)
+       if (layer == GTK_TEXT_VIEW_LAYER_BELOW_TEXT)
+       {
+               gtk_source_view_ensure_redrawn_rect_is_highlighted (view, cr);
+       }
+       else if (layer == GTK_TEXT_VIEW_LAYER_BELOW)
        {
-               /* check if the draw is for the text window first, and
-                * make sure the visible region is highlighted */
-               if (view->priv->source_buffer != NULL)
-               {
-                       GdkRectangle visible_rect;
-                       gdouble clip_x1, clip_y1, clip_x2, clip_y2;
-                       GtkTextIter iter1, iter2;
-
-                       gtk_text_view_get_visible_rect (text_view, &visible_rect);
-                       cairo_clip_extents (cr,
-                                           &clip_x1, &clip_y1,
-                                           &clip_x2, &clip_y2);
-
-                       gtk_text_view_get_line_at_y (text_view, &iter1,
-                                                    visible_rect.y + clip_y1, NULL);
-                       gtk_text_iter_backward_line (&iter1);
-                       gtk_text_view_get_line_at_y (text_view, &iter2,
-                                                    visible_rect.y + clip_y2, NULL);
-                       gtk_text_iter_forward_line (&iter2);
-
-                       DEBUG ({
-                               g_print ("    draw area: %d - %d\n", visible_rect.y + clip_y1,
-                                        visible_rect.y + clip_y2);
-                               g_print ("    lines to update: %d - %d\n",
-                                        gtk_text_iter_get_line (&iter1),
-                                        gtk_text_iter_get_line (&iter2));
-                       });
-
-                       _gtk_source_buffer_update_highlight (view->priv->source_buffer,
-                                                            &iter1, &iter2, FALSE);
-               }
-
                if (view->priv->background_pattern == GTK_SOURCE_BACKGROUND_PATTERN_TYPE_GRID &&
                    view->priv->background_pattern_color_set)
                {