textview: Add draw_layer vfunc

This allows subclasses to render things below and above the text
in the text view. This allows e.g. GtkSourceView to highlight the
cursor row and to render overlays for colum 80. This used to be done
by rendering before/after chaining up to the parent, but that doesn't
work anymore since the view now renders a background, and due to the
use of the pixel cache.

1 files changed, 22 insertions, 1 deletions

diff --git a/gtk/gtktextview.h b/gtk/gtktextview.h
index 46f57fd37e..aaa03562f8 100644
--- a/gtk/gtktextview.h
+++ b/gtk/gtktextview.h
@@ -68,6 +68,19 @@ typedef enum
 } GtkTextWindowType;
 
 /**
+ * GtkTextViewLayer:
+ * @GTK_TEXT_VIEW_LAYER_BELOW: The layer rendered below the text (but above the background).
+ * @GTK_TEXT_VIEW_LAYER_ABOVE: The layer rendered above the text.
+ *
+ * Used to reference the parts of #GtkTextView.
+ */
+typedef enum
+{
+  GTK_TEXT_VIEW_LAYER_BELOW,
+  GTK_TEXT_VIEW_LAYER_ABOVE
+} GtkTextViewLayer;
+
+/**
  * GTK_TEXT_VIEW_PRIORITY_VALIDATE:
  *
  * The priority at which the text view validates onscreen lines
@@ -86,6 +99,11 @@ struct _GtkTextView
   GtkTextViewPrivate *priv;
 };
 
+/**
+ * GtkTextViewClass:
+ * @parent_class: The object class structure needs to be the first
+ * @draw_layer: Draw layers below and above the text in the text window.
+ */
 struct _GtkTextViewClass
 {
   GtkContainerClass parent_class;
@@ -121,6 +139,10 @@ struct _GtkTextViewClass
 
   GtkTextBuffer * (* create_buffer) (GtkTextView *text_view);
 
+  void (* draw_layer)       (GtkWidget        *widget,
+			     GtkTextViewLayer layer,
+			     cairo_t          *cr);
+
   /* Padding for future expansion */
   void (*_gtk_reserved1) (void);
   void (*_gtk_reserved2) (void);
@@ -128,7 +150,6 @@ struct _GtkTextViewClass
   void (*_gtk_reserved4) (void);
   void (*_gtk_reserved5) (void);
   void (*_gtk_reserved6) (void);
-  void (*_gtk_reserved7) (void);
 };
 
 GDK_AVAILABLE_IN_ALL