[gtkmm] Widget: Added should_draw_window() and transform_cairo_context_to_window().

[Murray Cumming <murrayc src gnome org>]

commit 2d08702a5a2d91cefb3d414620bbe0bdba9a9ce5
Author: Murray Cumming <murrayc murrayc com>
Date:   Mon Feb 14 11:30:14 2011 +0100

    Widget: Added should_draw_window() and transform_cairo_context_to_window().
    
    * gtk/src/widget.[hg|ccg]: Added Widget::transform_cairo_context_to_window(),
    wrapping gtk_cairo_transform_to_window().
    Added Widget::should_draw_window(), wrapping gtk_cairo_should_draw_window().
    These are both protected because they are for use in Gtk::Container
    implementation.
    * tools/m4/convert_gtk.m4: Added a Cairo::Context conversion.

 ChangeLog               |   11 +++++++++++
 gtk/src/widget.ccg      |    6 ++++++
 gtk/src/widget.hg       |   21 ++++++++++++++++++++-
 tools/m4/convert_gtk.m4 |    1 +
 4 files changed, 38 insertions(+), 1 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 8fb1b60..125b420 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+2011-02-14  Murray Cumming  <murrayc murrayc com>
+
+	Widget: Added should_draw_window() and transform_cairo_context_to_window().
+
+	* gtk/src/widget.[hg|ccg]: Added Widget::transform_cairo_context_to_window(), 
+	wrapping gtk_cairo_transform_to_window().
+	Added Widget::should_draw_window(), wrapping gtk_cairo_should_draw_window().
+	These are both protected because they are for use in Gtk::Container 
+	implementation.
+	* tools/m4/convert_gtk.m4: Added a Cairo::Context conversion.
+
 2011-02-11  Murray Cumming  <murrayc murrayc com>
 
 	Make sure that we do not wrap the deprecated CellRenderer::get_size() vfunc.
diff --git a/gtk/src/widget.ccg b/gtk/src/widget.ccg
index c0a86a3..fa4dff7 100644
--- a/gtk/src/widget.ccg
+++ b/gtk/src/widget.ccg
@@ -646,4 +646,10 @@ void Widget::unset_cursor()
   gtk_widget_override_cursor(gobj(), 0, 0); 
 }
 
+
+void Widget::transform_cairo_context_to_window(const Cairo::RefPtr<Cairo::Context>& cr, const Glib::RefPtr<const Gdk::Window>& window)
+{
+  gtk_cairo_transform_to_window((cr)->cobj(), gobj(), const_cast<GdkWindow*>(Glib::unwrap<Gdk::Window>(window)));
+}
+
 } // namespace Gtk
diff --git a/gtk/src/widget.hg b/gtk/src/widget.hg
index f2a664f..ca040e9 100644
--- a/gtk/src/widget.hg
+++ b/gtk/src/widget.hg
@@ -856,7 +856,26 @@ protected:
   void set_window(const Glib::RefPtr<Gdk::Window>& window);
   _IGNORE(gtk_widget_set_window)
   
-  //TODO: Move this to protected when we can break API:
+  _WRAP_METHOD(static bool should_draw_window(const Cairo::RefPtr<const Cairo::Context>& cr, const Glib::RefPtr<const Gdk::Window>& window), gtk_cairo_should_draw_window)
+  
+ /** Transforms the given cairo context @a cr from widget-relative
+  * coordinates to window-relative coordinates.
+  * If the widget's window is not an ancestor of @a window, no
+  * modification will be applied.
+  *
+  * This is the inverse to the transformation GTK applies when
+  * preparing an expose event to be emitted with the Widget's draw
+  * signal. It is intended to help porting multiwindow widgets from
+  * GTK+ 2 to the rendering architecture of GTK+ 3.
+  * 
+  * @param cr The cairo context to transform.
+  * @param window The window to transform the context to.
+  *
+  * @newin{3,0}
+  */
+  void transform_cairo_context_to_window(const Cairo::RefPtr<Cairo::Context>& cr, const Glib::RefPtr<const Gdk::Window>& window);
+  _IGNORE(gtk_cairo_transform_to_window)
+  
   /**  Retrieves the widget's requisition.
    *
    * This method should only be used by widget implementations in
diff --git a/tools/m4/convert_gtk.m4 b/tools/m4/convert_gtk.m4
index aa6f2de..77f7833 100644
--- a/tools/m4/convert_gtk.m4
+++ b/tools/m4/convert_gtk.m4
@@ -614,6 +614,7 @@ _CONVERSION(`GtkPrintOperationResult',`PrintOperationResult',`($2)$3')
 _CONVERSION(`GtkPrintStatus',`PrintStatus',`($2)$3')
 
 _CONVERSION(`const Cairo::RefPtr<Cairo::Context>&',`cairo_t*',`($3)->cobj()')
+_CONVERSION(`const Cairo::RefPtr<const Cairo::Context>&',`cairo_t*',`const_cast<cairo_t*>(($3)->cobj())')
 _CONVERSION(`const Cairo::FontOptions&',`const cairo_font_options_t*',`($3).cobj()')