[goocanvas] Fixes to work with new GTK+ drawing code. Bug #700674.

[Damon Chaplin <damon src gnome org>]

commit 8f2c634d12d05ef2e7fdaf41f4e6bd7a28894e58
Author: Damon Chaplin <damon gnome org>
Date:   Thu Jul 18 21:59:04 2013 +0100

    Fixes to work with new GTK+ drawing code. Bug #700674.

 ChangeLog       |    6 ++++++
 src/goocanvas.c |   35 +++++++++++++++++++++++++++++++----
 2 files changed, 37 insertions(+), 4 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index a26f355..d8066d2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2013-07-18  Damon Chaplin  <damon gnome org>
+
+       * src/goocanvas.c (paint_static_items, goo_canvas_draw): tried to
+       fix drawing code to work with new GTK+ 3.9 drawing code. I'm not sure
+       it is 100% there yet, but the demo seems OK.
+
 2013-03-28  Murray Cumming  <murrayc murrayc com>
 
        Fix some introspection generation warnings.
diff --git a/src/goocanvas.c b/src/goocanvas.c
index d636fc5..507e6fa 100644
--- a/src/goocanvas.c
+++ b/src/goocanvas.c
@@ -2718,10 +2718,23 @@ paint_static_items (GooCanvas       *canvas,
                    GooCanvasBounds *clip_bounds)
 {
   GooCanvasPrivate *priv = GOO_CANVAS_GET_PRIVATE (canvas);
+  guint major_gtk_version, minor_gtk_version;
+  gboolean gtk_3_9 = FALSE;
+
+  major_gtk_version = gtk_get_major_version ();
+  minor_gtk_version = gtk_get_minor_version ();
+  if (major_gtk_version > 3
+      || (major_gtk_version == 3 && minor_gtk_version >= 9))
+    gtk_3_9 = TRUE;
 
   cairo_save (cr);
-  cairo_identity_matrix (cr);
-  cairo_translate (cr, -priv->static_window_x, -priv->static_window_y);
+  if (!gtk_3_9)
+    cairo_identity_matrix (cr);
+  /* FIXME: I'm not sure what we should be doing with 3.9. It doesn't seem
+     to flicker anyway. Maybe we aren't using X for scrolling windows any more
+     so we don't need to worry about redrawing before scrolling etc. */
+  if (!gtk_3_9)
+    cairo_translate (cr, -priv->static_window_x, -priv->static_window_y);
   /* FIXME: Uses pixels at present - use canvas units instead? */
   goo_canvas_item_paint (priv->static_root_item, cr, clip_bounds, 1.0);
   cairo_restore (cr);
@@ -2733,8 +2746,17 @@ goo_canvas_draw (GtkWidget      *widget,
                 cairo_t        *cr)
 {
   GooCanvas *canvas = GOO_CANVAS (widget);
+  GooCanvasPrivate *priv = GOO_CANVAS_GET_PRIVATE (canvas);
   GooCanvasBounds clip_bounds, bounds, root_item_bounds;
   double x1, y1, x2, y2;
+  guint major_gtk_version, minor_gtk_version;
+  gboolean gtk_3_9 = FALSE;
+
+  major_gtk_version = gtk_get_major_version ();
+  minor_gtk_version = gtk_get_minor_version ();
+  if (major_gtk_version > 3
+      || (major_gtk_version == 3 && minor_gtk_version >= 9))
+    gtk_3_9 = TRUE;
 
   if (!gtk_cairo_should_draw_window (cr, canvas->canvas_window))
     return FALSE;
@@ -2756,7 +2778,8 @@ goo_canvas_draw (GtkWidget      *widget,
   cairo_save (cr);
 
   /* Get rid of the translation passed in by GTK+. We use our own. */
-  cairo_identity_matrix (cr);
+  if (!gtk_3_9)
+    cairo_identity_matrix (cr);
 
   /* Set our default drawing settins - antialias, line width. */
   goo_canvas_setup_cairo_context (canvas, cr);
@@ -2778,9 +2801,13 @@ goo_canvas_draw (GtkWidget      *widget,
   goo_canvas_convert_from_window_pixels (canvas, &bounds.x1, &bounds.y1);
   goo_canvas_convert_from_window_pixels (canvas, &bounds.x2, &bounds.y2);
 
+  if (gtk_3_9)
+    cairo_translate (cr, priv->window_x, priv->window_y);
+
   /* Get rid of the current clip, as it uses the wrong coordinate space.
      FIXME: Maybe we should always set a clip with the new GTK+ drawing code. */
-  cairo_reset_clip (cr);
+  if (!gtk_3_9)
+    cairo_reset_clip (cr);
 
   /* Translate it to use the canvas pixel offsets (used when the canvas is
      smaller than the window and the anchor isn't set to NORTH_WEST). */