Add cairo_device_t

The device is a generic method for accessing the underlying interface
with the native graphics subsystem, typically the X connection or
perhaps the GL context. By exposing a cairo_device_t on a surface and
its various methods we enable finer control over interoperability with
external interactions of the device by applications. The use case in
mind is, for example, a multi-threaded gstreamer which needs to serialise
its own direct access to the device along with Cairo's across many
threads.

Secondly, the cairo_device_t is a unifying API for the mismash of
backend specific methods for controlling creation of surfaces with
explicit devices and a convenient hook for debugging and introspection.

The principal components of the API are the memory management of:

  cairo_device_reference(),
  cairo_device_finish() and
  cairo_device_destroy();

along with a pair of routines for serialising interaction:

  cairo_device_acquire() and
  cairo_device_release()

and a method to flush any outstanding accesses:

  cairo_device_flush().

The device for a particular surface may be retrieved using:

  cairo_surface_get_device().

The device returned is owned by the surface.

1 files changed, 4 insertions, 1 deletions

diff --git a/src/cairo-beos-surface.cpp b/src/cairo-beos-surface.cpp
index 68d08147..ebf62d9a 100644
--- a/src/cairo-beos-surface.cpp
+++ b/src/cairo-beos-surface.cpp
@@ -915,7 +915,10 @@ _cairo_beos_surface_create_internal (BView*   view,
     cairo_content_t content = CAIRO_CONTENT_COLOR;
     if (bmp && (bmp->ColorSpace() == B_RGBA32 || bmp->ColorSpace() == B_RGBA15))
 	content = CAIRO_CONTENT_COLOR_ALPHA;
-    _cairo_surface_init(&surface->base, &cairo_beos_surface_backend, content);
+    _cairo_surface_init (&surface->base,
+			 &cairo_beos_surface_backend,
+			 NULL, /* device */
+			 content);
 
     surface->view = view;
     surface->bitmap = bmp;