From 5ae0b9f912b7f5fd1700cbf18763a05493f55b62 Mon Sep 17 00:00:00 2001
From: Carl Worth <cworth@cworth.org>
Date: Mon, 27 Feb 2006 23:11:32 -0800
Subject: [PATCH] Implement cairo_surface_get_type

---
 src/cairo-directfb-surface.c  |  1 +
 src/cairo-glitz-surface.c     |  1 +
 src/cairo-image-surface.c     |  1 +
 src/cairo-meta-surface.c      |  1 +
 src/cairo-paginated-surface.c |  5 +++++
 src/cairo-pdf-surface.c       |  1 +
 src/cairo-ps-surface.c        |  1 +
 src/cairo-surface.c           | 15 +++++++++++++++
 src/cairo-svg-surface.c       |  1 +
 src/cairo-win32-surface.c     |  1 +
 src/cairo-xcb-surface.c       |  1 +
 src/cairo-xlib-surface.c      |  1 +
 src/cairoint.h                | 12 ++++++++++++
 13 files changed, 42 insertions(+)

diff --git a/src/cairo-directfb-surface.c b/src/cairo-directfb-surface.c
index be1791584..a02e56bf4 100644
--- a/src/cairo-directfb-surface.c
+++ b/src/cairo-directfb-surface.c
@@ -662,6 +662,7 @@ _cairo_directfb_surface_scaled_glyph_fini (cairo_scaled_glyph_t *scaled_glyph,
 
 
 static const cairo_surface_backend_t cairo_directfb_surface_backend = {
+		CAIRO_SURFACE_TYPE_DIRECTFB,    
 		_cairo_directfb_surface_create_similar,
 		_cairo_directfb_surface_finish,
 		_cairo_directfb_surface_acquire_source_image,
diff --git a/src/cairo-glitz-surface.c b/src/cairo-glitz-surface.c
index b62547236..667e231d5 100644
--- a/src/cairo-glitz-surface.c
+++ b/src/cairo-glitz-surface.c
@@ -2121,6 +2121,7 @@ _cairo_glitz_surface_flush (void *abstract_surface)
 }
 
 static const cairo_surface_backend_t cairo_glitz_surface_backend = {
+    CAIRO_SURFACE_TYPE_GLITZ,
     _cairo_glitz_surface_create_similar,
     _cairo_glitz_surface_finish,
     _cairo_glitz_surface_acquire_source_image,
diff --git a/src/cairo-image-surface.c b/src/cairo-image-surface.c
index 108e89b5e..06219464c 100644
--- a/src/cairo-image-surface.c
+++ b/src/cairo-image-surface.c
@@ -903,6 +903,7 @@ _cairo_surface_is_image (const cairo_surface_t *surface)
 }
 
 const cairo_surface_backend_t cairo_image_surface_backend = {
+    CAIRO_SURFACE_TYPE_IMAGE,
     _cairo_image_surface_create_similar,
     _cairo_image_surface_finish,
     _cairo_image_surface_acquire_source_image,
diff --git a/src/cairo-meta-surface.c b/src/cairo-meta-surface.c
index 6f824634c..f7aeb719c 100644
--- a/src/cairo-meta-surface.c
+++ b/src/cairo-meta-surface.c
@@ -557,6 +557,7 @@ _cairo_surface_is_meta (const cairo_surface_t *surface)
 }
 
 static const cairo_surface_backend_t cairo_meta_surface_backend = {
+    CAIRO_INTERNAL_SURFACE_TYPE_META,
     _cairo_meta_surface_create_similar,
     _cairo_meta_surface_finish,
     _cairo_meta_surface_acquire_source_image,
diff --git a/src/cairo-paginated-surface.c b/src/cairo-paginated-surface.c
index 6317d7083..4bb857265 100644
--- a/src/cairo-paginated-surface.c
+++ b/src/cairo-paginated-surface.c
@@ -111,6 +111,10 @@ _cairo_paginated_surface_create (cairo_surface_t	*target,
 
     _cairo_surface_init (&surface->base, &cairo_paginated_surface_backend);
 
+    /* Override surface->base.type with target's type so we don't leak
+     * evidence of the paginated wrapper out to the user. */
+    surface->base.type = cairo_surface_get_type (target);
+
     surface->content = content;
     surface->width = width;
     surface->height = height;
@@ -381,6 +385,7 @@ _cairo_paginated_surface_snapshot (void *abstract_other)
 }
 
 const cairo_surface_backend_t cairo_paginated_surface_backend = {
+    CAIRO_INTERNAL_SURFACE_TYPE_PAGINATED,
     NULL, /* create_similar */
     _cairo_paginated_surface_finish,
     _cairo_paginated_surface_acquire_source_image,
diff --git a/src/cairo-pdf-surface.c b/src/cairo-pdf-surface.c
index 289eeb961..cb8287bcf 100644
--- a/src/cairo-pdf-surface.c
+++ b/src/cairo-pdf-surface.c
@@ -1657,6 +1657,7 @@ _cairo_pdf_surface_get_font_options (void                  *abstract_surface,
 }
 
 static const cairo_surface_backend_t cairo_pdf_surface_backend = {
+    CAIRO_SURFACE_TYPE_PDF,
     _cairo_pdf_surface_create_similar,
     _cairo_pdf_surface_finish,
     NULL, /* acquire_source_image */
diff --git a/src/cairo-ps-surface.c b/src/cairo-ps-surface.c
index 371290cc2..6028b6d50 100644
--- a/src/cairo-ps-surface.c
+++ b/src/cairo-ps-surface.c
@@ -1322,6 +1322,7 @@ _cairo_ps_surface_fill (void			*abstract_surface,
 }
 
 static const cairo_surface_backend_t cairo_ps_surface_backend = {
+    CAIRO_SURFACE_TYPE_PS,
     NULL, /* create_similar */
     _cairo_ps_surface_finish,
     NULL, /* acquire_source_image */
diff --git a/src/cairo-surface.c b/src/cairo-surface.c
index 52aeafe46..a317e5b64 100644
--- a/src/cairo-surface.c
+++ b/src/cairo-surface.c
@@ -43,6 +43,7 @@
 
 const cairo_surface_t _cairo_surface_nil = {
     &cairo_image_surface_backend,	/* backend */
+    CAIRO_SURFACE_TYPE_IMAGE,
     -1,					/* ref_count */
     CAIRO_STATUS_NO_MEMORY,		/* status */
     FALSE,				/* finished */
@@ -59,6 +60,7 @@ const cairo_surface_t _cairo_surface_nil = {
 
 const cairo_surface_t _cairo_surface_nil_file_not_found = {
     &cairo_image_surface_backend,	/* backend */
+    CAIRO_SURFACE_TYPE_IMAGE,
     -1,					/* ref_count */
     CAIRO_STATUS_FILE_NOT_FOUND,	/* status */
     FALSE,				/* finished */
@@ -75,6 +77,7 @@ const cairo_surface_t _cairo_surface_nil_file_not_found = {
 
 const cairo_surface_t _cairo_surface_nil_read_error = {
     &cairo_image_surface_backend,	/* backend */
+    CAIRO_SURFACE_TYPE_IMAGE,
     -1,					/* ref_count */
     CAIRO_STATUS_READ_ERROR,		/* status */
     FALSE,				/* finished */
@@ -118,6 +121,16 @@ _cairo_surface_set_error (cairo_surface_t *surface,
     _cairo_error (status);
 }
 
+cairo_surface_type_t
+cairo_surface_get_type (cairo_surface_t *surface)
+{
+    /* We don't use surface->backend->type here so that some of the
+     * special "wrapper" surfaces such as cairo_paginated_surface_t
+     * can override surface->type with the type of the "child"
+     * surface. */
+    return surface->type;
+}
+
 /**
  * cairo_surface_status:
  * @surface: a #cairo_surface_t
@@ -141,6 +154,8 @@ _cairo_surface_init (cairo_surface_t			*surface,
 		     const cairo_surface_backend_t	*backend)
 {
     surface->backend = backend;
+    
+    surface->type = backend->type;
 
     surface->ref_count = 1;
     surface->status = CAIRO_STATUS_SUCCESS;
diff --git a/src/cairo-svg-surface.c b/src/cairo-svg-surface.c
index 5a2c92fff..a5b02c9b8 100644
--- a/src/cairo-svg-surface.c
+++ b/src/cairo-svg-surface.c
@@ -1221,6 +1221,7 @@ _cairo_svg_surface_get_font_options (void                  *abstract_surface,
 
 
 static const cairo_surface_backend_t cairo_svg_surface_backend = {
+	CAIRO_SURFACE_TYPE_SVG,
 	_cairo_svg_surface_create_similar,
 	_cairo_svg_surface_finish,
 	NULL, /* acquire_source_image */
diff --git a/src/cairo-win32-surface.c b/src/cairo-win32-surface.c
index b1811a134..9dacd1d37 100644
--- a/src/cairo-win32-surface.c
+++ b/src/cairo-win32-surface.c
@@ -1030,6 +1030,7 @@ _cairo_surface_is_win32 (cairo_surface_t *surface)
 }
 
 static const cairo_surface_backend_t cairo_win32_surface_backend = {
+    CAIRO_SURFACE_TYPE_WIN32,
     _cairo_win32_surface_create_similar,
     _cairo_win32_surface_finish,
     _cairo_win32_surface_acquire_source_image,
diff --git a/src/cairo-xcb-surface.c b/src/cairo-xcb-surface.c
index faa207c0d..78eafc0fa 100644
--- a/src/cairo-xcb-surface.c
+++ b/src/cairo-xcb-surface.c
@@ -1025,6 +1025,7 @@ _cairo_xcb_surface_get_extents (void		  *abstract_surface,
 }
 
 static const cairo_surface_backend_t cairo_xcb_surface_backend = {
+    CAIRO_SURFACE_TYPE_XCB,
     _cairo_xcb_surface_create_similar,
     _cairo_xcb_surface_finish,
     _cairo_xcb_surface_acquire_source_image,
diff --git a/src/cairo-xlib-surface.c b/src/cairo-xlib-surface.c
index 1ce7e890b..dc7d394e1 100644
--- a/src/cairo-xlib-surface.c
+++ b/src/cairo-xlib-surface.c
@@ -1675,6 +1675,7 @@ _cairo_xlib_surface_scaled_glyph_fini (cairo_scaled_glyph_t *scaled_glyph,
 				       cairo_scaled_font_t  *scaled_font);
 
 static const cairo_surface_backend_t cairo_xlib_surface_backend = {
+    CAIRO_SURFACE_TYPE_XLIB,
     _cairo_xlib_surface_create_similar,
     _cairo_xlib_surface_finish,
     _cairo_xlib_surface_acquire_source_image,
diff --git a/src/cairoint.h b/src/cairoint.h
index a1978a90d..124612346 100644
--- a/src/cairoint.h
+++ b/src/cairoint.h
@@ -256,6 +256,11 @@ typedef enum cairo_int_status {
     CAIRO_INT_STATUS_CACHE_EMPTY
 } cairo_int_status_t;
 
+typedef enum cairo_internal_surface_type {
+    CAIRO_INTERNAL_SURFACE_TYPE_META = 0x1000,
+    CAIRO_INTERNAL_SURFACE_TYPE_PAGINATED
+} cairo_internal_surface_type_t;
+
 typedef enum cairo_direction {
     CAIRO_DIRECTION_FORWARD,
     CAIRO_DIRECTION_REVERSE
@@ -604,6 +609,8 @@ typedef struct _cairo_stroke_style {
 } cairo_stroke_style_t;
 
 struct _cairo_surface_backend {
+    cairo_surface_type_t type;
+
     cairo_surface_t *
     (*create_similar)		(void			*surface,
 				 cairo_content_t	 content,
@@ -834,6 +841,11 @@ typedef struct _cairo_format_masks {
 struct _cairo_surface {
     const cairo_surface_backend_t *backend;
 
+    /* We allow surfaces to override the backend->type by shoving something
+     * else into surface->type. This is for "wrapper" surfaces that want to
+     * hide their internal type from the user-level API. */
+    cairo_surface_type_t type;
+
     unsigned int ref_count;
     cairo_status_t status;
     cairo_bool_t finished;