[gtk+/wip/css: 104/154] css: Add image implementation for urls

[Benjamin Otte <otte src gnome org>]

commit 56a6acbe1ccdd6bc415a6f6d07716d12dac948b9
Author: Benjamin Otte <otte redhat com>
Date:   Tue Dec 20 08:00:34 2011 +0100

    css: Add image implementation for urls

 gtk/Makefile.am             |    2 +
 gtk/gtkcssimage.c           |    5 +-
 gtk/gtkcssimageurl.c        |  223 +++++++++++++++++++++++++++++++++++++++++++
 gtk/gtkcssimageurlprivate.h |   54 +++++++++++
 4 files changed, 283 insertions(+), 1 deletions(-)
---
diff --git a/gtk/Makefile.am b/gtk/Makefile.am
index 1717480..301b763 100644
--- a/gtk/Makefile.am
+++ b/gtk/Makefile.am
@@ -411,6 +411,7 @@ gtk_private_h_sources =		\
 	gtkcontainerprivate.h   \
 	gtkcsscustompropertyprivate.h \
 	gtkcssimageprivate.h	\
+	gtkcssimageurlprivate.h	\
 	gtkcsslookupprivate.h	\
 	gtkcssparserprivate.h	\
 	gtkcssproviderprivate.h	\
@@ -587,6 +588,7 @@ gtk_base_c_sources = 		\
 	gtkcontainer.c		\
 	gtkcsscustomproperty.c	\
 	gtkcssimage.c		\
+	gtkcssimageurl.c	\
 	gtkcsslookup.c		\
 	gtkcssparser.c		\
 	gtkcssprovider.c	\
diff --git a/gtk/gtkcssimage.c b/gtk/gtkcssimage.c
index 2aec9bb..e46706c 100644
--- a/gtk/gtkcssimage.c
+++ b/gtk/gtkcssimage.c
@@ -22,6 +22,9 @@
 
 #include "gtkcssimageprivate.h"
 
+/* for the types only */
+#include "gtk/gtkcssimageurlprivate.h"
+
 G_DEFINE_ABSTRACT_TYPE (GtkCssImage, _gtk_css_image, G_TYPE_OBJECT)
 
 static int
@@ -165,7 +168,7 @@ _gtk_css_image_new_parse (GtkCssParser *parser,
   g_return_val_if_fail (parser != NULL, NULL);
   g_return_val_if_fail (G_IS_FILE (base), NULL);
 
-  image = g_object_new (GTK_TYPE_CSS_IMAGE, NULL);
+  image = g_object_new (GTK_TYPE_CSS_IMAGE_URL, NULL);
 
   klass = GTK_CSS_IMAGE_GET_CLASS (image);
   if (!klass->parse (image, parser, base))
diff --git a/gtk/gtkcssimageurl.c b/gtk/gtkcssimageurl.c
new file mode 100644
index 0000000..cc0509f
--- /dev/null
+++ b/gtk/gtkcssimageurl.c
@@ -0,0 +1,223 @@
+/*
+ * Copyright  2011 Red Hat Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * Authors: Benjamin Otte <otte gnome org>
+ */
+
+#include "config.h"
+
+#include "gtkcssimageurlprivate.h"
+
+#include "gtkcssprovider.h"
+
+G_DEFINE_TYPE (GtkCssImageUrl, _gtk_css_image_url, GTK_TYPE_CSS_IMAGE)
+
+static int
+gtk_css_image_url_get_width (GtkCssImage *image)
+{
+  GtkCssImageUrl *url = GTK_CSS_IMAGE_URL (image);
+
+  return cairo_image_surface_get_width (url->surface);
+}
+
+static int
+gtk_css_image_url_get_height (GtkCssImage *image)
+{
+  GtkCssImageUrl *url = GTK_CSS_IMAGE_URL (image);
+
+  return cairo_image_surface_get_height (url->surface);
+}
+
+static void
+gtk_css_image_url_draw (GtkCssImage        *image,
+                        cairo_t            *cr,
+                        double              width,
+                        double              height)
+{
+  GtkCssImageUrl *url = GTK_CSS_IMAGE_URL (image);
+
+  cairo_rectangle (cr, 0, 0, width, height);
+  cairo_scale (cr,
+               width / cairo_image_surface_get_width (url->surface),
+               height / cairo_image_surface_get_height (url->surface));
+  cairo_set_source_surface (cr, url->surface, 0, 0);
+  cairo_pattern_set_extend (cairo_get_source (cr), CAIRO_EXTEND_PAD);
+  cairo_fill (cr);
+}
+
+static GFile *
+gtk_css_parse_url (GtkCssParser *parser,
+                   GFile        *base)
+{
+  gchar *path;
+  GFile *file;
+
+  if (_gtk_css_parser_try (parser, "url", FALSE))
+    {
+      if (!_gtk_css_parser_try (parser, "(", TRUE))
+        {
+          _gtk_css_parser_skip_whitespace (parser);
+          if (_gtk_css_parser_try (parser, "(", TRUE))
+            {
+              GError *error;
+              
+              error = g_error_new_literal (GTK_CSS_PROVIDER_ERROR,
+                                           GTK_CSS_PROVIDER_ERROR_DEPRECATED,
+                                           "Whitespace between 'url' and '(' is deprecated");
+                             
+              _gtk_css_parser_take_error (parser, error);
+            }
+          else
+            {
+              _gtk_css_parser_error (parser, "Expected '(' after 'url'");
+              return NULL;
+            }
+        }
+
+      path = _gtk_css_parser_read_string (parser);
+      if (path == NULL)
+        return NULL;
+
+      if (!_gtk_css_parser_try (parser, ")", TRUE))
+        {
+          _gtk_css_parser_error (parser, "No closing ')' found for 'url'");
+          g_free (path);
+          return NULL;
+        }
+    }
+  else
+    {
+      path = _gtk_css_parser_try_name (parser, TRUE);
+      if (path == NULL)
+        {
+          _gtk_css_parser_error (parser, "Not a valid url");
+          return NULL;
+        }
+    }
+
+  file = g_file_resolve_relative_path (base, path);
+  g_free (path);
+
+  return file;
+}
+
+static gboolean
+gtk_css_image_url_parse (GtkCssImage  *image,
+                         GtkCssParser *parser,
+                         GFile        *base)
+{
+  GtkCssImageUrl *url = GTK_CSS_IMAGE_URL (image);
+  GdkPixbuf *pixbuf;
+  GFile *file;
+  char *path;
+  cairo_t *cr;
+  GError *error = NULL;
+
+  file = gtk_css_parse_url (parser, base);
+  if (file == NULL)
+    return FALSE;
+
+  path = g_file_get_path (file);
+  g_object_unref (file);
+
+  pixbuf = gdk_pixbuf_new_from_file (path, &error);
+  g_free (path);
+  if (pixbuf == NULL)
+    {
+      _gtk_css_parser_take_error (parser, error);
+      return FALSE;
+    }
+
+  url->surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32,
+                                             gdk_pixbuf_get_width (pixbuf),
+                                             gdk_pixbuf_get_height (pixbuf));
+  cr = cairo_create (url->surface);
+  gdk_cairo_set_source_pixbuf (cr, pixbuf, 0, 0);
+  cairo_paint (cr);
+  g_object_unref (pixbuf);
+
+  return TRUE;
+}
+
+static cairo_status_t
+surface_write (void                *closure,
+               const unsigned char *data,
+               unsigned int         length)
+{
+  g_byte_array_append (closure, data, length);
+
+  return CAIRO_STATUS_SUCCESS;
+}
+
+static void
+gtk_css_image_url_print (GtkCssImage *image,
+                         GString     *string)
+{
+#if CAIRO_HAS_PNG_FUNCTIONS
+  GtkCssImageUrl *url = GTK_CSS_IMAGE_URL (image);
+  GByteArray *array;
+  char *base64;
+  
+  array = g_byte_array_new ();
+  cairo_surface_write_to_png_stream (url->surface, surface_write, array);
+  base64 = g_base64_encode (array->data, array->len);
+  g_byte_array_free (array, TRUE);
+
+  g_string_append (string, "url(\"data:image/png;base64,");
+  g_string_append (string, base64);
+  g_string_append (string, "\")");
+
+  g_free (base64);
+#else
+  g_string_append (string, "none /* you need cairo png functions enabled to make this work */");
+#endif
+}
+
+static void
+gtk_css_image_url_dispose (GObject *object)
+{
+  GtkCssImageUrl *url = GTK_CSS_IMAGE_URL (object);
+
+  if (url->surface)
+    {
+      cairo_surface_destroy (url->surface);
+      url->surface = NULL;
+    }
+
+  G_OBJECT_CLASS (_gtk_css_image_url_parent_class)->dispose (object);
+}
+
+static void
+_gtk_css_image_url_class_init (GtkCssImageUrlClass *klass)
+{
+  GtkCssImageClass *image_class = GTK_CSS_IMAGE_CLASS (klass);
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  image_class->get_width = gtk_css_image_url_get_width;
+  image_class->get_height = gtk_css_image_url_get_height;
+  image_class->draw = gtk_css_image_url_draw;
+  image_class->parse = gtk_css_image_url_parse;
+  image_class->print = gtk_css_image_url_print;
+
+  object_class->dispose = gtk_css_image_url_dispose;
+}
+
+static void
+_gtk_css_image_url_init (GtkCssImageUrl *image_url)
+{
+}
+
diff --git a/gtk/gtkcssimageurlprivate.h b/gtk/gtkcssimageurlprivate.h
new file mode 100644
index 0000000..39041db
--- /dev/null
+++ b/gtk/gtkcssimageurlprivate.h
@@ -0,0 +1,54 @@
+/*
+ * Copyright  2011 Red Hat Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * Authors: Benjamin Otte <otte gnome org>
+ */
+
+#ifndef __GTK_CSS_IMAGE_URL_PRIVATE_H__
+#define __GTK_CSS_IMAGE_URL_PRIVATE_H__
+
+#include "gtk/gtkcssimageprivate.h"
+
+G_BEGIN_DECLS
+
+#define GTK_TYPE_CSS_IMAGE_URL           (_gtk_css_image_url_get_type ())
+#define GTK_CSS_IMAGE_URL(obj)           (G_TYPE_CHECK_INSTANCE_CAST (obj, GTK_TYPE_CSS_IMAGE_URL, GtkCssImageUrl))
+#define GTK_CSS_IMAGE_URL_CLASS(cls)     (G_TYPE_CHECK_CLASS_CAST (cls, GTK_TYPE_CSS_IMAGE_URL, GtkCssImageUrlClass))
+#define GTK_IS_CSS_IMAGE_URL(obj)        (G_TYPE_CHECK_INSTANCE_TYPE (obj, GTK_TYPE_CSS_IMAGE_URL))
+#define GTK_IS_CSS_IMAGE_URL_CLASS(obj)  (G_TYPE_CHECK_CLASS_TYPE (obj, GTK_TYPE_CSS_IMAGE_URL))
+#define GTK_CSS_IMAGE_URL_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GTK_TYPE_CSS_IMAGE_URL, GtkCssImageUrlClass))
+
+typedef struct _GtkCssImageUrl           GtkCssImageUrl;
+typedef struct _GtkCssImageUrlClass      GtkCssImageUrlClass;
+
+struct _GtkCssImageUrl
+{
+  GtkCssImage parent;
+
+  cairo_surface_t *surface;             /* the surface we render - guaranteed to be an image surface */
+};
+
+struct _GtkCssImageUrlClass
+{
+  GtkCssImageClass parent_class;
+};
+
+GType          _gtk_css_image_url_get_type             (void) G_GNUC_CONST;
+
+G_END_DECLS
+
+#endif /* __GTK_CSS_IMAGE_URL_PRIVATE_H__ */