[gtk+/wip/css: 109/154] cssimage: Add GtkCssImageGradient

[Paolo Borelli <pborelli src gnome org>]

commit e55f64032f24fe9562f0152ba0228b8f5ba48c56
Author: Benjamin Otte <otte redhat com>
Date:   Tue Dec 20 14:46:19 2011 +0100

    cssimage: Add GtkCssImageGradient

 gtk/Makefile.am                  |    2 +
 gtk/gtkcssimage.c                |    4 +-
 gtk/gtkcssimagegradient.c        |  319 ++++++++++++++++++++++++++++++++++++++
 gtk/gtkcssimagegradientprivate.h |   60 +++++++
 4 files changed, 384 insertions(+), 1 deletions(-)
---
diff --git a/gtk/Makefile.am b/gtk/Makefile.am
index 2b76cbc..c6b50d8 100644
--- a/gtk/Makefile.am
+++ b/gtk/Makefile.am
@@ -410,6 +410,7 @@ gtk_private_h_sources =		\
 	gtkcellareaboxcontextprivate.h	\
 	gtkcontainerprivate.h   \
 	gtkcsscustompropertyprivate.h \
+	gtkcssimagegradientprivate.h	\
 	gtkcssimageprivate.h	\
 	gtkcssimageurlprivate.h	\
 	gtkcsslookupprivate.h	\
@@ -588,6 +589,7 @@ gtk_base_c_sources = 		\
 	gtkcontainer.c		\
 	gtkcsscustomproperty.c	\
 	gtkcssimage.c		\
+	gtkcssimagegradient.c	\
 	gtkcssimageurl.c	\
 	gtkcsslookup.c		\
 	gtkcssparser.c		\
diff --git a/gtk/gtkcssimage.c b/gtk/gtkcssimage.c
index 968ab7d..adc7859 100644
--- a/gtk/gtkcssimage.c
+++ b/gtk/gtkcssimage.c
@@ -23,6 +23,7 @@
 #include "gtkcssimageprivate.h"
 
 /* for the types only */
+#include "gtk/gtkcssimagegradientprivate.h"
 #include "gtk/gtkcssimageurlprivate.h"
 
 G_DEFINE_ABSTRACT_TYPE (GtkCssImage, _gtk_css_image, G_TYPE_OBJECT)
@@ -166,7 +167,8 @@ _gtk_css_image_new_parse (GtkCssParser *parser,
     const char *prefix;
     GType (* type_func) (void);
   } image_types[] = {
-    { "url", _gtk_css_image_url_get_type }
+    { "url", _gtk_css_image_url_get_type },
+    { "-gtk-gradient", _gtk_css_image_gradient_get_type }
   };
   guint i;
 
diff --git a/gtk/gtkcssimagegradient.c b/gtk/gtkcssimagegradient.c
new file mode 100644
index 0000000..f56dd4b
--- /dev/null
+++ b/gtk/gtkcssimagegradient.c
@@ -0,0 +1,319 @@
+/*
+ * 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 "gtkcssimagegradientprivate.h"
+
+#include "gtkcssprovider.h"
+
+G_DEFINE_TYPE (GtkCssImageGradient, _gtk_css_image_gradient, GTK_TYPE_CSS_IMAGE)
+
+static GtkCssImage *
+gtk_css_image_gradient_compute (GtkCssImage     *image,
+                                GtkStyleContext *context)
+{
+  GtkCssImageGradient *gradient = GTK_CSS_IMAGE_GRADIENT (image);
+  GtkCssImageGradient *copy;
+
+  if (gradient->pattern)
+    return g_object_ref (gradient);
+
+  copy = g_object_new (GTK_TYPE_CSS_IMAGE_GRADIENT, NULL);
+  copy->gradient = gtk_gradient_ref (gradient->gradient);
+  copy->pattern = gtk_gradient_resolve_for_context (copy->gradient, context);
+
+  return GTK_CSS_IMAGE (copy);
+}
+
+static void
+gtk_css_image_gradient_draw (GtkCssImage        *image,
+                             cairo_t            *cr,
+                             double              width,
+                             double              height)
+{
+  GtkCssImageGradient *gradient = GTK_CSS_IMAGE_GRADIENT (image);
+
+  if (!gradient->pattern)
+    {
+      g_warning ("trying to paint unresolved gradient");
+      return;
+    }
+
+  cairo_scale (cr, width, height);
+
+  cairo_rectangle (cr, 0, 0, 1, 1);
+  cairo_set_source (cr, gradient->pattern);
+  cairo_fill (cr);
+}
+
+static gboolean
+gtk_css_image_gradient_parse (GtkCssImage  *image,
+                              GtkCssParser *parser,
+                              GFile        *base)
+{
+  GtkCssImageGradient *gradient = GTK_CSS_IMAGE_GRADIENT (image);
+
+  gradient->gradient = _gtk_gradient_parse (parser);
+
+  return gradient->gradient != NULL;
+}
+
+static void
+gtk_css_image_gradient_print (GtkCssImage *image,
+                              GString     *string)
+{
+  GtkCssImageGradient *gradient = GTK_CSS_IMAGE_GRADIENT (image);
+  char *s;
+
+  s = gtk_gradient_to_string (gradient->gradient);
+  g_string_append (string, s);
+  g_free (s);
+}
+
+static void
+gtk_css_image_gradient_dispose (GObject *object)
+{
+  GtkCssImageGradient *gradient = GTK_CSS_IMAGE_GRADIENT (object);
+
+  if (gradient->gradient)
+    {
+      gtk_gradient_unref (gradient->gradient);
+      gradient->gradient = NULL;
+    }
+  if (gradient->pattern)
+    {
+      cairo_pattern_destroy (gradient->pattern);
+      gradient->pattern = NULL;
+    }
+
+  G_OBJECT_CLASS (_gtk_css_image_gradient_parent_class)->dispose (object);
+}
+
+static void
+_gtk_css_image_gradient_class_init (GtkCssImageGradientClass *klass)
+{
+  GtkCssImageClass *image_class = GTK_CSS_IMAGE_CLASS (klass);
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  image_class->compute = gtk_css_image_gradient_compute;
+  image_class->draw = gtk_css_image_gradient_draw;
+  image_class->parse = gtk_css_image_gradient_parse;
+  image_class->print = gtk_css_image_gradient_print;
+
+  object_class->dispose = gtk_css_image_gradient_dispose;
+}
+
+static void
+_gtk_css_image_gradient_init (GtkCssImageGradient *image_gradient)
+{
+}
+
+GtkGradient *
+_gtk_gradient_parse (GtkCssParser *parser)
+{
+  GtkGradient *gradient;
+  cairo_pattern_type_t type;
+  gdouble coords[6];
+  guint i;
+
+  g_return_val_if_fail (parser != NULL, NULL);
+
+  if (!_gtk_css_parser_try (parser, "-gtk-gradient", TRUE))
+    {
+      _gtk_css_parser_error (parser,
+                             "Expected '-gtk-gradient'");
+      return NULL;
+    }
+
+  if (!_gtk_css_parser_try (parser, "(", TRUE))
+    {
+      _gtk_css_parser_error (parser,
+                             "Expected '(' after '-gtk-gradient'");
+      return NULL;
+    }
+
+  /* Parse gradient type */
+  if (_gtk_css_parser_try (parser, "linear", TRUE))
+    type = CAIRO_PATTERN_TYPE_LINEAR;
+  else if (_gtk_css_parser_try (parser, "radial", TRUE))
+    type = CAIRO_PATTERN_TYPE_RADIAL;
+  else
+    {
+      _gtk_css_parser_error (parser,
+                             "Gradient type must be 'radial' or 'linear'");
+      return NULL;
+    }
+
+  /* Parse start/stop position parameters */
+  for (i = 0; i < 2; i++)
+    {
+      if (! _gtk_css_parser_try (parser, ",", TRUE))
+        {
+          _gtk_css_parser_error (parser,
+                                 "Expected ','");
+          return NULL;
+        }
+
+      if (_gtk_css_parser_try (parser, "left", TRUE))
+        coords[i * 3] = 0;
+      else if (_gtk_css_parser_try (parser, "right", TRUE))
+        coords[i * 3] = 1;
+      else if (_gtk_css_parser_try (parser, "center", TRUE))
+        coords[i * 3] = 0.5;
+      else if (!_gtk_css_parser_try_double (parser, &coords[i * 3]))
+        {
+          _gtk_css_parser_error (parser,
+                                 "Expected a valid X coordinate");
+          return NULL;
+        }
+
+      if (_gtk_css_parser_try (parser, "top", TRUE))
+        coords[i * 3 + 1] = 0;
+      else if (_gtk_css_parser_try (parser, "bottom", TRUE))
+        coords[i * 3 + 1] = 1;
+      else if (_gtk_css_parser_try (parser, "center", TRUE))
+        coords[i * 3 + 1] = 0.5;
+      else if (!_gtk_css_parser_try_double (parser, &coords[i * 3 + 1]))
+        {
+          _gtk_css_parser_error (parser,
+                                 "Expected a valid Y coordinate");
+          return NULL;
+        }
+
+      if (type == CAIRO_PATTERN_TYPE_RADIAL)
+        {
+          /* Parse radius */
+          if (! _gtk_css_parser_try (parser, ",", TRUE))
+            {
+              _gtk_css_parser_error (parser,
+                                     "Expected ','");
+              return NULL;
+            }
+
+          if (! _gtk_css_parser_try_double (parser, &coords[(i * 3) + 2]))
+            {
+              _gtk_css_parser_error (parser,
+                                     "Expected a numer for the radius");
+              return NULL;
+            }
+        }
+    }
+
+  if (type == CAIRO_PATTERN_TYPE_LINEAR)
+    gradient = gtk_gradient_new_linear (coords[0], coords[1], coords[3], coords[4]);
+  else
+    gradient = gtk_gradient_new_radial (coords[0], coords[1], coords[2],
+                                        coords[3], coords[4], coords[5]);
+
+  while (_gtk_css_parser_try (parser, ",", TRUE))
+    {
+      GtkSymbolicColor *color;
+      gdouble position;
+
+      if (_gtk_css_parser_try (parser, "from", TRUE))
+        {
+          position = 0;
+
+          if (!_gtk_css_parser_try (parser, "(", TRUE))
+            {
+              gtk_gradient_unref (gradient);
+              _gtk_css_parser_error (parser,
+                                     "Expected '('");
+              return NULL;
+            }
+
+        }
+      else if (_gtk_css_parser_try (parser, "to", TRUE))
+        {
+          position = 1;
+
+          if (!_gtk_css_parser_try (parser, "(", TRUE))
+            {
+              gtk_gradient_unref (gradient);
+              _gtk_css_parser_error (parser,
+                                     "Expected '('");
+              return NULL;
+            }
+
+        }
+      else if (_gtk_css_parser_try (parser, "color-stop", TRUE))
+        {
+          if (!_gtk_css_parser_try (parser, "(", TRUE))
+            {
+              gtk_gradient_unref (gradient);
+              _gtk_css_parser_error (parser,
+                                     "Expected '('");
+              return NULL;
+            }
+
+          if (!_gtk_css_parser_try_double (parser, &position))
+            {
+              gtk_gradient_unref (gradient);
+              _gtk_css_parser_error (parser,
+                                     "Expected a valid number");
+              return NULL;
+            }
+
+          if (!_gtk_css_parser_try (parser, ",", TRUE))
+            {
+              gtk_gradient_unref (gradient);
+              _gtk_css_parser_error (parser,
+                                     "Expected a comma");
+              return NULL;
+            }
+        }
+      else
+        {
+          gtk_gradient_unref (gradient);
+          _gtk_css_parser_error (parser,
+                                 "Not a valid color-stop definition");
+          return NULL;
+        }
+
+      color = _gtk_css_parser_read_symbolic_color (parser);
+      if (color == NULL)
+        {
+          gtk_gradient_unref (gradient);
+          return NULL;
+        }
+
+      gtk_gradient_add_color_stop (gradient, position, color);
+      gtk_symbolic_color_unref (color);
+
+      if (!_gtk_css_parser_try (parser, ")", TRUE))
+        {
+          gtk_gradient_unref (gradient);
+          _gtk_css_parser_error (parser,
+                                 "Expected ')'");
+          return NULL;
+        }
+    }
+
+  if (!_gtk_css_parser_try (parser, ")", TRUE))
+    {
+      gtk_gradient_unref (gradient);
+      _gtk_css_parser_error (parser,
+                             "Expected ')'");
+      return NULL;
+    }
+
+  return gradient;
+}
diff --git a/gtk/gtkcssimagegradientprivate.h b/gtk/gtkcssimagegradientprivate.h
new file mode 100644
index 0000000..864240c
--- /dev/null
+++ b/gtk/gtkcssimagegradientprivate.h
@@ -0,0 +1,60 @@
+/*
+ * 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_GRADIENT_PRIVATE_H__
+#define __GTK_CSS_IMAGE_GRADIENT_PRIVATE_H__
+
+#include "gtk/gtkcssimageprivate.h"
+
+#include <gtk/gtkgradient.h>
+
+G_BEGIN_DECLS
+
+#define GTK_TYPE_CSS_IMAGE_GRADIENT           (_gtk_css_image_gradient_get_type ())
+#define GTK_CSS_IMAGE_GRADIENT(obj)           (G_TYPE_CHECK_INSTANCE_CAST (obj, GTK_TYPE_CSS_IMAGE_GRADIENT, GtkCssImageGradient))
+#define GTK_CSS_IMAGE_GRADIENT_CLASS(cls)     (G_TYPE_CHECK_CLASS_CAST (cls, GTK_TYPE_CSS_IMAGE_GRADIENT, GtkCssImageGradientClass))
+#define GTK_IS_CSS_IMAGE_GRADIENT(obj)        (G_TYPE_CHECK_INSTANCE_TYPE (obj, GTK_TYPE_CSS_IMAGE_GRADIENT))
+#define GTK_IS_CSS_IMAGE_GRADIENT_CLASS(obj)  (G_TYPE_CHECK_CLASS_TYPE (obj, GTK_TYPE_CSS_IMAGE_GRADIENT))
+#define GTK_CSS_IMAGE_GRADIENT_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GTK_TYPE_CSS_IMAGE_GRADIENT, GtkCssImageGradientClass))
+
+typedef struct _GtkCssImageGradient           GtkCssImageGradient;
+typedef struct _GtkCssImageGradientClass      GtkCssImageGradientClass;
+
+struct _GtkCssImageGradient
+{
+  GtkCssImage parent;
+
+  GtkGradient *gradient;
+  cairo_pattern_t *pattern;             /* the resolved gradient */
+};
+
+struct _GtkCssImageGradientClass
+{
+  GtkCssImageClass parent_class;
+};
+
+GType          _gtk_css_image_gradient_get_type             (void) G_GNUC_CONST;
+
+/* for lack of a better place to put it */
+GtkGradient *  _gtk_gradient_parse                          (GtkCssParser *parser);
+
+G_END_DECLS
+
+#endif /* __GTK_CSS_IMAGE_GRADIENT_PRIVATE_H__ */