css: Add support for -gtk-icontheme("icon-name")

This allows using icons from the icontheme as images in CSS. The
reasoning is that this allows to give the image control about how it's
scaled (by using the icon theme's scaling method. So we can get crisp
images at different resolutions.

1 files changed, 169 insertions, 0 deletions

diff --git a/gtk/gtkcssimageicontheme.c b/gtk/gtkcssimageicontheme.c
new file mode 100644
index 0000000000..a681fe2675
--- /dev/null
+++ b/gtk/gtkcssimageicontheme.c
@@ -0,0 +1,169 @@
+/*
+ * Copyright © 2012 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, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Benjamin Otte <otte@gnome.org>
+ */
+
+#include "config.h"
+
+#include "gtkcssimageiconthemeprivate.h"
+
+#include <math.h>
+
+#include "gtksettingsprivate.h"
+#include "gtkstyleproviderprivate.h"
+
+G_DEFINE_TYPE (GtkCssImageIconTheme, _gtk_css_image_icon_theme, GTK_TYPE_CSS_IMAGE)
+
+double
+gtk_css_image_icon_theme_get_aspect_ratio (GtkCssImage *image)
+{
+  /* icon theme icons only take a single size when requesting, so we insist on being square */
+  return 1.0;
+}
+
+static void
+gtk_css_image_icon_theme_draw (GtkCssImage        *image,
+                               cairo_t            *cr,
+                               double              width,
+                               double              height)
+{
+  GtkCssImageIconTheme *icon_theme = GTK_CSS_IMAGE_ICON_THEME (image);
+  GError *error = NULL;
+  GdkPixbuf *pixbuf;
+  gint size;
+
+  size = floor (MIN (width, height));
+  if (size <= 0)
+    return;
+
+  pixbuf = gtk_icon_theme_load_icon_for_scale (icon_theme->icon_theme,
+                                               icon_theme->name,
+                                               size,
+                                               icon_theme->scale,
+                                               GTK_ICON_LOOKUP_USE_BUILTIN,
+                                               &error);
+  if (pixbuf == NULL)
+    {
+      /* XXX: render missing icon image here? */
+      g_error_free (error);
+      return;
+    }
+
+  gdk_cairo_set_source_pixbuf (cr,
+                               pixbuf,
+                               (width - gdk_pixbuf_get_width (pixbuf)) / 2.0,
+                               (height - gdk_pixbuf_get_height (pixbuf)) / 2.0);
+  cairo_paint (cr);
+
+  g_object_unref (pixbuf);
+}
+
+
+static gboolean
+gtk_css_image_icon_theme_parse (GtkCssImage  *image,
+                            GtkCssParser *parser)
+{
+  GtkCssImageIconTheme *icon_theme = GTK_CSS_IMAGE_ICON_THEME (image);
+
+  if (!_gtk_css_parser_try (parser, "-gtk-icontheme(", TRUE))
+    {
+      _gtk_css_parser_error (parser, "Expected '-gtk-icontheme('");
+      return FALSE;
+    }
+
+  icon_theme->name = _gtk_css_parser_read_string (parser);
+  if (icon_theme->name == NULL)
+    return FALSE;
+
+  if (!_gtk_css_parser_try (parser, ")", TRUE))
+    {
+      _gtk_css_parser_error (parser, "Missing closing bracket at end of '-gtk-icontheme'");
+      return FALSE;
+    }
+
+  return TRUE;
+}
+
+static void
+gtk_css_image_icon_theme_print (GtkCssImage *image,
+                                GString     *string)
+{
+  GtkCssImageIconTheme *icon_theme = GTK_CSS_IMAGE_ICON_THEME (image);
+
+  g_string_append (string, "-gtk-icontheme(");
+  _gtk_css_print_string (string, icon_theme->name);
+  g_string_append (string, ")");
+}
+
+static GtkCssImage *
+gtk_css_image_icon_theme_compute (GtkCssImage             *image,
+                                  guint                    property_id,
+                                  GtkStyleProviderPrivate *provider,
+                                  int                      scale,
+                                  GtkCssComputedValues    *values,
+                                  GtkCssComputedValues    *parent_values,
+                                  GtkCssDependencies      *dependencies)
+{
+  GtkCssImageIconTheme *icon_theme = GTK_CSS_IMAGE_ICON_THEME (image);
+  GtkCssImageIconTheme *copy;
+  GtkSettings *settings;
+  GdkScreen *screen;
+
+  settings = _gtk_style_provider_private_get_settings (provider);
+  if (settings == NULL)
+    screen = gdk_screen_get_default ();
+  else
+    screen = _gtk_settings_get_screen (settings);
+
+  copy = g_object_new (GTK_TYPE_CSS_IMAGE_ICON_THEME, NULL);
+  copy->name = g_strdup (icon_theme->name);
+  copy->icon_theme = gtk_icon_theme_get_for_screen (screen);
+  copy->scale = scale;
+
+  return GTK_CSS_IMAGE (copy);
+}
+
+static gboolean
+gtk_css_image_icon_theme_equal (GtkCssImage *image1,
+                            GtkCssImage *image2)
+{
+  GtkCssImageIconTheme *icon_theme1 = GTK_CSS_IMAGE_ICON_THEME (image1);
+  GtkCssImageIconTheme *icon_theme2 = GTK_CSS_IMAGE_ICON_THEME (image2);
+
+  return g_str_equal (icon_theme1->name, icon_theme2->name);
+}
+
+static void
+_gtk_css_image_icon_theme_class_init (GtkCssImageIconThemeClass *klass)
+{
+  GtkCssImageClass *image_class = GTK_CSS_IMAGE_CLASS (klass);
+
+  image_class->get_aspect_ratio = gtk_css_image_icon_theme_get_aspect_ratio;
+  image_class->draw = gtk_css_image_icon_theme_draw;
+  image_class->parse = gtk_css_image_icon_theme_parse;
+  image_class->print = gtk_css_image_icon_theme_print;
+  image_class->compute = gtk_css_image_icon_theme_compute;
+  image_class->equal = gtk_css_image_icon_theme_equal;
+}
+
+static void
+_gtk_css_image_icon_theme_init (GtkCssImageIconTheme *icon_theme)
+{
+  icon_theme->icon_theme = gtk_icon_theme_get_default ();
+  icon_theme->scale = 1;
+}
+