[gtk+] Add a way to load recolored icons in CSS

[Matthias Clasen <matthiasc src gnome org>]

commit beec55a22bd80baad05428f84e1b99ae589f9171
Author: Matthias Clasen <mclasen redhat com>
Date:   Thu Jan 14 13:48:43 2016 -0500

    Add a way to load recolored icons in CSS
    
    This can come in handy to load images that are not in an icon theme,
    but still benefit from symbolic recoloring.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=760536

 gtk/Makefile.am                 |    2 +
 gtk/gtkcssimage.c               |    2 +
 gtk/gtkcssimagerecolor.c        |  215 +++++++++++++++++++++++++++++++++++++++
 gtk/gtkcssimagerecolorprivate.h |   54 ++++++++++
 4 files changed, 273 insertions(+), 0 deletions(-)
---
diff --git a/gtk/Makefile.am b/gtk/Makefile.am
index 527037a..98f0f5d 100644
--- a/gtk/Makefile.am
+++ b/gtk/Makefile.am
@@ -405,6 +405,7 @@ gtk_private_h_sources =             \
        gtkcssimageprivate.h    \
        gtkcssimagesurfaceprivate.h     \
        gtkcssimageurlprivate.h \
+       gtkcssimagerecolorprivate.h     \
        gtkcssimagescaledprivate.h      \
        gtkcssimagevalueprivate.h       \
        gtkcssimagewin32private.h       \
@@ -664,6 +665,7 @@ gtk_base_c_sources =                \
        gtkcssimageradial.c     \
        gtkcssimagesurface.c    \
        gtkcssimageurl.c        \
+       gtkcssimagerecolor.c    \
        gtkcssimagescaled.c     \
        gtkcssimagevalue.c      \
        gtkcssimagewin32.c      \
diff --git a/gtk/gtkcssimage.c b/gtk/gtkcssimage.c
index 23f4b06..6f14176 100644
--- a/gtk/gtkcssimage.c
+++ b/gtk/gtkcssimage.c
@@ -31,6 +31,7 @@
 #include "gtk/gtkcssimageradialprivate.h"
 #include "gtk/gtkcssimageurlprivate.h"
 #include "gtk/gtkcssimagescaledprivate.h"
+#include "gtk/gtkcssimagerecolorprivate.h"
 #include "gtk/gtkcssimagewin32private.h"
 
 G_DEFINE_ABSTRACT_TYPE (GtkCssImage, _gtk_css_image, G_TYPE_OBJECT)
@@ -419,6 +420,7 @@ gtk_css_image_get_parser_type (GtkCssParser *parser)
     { "-gtk-gradient", _gtk_css_image_gradient_get_type },
     { "-gtk-icontheme", _gtk_css_image_icon_theme_get_type },
     { "-gtk-scaled", _gtk_css_image_scaled_get_type },
+    { "-gtk-recolor", _gtk_css_image_recolor_get_type },
     { "-gtk-win32-theme-part", _gtk_css_image_win32_get_type },
     { "linear-gradient", _gtk_css_image_linear_get_type },
     { "repeating-linear-gradient", _gtk_css_image_linear_get_type },
diff --git a/gtk/gtkcssimagerecolor.c b/gtk/gtkcssimagerecolor.c
new file mode 100644
index 0000000..0d6948a
--- /dev/null
+++ b/gtk/gtkcssimagerecolor.c
@@ -0,0 +1,215 @@
+/*
+ * Copyright © 2016 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: Matthias Clasen <mclasen redhat com>
+ */
+
+#include "config.h"
+
+#include "gtkcssimagerecolorprivate.h"
+#include "gtkcssimageurlprivate.h"
+#include "gtkcssimagesurfaceprivate.h"
+#include "gtkcsspalettevalueprivate.h"
+#include "gtkcssrgbavalueprivate.h"
+#include "gtkiconthemeprivate.h"
+
+#include "gtkstyleproviderprivate.h"
+
+G_DEFINE_TYPE (GtkCssImageRecolor, _gtk_css_image_recolor, GTK_TYPE_CSS_IMAGE_URL)
+
+static void
+gtk_css_image_recolor_print (GtkCssImage *image,
+                             GString     *string)
+{
+  GtkCssImageUrl *url = GTK_CSS_IMAGE_URL (image);
+  GtkCssImageRecolor *recolor = GTK_CSS_IMAGE_RECOLOR (image);
+  char *uri;
+
+  g_string_append (string, "-gtk-recolor(url(");
+  uri = g_file_get_uri (url->file);
+  g_string_append (string, uri);
+  g_free (uri);
+  g_string_append (string, ")");
+  if (recolor->palette)
+    {
+      g_string_append (string, ",");
+      _gtk_css_value_print (recolor->palette, string);
+    }
+  g_string_append (string, ")");
+}
+
+static void
+gtk_css_image_recolor_dispose (GObject *object)
+{
+  GtkCssImageRecolor *recolor = GTK_CSS_IMAGE_RECOLOR (object);
+
+  if (recolor->palette)
+    {
+      _gtk_css_value_unref (recolor->palette);
+      recolor->palette = NULL;
+    }
+
+  G_OBJECT_CLASS (_gtk_css_image_recolor_parent_class)->dispose (object);
+}
+
+static void
+lookup_symbolic_colors (GtkCssStyle *style,
+                        GtkCssValue *palette,
+                        GdkRGBA     *color_out,
+                        GdkRGBA     *success_out,
+                        GdkRGBA     *warning_out,
+                        GdkRGBA     *error_out)
+{
+  GtkCssValue *color;
+  const GdkRGBA *lookup;
+
+  color = gtk_css_style_get_value (style, GTK_CSS_PROPERTY_COLOR);
+  *color_out = *_gtk_css_rgba_value_get_rgba (color);
+
+  lookup = gtk_css_palette_value_get_color (palette, "success");
+  if (lookup)
+    *success_out = *lookup;
+  else
+    *success_out = *color_out;
+
+  lookup = gtk_css_palette_value_get_color (palette, "warning");
+  if (lookup)
+    *warning_out = *lookup;
+  else
+    *warning_out = *color_out;
+
+  lookup = gtk_css_palette_value_get_color (palette, "error");
+  if (lookup)
+    *error_out = *lookup;
+  else
+    *error_out = *color_out;
+}
+
+static GtkCssImage *
+gtk_css_image_recolor_load (GtkCssImageRecolor *recolor,
+                            GtkCssStyle        *style,
+                            GtkCssValue        *palette)
+{
+  GtkCssImageUrl *url = GTK_CSS_IMAGE_URL (recolor);
+  GtkIconInfo *info;
+  GdkRGBA fg, success, warning, error;
+  GdkPixbuf *pixbuf;
+  GtkCssImage *image;
+
+  lookup_symbolic_colors (style, palette, &fg, &success, &warning, &error);
+
+  info = gtk_icon_info_new_for_file (url->file, 0, 1);
+  pixbuf = gtk_icon_info_load_symbolic (info, &fg, &success, &warning, &error, NULL, NULL);
+  g_object_unref (info);
+
+  if (pixbuf == NULL)
+    {
+      g_warning ("Failed to load icon");
+      return NULL;
+    }
+
+  image = _gtk_css_image_surface_new_for_pixbuf (pixbuf);
+  g_object_unref (pixbuf);
+
+  return image;
+}
+
+static GtkCssImage *
+gtk_css_image_recolor_compute (GtkCssImage             *image,
+                               guint                    property_id,
+                               GtkStyleProviderPrivate *provider,
+                               GtkCssStyle             *style,
+                               GtkCssStyle             *parent_style)
+{
+  GtkCssImageRecolor *recolor = GTK_CSS_IMAGE_RECOLOR (image);
+  GtkCssValue *palette;
+  GtkCssImage *img;
+
+  if (recolor->palette)
+    palette = _gtk_css_value_compute (recolor->palette, property_id, provider, style, parent_style);
+  else
+    palette = gtk_css_style_get_value (style, GTK_CSS_PROPERTY_ICON_PALETTE);
+
+  img = gtk_css_image_recolor_load (recolor, style, palette);
+
+  _gtk_css_value_unref (palette);
+
+  return img;
+}
+
+static gboolean
+gtk_css_image_recolor_parse (GtkCssImage  *image,
+                             GtkCssParser *parser)
+{
+  GtkCssImageUrl *url = GTK_CSS_IMAGE_URL (image);
+  GtkCssImageRecolor *recolor = GTK_CSS_IMAGE_RECOLOR (image);
+
+  if (!_gtk_css_parser_try (parser, "-gtk-recolor", TRUE))
+    {
+      _gtk_css_parser_error (parser, "'-gtk-recolor'");
+      return FALSE;
+    }
+
+  if (!_gtk_css_parser_try (parser, "(", TRUE))
+    {
+      _gtk_css_parser_error (parser, "Expected '(' after '-gtk-recolor'");
+      return FALSE;
+    }
+
+  url->file = _gtk_css_parser_read_url (parser);
+  if (url->file == NULL)
+    {
+      _gtk_css_parser_error (parser, "Expected a url here");
+      return FALSE;
+    }
+
+  if ( _gtk_css_parser_try (parser, ",", TRUE))
+    {
+      recolor->palette = gtk_css_palette_value_parse (parser);
+      if (recolor->palette == NULL)
+        {
+          _gtk_css_parser_error (parser, "A palette is required here");
+          return FALSE;
+        }
+    }
+
+  if (!_gtk_css_parser_try (parser, ")", TRUE))
+    {
+      _gtk_css_parser_error (parser,
+                             "Expected ')' at end of '-gtk-recolor'");
+      return FALSE;
+    }
+
+  return TRUE;
+}
+
+static void
+_gtk_css_image_recolor_class_init (GtkCssImageRecolorClass *klass)
+{
+  GtkCssImageClass *image_class = GTK_CSS_IMAGE_CLASS (klass);
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  image_class->parse = gtk_css_image_recolor_parse;
+  image_class->compute = gtk_css_image_recolor_compute;
+  image_class->print = gtk_css_image_recolor_print;
+
+  object_class->dispose = gtk_css_image_recolor_dispose;
+}
+
+static void
+_gtk_css_image_recolor_init (GtkCssImageRecolor *image_recolor)
+{
+}
diff --git a/gtk/gtkcssimagerecolorprivate.h b/gtk/gtkcssimagerecolorprivate.h
new file mode 100644
index 0000000..6f6f89f
--- /dev/null
+++ b/gtk/gtkcssimagerecolorprivate.h
@@ -0,0 +1,54 @@
+/*
+ * Copyright © 2016 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: Matthias Clasen <mclasen redhat com>
+ */
+
+#ifndef __GTK_CSS_IMAGE_RECOLOR_PRIVATE_H__
+#define __GTK_CSS_IMAGE_RECOLOR_PRIVATE_H__
+
+#include "gtk/gtkcssimageurlprivate.h"
+#include "gtk/gtkcssvalueprivate.h"
+
+G_BEGIN_DECLS
+
+#define GTK_TYPE_CSS_IMAGE_RECOLOR           (_gtk_css_image_recolor_get_type ())
+#define GTK_CSS_IMAGE_RECOLOR(obj)           (G_TYPE_CHECK_INSTANCE_CAST (obj, GTK_TYPE_CSS_IMAGE_RECOLOR, 
GtkCssImageRecolor))
+#define GTK_CSS_IMAGE_RECOLOR_CLASS(cls)     (G_TYPE_CHECK_CLASS_CAST (cls, GTK_TYPE_CSS_IMAGE_RECOLOR, 
GtkCssImageRecolorClass))
+#define GTK_IS_CSS_IMAGE_RECOLOR(obj)        (G_TYPE_CHECK_INSTANCE_TYPE (obj, GTK_TYPE_CSS_IMAGE_RECOLOR))
+#define GTK_IS_CSS_IMAGE_RECOLOR_CLASS(obj)  (G_TYPE_CHECK_CLASS_TYPE (obj, GTK_TYPE_CSS_IMAGE_RECOLOR))
+#define GTK_CSS_IMAGE_RECOLOR_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GTK_TYPE_CSS_IMAGE_RECOLOR, 
GtkCssImageRecolorClass))
+
+typedef struct _GtkCssImageRecolor           GtkCssImageRecolor;
+typedef struct _GtkCssImageRecolorClass      GtkCssImageRecolorClass;
+
+struct _GtkCssImageRecolor
+{
+  GtkCssImageUrl parent;
+
+  GtkCssValue *palette;
+};
+
+struct _GtkCssImageRecolorClass
+{
+  GtkCssImageClass parent_class;
+};
+
+GType          _gtk_css_image_recolor_get_type             (void) G_GNUC_CONST;
+
+G_END_DECLS
+
+#endif /* __GTK_CSS_IMAGE_RECOLOR_PRIVATE_H__ */