css: Introduct -gtk-icon-palette

This borrows heavily from the CSS4 fonts draft's font-palette, currently
found at https://drafts.csswg.org/css-fonts-4/#font-palette-control

The palette is mainly meant to trigger invalidations when colors used for
symbolic icons change, to potentially allow extending supported colors
in symbolic icons and to recolor all colors of a symbolic icon, not just
the main one.

The syntax for the property goes like this:
Name:        -gtk-icon-palette
Value:       default | name <color> [ , name <color> ]*
Initial:     default
Applies to:  all elements with icons
Inherited:   yes
Animatable:  yes, each color animated separately

The property defines a list of named colors to be used when looking up
icons. If a name is not defined, the value of the current "color"
property is used. Which names are relevant depends on the icons in use.
Currently symbolic icons make use of the names "success", "warning" and
"error".

"default" is the current behavior of the GTK when coloring symbolic
icons and is equal to the string
  success @success_color, warning @warning_color, error @error_color

Animation is crudely implemented by animating colors that are in both
palettes that are animated and otherwise keeping the color from the
palette that defined it. Note that this can cause a sharp cut at the
beginning or end of the animation when the color goes away and will
therefore be replaced with the color property.

You can see an example of animations at
http://gfycat.com/CautiousPeacefulIaerismetalmark

7 files changed, 360 insertions, 54 deletions

diff --git a/gtk/Makefile.am b/gtk/Makefile.am
index 43ebb9eff1..14981733bb 100644
--- a/gtk/Makefile.am
+++ b/gtk/Makefile.am
@@ -411,6 +411,7 @@ gtk_private_h_sources =		\
 	gtkcssnodeprivate.h		\
 	gtkcssnodedeclarationprivate.h	\
 	gtkcssnumbervalueprivate.h	\
+	gtkcsspalettevalueprivate.h	\
 	gtkcssparserprivate.h	\
 	gtkcsspathnodeprivate.h	\
 	gtkcsspositionvalueprivate.h	\
@@ -661,6 +662,7 @@ gtk_base_c_sources = 		\
 	gtkcssnode.c		\
 	gtkcssnodedeclaration.c	\
 	gtkcssnumbervalue.c	\
+	gtkcsspalettevalue.c	\
 	gtkcssparser.c		\
 	gtkcsspathnode.c	\
 	gtkcsspositionvalue.c	\
diff --git a/gtk/gtkcsscolorvalue.c b/gtk/gtkcsscolorvalue.c
index 7e78134580..6cd0cf0447 100644
--- a/gtk/gtkcsscolorvalue.c
+++ b/gtk/gtkcsscolorvalue.c
@@ -127,6 +127,8 @@ gtk_css_value_color_get_fallback (guint                    property_id,
                                        provider,
                                        style,
                                        parent_style);
+      case GTK_CSS_PROPERTY_ICON_PALETTE:
+        return _gtk_css_value_ref (gtk_css_style_get_value (style, GTK_CSS_PROPERTY_COLOR));
       default:
         if (property_id < GTK_CSS_PROPERTY_N_PROPERTIES)
           g_warning ("No fallback color defined for property '%s'", 
diff --git a/gtk/gtkcsspalettevalue.c b/gtk/gtkcsspalettevalue.c
new file mode 100644
index 0000000000..cf98968838
--- /dev/null
+++ b/gtk/gtkcsspalettevalue.c
@@ -0,0 +1,258 @@
+/* GTK - The GIMP Toolkit
+ * Copyright (C) 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 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/>.
+ */
+
+#include "config.h"
+
+#include "gtkcssiconthemevalueprivate.h"
+
+#include "gtkcsscolorvalueprivate.h"
+#include "gtkcssrgbavalueprivate.h"
+
+struct _GtkCssValue {
+  GTK_CSS_VALUE_BASE
+  GHashTable *colors;
+};
+
+static GtkCssValue *default_palette;
+
+static GtkCssValue *gtk_css_palette_value_new_empty (void);
+
+static void
+gtk_css_palette_value_add_color (GtkCssValue *value,
+                                 const char  *name,
+                                 GtkCssValue *color)
+{
+  g_hash_table_insert (value->colors, g_strdup (name), color);
+}
+
+static void
+gtk_css_value_palette_free (GtkCssValue *value)
+{
+  g_hash_table_unref (value->colors);
+
+  g_slice_free (GtkCssValue, value);
+}
+
+static GtkCssValue *
+gtk_css_value_palette_compute (GtkCssValue             *specified,
+                               guint                    property_id,
+                               GtkStyleProviderPrivate *provider,
+                               GtkCssStyle             *style,
+                               GtkCssStyle             *parent_style)
+{
+  GHashTableIter iter;
+  gpointer name, value;
+  GtkCssValue *computed_color;
+  GtkCssValue *result;
+  gboolean changes = FALSE;
+
+  result = gtk_css_palette_value_new_empty ();
+
+  g_hash_table_iter_init (&iter, specified->colors);
+  while (g_hash_table_iter_next (&iter, &name, &value))
+    {
+      computed_color = _gtk_css_value_compute (value, property_id, provider, style, parent_style);
+      changes |= computed_color != value;
+      gtk_css_palette_value_add_color (result, name, computed_color);
+    }
+
+  if (!changes)
+    {
+      _gtk_css_value_unref (result);
+      result = _gtk_css_value_ref (specified);
+    }
+
+  return result;
+}
+
+static gboolean
+gtk_css_value_palette_equal (const GtkCssValue *value1,
+                             const GtkCssValue *value2)
+{
+  gpointer name, color1, color2;
+  GHashTableIter iter;
+
+  if (g_hash_table_size (value1->colors) != g_hash_table_size (value2->colors))
+    return FALSE;
+
+  g_hash_table_iter_init (&iter, value1->colors);
+  while (g_hash_table_iter_next (&iter, &name, &color1))
+    {
+      color2 = g_hash_table_lookup (value2->colors, name);
+      if (color2 == NULL)
+        return FALSE;
+
+      if (!_gtk_css_value_equal (color1, color2))
+        return FALSE;
+    }
+
+  return TRUE;
+}
+
+static GtkCssValue *
+gtk_css_value_palette_transition (GtkCssValue *start,
+                                  GtkCssValue *end,
+                                  guint        property_id,
+                                  double       progress)
+{
+  gpointer name, start_color, end_color;
+  GHashTableIter iter;
+  GtkCssValue *result, *transition;
+
+  /* XXX: For colors that are only in start or end but not both,
+   * we don't transition but just keep the value.
+   * That causes an abrupt transition to currentColor at the end.
+   */
+
+  result = gtk_css_palette_value_new_empty ();
+
+  g_hash_table_iter_init (&iter, start->colors);
+  while (g_hash_table_iter_next (&iter, &name, &start_color))
+    {
+      end_color = g_hash_table_lookup (end->colors, name);
+      if (end_color == NULL)
+        transition = _gtk_css_value_ref (start_color);
+      else
+        transition = _gtk_css_value_transition (start_color, end_color, property_id, progress);
+
+      gtk_css_palette_value_add_color (result, name, transition);
+    }
+
+  g_hash_table_iter_init (&iter, end->colors);
+  while (g_hash_table_iter_next (&iter, &name, &end_color))
+    {
+      start_color = g_hash_table_lookup (start->colors, name);
+      if (start_color != NULL)
+        continue;
+
+      gtk_css_palette_value_add_color (result, name, _gtk_css_value_ref (end_color));
+    }
+
+  return result;
+}
+
+static void
+gtk_css_value_palette_print (const GtkCssValue *value,
+                             GString           *string)
+{
+  GHashTableIter iter;
+  gpointer name, color;
+  gboolean first = TRUE;
+
+  if (value == default_palette)
+    {
+      g_string_append (string, "default");
+      return;
+    }
+
+  g_hash_table_iter_init (&iter, value->colors);
+  while (g_hash_table_iter_next (&iter, &name, &color))
+    {
+      if (first)
+        first = FALSE;
+      else
+        g_string_append (string, ", ");
+      g_string_append (string, name);
+      g_string_append_c (string, ' ');
+      _gtk_css_value_print (color, string);
+    }
+}
+
+static const GtkCssValueClass GTK_CSS_VALUE_PALETTE = {
+  gtk_css_value_palette_free,
+  gtk_css_value_palette_compute,
+  gtk_css_value_palette_equal,
+  gtk_css_value_palette_transition,
+  gtk_css_value_palette_print
+};
+
+static GtkCssValue *
+gtk_css_palette_value_new_empty (void)
+{
+  GtkCssValue *result;
+
+  result = _gtk_css_value_new (GtkCssValue, &GTK_CSS_VALUE_PALETTE);
+  result->colors = g_hash_table_new_full (g_str_hash, g_str_equal,
+                                          g_free,
+                                          (GDestroyNotify) _gtk_css_value_unref);
+
+  return result;
+}
+
+GtkCssValue *
+gtk_css_palette_value_new_default (void)
+{
+  if (default_palette == NULL)
+    {
+      default_palette = gtk_css_palette_value_new_empty ();
+      gtk_css_palette_value_add_color (default_palette, "error", _gtk_css_color_value_new_name ("error_color"));
+      gtk_css_palette_value_add_color (default_palette, "warning", _gtk_css_color_value_new_name ("warning_color"));
+      gtk_css_palette_value_add_color (default_palette, "success", _gtk_css_color_value_new_name ("success_color"));
+    }
+
+  return _gtk_css_value_ref (default_palette);
+}
+
+GtkCssValue *
+gtk_css_palette_value_parse (GtkCssParser *parser)
+{
+  GtkCssValue *result, *color;
+  char *ident;
+
+  if (_gtk_css_parser_try (parser, "default", TRUE))
+    return gtk_css_palette_value_new_default ();
+  
+  result = gtk_css_palette_value_new_empty ();
+
+  do {
+    ident = _gtk_css_parser_try_ident (parser, TRUE);
+    if (ident == NULL)
+      {
+        _gtk_css_parser_error (parser, "expected color name");
+        _gtk_css_value_unref (result);
+        return NULL;
+      }
+    
+    color = _gtk_css_color_value_parse (parser);
+    if (color == NULL)
+      {
+        g_free (ident);
+        _gtk_css_value_unref (result);
+        return NULL;
+      }
+
+    gtk_css_palette_value_add_color (result, ident, color);
+    g_free (ident);
+  } while (_gtk_css_parser_try (parser, ",", TRUE));
+
+  return result;
+}
+
+const GdkRGBA *
+gtk_css_palette_value_get_color (GtkCssValue *value,
+                                 const char  *name)
+{
+  GtkCssValue *color;
+
+  g_return_val_if_fail (value->class == &GTK_CSS_VALUE_PALETTE, NULL);
+
+  color = g_hash_table_lookup (value->colors, name);
+  if (color == NULL)
+    return NULL;
+
+  return _gtk_css_rgba_value_get_rgba (color);
+}
diff --git a/gtk/gtkcsspalettevalueprivate.h b/gtk/gtkcsspalettevalueprivate.h
new file mode 100644
index 0000000000..b422494a8a
--- /dev/null
+++ b/gtk/gtkcsspalettevalueprivate.h
@@ -0,0 +1,37 @@
+/*
+ * 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: Alexander Larsson <alexl@gnome.org>
+ */
+
+#ifndef __GTK_CSS_PALETTE_VALUE_PRIVATE_H__
+#define __GTK_CSS_PALETTE_VALUE_PRIVATE_H__
+
+#include "gtkcssparserprivate.h"
+#include "gtkcssvalueprivate.h"
+
+G_BEGIN_DECLS
+
+GtkCssValue *   gtk_css_palette_value_new_default       (void);
+
+GtkCssValue *   gtk_css_palette_value_parse             (GtkCssParser        *parser);
+
+const GdkRGBA * gtk_css_palette_value_get_color         (GtkCssValue         *value,
+                                                         const char          *color_name);
+
+G_END_DECLS
+
+#endif /* __GTK_CSS_PALETTE_VALUE_PRIVATE_H__ */
diff --git a/gtk/gtkcssstylepropertyimpl.c b/gtk/gtkcssstylepropertyimpl.c
index 5c48ce8a5b..60030817eb 100644
--- a/gtk/gtkcssstylepropertyimpl.c
+++ b/gtk/gtkcssstylepropertyimpl.c
@@ -53,6 +53,7 @@
 #include "gtkcssinitialvalueprivate.h"
 #include "gtkcssenumvalueprivate.h"
 #include "gtkcssnumbervalueprivate.h"
+#include "gtkcsspalettevalueprivate.h"
 #include "gtkcsspositionvalueprivate.h"
 #include "gtkcssrepeatvalueprivate.h"
 #include "gtkcssrgbavalueprivate.h"
@@ -506,6 +507,13 @@ image_effect_parse (GtkCssStyleProperty *property,
 }
 
 static GtkCssValue *
+icon_palette_parse (GtkCssStyleProperty *property,
+		    GtkCssParser        *parser)
+{
+  return gtk_css_palette_value_parse (parser);
+}
+
+static GtkCssValue *
 icon_style_parse (GtkCssStyleProperty *property,
 		  GtkCssParser        *parser)
 {
@@ -1727,6 +1735,16 @@ _gtk_css_style_property_init_properties (void)
 					  NULL,
 					  NULL,
 					  _gtk_css_icon_effect_value_new (GTK_CSS_ICON_EFFECT_NONE));
+  gtk_css_style_property_register        ("-gtk-icon-palette",
+					  GTK_CSS_PROPERTY_ICON_PALETTE,
+					  G_TYPE_NONE,
+					  GTK_STYLE_PROPERTY_ANIMATED | GTK_STYLE_PROPERTY_INHERIT,
+                                          GTK_CSS_AFFECTS_ICON,
+					  icon_palette_parse,
+					  NULL,
+					  NULL,
+					  gtk_css_palette_value_new_default ());
+
 
 G_GNUC_BEGIN_IGNORE_DEPRECATIONS
   gtk_css_style_property_register        ("engine",
diff --git a/gtk/gtkcsstypesprivate.h b/gtk/gtkcsstypesprivate.h
index 631b59376b..692bea9110 100644
--- a/gtk/gtkcsstypesprivate.h
+++ b/gtk/gtkcsstypesprivate.h
@@ -217,6 +217,7 @@ enum { /*< skip >*/
   GTK_CSS_PROPERTY_ANIMATION_FILL_MODE,
   GTK_CSS_PROPERTY_OPACITY,
   GTK_CSS_PROPERTY_GTK_IMAGE_EFFECT,
+  GTK_CSS_PROPERTY_ICON_PALETTE,
   GTK_CSS_PROPERTY_ENGINE,
   GTK_CSS_PROPERTY_GTK_KEY_BINDINGS,
   /* add more */
diff --git a/gtk/gtkicontheme.c b/gtk/gtkicontheme.c
index 38d5d36602..a440510139 100644
--- a/gtk/gtkicontheme.c
+++ b/gtk/gtkicontheme.c
@@ -38,6 +38,8 @@
 #endif /* G_OS_WIN32 */
 
 #include "gtkicontheme.h"
+#include "gtkcsspalettevalueprivate.h"
+#include "gtkcssrgbavalueprivate.h"
 #include "gtkdebug.h"
 #include "deprecated/gtkiconfactory.h"
 #include "gtkiconcache.h"
@@ -45,6 +47,7 @@
 #include "gtkmain.h"
 #include "deprecated/gtknumerableiconprivate.h"
 #include "gtksettingsprivate.h"
+#include "gtkstylecontextprivate.h"
 #include "gtkprivate.h"
 
 #undef GDK_DEPRECATED
@@ -4663,6 +4666,39 @@ gtk_icon_info_load_symbolic (GtkIconInfo    *icon_info,
                                                error);
 }
 
+static void
+lookup_colors_from_style_context (GtkStyleContext *context,
+                                  GdkRGBA         *color_out,
+                                  GdkRGBA         *success_out,
+                                  GdkRGBA         *warning_out,
+                                  GdkRGBA         *error_out)
+{
+  GtkCssValue *palette, *color;
+  const GdkRGBA *lookup;
+
+  color = _gtk_style_context_peek_property (context, GTK_CSS_PROPERTY_COLOR);
+  palette = _gtk_style_context_peek_property (context, GTK_CSS_PROPERTY_ICON_PALETTE);
+  *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;
+}
+
 /**
  * gtk_icon_info_load_symbolic_for_context:
  * @icon_info: a #GtkIconInfo
@@ -4694,16 +4730,10 @@ gtk_icon_info_load_symbolic_for_context (GtkIconInfo      *icon_info,
                                          gboolean         *was_symbolic,
                                          GError          **error)
 {
-  GdkRGBA *color = NULL;
   GdkRGBA fg;
-  GdkRGBA *fgp;
   GdkRGBA success_color;
-  GdkRGBA *success_colorp;
   GdkRGBA warning_color;
-  GdkRGBA *warning_colorp;
   GdkRGBA error_color;
-  GdkRGBA *error_colorp;
-  GtkStateFlags state;
   gboolean is_symbolic;
 
   g_return_val_if_fail (icon_info != NULL, NULL);
@@ -4717,29 +4747,11 @@ gtk_icon_info_load_symbolic_for_context (GtkIconInfo      *icon_info,
   if (!is_symbolic)
     return gtk_icon_info_load_icon (icon_info, error);
 
-  fgp = success_colorp = warning_colorp = error_colorp = NULL;
-
-  state = gtk_style_context_get_state (context);
-  gtk_style_context_get (context, state, "color", &color, NULL);
-  if (color)
-    {
-      fg = *color;
-      fgp = &fg;
-      gdk_rgba_free (color);
-    }
-
-  if (gtk_style_context_lookup_color (context, "success_color", &success_color))
-    success_colorp = &success_color;
-
-  if (gtk_style_context_lookup_color (context, "warning_color", &warning_color))
-    warning_colorp = &warning_color;
-
-  if (gtk_style_context_lookup_color (context, "error_color", &error_color))
-    error_colorp = &error_color;
+  lookup_colors_from_style_context (context, &fg, &success_color, &warning_color, &error_color);
 
   return gtk_icon_info_load_symbolic_internal (icon_info,
-                                               fgp, success_colorp,
-                                               warning_colorp, error_colorp,
+                                               &fg, &success_color,
+                                               &warning_color, &error_color,
                                                TRUE,
                                                error);
 }
@@ -4991,43 +5003,19 @@ gtk_icon_info_load_symbolic_for_context_async (GtkIconInfo         *icon_info,
                                                GAsyncReadyCallback  callback,
                                                gpointer             user_data)
 {
-  GdkRGBA *color = NULL;
   GdkRGBA fg;
-  GdkRGBA *fgp;
   GdkRGBA success_color;
-  GdkRGBA *success_colorp;
   GdkRGBA warning_color;
-  GdkRGBA *warning_colorp;
   GdkRGBA error_color;
-  GdkRGBA *error_colorp;
-  GtkStateFlags state;
 
   g_return_if_fail (icon_info != NULL);
   g_return_if_fail (context != NULL);
 
-  fgp = success_colorp = warning_colorp = error_colorp = NULL;
-
-  state = gtk_style_context_get_state (context);
-  gtk_style_context_get (context, state, "color", &color, NULL);
-  if (color)
-    {
-      fg = *color;
-      fgp = &fg;
-      gdk_rgba_free (color);
-    }
-
-  if (gtk_style_context_lookup_color (context, "success_color", &success_color))
-    success_colorp = &success_color;
-
-  if (gtk_style_context_lookup_color (context, "warning_color", &warning_color))
-    warning_colorp = &warning_color;
-
-  if (gtk_style_context_lookup_color (context, "error_color", &error_color))
-    error_colorp = &error_color;
+  lookup_colors_from_style_context (context, &fg, &success_color, &warning_color, &error_color);
 
   gtk_icon_info_load_symbolic_async (icon_info,
-                                     fgp, success_colorp,
-                                     warning_colorp, error_colorp,
+                                     &fg, &success_color,
+                                     &warning_color, &error_color,
                                      cancellable, callback, user_data);
 }