[gtk+/gtk-style-context] Add a GtkStyleContext-variant of symbolic icon loading

[Matthias Clasen <matthiasc src gnome org>]

commit da23708d41eaff5ae4b4a37dae4987d3f73f56ae
Author: Matthias Clasen <mclasen redhat com>
Date:   Wed Nov 24 14:40:31 2010 -0500

    Add a GtkStyleContext-variant of symbolic icon loading

 gtk/gtkicontheme.c |   92 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 gtk/gtkicontheme.h |    5 +++
 2 files changed, 97 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkicontheme.c b/gtk/gtkicontheme.c
index cd55c3f..da551e5 100644
--- a/gtk/gtkicontheme.c
+++ b/gtk/gtkicontheme.c
@@ -3071,6 +3071,16 @@ gdk_color_to_css (GdkColor *color)
                           color->blue >> 8);
 }
 
+static gchar *
+gdk_rgba_to_css (GdkRGBA *color)
+{
+  return g_strdup_printf ("rgba(%d,%d,%d,%f)",
+                          (gint)(color->red * 255),
+                          (gint)(color->green * 255),
+                          (gint)(color->blue * 255),
+                          color->alpha);
+}
+
 static GdkPixbuf *
 _gtk_icon_info_load_symbolic_internal (GtkIconInfo  *icon_info,
                                        const gchar  *css_fg,
@@ -3236,6 +3246,88 @@ gtk_icon_info_load_symbolic (GtkIconInfo  *icon_info,
 }
 
 /**
+ * gtk_icon_info_load_symbolic_for_context:
+ * @icon_info: a #GtkIconInfo
+ * context: a #GtkStyleContext
+ * @was_symbolic: (allow-none): a #gboolean, returns whether the loaded icon
+ *     was a symbolic one and whether the @fg color was applied to it.
+ * @error: (allow-none): location to store error information on failure,
+ *     or %NULL.
+ *
+ * Loads an icon, modifying it to match the system colors for the foreground,
+ * success, warning and error colors provided. If the icon is not a symbolic
+ * one, the function will return the result from gtk_icon_info_load_icon().
+ *
+ * This allows loading symbolic icons that will match the system theme.
+ *
+ * See gtk_icon_info_load_symbolic() for more details.
+ *
+ * Return value: (transfer full): a #GdkPixbuf representing the loaded icon
+ *
+ * Since: 3.0
+ **/
+GdkPixbuf *
+gtk_icon_info_load_symbolic_for_context (GtkIconInfo      *icon_info,
+                                         GtkStyleContext  *context,
+                                         gboolean         *was_symbolic,
+                                         GError          **error)
+{
+  GdkPixbuf *pixbuf;
+  GdkRGBA *color;
+  gchar *css_fg, *css_success;
+  gchar *css_warning, *css_error;
+
+  if (!icon_info->filename ||
+      !g_str_has_suffix (icon_info->filename, "-symbolic.svg"))
+    {
+      if (was_symbolic)
+        *was_symbolic = FALSE;
+      return gtk_icon_info_load_icon (icon_info, error);
+    }
+
+  if (was_symbolic)
+    *was_symbolic = TRUE;
+
+  if (gtk_style_context_lookup_color (context, "color", color))
+    {
+      css_fg = gdk_rgba_to_css (color);
+      gdk_rgba_free (color);
+    }
+
+  css_success = css_warning = css_error = NULL;
+
+  if (gtk_style_context_lookup_color (context, "success_color", color))
+    {
+      css_success = gdk_rgba_to_css (color);
+      gdk_rgba_free (color);
+    }
+
+  if (gtk_style_context_lookup_color (context, "warning_color", color))
+    {
+      css_warning = gdk_rgba_to_css (color);
+      gdk_rgba_free (color);
+    }
+
+  if (gtk_style_context_lookup_color (context, "error_color", color))
+    {
+      css_error = gdk_rgba_to_css (color);
+      gdk_rgba_free (color);
+    }
+
+  pixbuf = _gtk_icon_info_load_symbolic_internal (icon_info,
+                                                  css_fg, css_success,
+                                                  css_warning, css_error,
+                                                  error);
+
+  g_free (css_fg);
+  g_free (css_success);
+  g_free (css_warning);
+  g_free (css_error);
+
+  return pixbuf;
+}
+
+/**
  * gtk_icon_info_load_symbolic_for_style:
  * @icon_info: a #GtkIconInfo
  * @style: a #GtkStyle to take the colors from
diff --git a/gtk/gtkicontheme.h b/gtk/gtkicontheme.h
index f493ba9..07042ef 100644
--- a/gtk/gtkicontheme.h
+++ b/gtk/gtkicontheme.h
@@ -27,6 +27,7 @@
 #include <gdk-pixbuf/gdk-pixbuf.h>
 #include <gdk/gdk.h>
 #include <gtk/gtkstyle.h>
+#include <gtk/gtkstylecontext.h>
 
 G_BEGIN_DECLS
 
@@ -178,6 +179,10 @@ GdkPixbuf *           gtk_icon_info_load_symbolic      (GtkIconInfo   *icon_info
                                                         GdkRGBA       *error_color,
                                                         gboolean      *was_symbolic,
                                                         GError       **error);
+GdkPixbuf *           gtk_icon_info_load_symbolic_for_context (GtkIconInfo      *icon_info,
+                                                               GtkStyleContext  *context,
+                                                               gboolean         *was_symbolic,
+                                                               GError          **error);
 GdkPixbuf *           gtk_icon_info_load_symbolic_for_style  (GtkIconInfo   *icon_info,
                                                               GtkStyle      *style,
                                                               GtkStateType   state,