[nautilus: 1/9] eel-gdk-extensions: add eel_make_color_inactive() to public API

[Cosimo Cecchi <cosimoc src gnome org>]

commit 42e726853157e561dc99d61180cae036f751fef8
Author: Cosimo Cecchi <cosimoc gnome org>
Date:   Thu Oct 7 11:24:16 2010 +0200

    eel-gdk-extensions: add eel_make_color_inactive() to public API

 eel/eel-gdk-extensions.c |   30 ++++++++++++++++++++++++++++++
 eel/eel-gdk-extensions.h |    2 ++
 2 files changed, 32 insertions(+), 0 deletions(-)
---
diff --git a/eel/eel-gdk-extensions.c b/eel/eel-gdk-extensions.c
index 31ff008..2dc66c3 100644
--- a/eel/eel-gdk-extensions.c
+++ b/eel/eel-gdk-extensions.c
@@ -474,6 +474,36 @@ eel_cairo_draw_layout_with_drop_shadow (cairo_t             *cr,
 	cairo_restore (cr);
 }
 
+#define CLAMP_COLOR(v) (t = (v), CLAMP (t, 0, G_MAXUSHORT))
+#define SATURATE(v) ((1.0 - saturation) * intensity + saturation * (v))
+
+void
+eel_make_color_inactive (GdkColor *color)
+{
+	double intensity, saturation;
+	gushort t;
+
+	saturation = 0.7;
+	intensity = color->red * 0.30 + color->green * 0.59 + color->blue * 0.11;
+	color->red = SATURATE (color->red);
+	color->green = SATURATE (color->green);
+	color->blue = SATURATE (color->blue);
+
+	if (intensity > G_MAXUSHORT / 2) {
+		color->red *= 0.9;
+		color->green *= 0.9;
+		color->blue *= 0.9;
+	} else {
+		color->red *= 1.25;
+		color->green *= 1.25;
+		color->blue *= 1.25;
+	}
+
+	color->red = CLAMP_COLOR (color->red);
+	color->green = CLAMP_COLOR (color->green);
+	color->blue = CLAMP_COLOR (color->blue);
+}
+
 #if ! defined (EEL_OMIT_SELF_CHECK)
 
 static char *
diff --git a/eel/eel-gdk-extensions.h b/eel/eel-gdk-extensions.h
index b3778c6..b135264 100644
--- a/eel/eel-gdk-extensions.h
+++ b/eel/eel-gdk-extensions.h
@@ -123,4 +123,6 @@ void                eel_cairo_draw_layout_with_drop_shadow (cairo_t
 							    int                  x,
 							    int                  y,
 							    PangoLayout         *layout);
+void                eel_make_color_inactive                (GdkColor            *color);
+
 #endif /* EEL_GDK_EXTENSIONS_H */