import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

layout/base/nsCSSColorUtils.h

@@ -0,0 +1,41 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* functions that manipulate colors */
+
+#ifndef __nsCSSColorUtils_h
+#define __nsCSSColorUtils_h
+
+#include "nsColor.h"
+
+// "Sufficient contrast" is determined by
+// "Techniques For Accessibility Evalution And Repair Tools".
+// See http://www.w3.org/TR/AERT#color-contrast
+#define NS_SUFFICIENT_LUMINOSITY_DIFFERENCE 125000
+#define NS_LUMINOSITY_DIFFERENCE(a, b) \
+          int32_t(mozilla::Abs( \
+            NS_GetLuminosity(a | 0xff000000) - NS_GetLuminosity(b | 0xff000000)))
+
+// To determine colors based on the background brightness and border color
+void NS_GetSpecial3DColors(nscolor aResult[2],
+                           nscolor aBackgroundColor,
+                           nscolor aBorderColor);
+
+// Determins brightness for a specific color
+int NS_GetBrightness(uint8_t aRed, uint8_t aGreen, uint8_t aBlue);
+
+// Get Luminosity of a specific color. That is same as Y of YIQ color space.
+// The range of return value is 0 to 255000.
+int32_t NS_GetLuminosity(nscolor aColor);
+
+// function to convert from RGBA color space to HSVA color space 
+void NS_RGB2HSV(nscolor aColor, uint16_t &aHue, uint16_t &aSat,
+                uint16_t &aValue, uint8_t &aAlpha);
+
+// function to convert from HSVA color space to RGBA color space 
+void NS_HSV2RGB(nscolor &aColor, uint16_t aHue, uint16_t aSat, uint16_t aValue,
+                uint8_t aAlpha);
+
+#endif