chrome/common/themes/autogenerated_theme_util.h

// Copyright 2019 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CHROME_COMMON_THEMES_AUTOGENERATED_THEME_UTIL_H_
#define CHROME_COMMON_THEMES_AUTOGENERATED_THEME_UTIL_H_

#include "third_party/skia/include/core/SkColor.h"

// Constants for autogenerated themes.
// Minimum contrast for active tab and frame color to avoid isolation line in
// the tab strip.
constexpr float kAutogeneratedThemeActiveTabMinContrast = 1.3f;
constexpr float kAutogeneratedThemeActiveTabPreferredContrast = 1.6f;
constexpr float kAutogeneratedThemeActiveTabPreferredContrastForDark = 1.7f;

// Contrast between foreground and background.
constexpr float kAutogeneratedThemeTextPreferredContrast = 7.0f;

struct AutogeneratedThemeColors {
  SkColor frame_color;
  SkColor frame_text_color;
  SkColor active_tab_color;
  SkColor active_tab_text_color;
  SkColor ntp_color;
};

// Generates theme colors for the given `color`.
AutogeneratedThemeColors GetAutogeneratedThemeColors(SkColor color);

// Calculates a contrasting color for a given `color` by changing the color's
// luminance. Returns a lighter color if the color is very dark or a darker
// color otherwise.
SkColor GetContrastingColor(SkColor color, float luminosity_change);

#endif  // CHROME_COMMON_THEMES_AUTOGENERATED_THEME_UTIL_H_