contrastCheck method

bool contrastCheck(double fontSize, Color textColor, Color backgroundColor, WCAG wcag,)

This method should be called when you want to check the contrast color from your text color and your background color paramsfontSize for the text font sizes paramstextColor for the text color paramsbackgroundColor for the text background color paramswcag for the contrast type do you want, WCAG.AA or WCAG.AAA

Implementation

bool contrastCheck(
  double fontSize,
  Color textColor,
  Color backgroundColor,
  WCAG wcag,
) {
  /// This is for initiating the return value from this method.
  /// If the contrast is accepted, it will be changed to `True`
  bool isContrast = false;

  /// Returns a brightness value between 0 for darkest and 1 for lightest.
  /// for both colors textColor and backgroundColor
  ///
  /// Represents the relative luminance of the color. This value is computationally
  /// expensive to calculate.
  ///
  /// See <https://en.wikipedia.org/wiki/Relative_luminance>.
  var lum1 = textColor.computeLuminance();
  var lum2 = backgroundColor.computeLuminance();

  /// [brightest] is the relative luminance of the lighter of the foreground
  /// or background colors, and
  ///
  /// [darkest] is the relative luminance of the darker of the foreground
  /// or background colors.
  var brightest = max(lum1, lum2);
  var darkest = min(lum1, lum2);

  /// Calculate the contrast ratio using the following formula.
  double contrast = (brightest + 0.05) / (darkest + 0.05);

  /// AA – This is the sweet spot for text sizes below ~18.6pt.
  /// This is a score of at least 4.5 . AAA – This is enhanced contrast with
  /// a score of at least 7.0 . Think longer form articles that will be read
  /// for a significant period of time.
  ///

  if (wcag == WCAG.AA) {
    if (fontSize <= 18.6) {
      if (contrast >= 4.5)
        isContrast = true;
      else
        isContrast = false;
    } else {
      if (contrast >= 3)
        isContrast = true;
      else
        isContrast = false;
    }
    /// This is the result log for knowing the result of your choose
    print("WCAG AA: $isContrast");
  } else {
    if (fontSize <= 18.6) {
      if (contrast >= 7)
        isContrast = true;
      else
        isContrast = false;
    } else {
      if (contrast >= 4.5)
        isContrast = true;
      else
        isContrast = false;
    }
    /// This is the result log for knowing the result of your choose
    print("WCAG AAA: $isContrast");
  }

  /// This will be returning your contrast checker status
  return isContrast;
}