Allow parsing of color value compatible with System.Drawing

lisurc

Having the library parse color values such as "red" or "green" to convert them to CssColor objects would be nice. Version 1.0.0.3 does not seem to support this. I think the System.Drawing.Color methods could be used to achieve this.

Athari

I want to preserve compatibility with results from Fixrefox's parser, so the `Color` property will remain as is. However, to simplify operations with named colors, I've added `CalculatedColor` property. You can also use new overloads of `CssColor` factory methods. ``` cs [TestMethod] public void ParseSheet_Simple_ColorName () { var loader = new CssLoader(); var css = loader.ParseSheet("h1 { color: red; }", SheetUri, BaseUri); var h1 = css.StyleRules.Single(); var h1color = h1.Declaration.Data.Single(); Assert.AreEqual(CssProperty.Color, h1color.Property); Assert.AreEqual(CssColor.RGB(0xFF, 0x00, 0x00), h1color.Value.CalculatedColor); Assert.AreEqual(CssColor.RGB(0xFF, 0x00, 0x00), CssColor.ColorNameToRGB(h1color.Value.String)); } ``` Note that `CssColor.EnumColor` values (`"inactivecaptiontext"`, `"-moz-dialog"` etc.) will not be converted. See https://github.com/Athari/CsCss/releases/tag/v1.0.1.0

Athari

Renamed `CssValue.CalculatedColor` to `ComputedColor` (to use usual CSS terminology).

lisurc

Thanks for your updates. With your addition of <code>CssColor.ColorNameToRGB</code> I've actually added some extension methods to my code base on <code>CssDeclaration</code> to ease <code>CssColor</code> value retrieval and conversion for other color properties (BackgroundColor, BorderColor, etc.). ``` csharp public static Nullable<CssColor> GetComputedColor(this CssDeclaration decl, CssProperty property) { CssValue value = decl.GetValue(property); if (value != null) { if (value.Unit == CssUnit.Color) { return value.Color; } if (value.Unit == CssUnit.String) { return CssColor.ColorNameToRGB(value.String); } } return null; } public static int ToArgb(this CssColor color) { return (color.A << 24) | (color.R << 16) | (color.G << 8) | color.B; } ``` Not sure that fits the spirit of the code base but that came being quite handy for me.

Athari

The first method moves `CssValue` property one level lower. In the library, it would only be meaningful if applied to all properties, but that would cause too much noise. Besides, I don't see much difference between the first two lines: ``` cs decl.GetComputedColor(CssProperty.Color); decl.GetValue(CssProperty.Color).ComputedColor; // 6 characters more decl.Color.ComputedColor; // if property is known at compile time ``` The second method is application-specific, as byte order varies between graphics libraries (RGB and BGR are both common).