/// <summary>
/// Parses a color value in CSS style; e.g. #ff0000, RED, RGB(255,0,0), RGB(100%, 0, 0)
/// </summary>
/// <param name="str">color substring value to parse</param>
/// <param name="idx">substring start idx </param>
/// <param name="length">substring length</param>
/// <param name="color">return the parsed color</param>
/// <returns>true - valid color, false - otherwise</returns>
static bool TryGetColor(string str, int idx, int length, out CssColor color)
{
try
{
if (!string.IsNullOrEmpty(str))
{
if (length > 1 && str[idx] == '#')
{
return GetColorByHex(str, idx, length, out color);
}
else if (length > 10 && SubStringEquals(str, idx, 4, "rgb(") && str[length - 1] == ')')
{
return GetColorByRgb(str, idx, length, out color);
}
else if (length > 13 && SubStringEquals(str, idx, 5, "rgba(") && str[length - 1] == ')')
{
return GetColorByRgba(str, idx, length, out color);
}
else
{
return GetColorByName(str, idx, length, out color);
}
}
}
catch
{ }
color = CssColor.Black;
return false;
}
public static CssColor AsColor(WebDom.CssCodeValueExpression value)
{
if (value.EvaluatedAs != WebDom.CssValueEvaluatedAs.Color)
{
if (value is WebDom.CssCodeColor)
{
return(((WebDom.CssCodeColor)value).ActualColor);
}
else
{
CssColor actualColor = CssValueParser2.GetActualColor(value.GetTranslatedStringValue());
value.SetColorValue(actualColor);
return(actualColor);
}
}
return(value.GetCacheColor());
}
/// <summary>
/// Get color by given name, including .NET name.
/// </summary>
/// <returns>true - valid color, false - otherwise</returns>
private static bool GetColorByName(string str, int idx, int length, out CssColor color)
{
color = CssColor.FromName(str.Substring(idx, length));
return color.A > 0;
}
/// <summary>
/// Get color by parsing given RGBA value color string (RGBA(255,180,90,180))
/// </summary>
/// <returns>true - valid color, false - otherwise</returns>
private static bool GetColorByRgba(string str, int idx, int length, out CssColor color)
{
int r = -1;
int g = -1;
int b = -1;
int a = -1;
if (length > 13)
{
int s = idx + 5;
r = ParseIntAtIndex(str, ref s);
if (s < idx + length)
{
g = ParseIntAtIndex(str, ref s);
}
if (s < idx + length)
{
b = ParseIntAtIndex(str, ref s);
}
if (s < idx + length)
{
a = ParseIntAtIndex(str, ref s);
}
}
if (r > -1 && g > -1 && b > -1 && a > -1)
{
color = CssColor.FromArgb(a, r, g, b);
return true;
}
color = CssColor.Empty;
return false;
}
/// <summary>
/// Get color by parsing given hex value color string (#A28B34).
/// </summary>
/// <returns>true - valid color, false - otherwise</returns>
private static bool GetColorByHex(string str, int idx, int length, out CssColor color)
{
int r = -1;
int g = -1;
int b = -1;
if (length == 7)
{
r = ParseHexInt(str, idx + 1, 2);
g = ParseHexInt(str, idx + 3, 2);
b = ParseHexInt(str, idx + 5, 2);
}
else if (length == 4)
{
r = ParseHexInt(str, idx + 1, 1);
r = r * 16 + r;
g = ParseHexInt(str, idx + 2, 1);
g = g * 16 + g;
b = ParseHexInt(str, idx + 3, 1);
b = b * 16 + b;
}
if (r > -1 && g > -1 && b > -1)
{
color = CssColor.FromArgb(r, g, b);
return true;
}
color = CssColor.Empty;
return false;
}
public static string ToHexColor(this CssColor color)
{
return(string.Concat("#", color.R.ToString("X"), color.G.ToString("X"), color.B.ToString("X")));
}
public CssCodeColor(CssColor color)
: base(CssValueHint.HexColor)
{
this.color = color;
SetColorValue(color);
}
public void SetColorValue(CssColor color)
{
this.evaluatedAs = CssValueEvaluatedAs.Color;
this.cachedColor = color;
}
public CssCodeColor(CssColor color)
: base(CssValueHint.HexColor)
{
this.color = color;
SetColorValue(color);
}
public void SetColorValue(CssColor color)
{
this.evaluatedAs = CssValueEvaluatedAs.Color;
this.cachedColor = color;
}