/// <summary>
/// Skip over a complete block of unknown content
/// </summary>
public override bool Parse(ItemFactory itemFactory, ITextProvider text, TokenStream tokens)
{
// Save the opening token for this block
OpenBlock = Children.AddCurrentAndAdvance(tokens, null);
CssTokenType matchingEndType = GetMatchingTokenType(OpenBlock.TokenType);
Debug.Assert(matchingEndType != CssTokenType.Unknown);
// Search for the matching end of the block
bool invalidBlock = false;
while (!invalidBlock &&
tokens.CurrentToken.TokenType != matchingEndType &&
!tokens.CurrentToken.IsScopeBlocker())
{
// Treat the contents of the block as property values so that units, functions, etc. get parsed
ParseItem pi = PropertyValueHelpers.ParsePropertyValue(this, itemFactory, text, tokens);
if (pi != null)
{
Children.Add(pi);
}
else
{
switch (tokens.CurrentToken.TokenType)
{
case CssTokenType.CloseCurlyBrace:
case CssTokenType.CloseFunctionBrace:
case CssTokenType.CloseSquareBracket:
// Found a non-matching end brace/bracket, so stop parsing
invalidBlock = true;
break;
default:
Children.AddUnknownAndAdvance(itemFactory, text, tokens);
break;
}
}
}
if (tokens.CurrentToken.TokenType == matchingEndType)
{
CloseBlock = Children.AddCurrentAndAdvance(tokens, null);
}
else
{
OpenBlock.AddParseError(ParseErrorType.CloseBraceMismatch, ParseErrorLocation.AfterItem);
}
return(Children.Count > 0);
}
protected virtual void ParsePropertyValue(ItemFactory itemFactory, ITextProvider text, TokenStream tokens)
{
ParseItem item = PropertyValueHelpers.ParsePropertyValue(this, itemFactory, text, tokens);
if (item != null)
{
Values.Add(item);
Children.Add(item);
}
else
{
Children.AddUnknownAndAdvance(itemFactory, text, tokens, ParseErrorType.PropertyValueExpected);
}
}
protected virtual void ParseArgument(ItemFactory itemFactory, ITextProvider text, TokenStream tokens)
{
while (!tokens.CurrentToken.IsFunctionArgumentTerminator())
{
ParseItem pi = PropertyValueHelpers.ParsePropertyValue(this, itemFactory, text, tokens);
if (pi != null)
{
ArgumentItems.Add(pi);
Children.Add(pi);
}
else
{
// An unknown item is not an error
pi = Children.AddUnknownAndAdvance(itemFactory, text, tokens);
ArgumentItems.Add(pi);
}
}
}
/// <summary>
/// This helps the ColorParser class to figure out the values of each color argument.
/// If the output argumentValue is float.NaN then the argument can still be valid, but
/// its actualy value cannot be determined.
/// </summary>
internal virtual bool GetColorArgumentValue(int argumentIndex, bool looseParsing, out float argumentValue)
{
argumentValue = 0;
FunctionArgument colorArgument = (argumentIndex >= 0 && argumentIndex < Arguments.Count)
? Arguments[argumentIndex] as FunctionArgument
: null;
// Make sure the argument has the right number of children
if (colorArgument == null ||
colorArgument.ArgumentItems.Count == 0 ||
(!looseParsing && colorArgument.ArgumentItems.Count != 1))
{
return(false);
}
ParseItem colorNumber = colorArgument.ArgumentItems[0];
UnitType unitType = PropertyValueHelpers.GetUnitType(colorNumber);
if (argumentIndex > 3)
{
// No color function has more than four arguments
return(false);
}
else if (argumentIndex == 3)
{
// It's the alpha value
if (ColorFunction == ColorFunctionType.Rgba || ColorFunction == ColorFunctionType.Hsla)
{
if (PropertyValueHelpers.IsValidNumber(colorNumber))
{
if (float.TryParse(colorNumber.Text, NumberStyles.Number, NumberFormatInfo.InvariantInfo, out argumentValue))
{
return(true);
}
}
}
}
else if (ColorFunction == ColorFunctionType.Rgb || ColorFunction == ColorFunctionType.Rgba)
{
// Red, Green, and Blue are always a <percentage> or <integer>
if (unitType == UnitType.Percentage)
{
if (float.TryParse(colorNumber.Text.TrimEnd('%'), NumberStyles.Number, NumberFormatInfo.InvariantInfo, out argumentValue))
{
argumentValue /= 100.0f;
return(true);
}
}
else if (PropertyValueHelpers.IsValidInteger(colorNumber))
{
if (int.TryParse(colorNumber.Text, out int intValue))
{
argumentValue = intValue / 255.0f;
return(true);
}
}
}
else if (argumentIndex == 0)
{
// Hue is always a <number>
if (PropertyValueHelpers.IsValidNumber(colorNumber))
{
if (float.TryParse(colorNumber.Text, NumberStyles.Number, NumberFormatInfo.InvariantInfo, out argumentValue))
{
argumentValue /= 360.0f;
return(true);
}
}
}
else
{
// Saturation and Lightness are always a percentage
if (unitType == UnitType.Percentage)
{
if (float.TryParse(colorNumber.Text.TrimEnd('%'), NumberStyles.Number, NumberFormatInfo.InvariantInfo, out argumentValue))
{
argumentValue /= 100.0f;
return(true);
}
}
}
return(false);
}