private static ICssValue ParseRepeat(this StringSource source, Func <StringSource, ICssValue> parseCount, Func <StringSource, ICssValue> parseValue)
{
var pos = source.Index;
var ident = source.ParseIdent();
if (ident.Isi(FunctionNames.Repeat) && source.Current == Symbols.RoundBracketOpen)
{
var c = source.SkipCurrentAndSpaces();
var count = parseCount(source);
c = source.SkipSpaces();
if (count != null && c == Symbols.Comma)
{
source.SkipCurrentAndSpaces();
var value = parseValue(source);
c = source.SkipSpacesAndComments();
if (value != null && c == Symbols.RoundBracketClose)
{
source.Next();
return(new Repeat(count, value));
}
}
}
source.BackTo(pos);
return(null);
}
public static ICssValue ParseAutoTrackList(this StringSource source)
{
var values = new List <ICssValue>();
var pos = source.Index;
var head = source.ParseRepeatValue(s => s.ParseFixedSize() ?? s.ParseFixedRepeat(), true);
if (head != null)
{
values.Add(head);
}
source.SkipSpacesAndComments();
var repeat = source.ParseAutoRepeat();
if (repeat == null)
{
source.BackTo(pos);
return(null);
}
values.Add(repeat);
source.SkipSpacesAndComments();
var tail = source.ParseRepeatValue(s => s.ParseFixedSize() ?? s.ParseFixedRepeat(), true);
source.SkipSpacesAndComments();
if (tail != null)
{
values.Add(tail);
}
return(new CssTupleValue(values.ToArray()));
}
public static LineNames ParseLineNames(this StringSource source)
{
var pos = source.Index;
if (source.Current == Symbols.SquareBracketOpen)
{
source.SkipCurrentAndSpaces();
var names = new List <String>();
while (!source.IsDone)
{
var name = source.ParseIdent();
if (name == null)
{
break;
}
names.Add(name);
var current = source.SkipSpacesAndComments();
if (current == Symbols.SquareBracketClose)
{
source.Next();
return(new LineNames(names));
}
}
}
source.BackTo(pos);
return(null);
}
public static ICssValue ParseFixedSize(this StringSource source)
{
var length = source.ParseDistanceOrCalc();
if (length == null)
{
var pos = source.Index;
var ident = source.ParseIdent();
if (ident.Isi(FunctionNames.Minmax) && source.Current == Symbols.RoundBracketOpen)
{
var c = source.SkipCurrentAndSpaces();
var min = source.ParseTrackBreadth(false);
c = source.SkipSpaces();
if (min != null && c == Symbols.Comma)
{
source.SkipCurrentAndSpaces();
var max = source.ParseTrackBreadth();
c = source.SkipSpacesAndComments();
if (max != null && c == Symbols.RoundBracketClose && (min is Length? || max is Length?))
{
source.Next();
return(new Minmax(min, max));
}
}
}
source.BackTo(pos);
return(null);
}
return(length);
}
private static IConditionFunction ConjunctionOrDisjunction(StringSource source)
{
var condition = Group(source);
source.SkipSpacesAndComments();
var pos = source.Index;
var ident = source.ParseIdent();
if (ident != null)
{
var isAnd = ident.Is(CssKeywords.And);
var isOr = ident.Is(CssKeywords.Or);
if (isAnd || isOr)
{
var conditions = Scan(source, ident, condition);
if (isAnd)
{
return(new AndCondition(conditions));
}
else if (isOr)
{
return(new OrCondition(conditions));
}
}
}
source.BackTo(pos);
return(condition);
}
/// <summary>
/// Parses a linear gradient.
/// https://developer.mozilla.org/en-US/docs/Web/CSS/linear-gradient
/// </summary>
private static IGradient ParseLinearGradient(StringSource source, Boolean repeating)
{
var start = source.Index;
var angle = ParseLinearAngle(source);
if (angle != null)
{
var current = source.SkipSpacesAndComments();
if (current != Symbols.Comma)
{
return(null);
}
source.SkipCurrentAndSpaces();
}
else
{
source.BackTo(start);
}
var stops = ParseGradientStops(source);
if (stops != null && source.Current == Symbols.RoundBracketClose)
{
source.SkipCurrentAndSpaces();
return(new LinearGradient(angle, stops, repeating));
}
return(null);
}
public static ICssTimingFunctionValue ParseTimingFunction(this StringSource source)
{
var pos = source.Index;
var result = default(ICssTimingFunctionValue);
var ident = source.ParseIdent();
if (ident != null)
{
if (source.Current == Symbols.RoundBracketOpen)
{
var function = default(Func <StringSource, ICssTimingFunctionValue>);
if (TimingFunctions.TryGetValue(ident, out function))
{
source.SkipCurrentAndSpaces();
result = function.Invoke(source);
}
}
else
{
Map.TimingFunctions.TryGetValue(ident, out result);
}
}
if (result == null)
{
source.BackTo(pos);
}
return(result);
}
private static ICssValue ParseRepeatValue(this StringSource source, Func <StringSource, ICssValue> parseTrack, Boolean hasSize = false)
{
var values = new List <ICssValue>();
var pos = source.Index;
while (!source.IsDone)
{
var names = source.ParseLineNames();
source.SkipSpacesAndComments();
if (names != null)
{
values.Add(names);
}
var size = parseTrack(source);
source.SkipSpacesAndComments();
if (size == null)
{
break;
}
hasSize = true;
values.Add(size);
}
if (hasSize)
{
return(new CssTupleValue(values.ToArray()));
}
source.BackTo(pos);
return(null);
}
public static IEnumerable <IDocumentFunction> ParseDocumentFunctions(this StringSource source, IDocumentFunctionFactory factory)
{
var functions = new List <IDocumentFunction>();
while (!source.IsDone)
{
var current = source.SkipSpacesAndComments();
if (functions.Count > 0)
{
if (current != Symbols.Comma)
{
return(null);
}
source.SkipCurrentAndSpaces();
}
var position = source.Index;
var uri = source.ParseUri();
var name = FunctionNames.Url;
var data = uri?.Path;
if (uri == null)
{
source.BackTo(position);
name = source.ParseIdent();
var start = source.Current;
if (name == null || start != Symbols.RoundBracketOpen)
{
return(null);
}
source.SkipCurrentAndSpaces();
data = source.ParseString();
var end = source.SkipSpacesAndComments();
if (end != Symbols.RoundBracketClose)
{
return(null);
}
source.SkipCurrentAndSpaces();
}
var function = factory.Create(name, data);
if (function == null)
{
return(null);
}
functions.Add(function);
}
return(functions);
}
public static String TakeUntilClosed(this StringSource source)
{
var start = source.Index;
var open = 1;
var current = source.Current;
var lastNonWhitespace = start;
while (!source.IsDone)
{
if (current == Symbols.RoundBracketOpen)
{
open++;
}
else if (current == Symbols.RoundBracketClose && --open == 0)
{
break;
}
else if (current == Symbols.Solidus && source.Peek() == Symbols.Asterisk)
{
source.Next();
current = source.SkipCssComment();
continue;
}
else if (current.IsOneOf(Symbols.SingleQuote, Symbols.DoubleQuote))
{
source.ParseString();
current = source.Current;
lastNonWhitespace = source.Index;
continue;
}
else if (current == Symbols.ReverseSolidus && source.IsValidEscape())
{
source.ConsumeEscape();
current = source.Current;
lastNonWhitespace = source.Index;
continue;
}
else if (current.IsSpaceCharacter())
{
current = source.SkipSpacesAndComments();
continue;
}
current = source.Next();
lastNonWhitespace = source.Index;
}
var end = source.Index;
source.BackTo(lastNonWhitespace);
var content = source.Substring(start);
source.NextTo(end);
return(content);
}
public static Unit ParseUnit(this StringSource source)
{
var pos = source.Index;
var result = UnitStart(source);
if (result == null)
{
source.BackTo(pos);
}
return(result);
}
public static Color?ParseColor(this StringSource source)
{
var pos = source.Index;
var result = Start(source);
if (result == null)
{
source.BackTo(pos);
}
return(result);
}
public static Length?ParseDistance(this StringSource source)
{
var pos = source.Index;
var test = source.ParseUnit();
var length = GetLength(test);
if (!length.HasValue)
{
source.BackTo(pos);
}
return(length);
}
public static Boolean IsIdentifier(this StringSource source, String identifier)
{
var pos = source.Index;
var test = source.ParseIdent();
if (test != null && test.Isi(identifier))
{
return(true);
}
source.BackTo(pos);
return(false);
}
public static Int32?ParseNaturalInteger(this StringSource source)
{
var pos = source.Index;
var element = source.ParseInteger();
if (element.HasValue && element.Value >= 0)
{
return(element);
}
source.BackTo(pos);
return(null);
}
public static Int32?ParseWeightInteger(this StringSource source)
{
var pos = source.Index;
var element = source.ParsePositiveInteger();
if (element.HasValue && IsWeight(element.Value))
{
return(element);
}
source.BackTo(pos);
return(null);
}
public static Int32?ParseBinary(this StringSource source)
{
var pos = source.Index;
var element = source.ParseInteger();
if (element.HasValue && (element.Value == 0 || element.Value == 1))
{
return(element);
}
source.BackTo(pos);
return(null);
}
public static Double?ParseGreaterOrEqualOneNumber(this StringSource source)
{
var pos = source.Index;
var element = source.ParseNumber();
if (element.HasValue && element.Value >= 1f)
{
return(element);
}
source.BackTo(pos);
return(null);
}
public static Double?ParsePercent(this StringSource source)
{
var pos = source.Index;
var test = source.ParseUnit();
if (test?.Dimension == "%" &&
Double.TryParse(test.Value, NumberStyles.Float, CultureInfo.InvariantCulture, out var value))
{
return(value * 0.01);
}
source.BackTo(pos);
return(null);
}
private static RadialGradient.SizeMode?ToSizeMode(StringSource source)
{
var pos = source.Index;
var ident = source.ParseIdent();
var result = RadialGradient.SizeMode.None;
if (ident != null && Map.RadialGradientSizeModes.TryGetValue(ident, out result))
{
return(result);
}
source.BackTo(pos);
return(null);
}
public static ICssGradientFunctionValue ParseGradient(this StringSource source)
{
var pos = source.Index;
var ident = source.ParseIdent();
if (ident != null && source.Current == Symbols.RoundBracketOpen && GradientFunctions.TryGetValue(ident, out var function))
{
source.SkipCurrentAndSpaces();
return(function.Invoke(source));
}
source.BackTo(pos);
return(null);
}
public static Double?ParsePercent(this StringSource source)
{
var pos = source.Index;
var test = source.ParseUnit();
if (test != null && test.Dimension == "%")
{
var value = Double.Parse(test.Value, CultureInfo.InvariantCulture);
return(value * 0.01);
}
source.BackTo(pos);
return(null);
}
public static Length?ParseLength(this StringSource source)
{
var pos = source.Index;
var test = source.ParseUnit();
var length = GetLength(test);
if (!length.HasValue || length.Value.Type == Length.Unit.Percent)
{
source.BackTo(pos);
return(null);
}
return(length);
}
public static ICssValue ParseConstant <T>(this StringSource source, IDictionary <String, T> values)
where T : struct
{
var pos = source.Index;
var ident = source.ParseIdent();
if (ident != null && values.TryGetValue(ident, out T mode))
{
return(mode as ICssValue ?? new Constant <T>(ident.ToLowerInvariant(), mode));
}
source.BackTo(pos);
return(null);
}
public static String ParseAnimatableIdent(this StringSource source)
{
var pos = source.Index;
var test = source.ParseNormalizedIdent();
//TODO Replace Animatables with call to DeclarationFactory - get from flags
if (test != null && (test.Isi(CssKeywords.All) || Animatables.Contains(test)))
{
return(test);
}
source.BackTo(pos);
return(null);
}
public ICssValue Convert(StringSource source)
{
var pos = source.Index;
var ident = source.ParseIdent();
var mode = default(T);
if (ident != null && _values.TryGetValue(ident, out mode))
{
return(new Constant <T>(ident.ToLowerInvariant(), mode));
}
source.BackTo(pos);
return(null);
}
public static Double?ParseRatio(this StringSource source)
{
var pos = source.Index;
var top = source.ParseNumber();
var c = source.SkipGetSkip();
var bottom = source.ParseNumber();
if (top.HasValue && bottom.HasValue && c == Symbols.Solidus)
{
return(top.Value / bottom.Value);
}
source.BackTo(pos);
return(null);
}
public static IKeyframeSelector ParseKeyframeSelector(this StringSource source)
{
var stops = new List <Double>();
var current = source.SkipSpacesAndComments();
while (current != Symbols.EndOfFile)
{
var start = source.Index;
var id = source.ParseIdent();
if (id == null)
{
source.BackTo(start);
var test = source.ParsePercent();
if (!test.HasValue)
{
return(null);
}
stops.Add(test.Value);
}
else if (id.Is(CssKeywords.From))
{
stops.Add(0f);
}
else if (id.Is(CssKeywords.To))
{
stops.Add(1f);
}
else
{
return(null);
}
current = source.SkipSpacesAndComments();
if (current != Symbols.Comma)
{
break;
}
current = source.SkipCurrentAndSpaces();
}
return(new KeyframeSelector(stops));
}
public static CssCalcValue ParseCalc(this StringSource source)
{
var pos = source.Index;
if (source.IsFunction(FunctionNames.Calc))
{
var expression = source.ParseExpression();
if (expression != null)
{
return(new CssCalcValue(expression));
}
}
source.BackTo(pos);
return(null);
}
public static Boolean IsFunction(this StringSource source, String name)
{
var rest = source.Content.Length - source.Index;
if (rest >= name.Length + 2)
{
var length = 0;
var current = source.Current;
var pos = source.Index;
while (length < name.Length)
{
if (current == Symbols.ReverseSolidus && source.IsValidEscape())
{
var next = source.ConsumeEscape();
if (next.Length != 1)
{
break;
}
current = next[0];
}
if (Char.ToLowerInvariant(current) != Char.ToLowerInvariant(name[length]))
{
break;
}
length++;
current = source.Next();
}
if (length == name.Length && current == Symbols.RoundBracketOpen)
{
source.SkipCurrentAndSpaces();
return(true);
}
source.BackTo(pos);
}
return(false);
}
