DartStyleExpression? buildDartStyleNode()

in lib/parser.dart [1899:2032]
101 lines of code
45 McCabe index (conditional complexity)

  DartStyleExpression? buildDartStyleNode(
      int styleType, Expressions exprs, List<DartStyleExpression> dartStyles) {
    switch (styleType) {
      // Properties in order:
      //
      //     font-style font-variant font-weight font-size/line-height font-family
      //
      // The font-size and font-family values are required. If other values are
      // missing; a default, if it exist, will be used.
      case _fontPartFont:
        var processor = ExpressionsProcessor(exprs);
        return _mergeFontStyles(processor.processFont(), dartStyles);
      case _fontPartFamily:
        var processor = ExpressionsProcessor(exprs);

        try {
          return _mergeFontStyles(processor.processFontFamily(), dartStyles);
        } catch (fontException) {
          _error('$fontException', _peekToken.span);
        }
        break;
      case _fontPartSize:
        var processor = ExpressionsProcessor(exprs);
        return _mergeFontStyles(processor.processFontSize(), dartStyles);
      case _fontPartStyle:
        // Possible style values:
        //   normal [default]
        //   italic
        //   oblique
        //   inherit

        // TODO(terry): TBD
        break;
      case _fontPartVariant:
        // Possible variant values:
        //   normal  [default]
        //   small-caps
        //   inherit

        // TODO(terry): TBD
        break;
      case _fontPartWeight:
        // Possible weight values:
        //   normal [default]
        //   bold
        //   bolder
        //   lighter
        //   100 - 900
        //   inherit

        // TODO(terry): Only 'normal', 'bold', or values of 100-900 supoorted
        //              need to handle bolder, lighter, and inherit.  See
        //              https://github.com/dart-lang/csslib/issues/1
        var expr = exprs.expressions[0];
        if (expr is NumberTerm) {
          var fontExpr = FontExpression(expr.span, weight: expr.value as int?);
          return _mergeFontStyles(fontExpr, dartStyles);
        } else if (expr is LiteralTerm) {
          var weight = _nameToFontWeight[expr.value.toString()];
          if (weight != null) {
            var fontExpr = FontExpression(expr.span, weight: weight);
            return _mergeFontStyles(fontExpr, dartStyles);
          }
        }
        break;
      case _lineHeightPart:
        if (exprs.expressions.length == 1) {
          var expr = exprs.expressions[0];
          if (expr is UnitTerm) {
            var unitTerm = expr;
            // TODO(terry): Need to handle other units and LiteralTerm normal
            //              See https://github.com/dart-lang/csslib/issues/2.
            if (unitTerm.unit == TokenKind.UNIT_LENGTH_PX ||
                unitTerm.unit == TokenKind.UNIT_LENGTH_PT) {
              var fontExpr = FontExpression(expr.span,
                  lineHeight: LineHeight(expr.value as num, inPixels: true));
              return _mergeFontStyles(fontExpr, dartStyles);
            } else if (isChecked) {
              _warning('Unexpected unit for line-height', expr.span);
            }
          } else if (expr is NumberTerm) {
            var fontExpr = FontExpression(expr.span,
                lineHeight: LineHeight(expr.value as num, inPixels: false));
            return _mergeFontStyles(fontExpr, dartStyles);
          } else if (isChecked) {
            _warning('Unexpected value for line-height', expr.span);
          }
        }
        break;
      case _marginPartMargin:
        return MarginExpression.boxEdge(exprs.span, processFourNums(exprs));
      case _borderPartBorder:
        for (var expr in exprs.expressions) {
          var v = marginValue(expr);
          if (v != null) {
            final box = BoxEdge.uniform(v);
            return BorderExpression.boxEdge(exprs.span, box);
          }
        }
        break;
      case _borderPartWidth:
        var v = marginValue(exprs.expressions[0]);
        if (v != null) {
          final box = BoxEdge.uniform(v);
          return BorderExpression.boxEdge(exprs.span, box);
        }
        break;
      case _paddingPartPadding:
        return PaddingExpression.boxEdge(exprs.span, processFourNums(exprs));
      case _marginPartLeft:
      case _marginPartTop:
      case _marginPartRight:
      case _marginPartBottom:
      case _borderPartLeft:
      case _borderPartTop:
      case _borderPartRight:
      case _borderPartBottom:
      case _borderPartLeftWidth:
      case _borderPartTopWidth:
      case _borderPartRightWidth:
      case _borderPartBottomWidth:
      case _heightPart:
      case _widthPart:
      case _paddingPartLeft:
      case _paddingPartTop:
      case _paddingPartRight:
      case _paddingPartBottom:
        if (exprs.expressions.isNotEmpty) {
          return processOneNumber(exprs, styleType);
        }
        break;
    }
    return null;
  }