Implement font-variant-numeric

third_party/WebKit/Source/platform/fonts/FontVariantNumeric.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef FontVariantNumeric_h
+#define FontVariantNumeric_h
+
+#include "wtf/Allocator.h"
+
+namespace blink {
+
+class FontVariantNumeric {
+    STACK_ALLOCATED();
+
+public:
+
+    enum NumericFigure {
+        NormalFigure = 0,
+        LiningNums,
+        OldstyleNums
+    };
+
+    enum NumericSpacing {
+        NormalSpacing = 0,
+        ProportionalNums,
+        TabularNums
+    };
+
+    enum NumericFraction {
+        NormalFraction = 0,
+        DiagonalFractions,
+        StackedFractions
+    };
+
+    enum Ordinal {
+        OrdinalOff = 0,
+        OrdinalOn
+    };
+
+    enum SlashedZero {
+        SlashedZeroOff = 0,
+        SlashedZeroOn
+    };
+
+    FontVariantNumeric() : m_fieldsAsUnsigned(0) { }
+
+    static FontVariantNumeric initializeFromUnsigned(unsigned initValue)
+    {
+        return FontVariantNumeric(initValue);
+    }
+
+    void setNumericFigure(NumericFigure figure) { m_fields.m_numericFigure = figure; };
+    void setNumericSpacing(NumericSpacing spacing) { m_fields.m_numericSpacing = spacing; };
+    void setNumericFraction(NumericFraction fraction) { m_fields.m_numericFraction = fraction; };
+    void setOrdinal(Ordinal ordinal) { m_fields.m_ordinal = ordinal; };
+    void setSlashedZero(SlashedZero slashedZero) { m_fields.m_slashedZero = slashedZero; };
+
+    NumericFigure numericFigureValue() const { return static_cast<NumericFigure>(m_fields.m_numericFigure); }
+    NumericSpacing numericSpacingValue() const { return static_cast<NumericSpacing>(m_fields.m_numericSpacing); }
+    NumericFraction numericFractionValue() const { return static_cast<NumericFraction>(m_fields.m_numericFraction); }
+    Ordinal ordinalValue() const { return static_cast<Ordinal>(m_fields.m_ordinal); };
+    SlashedZero slashedZeroValue() const { return static_cast<SlashedZero>(m_fields.m_slashedZero); }
+
+    bool isAllNormal() { return !m_fieldsAsUnsigned; }
+
+    bool operator==(const FontVariantNumeric& other) const
+    {
+        return m_fieldsAsUnsigned == other.m_fieldsAsUnsigned;
+    }
+
+private:
+    FontVariantNumeric(unsigned initValue) : m_fieldsAsUnsigned(initValue) { }
+
+    struct BitFields {
+        unsigned m_numericFigure : 2;
+        unsigned m_numericSpacing : 2;
+        unsigned m_numericFraction : 2;
+        unsigned m_ordinal : 1;
+        unsigned m_slashedZero : 1;
+    };
+
+
+    union {
+        BitFields m_fields;
+        unsigned m_fieldsAsUnsigned;
+    };
+    static_assert(sizeof(BitFields) == sizeof(unsigned), "Mapped union types must match in size.");
+
+    // Used in setVariant to store the value in m_fields.m_variantNumeric;
+    friend class FontDescription;
+};
+
+}
+
+#endif // FontVariantNumeric_h