1/*
2 * Copyright 2016 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#ifndef SkSVGValue_DEFINED
9#define SkSVGValue_DEFINED
10
11#include "include/core/SkColor.h"
12#include "include/core/SkMatrix.h"
13#include "include/core/SkPath.h"
14#include "include/core/SkTypes.h"
15#include "include/private/SkNoncopyable.h"
16#include "modules/svg/include/SkSVGTypes.h"
17
18class SkSVGValue : public SkNoncopyable {
19public:
20    enum class Type {
21        kColor,
22        kFilter,
23        kLength,
24        kNumber,
25        kObjectBoundingBoxUnits,
26        kPreserveAspectRatio,
27        kStopColor,
28        kString,
29        kTransform,
30        kViewBox,
31    };
32
33    Type type() const { return fType; }
34
35    template <typename T>
36    const T* as() const {
37        return fType == T::TYPE ? static_cast<const T*>(this) : nullptr;
38    }
39
40protected:
41    SkSVGValue(Type t) : fType(t) { }
42
43private:
44    Type fType;
45
46    using INHERITED = SkNoncopyable;
47};
48
49template <typename T, SkSVGValue::Type ValueType>
50class SkSVGWrapperValue final : public SkSVGValue {
51public:
52    static constexpr Type TYPE = ValueType;
53
54    explicit SkSVGWrapperValue(const T& v)
55        : INHERITED(ValueType)
56        , fWrappedValue(v) { }
57
58    operator const T&() const { return fWrappedValue; }
59    const T* operator->() const { return &fWrappedValue; }
60
61private:
62    // Stack-only
63    void* operator new(size_t) = delete;
64    void* operator new(size_t, void*) = delete;
65
66    const T& fWrappedValue;
67
68    using INHERITED = SkSVGValue;
69};
70
71using SkSVGColorValue        = SkSVGWrapperValue<SkSVGColorType    , SkSVGValue::Type::kColor     >;
72using SkSVGLengthValue       = SkSVGWrapperValue<SkSVGLength       , SkSVGValue::Type::kLength    >;
73using SkSVGTransformValue    = SkSVGWrapperValue<SkSVGTransformType, SkSVGValue::Type::kTransform >;
74using SkSVGViewBoxValue      = SkSVGWrapperValue<SkSVGViewBoxType  , SkSVGValue::Type::kViewBox   >;
75using SkSVGNumberValue       = SkSVGWrapperValue<SkSVGNumberType   , SkSVGValue::Type::kNumber    >;
76using SkSVGStringValue       = SkSVGWrapperValue<SkSVGStringType   , SkSVGValue::Type::kString    >;
77using SkSVGStopColorValue    = SkSVGWrapperValue<SkSVGStopColor    , SkSVGValue::Type::kStopColor >;
78
79using SkSVGPreserveAspectRatioValue    = SkSVGWrapperValue<SkSVGPreserveAspectRatio,
80                                                           SkSVGValue::Type::kPreserveAspectRatio>;
81
82using SkSVGObjectBoundingBoxUnitsValue = SkSVGWrapperValue<SkSVGObjectBoundingBoxUnits,
83                                                           SkSVGValue::Type::kObjectBoundingBoxUnits>;
84
85#endif // SkSVGValue_DEFINED
86