[SVGDom/experimental] Initial SVGLength support

experimental/svg/model/SkSVGTypes.h

+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkSVGTypes_DEFINED
+#define SkSVGTypes_DEFINED
+
+#include "SkColor.h"
+#include "SkScalar.h"
+#include "SkTypes.h"
+
+class SkSVGNumber {
+public:
+    constexpr SkSVGNumber()                    : fValue(0) {}
+    explicit constexpr SkSVGNumber(SkScalar v) : fValue(v) {}
+    SkSVGNumber(const SkSVGNumber&)            = default;
+    SkSVGNumber& operator=(const SkSVGNumber&) = default;
+
+
+    const SkScalar& value() const { return fValue; }
+
+    operator const SkScalar&() const { return fValue; }
+
+private:
+    SkScalar fValue;
+};
+
+class SkSVGLength {
+public:
+    enum class Unit {
+        kUnknown,
+        kNumber,
+        kPercentage,
+        kEMS,
+        kEXS,
+        kPX,
+        kCM,
+        kMM,
+        kIN,
+        kPT,
+        kPC,
+    };
+
+    constexpr SkSVGLength()                    : fValue(0), fUnit(Unit::kUnknown) {}
+    explicit constexpr SkSVGLength(SkScalar v, Unit u = Unit::kNumber)
+        : fValue(v), fUnit(u) {}
+    SkSVGLength(const SkSVGLength&)            = default;
+    SkSVGLength& operator=(const SkSVGLength&) = default;
+
+    const SkScalar& value() const { return fValue; }
+    const Unit&     unit()  const { return fUnit;  }
+
+private:
+    SkScalar fValue;
+    Unit     fUnit;
+};
+
+class SkSVGColor {
+public:
+    constexpr SkSVGColor()                   : fValue(SK_ColorBLACK) {}
+    explicit constexpr SkSVGColor(SkColor c) : fValue(c) {}
+
+    operator const SkColor&() const { return fValue; }
+
+private:
+    SkColor fValue;
+};
+
+#endif // SkSVGTypes_DEFINED