[SVGDom] Add <line> support

experimental/svg/model/SkSVGLine.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 SkSVGLine_DEFINED
+#define SkSVGLine_DEFINED
+
+#include "SkSVGShape.h"
+#include "SkSVGTypes.h"
+
+class SkSVGLine final : public SkSVGShape {
+public:
+    virtual ~SkSVGLine() = default;
+    static sk_sp<SkSVGLine> Make() { return sk_sp<SkSVGLine>(new SkSVGLine()); }
+
+    void setX1(const SkSVGLength&);
+    void setY1(const SkSVGLength&);
+    void setX2(const SkSVGLength&);
+    void setY2(const SkSVGLength&);
+
+protected:
+    void onSetAttribute(SkSVGAttribute, const SkSVGValue&) override;
+
+    void onDraw(SkCanvas*, const SkSVGLengthContext&, const SkPaint&) const override;
+
+private:
+    SkSVGLine();
+
+    SkSVGLength fX1 = SkSVGLength(0);
+    SkSVGLength fY1 = SkSVGLength(0);
+    SkSVGLength fX2 = SkSVGLength(0);
+    SkSVGLength fY2 = SkSVGLength(0);
+
+    typedef SkSVGShape INHERITED;
+};
+
+#endif // SkSVGLine_DEFINED