[SVGDom] <polygon> & <polyline> support

experimental/svg/model/SkSVGPoly.cpp

+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkCanvas.h"
+#include "SkSVGRenderContext.h"
+#include "SkSVGPoly.h"
+#include "SkSVGValue.h"
+
+SkSVGPoly::SkSVGPoly(SkSVGTag t) : INHERITED(t) {}
+
+void SkSVGPoly::setPoints(const SkSVGPointsType& pts) {
+    fPath.reset();
+    fPath.addPoly(pts.value().begin(),
+                  pts.value().count(),
+                  this->tag() == SkSVGTag::kPolygon); // only polygons are auto-closed
+}
+
+void SkSVGPoly::onSetAttribute(SkSVGAttribute attr, const SkSVGValue& v) {
+    switch (attr) {
+    case SkSVGAttribute::kPoints:
+        if (const auto* pts = v.as<SkSVGPointsValue>()) {
+            this->setPoints(*pts);
+        }
+        break;
+    default:
+        this->INHERITED::onSetAttribute(attr, v);
+    }
+}
+
+void SkSVGPoly::onDraw(SkCanvas* canvas, const SkSVGLengthContext&, const SkPaint& paint) const {
+    canvas->drawPath(fPath, paint);
+}