[SVGDom] Initial linear gradient support

experimental/svg/model/SkSVGStop.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 "SkSVGRenderContext.h"
+#include "SkSVGStop.h"
+#include "SkSVGValue.h"
+
+SkSVGStop::SkSVGStop() : INHERITED(SkSVGTag::kStop) {}
+
+void SkSVGStop::setOffset(const SkSVGLength& offset) {
+    fOffset = offset;
+}
+
+void SkSVGStop::setStopColor(const SkSVGColorType& color) {
+    fStopColor = color;
+}
+
+void SkSVGStop::setStopOpacity(const SkSVGNumberType& opacity) {
+    fStopOpacity = SkTPin<SkScalar>(opacity.value(), 0, 1);
+}
+
+void SkSVGStop::onSetAttribute(SkSVGAttribute attr, const SkSVGValue& v) {
+    switch (attr) {
+    case SkSVGAttribute::kOffset:
+        if (const auto* offset = v.as<SkSVGLengthValue>()) {
+            this->setOffset(*offset);
+        }
+        break;
+    case SkSVGAttribute::kStopColor:
+        if (const auto* color = v.as<SkSVGColorValue>()) {
+            this->setStopColor(*color);
+        }
+        break;
+    case SkSVGAttribute::kStopOpacity:
+        if (const auto* opacity = v.as<SkSVGNumberValue>()) {
+            this->setStopOpacity(*opacity);
+        }
+        break;
+    default:
+        this->INHERITED::onSetAttribute(attr, v);
+    }
+}