[SVGDom] Linear gradient 'spreadMethod' support

experimental/svg/model/SkSVGLinearGradient.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 "SkGradientShader.h"
 #include "SkSVGLinearGradient.h"
 #include "SkSVGRenderContext.h"
 #include "SkSVGStop.h"
 #include "SkSVGValue.h"
 
 SkSVGLinearGradient::SkSVGLinearGradient() : INHERITED(SkSVGTag::kLinearGradient) {}
 
 void SkSVGLinearGradient::setHref(const SkSVGStringType& href) {
     fHref = std::move(href);
 }
 
+void SkSVGLinearGradient::setSpreadMethod(const SkSVGSpreadMethod& spread) {
+    fSpreadMethod = spread;
+}
+
 void SkSVGLinearGradient::setX1(const SkSVGLength& x1) {
     fX1 = x1;
 }
 
 void SkSVGLinearGradient::setY1(const SkSVGLength& y1) {
     fY1 = y1;
 }
 
 void SkSVGLinearGradient::setX2(const SkSVGLength& x2) {
     fX2 = x2;
 }
 
 void SkSVGLinearGradient::setY2(const SkSVGLength& y2) {
     fY2 = y2;
 }
 
 void SkSVGLinearGradient::onSetAttribute(SkSVGAttribute attr, const SkSVGValue& v) {
     switch (attr) {
     case SkSVGAttribute::kHref:
         if (const auto* href = v.as<SkSVGStringValue>()) {
             this->setHref(*href);
         }
         break;
+    case SkSVGAttribute::kSpreadMethod:
+        if (const auto* spread = v.as<SkSVGSpreadMethodValue>()) {
+            this->setSpreadMethod(*spread);
+        }
+        break;
     case SkSVGAttribute::kX1:
         if (const auto* x1 = v.as<SkSVGLengthValue>()) {
             this->setX1(*x1);
         }
         break;
     case SkSVGAttribute::kY1:
         if (const auto* y1 = v.as<SkSVGLengthValue>()) {
             this->setY1(*y1);
         }
         break;
@@ skipping 50 matching lines @@
 
     const SkPoint pts[2] = { {x1, y1}, {x2, y2}};
     SkSTArray<2, SkColor , true> colors;
     SkSTArray<2, SkScalar, true> pos;
 
     this->collectColorStops(ctx, &pos, &colors);
     // TODO:
     //       * stop (lazy?) sorting
     //       * href loop detection
     //       * href attribute inheritance (not just color stops)
-    //       * spreadMethods support
     //       * objectBoundingBox units support
 
+    static_assert(static_cast<SkShader::TileMode>(SkSVGSpreadMethod::Type::kPad) ==
+                  SkShader::kClamp_TileMode, "SkSVGSpreadMethod::Type is out of sync");
+    static_assert(static_cast<SkShader::TileMode>(SkSVGSpreadMethod::Type::kRepeat) ==
+                  SkShader::kRepeat_TileMode, "SkSVGSpreadMethod::Type is out of sync");
+    static_assert(static_cast<SkShader::TileMode>(SkSVGSpreadMethod::Type::kReflect) ==
+                  SkShader::kMirror_TileMode, "SkSVGSpreadMethod::Type is out of sync");
+    const auto tileMode = static_cast<SkShader::TileMode>(fSpreadMethod.type());
+
     paint->setShader(SkGradientShader::MakeLinear(pts, colors.begin(), pos.begin(), colors.count(),
-                                                  SkShader::kClamp_TileMode));
+                                                  tileMode));
     return true;
 }