[SVGDom] Add 'stroke-dasharray' support

https://www.w3.org/TR/SVG/painting.html#StrokeDasharrayProperty
Change-Id: I9a63ebbd958d661c865ed405570b86cca68f63bf
Reviewed-on: https://skia-review.googlesource.com/59700
Commit-Queue: Florin Malita <fmalita@chromium.org>
Reviewed-by: Robert Phillips <robertphillips@google.com>

1 files changed, 34 insertions, 0 deletions

diff --git a/experimental/svg/model/SkSVGRenderContext.cpp b/experimental/svg/model/SkSVGRenderContext.cpp
index 8ee5ffcbe6..61551c4858 100644
--- a/experimental/svg/model/SkSVGRenderContext.cpp
+++ b/experimental/svg/model/SkSVGRenderContext.cpp
@@ -6,6 +6,7 @@
  */
 
 #include "SkCanvas.h"
+#include "SkDashPathEffect.h"
 #include "SkPath.h"
 #include "SkSVGAttribute.h"
 #include "SkSVGNode.h"
@@ -154,6 +155,38 @@ void commitToPaint<SkSVGAttribute::kFillOpacity>(const SkSVGPresentationAttribut
 }
 
 template <>
+void commitToPaint<SkSVGAttribute::kStrokeDashArray>(const SkSVGPresentationAttributes& attrs,
+                                                     const SkSVGRenderContext& ctx,
+                                                     SkSVGPresentationContext* pctx) {
+    const auto& dashArray = attrs.fStrokeDashArray.get();
+    if (dashArray->type() != SkSVGDashArray::Type::kDashArray) {
+        return;
+    }
+
+    const auto count = dashArray->dashArray().count();
+    SkSTArray<128, SkScalar, true> intervals(count);
+    for (const auto& dash : dashArray->dashArray()) {
+        intervals.push_back(ctx.lengthContext().resolve(dash,
+                                                        SkSVGLengthContext::LengthType::kOther));
+    }
+
+    if (count & 1) {
+        // If an odd number of values is provided, then the list of values
+        // is repeated to yield an even number of values.
+        intervals.push_back_n(count);
+        memcpy(intervals.begin() + count, intervals.begin(), count);
+    }
+
+    SkASSERT((intervals.count() & 1) == 0);
+
+    // TODO: phase support
+    const SkScalar phase = 0;
+    pctx->fStrokePaint.setPathEffect(SkDashPathEffect::Make(intervals.begin(),
+                                                            intervals.count(),
+                                                            phase));
+}
+
+template <>
 void commitToPaint<SkSVGAttribute::kStrokeLineCap>(const SkSVGPresentationAttributes& attrs,
                                                    const SkSVGRenderContext&,
                                                    SkSVGPresentationContext* pctx) {
@@ -297,6 +330,7 @@ void SkSVGRenderContext::applyPresentationAttributes(const SkSVGPresentationAttr
     ApplyLazyInheritedAttribute(FillRule);
     ApplyLazyInheritedAttribute(ClipRule);
     ApplyLazyInheritedAttribute(Stroke);
+    ApplyLazyInheritedAttribute(StrokeDashArray);
     ApplyLazyInheritedAttribute(StrokeLineCap);
     ApplyLazyInheritedAttribute(StrokeLineJoin);
     ApplyLazyInheritedAttribute(StrokeMiterLimit);