CSS animation for SVG presentation attribute 'd'

third_party/WebKit/Source/core/animation/animatable/AnimatablePath.cpp

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "config.h"
+#include "core/animation/animatable/AnimatablePath.h"
+
+#include "core/svg/SVGPathBlender.h"
+#include "core/svg/SVGPathByteStreamBuilder.h"
+#include "core/svg/SVGPathByteStreamSource.h"
+#include "core/svg/SVGPathUtilities.h"
+
+namespace blink {
+
+bool AnimatablePath::usesDefaultInterpolationWith(const AnimatableValue* value) const
+{
+    // Default interpolation is used if the paths have different lengths,
+    // or the paths have a segment with different types (ignoring "relativeness").
+
+    SVGPathByteStreamSource fromSource(pathValue()->byteStream());
+    SVGPathByteStreamSource toSource(toAnimatablePath(value)->pathValue()->byteStream());
+
+    while (fromSource.hasMoreData()) {
+        if (!toSource.hasMoreData())
+            return true;
+
+        PathSegmentData fromSeg = fromSource.parseSegment();
+        PathSegmentData toSeg = toSource.parseSegment();
+        ASSERT(fromSeg.command != PathSegUnknown);
+        ASSERT(toSeg.command != PathSegUnknown);
+
+        if (toAbsolutePathSegType(fromSeg.command) != toAbsolutePathSegType(toSeg.command))
+            return true;
+    }
+
+    return toSource.hasMoreData();
+}
+
+PassRefPtr<AnimatableValue> AnimatablePath::interpolateTo(const AnimatableValue* value, double fraction) const
+{
+    if (usesDefaultInterpolationWith(value))
+        return defaultInterpolateTo(this, value, fraction);
+
+    OwnPtr<SVGPathByteStream> byteStream = SVGPathByteStream::create();
+    SVGPathByteStreamBuilder builder(*byteStream);
+
+    SVGPathByteStreamSource fromSource(pathValue()->byteStream());
+    SVGPathByteStreamSource toSource(toAnimatablePath(value)->pathValue()->byteStream());
+
+    SVGPathBlender blender(&fromSource, &toSource, &builder);
+    bool ok = blender.blendAnimatedPath(fraction);
+    ASSERT_UNUSED(ok, ok);
+    return AnimatablePath::create(CSSPathValue::create(byteStream.release()));
+}
+
+bool AnimatablePath::equalTo(const AnimatableValue* value) const
+{
+    return pathValue()->equals(*toAnimatablePath(value)->pathValue());
+}
+
+} // namespace blink