1 files changed, 104 insertions, 0 deletions
diff --git a/dom/svg/SVGMotionSMILPathUtils.h b/dom/svg/SVGMotionSMILPathUtils.h
new file mode 100644
index 0000000000..f866a43f5e
--- /dev/null
+++ b/dom/svg/SVGMotionSMILPathUtils.h
@@ -0,0 +1,104 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* Helper class to help with generating anonymous path elements for
+   <animateMotion> elements to use. */
+
+#ifndef DOM_SVG_SVGMOTIONSMILPATHUTILS_H_
+#define DOM_SVG_SVGMOTIONSMILPATHUTILS_H_
+
+#include "mozilla/Attributes.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/SMILParserUtils.h"
+#include "mozilla/gfx/2D.h"
+#include "gfxPlatform.h"
+#include "nsDebug.h"
+#include "nsStringFwd.h"
+#include "nsTArray.h"
+
+namespace mozilla {
+
+namespace dom {
+class SVGElement;
+}
+
+class SVGMotionSMILPathUtils {
+  using DrawTarget = mozilla::gfx::DrawTarget;
+  using Path = mozilla::gfx::Path;
+  using PathBuilder = mozilla::gfx::PathBuilder;
+
+ public:
+  // Class to assist in generating a Path, based on
+  // coordinates in the <animateMotion> from/by/to/values attributes.
+  class PathGenerator {
+   public:
+    explicit PathGenerator(const dom::SVGElement* aSVGElement)
+        : mSVGElement(aSVGElement), mHaveReceivedCommands(false) {
+      RefPtr<DrawTarget> drawTarget =
+          gfxPlatform::GetPlatform()->ScreenReferenceDrawTarget();
+      NS_ASSERTION(
+          gfxPlatform::GetPlatform()->SupportsAzureContentForDrawTarget(
+              drawTarget),
+          "Should support Moz2D content drawing");
+
+      mPathBuilder = drawTarget->CreatePathBuilder();
+    }
+
+    // Methods for adding various path commands to output path.
+    // Note: aCoordPairStr is expected to be a whitespace and/or
+    // comma-separated x,y coordinate-pair -- see description of
+    // "the specified values for from, by, to, and values" at
+    //    http://www.w3.org/TR/SVG11/animate.html#AnimateMotionElement
+    void MoveToOrigin();
+    bool MoveToAbsolute(const nsAString& aCoordPairStr);
+    bool LineToAbsolute(const nsAString& aCoordPairStr,
+                        double& aSegmentDistance);
+    bool LineToRelative(const nsAString& aCoordPairStr,
+                        double& aSegmentDistance);
+
+    // Accessor to let clients check if we've received any commands yet.
+    inline bool HaveReceivedCommands() { return mHaveReceivedCommands; }
+    // Accessor to get the finalized path
+    already_AddRefed<Path> GetResultingPath();
+
+   protected:
+    // Helper methods
+    bool ParseCoordinatePair(const nsAString& aCoordPairStr, float& aXVal,
+                             float& aYVal);
+
+    // Member data
+    const dom::SVGElement* mSVGElement;  // context for converting to user units
+    RefPtr<PathBuilder> mPathBuilder;
+    bool mHaveReceivedCommands;
+  };
+
+  // Class to assist in passing each subcomponent of a |values| attribute to
+  // a PathGenerator, for generating a corresponding Path.
+  class MOZ_STACK_CLASS MotionValueParser
+      : public SMILParserUtils::GenericValueParser {
+   public:
+    MotionValueParser(PathGenerator* aPathGenerator,
+                      FallibleTArray<double>* aPointDistances)
+        : mPathGenerator(aPathGenerator),
+          mPointDistances(aPointDistances),
+          mDistanceSoFar(0.0) {
+      MOZ_ASSERT(mPointDistances->IsEmpty(),
+                 "expecting point distances array to start empty");
+    }
+
+    // SMILParserUtils::GenericValueParser interface
+    virtual bool Parse(const nsAString& aValueStr) override;
+
+   protected:
+    PathGenerator* mPathGenerator;
+    FallibleTArray<double>* mPointDistances;
+    double mDistanceSoFar;
+  };
+};
+
+}  // namespace mozilla
+
+#endif  // DOM_SVG_SVGMOTIONSMILPATHUTILS_H_