1 files changed, 190 insertions, 0 deletions
diff --git a/dom/svg/SVGFragmentIdentifier.cpp b/dom/svg/SVGFragmentIdentifier.cpp
new file mode 100644
index 0000000000..b274ef279b
--- /dev/null
+++ b/dom/svg/SVGFragmentIdentifier.cpp
@@ -0,0 +1,190 @@
+/* -*- 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/. */
+
+#include "SVGFragmentIdentifier.h"
+
+#include "mozilla/dom/SVGSVGElement.h"
+#include "mozilla/dom/SVGViewElement.h"
+#include "mozilla/SVGOuterSVGFrame.h"
+#include "nsCharSeparatedTokenizer.h"
+#include "SVGAnimatedTransformList.h"
+
+namespace mozilla {
+
+using namespace dom;
+
+static bool IsMatchingParameter(const nsAString& aString,
+                                const nsAString& aParameterName) {
+  // The first two tests ensure aString.Length() > aParameterName.Length()
+  // so it's then safe to do the third test
+  return StringBeginsWith(aString, aParameterName) && aString.Last() == ')' &&
+         aString.CharAt(aParameterName.Length()) == '(';
+}
+
+static SVGViewElement* GetViewElement(Document* aDocument,
+                                      const nsAString& aId) {
+  Element* element = aDocument->GetElementById(aId);
+  return (element && element->IsSVGElement(nsGkAtoms::view))
+             ? static_cast<SVGViewElement*>(element)
+             : nullptr;
+}
+
+// Handles setting/clearing the root's mSVGView pointer.
+class MOZ_RAII AutoSVGViewHandler {
+ public:
+  explicit AutoSVGViewHandler(SVGSVGElement* aRoot)
+      : mRoot(aRoot), mValid(false) {
+    mWasOverridden = mRoot->UseCurrentView();
+    mRoot->mSVGView = nullptr;
+    mRoot->mCurrentViewID = nullptr;
+  }
+
+  ~AutoSVGViewHandler() {
+    if (!mWasOverridden && !mValid) {
+      // we weren't overridden before and we aren't
+      // overridden now so nothing has changed.
+      return;
+    }
+    if (mValid) {
+      mRoot->mSVGView = std::move(mSVGView);
+    }
+    mRoot->InvalidateTransformNotifyFrame();
+    if (nsIFrame* f = mRoot->GetPrimaryFrame()) {
+      if (SVGOuterSVGFrame* osf = do_QueryFrame(f)) {
+        osf->MaybeSendIntrinsicSizeAndRatioToEmbedder();
+      }
+    }
+  }
+
+  void CreateSVGView() {
+    MOZ_ASSERT(!mSVGView, "CreateSVGView should not be called multiple times");
+    mSVGView = MakeUnique<SVGView>();
+  }
+
+  bool ProcessAttr(const nsAString& aToken, const nsAString& aParams) {
+    MOZ_ASSERT(mSVGView, "CreateSVGView should have been called");
+
+    // SVGViewAttributes may occur in any order, but each type may only occur
+    // at most one time in a correctly formed SVGViewSpec.
+    // If we encounter any attribute more than once or get any syntax errors
+    // we're going to return false and cancel any changes.
+
+    if (IsMatchingParameter(aToken, u"viewBox"_ns)) {
+      if (mSVGView->mViewBox.IsExplicitlySet() ||
+          NS_FAILED(
+              mSVGView->mViewBox.SetBaseValueString(aParams, mRoot, false))) {
+        return false;
+      }
+    } else if (IsMatchingParameter(aToken, u"preserveAspectRatio"_ns)) {
+      if (mSVGView->mPreserveAspectRatio.IsExplicitlySet() ||
+          NS_FAILED(mSVGView->mPreserveAspectRatio.SetBaseValueString(
+              aParams, mRoot, false))) {
+        return false;
+      }
+    } else if (IsMatchingParameter(aToken, u"transform"_ns)) {
+      if (mSVGView->mTransforms) {
+        return false;
+      }
+      mSVGView->mTransforms = MakeUnique<SVGAnimatedTransformList>();
+      if (NS_FAILED(
+              mSVGView->mTransforms->SetBaseValueString(aParams, mRoot))) {
+        return false;
+      }
+    } else if (IsMatchingParameter(aToken, u"zoomAndPan"_ns)) {
+      if (mSVGView->mZoomAndPan.IsExplicitlySet()) {
+        return false;
+      }
+      nsAtom* valAtom = NS_GetStaticAtom(aParams);
+      if (!valAtom || !mSVGView->mZoomAndPan.SetBaseValueAtom(valAtom, mRoot)) {
+        return false;
+      }
+    } else {
+      return false;
+    }
+    return true;
+  }
+
+  void SetValid() { mValid = true; }
+
+ private:
+  SVGSVGElement* mRoot;
+  UniquePtr<SVGView> mSVGView;
+  bool mValid;
+  bool mWasOverridden;
+};
+
+bool SVGFragmentIdentifier::ProcessSVGViewSpec(const nsAString& aViewSpec,
+                                               SVGSVGElement* aRoot) {
+  AutoSVGViewHandler viewHandler(aRoot);
+
+  if (!IsMatchingParameter(aViewSpec, u"svgView"_ns)) {
+    return false;
+  }
+
+  // Each token is a SVGViewAttribute
+  int32_t bracketPos = aViewSpec.FindChar('(');
+  uint32_t lengthOfViewSpec = aViewSpec.Length() - bracketPos - 2;
+  nsCharSeparatedTokenizerTemplate<NS_TokenizerIgnoreNothing> tokenizer(
+      Substring(aViewSpec, bracketPos + 1, lengthOfViewSpec), ';');
+
+  if (!tokenizer.hasMoreTokens()) {
+    return false;
+  }
+  viewHandler.CreateSVGView();
+
+  do {
+    nsAutoString token(tokenizer.nextToken());
+
+    bracketPos = token.FindChar('(');
+    if (bracketPos < 1 || token.Last() != ')') {
+      // invalid SVGViewAttribute syntax
+      return false;
+    }
+
+    const nsAString& params =
+        Substring(token, bracketPos + 1, token.Length() - bracketPos - 2);
+
+    if (!viewHandler.ProcessAttr(token, params)) {
+      return false;
+    }
+
+  } while (tokenizer.hasMoreTokens());
+
+  viewHandler.SetValid();
+  return true;
+}
+
+bool SVGFragmentIdentifier::ProcessFragmentIdentifier(
+    Document* aDocument, const nsAString& aAnchorName) {
+  MOZ_ASSERT(aDocument->GetRootElement()->IsSVGElement(nsGkAtoms::svg),
+             "expecting an SVG root element");
+
+  SVGSVGElement* rootElement =
+      static_cast<SVGSVGElement*>(aDocument->GetRootElement());
+
+  const SVGViewElement* viewElement = GetViewElement(aDocument, aAnchorName);
+
+  if (viewElement) {
+    if (!rootElement->mCurrentViewID) {
+      rootElement->mCurrentViewID = MakeUnique<nsString>();
+    }
+    *rootElement->mCurrentViewID = aAnchorName;
+    rootElement->mSVGView = nullptr;
+    rootElement->InvalidateTransformNotifyFrame();
+    if (nsIFrame* f = rootElement->GetPrimaryFrame()) {
+      if (SVGOuterSVGFrame* osf = do_QueryFrame(f)) {
+        osf->MaybeSendIntrinsicSizeAndRatioToEmbedder();
+      }
+    }
+    // not an svgView()-style fragment identifier, return false so the caller
+    // continues processing to match any :target pseudo elements
+    return false;
+  }
+
+  return ProcessSVGViewSpec(aAnchorName, rootElement);
+}
+
+}  // namespace mozilla