gecko-dev/dom/svg/SVGFragmentIdentifier.cpp

188 строки
6.0 KiB
C++

/* -*- 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 "nsContentUtils.h" // for nsCharSeparatedTokenizerTemplate
#include "nsSVGAnimatedTransformList.h"
#include "nsCharSeparatedTokenizer.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()) == '(';
}
inline bool IgnoreWhitespace(char16_t aChar) { return false; }
static SVGViewElement* GetViewElement(nsIDocument* 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 MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
: mRoot(aRoot), mValid(false) {
MOZ_GUARD_OBJECT_NOTIFIER_INIT;
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 = mSVGView;
}
mRoot->InvalidateTransformNotifyFrame();
}
void CreateSVGView() {
MOZ_ASSERT(!mSVGView, "CreateSVGView should not be called multiple times");
mSVGView = new 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, NS_LITERAL_STRING("viewBox"))) {
if (mSVGView->mViewBox.IsExplicitlySet() ||
NS_FAILED(
mSVGView->mViewBox.SetBaseValueString(aParams, mRoot, false))) {
return false;
}
} else if (IsMatchingParameter(aToken,
NS_LITERAL_STRING("preserveAspectRatio"))) {
if (mSVGView->mPreserveAspectRatio.IsExplicitlySet() ||
NS_FAILED(mSVGView->mPreserveAspectRatio.SetBaseValueString(
aParams, mRoot, false))) {
return false;
}
} else if (IsMatchingParameter(aToken, NS_LITERAL_STRING("transform"))) {
if (mSVGView->mTransforms) {
return false;
}
mSVGView->mTransforms = new nsSVGAnimatedTransformList();
if (NS_FAILED(
mSVGView->mTransforms->SetBaseValueString(aParams, mRoot))) {
return false;
}
} else if (IsMatchingParameter(aToken, NS_LITERAL_STRING("zoomAndPan"))) {
if (mSVGView->mZoomAndPan.IsExplicitlySet()) {
return false;
}
nsAtom* valAtom = NS_GetStaticAtom(aParams);
if (!valAtom ||
NS_FAILED(mSVGView->mZoomAndPan.SetBaseValueAtom(valAtom, mRoot))) {
return false;
}
} else {
return false;
}
return true;
}
void SetValid() { mValid = true; }
private:
SVGSVGElement* mRoot;
nsAutoPtr<SVGView> mSVGView;
bool mValid;
bool mWasOverridden;
MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
};
bool SVGFragmentIdentifier::ProcessSVGViewSpec(const nsAString& aViewSpec,
SVGSVGElement* aRoot) {
AutoSVGViewHandler viewHandler(aRoot);
if (!IsMatchingParameter(aViewSpec, NS_LITERAL_STRING("svgView"))) {
return false;
}
// Each token is a SVGViewAttribute
int32_t bracketPos = aViewSpec.FindChar('(');
uint32_t lengthOfViewSpec = aViewSpec.Length() - bracketPos - 2;
nsCharSeparatedTokenizerTemplate<IgnoreWhitespace> 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(
nsIDocument* 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 = new nsString();
}
*rootElement->mCurrentViewID = aAnchorName;
rootElement->mSVGView = nullptr;
rootElement->InvalidateTransformNotifyFrame();
// 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