gecko-dev/dom/svg/SVGFragmentIdentifier.cpp
2015-05-03 15:32:37 -04:00

288 lines
9.2 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"
using namespace mozilla;
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 dom::SVGViewElement*
GetViewElement(nsIDocument* aDocument, const nsAString& aId)
{
dom::Element* element = aDocument->GetElementById(aId);
return (element && element->IsSVGElement(nsGkAtoms::view)) ?
static_cast<dom::SVGViewElement*>(element) : nullptr;
}
void
SVGFragmentIdentifier::SaveOldPreserveAspectRatio(dom::SVGSVGElement* root)
{
if (root->mPreserveAspectRatio.IsExplicitlySet()) {
root->SetPreserveAspectRatioProperty(root->mPreserveAspectRatio.GetBaseValue());
}
}
void
SVGFragmentIdentifier::RestoreOldPreserveAspectRatio(dom::SVGSVGElement* root)
{
const SVGPreserveAspectRatio* oldPARPtr = root->GetPreserveAspectRatioProperty();
if (oldPARPtr) {
root->mPreserveAspectRatio.SetBaseValue(*oldPARPtr, root);
} else if (root->mPreserveAspectRatio.IsExplicitlySet()) {
mozilla::ErrorResult error;
root->RemoveAttribute(NS_LITERAL_STRING("preserveAspectRatio"), error);
}
}
void
SVGFragmentIdentifier::SaveOldViewBox(dom::SVGSVGElement* root)
{
if (root->mViewBox.IsExplicitlySet()) {
root->SetViewBoxProperty(root->mViewBox.GetBaseValue());
}
}
void
SVGFragmentIdentifier::RestoreOldViewBox(dom::SVGSVGElement* root)
{
const nsSVGViewBoxRect* oldViewBoxPtr = root->GetViewBoxProperty();
if (oldViewBoxPtr) {
root->mViewBox.SetBaseValue(*oldViewBoxPtr, root);
} else if (root->mViewBox.IsExplicitlySet()) {
mozilla::ErrorResult error;
root->RemoveAttribute(NS_LITERAL_STRING("viewBox"), error);
}
}
void
SVGFragmentIdentifier::SaveOldZoomAndPan(dom::SVGSVGElement* root)
{
if (root->mEnumAttributes[dom::SVGSVGElement::ZOOMANDPAN].IsExplicitlySet()) {
root->SetZoomAndPanProperty(root->mEnumAttributes[dom::SVGSVGElement::ZOOMANDPAN].GetBaseValue());
}
}
void
SVGFragmentIdentifier::RestoreOldZoomAndPan(dom::SVGSVGElement* root)
{
uint16_t oldZoomAndPan = root->GetZoomAndPanProperty();
if (oldZoomAndPan != SVG_ZOOMANDPAN_UNKNOWN) {
root->mEnumAttributes[dom::SVGSVGElement::ZOOMANDPAN].SetBaseValue(oldZoomAndPan, root);
} else if (root->mEnumAttributes[dom::SVGSVGElement::ZOOMANDPAN].IsExplicitlySet()) {
mozilla::ErrorResult error;
root->RemoveAttribute(NS_LITERAL_STRING("zoomAndPan"), error);
}
}
void
SVGFragmentIdentifier::SaveOldTransform(dom::SVGSVGElement* root)
{
nsSVGAnimatedTransformList* transformList = root->GetAnimatedTransformList();
if (transformList && transformList->IsExplicitlySet()) {
root->SetTransformProperty(transformList->GetBaseValue());
}
}
void
SVGFragmentIdentifier::RestoreOldTransform(dom::SVGSVGElement* root)
{
const SVGTransformList* oldTransformPtr = root->GetTransformProperty();
if (oldTransformPtr) {
root->GetAnimatedTransformList(nsSVGElement::DO_ALLOCATE)->SetBaseValue(*oldTransformPtr);
} else {
nsSVGAnimatedTransformList* transformList = root->GetAnimatedTransformList();
if (transformList && transformList->IsExplicitlySet()) {
mozilla::ErrorResult error;
root->RemoveAttribute(NS_LITERAL_STRING("transform"), error);
}
}
}
bool
SVGFragmentIdentifier::ProcessSVGViewSpec(const nsAString& aViewSpec,
dom::SVGSVGElement* root)
{
if (!IsMatchingParameter(aViewSpec, NS_LITERAL_STRING("svgView"))) {
return false;
}
// 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.
bool viewBoxFound = false;
bool preserveAspectRatioFound = false;
bool transformFound = false;
bool zoomAndPanFound = 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;
}
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 (IsMatchingParameter(token, NS_LITERAL_STRING("viewBox"))) {
if (viewBoxFound ||
NS_FAILED(root->mViewBox.SetBaseValueString(
params, root, true))) {
return false;
}
viewBoxFound = true;
} else if (IsMatchingParameter(token, NS_LITERAL_STRING("preserveAspectRatio"))) {
if (preserveAspectRatioFound ||
NS_FAILED(root->mPreserveAspectRatio.SetBaseValueString(
params, root, true))) {
return false;
}
preserveAspectRatioFound = true;
} else if (IsMatchingParameter(token, NS_LITERAL_STRING("transform"))) {
if (transformFound ||
NS_FAILED(root->GetAnimatedTransformList(nsSVGElement::DO_ALLOCATE)->
SetBaseValueString(params))) {
return false;
}
transformFound = true;
} else if (IsMatchingParameter(token, NS_LITERAL_STRING("zoomAndPan"))) {
if (zoomAndPanFound) {
return false;
}
nsIAtom* valAtom = NS_GetStaticAtom(params);
if (!valAtom) {
return false;
}
const nsSVGEnumMapping* mapping = dom::SVGSVGElement::sZoomAndPanMap;
while (mapping->mKey) {
if (valAtom == *(mapping->mKey)) {
// If we've got a valid zoomAndPan value, then set it on our root element.
if (NS_FAILED(root->mEnumAttributes[dom::SVGSVGElement::ZOOMANDPAN].SetBaseValue(
mapping->mVal, root))) {
return false;
}
break;
}
mapping++;
}
if (!mapping->mKey) {
// Unrecognised zoomAndPan value
return false;
}
zoomAndPanFound = true;
} else {
// We don't support viewTarget currently
return false;
}
} while (tokenizer.hasMoreTokens());
if (root->mUseCurrentView) {
// A previous SVGViewSpec may have overridden some attributes.
// If they are no longer overridden we need to restore the old values.
if (!transformFound) {
RestoreOldTransform(root);
}
if (!viewBoxFound) {
RestoreOldViewBox(root);
}
if (!preserveAspectRatioFound) {
RestoreOldPreserveAspectRatio(root);
}
if (!zoomAndPanFound) {
RestoreOldZoomAndPan(root);
}
}
return true;
}
bool
SVGFragmentIdentifier::ProcessFragmentIdentifier(nsIDocument* aDocument,
const nsAString& aAnchorName)
{
MOZ_ASSERT(aDocument->GetRootElement()->IsSVGElement(nsGkAtoms::svg),
"expecting an SVG root element");
dom::SVGSVGElement* rootElement =
static_cast<dom::SVGSVGElement*>(aDocument->GetRootElement());
if (!rootElement->mUseCurrentView) {
SaveOldViewBox(rootElement);
SaveOldPreserveAspectRatio(rootElement);
SaveOldZoomAndPan(rootElement);
}
const dom::SVGViewElement* viewElement = GetViewElement(aDocument, aAnchorName);
if (viewElement) {
if (!rootElement->mCurrentViewID) {
rootElement->mCurrentViewID = new nsString();
}
*rootElement->mCurrentViewID = aAnchorName;
rootElement->mUseCurrentView = true;
rootElement->InvalidateTransformNotifyFrame();
// not an svgView()-style fragment identifier, return false so the caller
// continues processing to match any :target pseudo elements
return false;
}
bool wasOverridden = !!rootElement->mCurrentViewID;
rootElement->mCurrentViewID = nullptr;
rootElement->mUseCurrentView = ProcessSVGViewSpec(aAnchorName, rootElement);
if (rootElement->mUseCurrentView) {
return true;
}
RestoreOldViewBox(rootElement);
rootElement->ClearViewBoxProperty();
RestoreOldPreserveAspectRatio(rootElement);
rootElement->ClearPreserveAspectRatioProperty();
RestoreOldZoomAndPan(rootElement);
rootElement->ClearZoomAndPanProperty();
RestoreOldTransform(rootElement);
rootElement->ClearTransformProperty();
if (wasOverridden) {
rootElement->InvalidateTransformNotifyFrame();
}
return false;
}