gecko-dev/dom/base/nsDOMMutationObserver.h

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/* -*- Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 8; -*- */
/* vim: set sw=4 ts=8 et 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/. */
#ifndef nsDOMMutationObserver_h
#define nsDOMMutationObserver_h
#include "mozilla/Attributes.h"
#include "nsCycleCollectionParticipant.h"
#include "nsPIDOMWindow.h"
#include "nsIScriptContext.h"
#include "nsStubMutationObserver.h"
#include "nsCOMArray.h"
#include "nsTArray.h"
#include "nsAutoPtr.h"
#include "nsIVariant.h"
#include "nsContentList.h"
#include "mozilla/dom/Element.h"
#include "nsClassHashtable.h"
#include "nsNodeUtils.h"
#include "nsIDOMMutationEvent.h"
#include "nsWrapperCache.h"
#include "mozilla/dom/MutationObserverBinding.h"
#include "nsIDocument.h"
class nsDOMMutationObserver;
using mozilla::dom::MutationObservingInfo;
class nsDOMMutationRecord : public nsISupports,
public nsWrapperCache
{
virtual ~nsDOMMutationRecord() {}
public:
nsDOMMutationRecord(nsIAtom* aType, nsISupports* aOwner)
: mType(aType), mAttrNamespace(NullString()), mPrevValue(NullString()), mOwner(aOwner)
{
}
nsISupports* GetParentObject() const
{
return mOwner;
}
virtual JSObject* WrapObject(JSContext* aCx) MOZ_OVERRIDE
{
return mozilla::dom::MutationRecordBinding::Wrap(aCx, this);
}
NS_DECL_CYCLE_COLLECTING_ISUPPORTS
NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(nsDOMMutationRecord)
void GetType(mozilla::dom::DOMString& aRetVal) const
{
aRetVal.SetOwnedAtom(mType, mozilla::dom::DOMString::eNullNotExpected);
}
nsINode* GetTarget() const
{
return mTarget;
}
nsINodeList* AddedNodes();
nsINodeList* RemovedNodes();
nsINode* GetPreviousSibling() const
{
return mPreviousSibling;
}
nsINode* GetNextSibling() const
{
return mNextSibling;
}
void GetAttributeName(mozilla::dom::DOMString& aRetVal) const
{
aRetVal.SetOwnedAtom(mAttrName, mozilla::dom::DOMString::eTreatNullAsNull);
}
void GetAttributeNamespace(mozilla::dom::DOMString& aRetVal) const
{
aRetVal.SetOwnedString(mAttrNamespace);
}
void GetOldValue(mozilla::dom::DOMString& aRetVal) const
{
aRetVal.SetOwnedString(mPrevValue);
}
nsCOMPtr<nsINode> mTarget;
nsCOMPtr<nsIAtom> mType;
nsCOMPtr<nsIAtom> mAttrName;
nsString mAttrNamespace;
nsString mPrevValue;
nsRefPtr<nsSimpleContentList> mAddedNodes;
nsRefPtr<nsSimpleContentList> mRemovedNodes;
nsCOMPtr<nsINode> mPreviousSibling;
nsCOMPtr<nsINode> mNextSibling;
nsRefPtr<nsDOMMutationRecord> mNext;
nsCOMPtr<nsISupports> mOwner;
};
// Base class just prevents direct access to
// members to make sure we go through getters/setters.
class nsMutationReceiverBase : public nsStubMutationObserver
{
public:
virtual ~nsMutationReceiverBase() { }
nsDOMMutationObserver* Observer();
nsINode* Target() { return mParent ? mParent->Target() : mTarget; }
nsINode* RegisterTarget() { return mRegisterTarget; }
bool Subtree() { return mParent ? mParent->Subtree() : mSubtree; }
void SetSubtree(bool aSubtree)
{
NS_ASSERTION(!mParent, "Shouldn't have parent");
mSubtree = aSubtree;
}
bool ChildList() { return mParent ? mParent->ChildList() : mChildList; }
void SetChildList(bool aChildList)
{
NS_ASSERTION(!mParent, "Shouldn't have parent");
mChildList = aChildList;
}
bool CharacterData()
{
return mParent ? mParent->CharacterData() : mCharacterData;
}
void SetCharacterData(bool aCharacterData)
{
NS_ASSERTION(!mParent, "Shouldn't have parent");
mCharacterData = aCharacterData;
}
bool CharacterDataOldValue()
{
return mParent ? mParent->CharacterDataOldValue() : mCharacterDataOldValue;
}
void SetCharacterDataOldValue(bool aOldValue)
{
NS_ASSERTION(!mParent, "Shouldn't have parent");
mCharacterDataOldValue = aOldValue;
}
bool Attributes() { return mParent ? mParent->Attributes() : mAttributes; }
void SetAttributes(bool aAttributes)
{
NS_ASSERTION(!mParent, "Shouldn't have parent");
mAttributes = aAttributes;
}
bool AllAttributes()
{
return mParent ? mParent->AllAttributes()
: mAllAttributes;
}
void SetAllAttributes(bool aAll)
{
NS_ASSERTION(!mParent, "Shouldn't have parent");
mAllAttributes = aAll;
}
bool AttributeOldValue() {
return mParent ? mParent->AttributeOldValue()
: mAttributeOldValue;
}
void SetAttributeOldValue(bool aOldValue)
{
NS_ASSERTION(!mParent, "Shouldn't have parent");
mAttributeOldValue = aOldValue;
}
nsCOMArray<nsIAtom>& AttributeFilter() { return mAttributeFilter; }
void SetAttributeFilter(nsCOMArray<nsIAtom>& aFilter)
{
NS_ASSERTION(!mParent, "Shouldn't have parent");
mAttributeFilter.Clear();
mAttributeFilter.AppendObjects(aFilter);
}
void AddClone(nsMutationReceiverBase* aClone)
{
mTransientReceivers.AppendObject(aClone);
}
void RemoveClone(nsMutationReceiverBase* aClone)
{
mTransientReceivers.RemoveObject(aClone);
}
protected:
nsMutationReceiverBase(nsINode* aTarget, nsDOMMutationObserver* aObserver)
: mTarget(aTarget), mObserver(aObserver), mRegisterTarget(aTarget)
{
mRegisterTarget->AddMutationObserver(this);
mRegisterTarget->SetMayHaveDOMMutationObserver();
mRegisterTarget->OwnerDoc()->SetMayHaveDOMMutationObservers();
}
nsMutationReceiverBase(nsINode* aRegisterTarget,
nsMutationReceiverBase* aParent)
: mTarget(nullptr), mObserver(nullptr), mParent(aParent),
mRegisterTarget(aRegisterTarget), mKungFuDeathGrip(aParent->Target())
{
NS_ASSERTION(mParent->Subtree(), "Should clone a non-subtree observer!");
mRegisterTarget->AddMutationObserver(this);
mRegisterTarget->SetMayHaveDOMMutationObserver();
mRegisterTarget->OwnerDoc()->SetMayHaveDOMMutationObservers();
}
bool ObservesAttr(mozilla::dom::Element* aElement,
int32_t aNameSpaceID,
nsIAtom* aAttr)
{
if (mParent) {
return mParent->ObservesAttr(aElement, aNameSpaceID, aAttr);
}
if (!Attributes() || (!Subtree() && aElement != Target())) {
return false;
}
if (AllAttributes()) {
return true;
}
if (aNameSpaceID != kNameSpaceID_None) {
return false;
}
nsCOMArray<nsIAtom>& filters = AttributeFilter();
for (int32_t i = 0; i < filters.Count(); ++i) {
if (filters[i] == aAttr) {
return true;
}
}
return false;
}
// The target for the MutationObserver.observe() method.
nsINode* mTarget;
nsDOMMutationObserver* mObserver;
nsRefPtr<nsMutationReceiverBase> mParent; // Cleared after microtask.
// The node to which Gecko-internal nsIMutationObserver was registered to.
// This is different than mTarget when dealing with transient observers.
nsINode* mRegisterTarget;
nsCOMArray<nsMutationReceiverBase> mTransientReceivers;
// While we have transient receivers, keep the original mutation receiver
// alive so it doesn't go away and disconnect all its transient receivers.
nsCOMPtr<nsINode> mKungFuDeathGrip;
private:
bool mSubtree;
bool mChildList;
bool mCharacterData;
bool mCharacterDataOldValue;
bool mAttributes;
bool mAllAttributes;
bool mAttributeOldValue;
nsCOMArray<nsIAtom> mAttributeFilter;
};
class nsMutationReceiver : public nsMutationReceiverBase
{
protected:
virtual ~nsMutationReceiver() { Disconnect(false); }
public:
nsMutationReceiver(nsINode* aTarget, nsDOMMutationObserver* aObserver);
nsMutationReceiver(nsINode* aRegisterTarget, nsMutationReceiverBase* aParent)
: nsMutationReceiverBase(aRegisterTarget, aParent)
{
NS_ASSERTION(!static_cast<nsMutationReceiver*>(aParent)->GetParent(),
"Shouldn't create deep observer hierarchies!");
aParent->AddClone(this);
}
nsMutationReceiver* GetParent()
{
return static_cast<nsMutationReceiver*>(mParent.get());
}
void RemoveClones()
{
for (int32_t i = 0; i < mTransientReceivers.Count(); ++i) {
nsMutationReceiver* r =
static_cast<nsMutationReceiver*>(mTransientReceivers[i]);
r->DisconnectTransientReceiver();
}
mTransientReceivers.Clear();
}
void DisconnectTransientReceiver()
{
if (mRegisterTarget) {
mRegisterTarget->RemoveMutationObserver(this);
mRegisterTarget = nullptr;
}
mParent = nullptr;
NS_ASSERTION(!mTarget, "Should not have mTarget");
NS_ASSERTION(!mObserver, "Should not have mObserver");
}
void Disconnect(bool aRemoveFromObserver);
NS_DECL_AND_IMPL_ZEROING_OPERATOR_NEW
NS_DECL_ISUPPORTS
NS_DECL_NSIMUTATIONOBSERVER_ATTRIBUTEWILLCHANGE
NS_DECL_NSIMUTATIONOBSERVER_CHARACTERDATAWILLCHANGE
NS_DECL_NSIMUTATIONOBSERVER_CONTENTAPPENDED
NS_DECL_NSIMUTATIONOBSERVER_CONTENTINSERTED
NS_DECL_NSIMUTATIONOBSERVER_CONTENTREMOVED
NS_DECL_NSIMUTATIONOBSERVER_NODEWILLBEDESTROYED
virtual void AttributeSetToCurrentValue(nsIDocument* aDocument,
mozilla::dom::Element* aElement,
int32_t aNameSpaceID,
nsIAtom* aAttribute) MOZ_OVERRIDE
{
// We can reuse AttributeWillChange implementation.
AttributeWillChange(aDocument, aElement, aNameSpaceID, aAttribute,
nsIDOMMutationEvent::MODIFICATION);
}
};
#define NS_DOM_MUTATION_OBSERVER_IID \
{ 0x0c3b91f8, 0xcc3b, 0x4b08, \
{ 0x9e, 0xab, 0x07, 0x47, 0xa9, 0xe4, 0x65, 0xb4 } }
class nsDOMMutationObserver : public nsISupports,
public nsWrapperCache
{
public:
nsDOMMutationObserver(already_AddRefed<nsPIDOMWindow>&& aOwner,
mozilla::dom::MutationCallback& aCb)
: mOwner(aOwner), mLastPendingMutation(nullptr), mPendingMutationCount(0),
mCallback(&aCb), mWaitingForRun(false), mId(++sCount)
{
}
NS_DECL_CYCLE_COLLECTING_ISUPPORTS
NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(nsDOMMutationObserver)
NS_DECLARE_STATIC_IID_ACCESSOR(NS_DOM_MUTATION_OBSERVER_IID)
static already_AddRefed<nsDOMMutationObserver>
Constructor(const mozilla::dom::GlobalObject& aGlobal,
mozilla::dom::MutationCallback& aCb,
mozilla::ErrorResult& aRv);
virtual JSObject* WrapObject(JSContext* aCx) MOZ_OVERRIDE
{
return mozilla::dom::MutationObserverBinding::Wrap(aCx, this);
}
nsISupports* GetParentObject() const
{
return mOwner;
}
void Observe(nsINode& aTarget,
const mozilla::dom::MutationObserverInit& aOptions,
mozilla::ErrorResult& aRv);
void Disconnect();
void TakeRecords(nsTArray<nsRefPtr<nsDOMMutationRecord> >& aRetVal);
void HandleMutation();
void GetObservingInfo(nsTArray<Nullable<MutationObservingInfo> >& aResult);
mozilla::dom::MutationCallback* MutationCallback() { return mCallback; }
void AppendMutationRecord(already_AddRefed<nsDOMMutationRecord> aRecord)
{
nsRefPtr<nsDOMMutationRecord> record = aRecord;
MOZ_ASSERT(record);
if (!mLastPendingMutation) {
MOZ_ASSERT(!mFirstPendingMutation);
mFirstPendingMutation = record.forget();
mLastPendingMutation = mFirstPendingMutation;
} else {
MOZ_ASSERT(mFirstPendingMutation);
mLastPendingMutation->mNext = record.forget();
mLastPendingMutation = mLastPendingMutation->mNext;
}
++mPendingMutationCount;
}
void ClearPendingRecords()
{
mFirstPendingMutation = nullptr;
mLastPendingMutation = nullptr;
mPendingMutationCount = 0;
}
// static methods
static void HandleMutations()
{
if (sScheduledMutationObservers) {
HandleMutationsInternal();
}
}
static void EnterMutationHandling();
static void LeaveMutationHandling();
static void Shutdown();
protected:
virtual ~nsDOMMutationObserver();
friend class nsMutationReceiver;
friend class nsAutoMutationBatch;
nsMutationReceiver* GetReceiverFor(nsINode* aNode, bool aMayCreate);
void RemoveReceiver(nsMutationReceiver* aReceiver);
already_AddRefed<nsIVariant> TakeRecords();
void GetAllSubtreeObserversFor(nsINode* aNode,
nsTArray<nsMutationReceiver*>& aObservers);
void ScheduleForRun();
void RescheduleForRun();
nsDOMMutationRecord* CurrentRecord(nsIAtom* aType);
bool HasCurrentRecord(const nsAString& aType);
bool Suppressed()
{
if (mOwner) {
nsCOMPtr<nsIDocument> d = mOwner->GetExtantDoc();
return d && d->IsInSyncOperation();
}
return false;
}
static void HandleMutationsInternal();
static void AddCurrentlyHandlingObserver(nsDOMMutationObserver* aObserver);
nsCOMPtr<nsPIDOMWindow> mOwner;
nsCOMArray<nsMutationReceiver> mReceivers;
nsClassHashtable<nsISupportsHashKey,
nsCOMArray<nsMutationReceiver> > mTransientReceivers;
// MutationRecords which are being constructed.
nsAutoTArray<nsDOMMutationRecord*, 4> mCurrentMutations;
// MutationRecords which will be handed to the callback at the end of
// the microtask.
nsRefPtr<nsDOMMutationRecord> mFirstPendingMutation;
nsDOMMutationRecord* mLastPendingMutation;
uint32_t mPendingMutationCount;
nsRefPtr<mozilla::dom::MutationCallback> mCallback;
bool mWaitingForRun;
uint64_t mId;
static uint64_t sCount;
static nsAutoTArray<nsRefPtr<nsDOMMutationObserver>, 4>* sScheduledMutationObservers;
static nsDOMMutationObserver* sCurrentObserver;
static uint32_t sMutationLevel;
static nsAutoTArray<nsAutoTArray<nsRefPtr<nsDOMMutationObserver>, 4>, 4>*
sCurrentlyHandlingObservers;
};
NS_DEFINE_STATIC_IID_ACCESSOR(nsDOMMutationObserver, NS_DOM_MUTATION_OBSERVER_IID)
class nsAutoMutationBatch
{
public:
nsAutoMutationBatch()
: mPreviousBatch(nullptr), mBatchTarget(nullptr), mRemovalDone(false),
mFromFirstToLast(false), mAllowNestedBatches(false)
{
}
nsAutoMutationBatch(nsINode* aTarget, bool aFromFirstToLast,
bool aAllowNestedBatches)
: mPreviousBatch(nullptr), mBatchTarget(nullptr), mRemovalDone(false),
mFromFirstToLast(false), mAllowNestedBatches(false)
{
Init(aTarget, aFromFirstToLast, aAllowNestedBatches);
}
void Init(nsINode* aTarget, bool aFromFirstToLast, bool aAllowNestedBatches)
{
if (aTarget && aTarget->OwnerDoc()->MayHaveDOMMutationObservers()) {
if (sCurrentBatch && !sCurrentBatch->mAllowNestedBatches) {
return;
}
mBatchTarget = aTarget;
mFromFirstToLast = aFromFirstToLast;
mAllowNestedBatches = aAllowNestedBatches;
mPreviousBatch = sCurrentBatch;
sCurrentBatch = this;
nsDOMMutationObserver::EnterMutationHandling();
}
}
void RemovalDone() { mRemovalDone = true; }
static bool IsRemovalDone() { return sCurrentBatch->mRemovalDone; }
void SetPrevSibling(nsINode* aNode) { mPrevSibling = aNode; }
void SetNextSibling(nsINode* aNode) { mNextSibling = aNode; }
void Done();
~nsAutoMutationBatch() { NodesAdded(); }
static bool IsBatching()
{
return !!sCurrentBatch;
}
static nsAutoMutationBatch* GetCurrentBatch()
{
return sCurrentBatch;
}
static void UpdateObserver(nsDOMMutationObserver* aObserver,
bool aWantsChildList)
{
uint32_t l = sCurrentBatch->mObservers.Length();
for (uint32_t i = 0; i < l; ++i) {
if (sCurrentBatch->mObservers[i].mObserver == aObserver) {
if (aWantsChildList) {
sCurrentBatch->mObservers[i].mWantsChildList = aWantsChildList;
}
return;
}
}
BatchObserver* bo = sCurrentBatch->mObservers.AppendElement();
bo->mObserver = aObserver;
bo->mWantsChildList = aWantsChildList;
}
static nsINode* GetBatchTarget() { return sCurrentBatch->mBatchTarget; }
// Mutation receivers notify the batch about removed child nodes.
static void NodeRemoved(nsIContent* aChild)
{
if (IsBatching() && !sCurrentBatch->mRemovalDone) {
uint32_t len = sCurrentBatch->mRemovedNodes.Length();
if (!len ||
sCurrentBatch->mRemovedNodes[len - 1] != aChild) {
sCurrentBatch->mRemovedNodes.AppendElement(aChild);
}
}
}
// Called after new child nodes have been added to the batch target.
void NodesAdded()
{
if (sCurrentBatch != this) {
return;
}
nsIContent* c =
mPrevSibling ? mPrevSibling->GetNextSibling() :
mBatchTarget->GetFirstChild();
for (; c != mNextSibling; c = c->GetNextSibling()) {
mAddedNodes.AppendElement(c);
}
Done();
}
private:
struct BatchObserver
{
nsDOMMutationObserver* mObserver;
bool mWantsChildList;
};
static nsAutoMutationBatch* sCurrentBatch;
nsAutoMutationBatch* mPreviousBatch;
nsAutoTArray<BatchObserver, 2> mObservers;
nsTArray<nsCOMPtr<nsIContent> > mRemovedNodes;
nsTArray<nsCOMPtr<nsIContent> > mAddedNodes;
nsINode* mBatchTarget;
bool mRemovalDone;
bool mFromFirstToLast;
bool mAllowNestedBatches;
nsCOMPtr<nsINode> mPrevSibling;
nsCOMPtr<nsINode> mNextSibling;
};
inline
nsDOMMutationObserver*
nsMutationReceiverBase::Observer()
{
return mParent ?
mParent->Observer() : static_cast<nsDOMMutationObserver*>(mObserver);
}
#endif