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/* -*- 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
#ifndef nsIMutationObserver_h
#define nsIMutationObserver_h
#include "nsISupports.h"
#include "mozilla/Assertions.h"
#include "mozilla/DoublyLinkedList.h"
class nsAttrValue;
class nsAtom;
class nsIContent;
class nsINode;
namespace mozilla::dom {
class Element;
} // namespace mozilla::dom
#define NS_IMUTATION_OBSERVER_IID \
{ \
0x6d674c17, 0x0fbc, 0x4633, { \
0x8f, 0x46, 0x73, 0x4e, 0x87, 0xeb, 0xf0, 0xc7 \
} \
}
/**
* Information details about a characterdata change. Basically, we
* view all changes as replacements of a length of text at some offset
* with some other text (of possibly some other length).
*/
struct CharacterDataChangeInfo {
/**
* True if this character data change is just an append.
*/
bool mAppend;
/**
* The offset in the text where the change occurred.
*/
uint32_t mChangeStart;
/**
* The offset such that mChangeEnd - mChangeStart is equal to the length of
* the text we removed. If this was a pure insert, append or a result of
* `splitText()` this is equal to mChangeStart.
*/
uint32_t mChangeEnd;
uint32_t LengthOfRemovedText() const {
MOZ_ASSERT(mChangeStart <= mChangeEnd);
return mChangeEnd - mChangeStart;
}
/**
* The length of the text that was inserted in place of the removed text. If
* this was a pure text removal, this is 0.
*/
uint32_t mReplaceLength;
/**
* The net result is that mChangeStart characters at the beginning of the
* text remained as they were. The next mChangeEnd - mChangeStart characters
* were removed, and mReplaceLength characters were inserted in their place.
* The text that used to begin at mChangeEnd now begins at
* mChangeStart + mReplaceLength.
*/
struct MOZ_STACK_CLASS Details {
enum {
eMerge, // two text nodes are merged as a result of normalize()
eSplit // a text node is split as a result of splitText()
} mType;
/**
* For eMerge it's the text node that will be removed, for eSplit it's the
* new text node.
*/
nsIContent* MOZ_NON_OWNING_REF mNextSibling;
};
/**
* Used for splitText() and normalize(), otherwise null.
*/
Details* mDetails;
};
/**
* Mutation observer interface
*
* See nsINode::AddMutationObserver, nsINode::RemoveMutationObserver for how to
* attach or remove your observers. nsINode stores mutation observers using a
* mozilla::SafeDoublyLinkedList, which is a specialization of the
* DoublyLinkedList allowing for adding/removing elements while iterating.
* If a mutation observer is intended to be added to multiple nsINode instances,
* derive from nsMultiMutationObserver.
*
* WARNING: During these notifications, you are not allowed to perform
* any mutations to the current or any other document, or start a
* network load. If you need to perform such operations do that
* during the _last_ nsIDocumentObserver::EndUpdate notification. The
* exception for this is ParentChainChanged, where mutations should be
* done from an async event, as the notification might not be
* surrounded by BeginUpdate/EndUpdate calls.
*/
class nsIMutationObserver
: public nsISupports,
mozilla::DoublyLinkedListElement<nsIMutationObserver> {
friend struct mozilla::GetDoublyLinkedListElement<nsIMutationObserver>;
public:
NS_DECLARE_STATIC_IID_ACCESSOR(NS_IMUTATION_OBSERVER_IID)
/**
* Notification that the node value of a data node (text, cdata, pi, comment)
* will be changed.
*
* This notification is not sent when a piece of content is
* added/removed from the document (the other notifications are used
* for that).
*
* @param aContent The piece of content that changed. Is never null.
* @param aInfo The structure with information details about the change.
*
* @note Callers of this method might not hold a strong reference to the
* observer. The observer is responsible for making sure it stays
* alive for the duration of the call as needed. The observer may
* assume that this call will happen when there are script blockers on
* the stack.
*/
virtual void CharacterDataWillChange(nsIContent* aContent,
const CharacterDataChangeInfo&) = 0;
/**
* Notification that the node value of a data node (text, cdata, pi, comment)
* has changed.
*
* This notification is not sent when a piece of content is
* added/removed from the document (the other notifications are used
* for that).
*
* @param aContent The piece of content that changed. Is never null.
* @param aInfo The structure with information details about the change.
*
* @note Callers of this method might not hold a strong reference to the
* observer. The observer is responsible for making sure it stays
* alive for the duration of the call as needed. The observer may
* assume that this call will happen when there are script blockers on
* the stack.
*/
virtual void CharacterDataChanged(nsIContent* aContent,
const CharacterDataChangeInfo&) = 0;
/**
* Notification that an attribute of an element will change. This
* can happen before the BeginUpdate for the change and may not
* always be followed by an AttributeChanged (in particular, if the
* attribute doesn't actually change there will be no corresponding
* AttributeChanged).
*
* @param aContent The element whose attribute will change
* @param aNameSpaceID The namespace id of the changing attribute
* @param aAttribute The name of the changing attribute
* @param aModType Whether or not the attribute will be added, changed, or
* removed. The constants are defined in
* MutationEvent.webidl.
*
* @note Callers of this method might not hold a strong reference to the
* observer. The observer is responsible for making sure it stays
* alive for the duration of the call as needed. The observer may
* assume that this call will happen when there are script blockers on
* the stack.
*/
virtual void AttributeWillChange(mozilla::dom::Element* aElement,
int32_t aNameSpaceID, nsAtom* aAttribute,
int32_t aModType) = 0;
/**
* Notification that an attribute of an element has changed.
*
* @param aElement The element whose attribute changed
* @param aNameSpaceID The namespace id of the changed attribute
* @param aAttribute The name of the changed attribute
* @param aModType Whether or not the attribute was added, changed, or
* removed. The constants are defined in
* MutationEvent.webidl.
* @param aOldValue The old value, if either the old value or the new
* value are StoresOwnData() (or absent); null otherwise.
*
* @note Callers of this method might not hold a strong reference to the
* observer. The observer is responsible for making sure it stays
* alive for the duration of the call as needed. The observer may
* assume that this call will happen when there are script blockers on
* the stack.
*/
virtual void AttributeChanged(mozilla::dom::Element* aElement,
int32_t aNameSpaceID, nsAtom* aAttribute,
int32_t aModType,
const nsAttrValue* aOldValue) = 0;
/**
* Notification that an attribute of an element has been
* set to the value it already had.
*
* @param aElement The element whose attribute changed
* @param aNameSpaceID The namespace id of the changed attribute
* @param aAttribute The name of the changed attribute
*/
virtual void AttributeSetToCurrentValue(mozilla::dom::Element* aElement,
int32_t aNameSpaceID,
nsAtom* aAttribute) {}
/**
* Notification that one or more content nodes have been appended to the
* child list of another node in the tree.
*
* @param aFirstNewContent the first node appended.
*
* @note Callers of this method might not hold a strong reference to the
* observer. The observer is responsible for making sure it stays
* alive for the duration of the call as needed. The observer may
* assume that this call will happen when there are script blockers on
* the stack.
*/
virtual void ContentAppended(nsIContent* aFirstNewContent) = 0;
/**
* Notification that a content node has been inserted as child to another
* node in the tree.
*
* @param aChild The newly inserted child.
*
* @note Callers of this method might not hold a strong reference to the
* observer. The observer is responsible for making sure it stays
* alive for the duration of the call as needed. The observer may
* assume that this call will happen when there are script blockers on
* the stack.
*/
virtual void ContentInserted(nsIContent* aChild) = 0;
/**
* Notification that a content node has been removed from the child list of
* another node in the tree.
*
* @param aChild The child that was removed.
* @param aPreviousSibling The previous sibling to the child that was removed.
* Can be null if there was no previous sibling.
*
* @note Callers of this method might not hold a strong reference to the
* observer. The observer is responsible for making sure it stays
* alive for the duration of the call as needed. The observer may
* assume that this call will happen when there are script blockers on
* the stack.
*/
virtual void ContentRemoved(nsIContent* aChild,
nsIContent* aPreviousSibling) = 0;
/**
* The node is in the process of being destroyed. Calling QI on the node is
* not supported, however it is possible to get children and flags through
* nsINode as well as calling IsContent and casting to nsIContent to get
* attributes.
*
* NOTE: This notification is only called on observers registered directly
* on the node. This is because when the node is destroyed it can not have
* any ancestors. If you want to know when a descendant node is being
* removed from the observed node, use the ContentRemoved notification.
*
* @param aNode The node being destroyed.
*
* @note Callers of this method might not hold a strong reference to
* the observer. The observer is responsible for making sure it
* stays alive for the duration of the call as needed.
*/
virtual void NodeWillBeDestroyed(nsINode* aNode) = 0;
/**
* Notification that the node's parent chain has changed. This
* happens when either the node or one of its ancestors is inserted
* or removed as a child of another node.
*
* Note that when a node is inserted this notification is sent to
* all descendants of that node, since all such nodes have their
* parent chain changed.
*
* @param aContent The piece of content that had its parent changed.
*
* @note Callers of this method might not hold a strong reference to
* the observer. The observer is responsible for making sure it
* stays alive for the duration of the call as needed.
*/
virtual void ParentChainChanged(nsIContent* aContent) = 0;
virtual void ARIAAttributeDefaultWillChange(mozilla::dom::Element* aElement,
nsAtom* aAttribute,
int32_t aModType) = 0;
virtual void ARIAAttributeDefaultChanged(mozilla::dom::Element* aElement,
nsAtom* aAttribute,
int32_t aModType) = 0;
enum : uint32_t {
kNone = 0,
kCharacterDataWillChange = 1 << 0,
kCharacterDataChanged = 1 << 1,
kAttributeWillChange = 1 << 2,
kAttributeChanged = 1 << 3,
kAttributeSetToCurrentValue = 1 << 4,
kContentAppended = 1 << 5,
kContentInserted = 1 << 6,
kContentRemoved = 1 << 7,
kNodeWillBeDestroyed = 1 << 8,
kParentChainChanged = 1 << 9,
kARIAAttributeDefaultWillChange = 1 << 10,
kARIAAttributeDefaultChanged = 1 << 11,
kBeginUpdate = 1 << 12,
kEndUpdate = 1 << 13,
kBeginLoad = 1 << 14,
kEndLoad = 1 << 15,
kElementStateChanged = 1 << 16,
kAnimationAdded = 1 << 17,
kAnimationChanged = 1 << 18,
kAnimationRemoved = 1 << 19,
kAll = 0xFFFFFFFF
};
void SetEnabledCallbacks(uint32_t aCallbacks) {
mEnabledCallbacks = aCallbacks;
}
bool IsCallbackEnabled(uint32_t aCallback) const {
return mEnabledCallbacks & aCallback;
}
private:
uint32_t mEnabledCallbacks = kAll;
};
NS_DEFINE_STATIC_IID_ACCESSOR(nsIMutationObserver, NS_IMUTATION_OBSERVER_IID)
#define NS_DECL_NSIMUTATIONOBSERVER_CHARACTERDATAWILLCHANGE \
virtual void CharacterDataWillChange( \
nsIContent* aContent, const CharacterDataChangeInfo& aInfo) override;
#define NS_DECL_NSIMUTATIONOBSERVER_CHARACTERDATACHANGED \
virtual void CharacterDataChanged( \
nsIContent* aContent, const CharacterDataChangeInfo& aInfo) override;
#define NS_DECL_NSIMUTATIONOBSERVER_ATTRIBUTEWILLCHANGE \
virtual void AttributeWillChange(mozilla::dom::Element* aElement, \
int32_t aNameSpaceID, nsAtom* aAttribute, \
int32_t aModType) override;
#define NS_DECL_NSIMUTATIONOBSERVER_ATTRIBUTECHANGED \
virtual void AttributeChanged(mozilla::dom::Element* aElement, \
int32_t aNameSpaceID, nsAtom* aAttribute, \
int32_t aModType, \
const nsAttrValue* aOldValue) override;
#define NS_DECL_NSIMUTATIONOBSERVER_CONTENTAPPENDED \
virtual void ContentAppended(nsIContent* aFirstNewContent) override;
#define NS_DECL_NSIMUTATIONOBSERVER_CONTENTINSERTED \
virtual void ContentInserted(nsIContent* aChild) override;
#define NS_DECL_NSIMUTATIONOBSERVER_CONTENTREMOVED \
virtual void ContentRemoved(nsIContent* aChild, \
nsIContent* aPreviousSibling) override;
#define NS_DECL_NSIMUTATIONOBSERVER_NODEWILLBEDESTROYED \
virtual void NodeWillBeDestroyed(nsINode* aNode) override;
#define NS_DECL_NSIMUTATIONOBSERVER_PARENTCHAINCHANGED \
virtual void ParentChainChanged(nsIContent* aContent) override;
#define NS_DECL_NSIMUTATIONOBSERVER_ARIAATTRIBUTEDEFAULTWILLCHANGE \
virtual void ARIAAttributeDefaultWillChange( \
mozilla::dom::Element* aElement, nsAtom* aAttribute, int32_t aModType) \
override;
#define NS_DECL_NSIMUTATIONOBSERVER_ARIAATTRIBUTEDEFAULTCHANGED \
virtual void ARIAAttributeDefaultChanged( \
mozilla::dom::Element* aElement, nsAtom* aAttribute, int32_t aModType) \
override;
#define NS_DECL_NSIMUTATIONOBSERVER \
NS_DECL_NSIMUTATIONOBSERVER_CHARACTERDATAWILLCHANGE \
NS_DECL_NSIMUTATIONOBSERVER_CHARACTERDATACHANGED \
NS_DECL_NSIMUTATIONOBSERVER_ATTRIBUTEWILLCHANGE \
NS_DECL_NSIMUTATIONOBSERVER_ATTRIBUTECHANGED \
NS_DECL_NSIMUTATIONOBSERVER_CONTENTAPPENDED \
NS_DECL_NSIMUTATIONOBSERVER_CONTENTINSERTED \
NS_DECL_NSIMUTATIONOBSERVER_CONTENTREMOVED \
NS_DECL_NSIMUTATIONOBSERVER_NODEWILLBEDESTROYED \
NS_DECL_NSIMUTATIONOBSERVER_PARENTCHAINCHANGED \
NS_DECL_NSIMUTATIONOBSERVER_ARIAATTRIBUTEDEFAULTWILLCHANGE \
NS_DECL_NSIMUTATIONOBSERVER_ARIAATTRIBUTEDEFAULTCHANGED
#define NS_IMPL_NSIMUTATIONOBSERVER_CORE_STUB(_class) \
void _class::NodeWillBeDestroyed(nsINode* aNode) {}
#define NS_IMPL_NSIMUTATIONOBSERVER_CONTENT(_class) \
void _class::CharacterDataWillChange( \
nsIContent* aContent, const CharacterDataChangeInfo& aInfo) {} \
void _class::CharacterDataChanged(nsIContent* aContent, \
const CharacterDataChangeInfo& aInfo) {} \
void _class::AttributeWillChange(mozilla::dom::Element* aElement, \
int32_t aNameSpaceID, nsAtom* aAttribute, \
int32_t aModType) {} \
void _class::AttributeChanged( \
mozilla::dom::Element* aElement, int32_t aNameSpaceID, \
nsAtom* aAttribute, int32_t aModType, const nsAttrValue* aOldValue) {} \
void _class::ContentAppended(nsIContent* aFirstNewContent) {} \
void _class::ContentInserted(nsIContent* aChild) {} \
void _class::ContentRemoved(nsIContent* aChild, \
nsIContent* aPreviousSibling) {} \
void _class::ParentChainChanged(nsIContent* aContent) {} \
void _class::ARIAAttributeDefaultWillChange( \
mozilla::dom::Element* aElement, nsAtom* aAttribute, int32_t aModType) { \
} \
void _class::ARIAAttributeDefaultChanged( \
mozilla::dom::Element* aElement, nsAtom* aAttribute, int32_t aModType) { \
}
#endif /* nsIMutationObserver_h */