/* -*- 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/. */ #ifndef nsIMutationObserver_h #define nsIMutationObserver_h #include "nsISupports.h" #include "mozilla/Assertions.h" class nsAttrValue; class nsAtom; class nsIContent; class nsINode; namespace mozilla { namespace dom { class Element; } // namespace dom } // namespace mozilla #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. * * 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 { 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. * @param aNewValue The new value, IF it has been preparsed by * BeforeSetAttr, otherwise null. * * @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 the root of a native anonymous has been added * or removed. * * @param aContent Anonymous node that's been added or removed * @param aIsRemove True if it's a removal, false if an addition */ virtual void NativeAnonymousChildListChange(nsIContent* aContent, bool aIsRemove) {} /** * 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(const 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; }; 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_NATIVEANONYMOUSCHILDLISTCHANGE \ virtual void NativeAnonymousChildListChange(nsIContent* aContent, \ bool aIsRemove) 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(const nsINode* aNode) override; #define NS_DECL_NSIMUTATIONOBSERVER_PARENTCHAINCHANGED \ virtual void ParentChainChanged(nsIContent* aContent) override; #define NS_DECL_NSIMUTATIONOBSERVER \ NS_DECL_NSIMUTATIONOBSERVER_CHARACTERDATAWILLCHANGE \ NS_DECL_NSIMUTATIONOBSERVER_CHARACTERDATACHANGED \ NS_DECL_NSIMUTATIONOBSERVER_ATTRIBUTEWILLCHANGE \ NS_DECL_NSIMUTATIONOBSERVER_NATIVEANONYMOUSCHILDLISTCHANGE \ NS_DECL_NSIMUTATIONOBSERVER_ATTRIBUTECHANGED \ NS_DECL_NSIMUTATIONOBSERVER_CONTENTAPPENDED \ NS_DECL_NSIMUTATIONOBSERVER_CONTENTINSERTED \ NS_DECL_NSIMUTATIONOBSERVER_CONTENTREMOVED \ NS_DECL_NSIMUTATIONOBSERVER_NODEWILLBEDESTROYED \ NS_DECL_NSIMUTATIONOBSERVER_PARENTCHAINCHANGED #define NS_IMPL_NSIMUTATIONOBSERVER_CORE_STUB(_class) \ void _class::NodeWillBeDestroyed(const 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::NativeAnonymousChildListChange(nsIContent* aContent, \ bool aIsRemove) {} \ 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) {} #endif /* nsIMutationObserver_h */