/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ /************************************************************************* * * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * Copyright 2000, 2010 Oracle and/or its affiliates. * * OpenOffice.org - a multi-platform office productivity suite * * This file is part of OpenOffice.org. * * OpenOffice.org is free software: you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License version 3 * only, as published by the Free Software Foundation. * * OpenOffice.org is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License version 3 for more details * (a copy is included in the LICENSE file that accompanied this code). * * You should have received a copy of the GNU Lesser General Public License * version 3 along with OpenOffice.org. If not, see * * for a copy of the LGPLv3 License. * ************************************************************************/ #ifndef _CALBCK_HXX #define _CALBCK_HXX #include #include "swdllapi.h" #include class SwModify; class SwClientIter; class SfxPoolItem; class SfxHint; /* SwModify and SwClient cooperate in propagating attribute changes. If an attribute changes, the change is notified to all dependent formats and other interested objects, e.g. Nodes. The clients will detect if the change affects them. It could be that the changed attribute is overruled in the receiving object so that its change does not become effective or that the receiver is not interested in the particular attribute in general (though probably in other attributes of the SwModify object they are registered in). As SwModify objects are derived from SwClient, they can create a chain of SwClient objects where changes can get propagated through. Each SwClient can be registered at only one SwModify object, while each SwModify object is connected to a list of SwClient objects. If an object derived from SwClient wants to get notifications from more than one SwModify object, it must create additional SwClient objects. The SwDepend class allows to handle their notifications in the same notification callback as it forwards the Modify() calls it receives to a "master" SwClient implementation. The SwClientIter class allows to iterate over the SwClient objects registered at an SwModify. For historical reasons its ability to use TypeInfo to restrict this iteration to objects of a particular type created a lot of code that misuses SwClient-SwModify relationships that basically should be used only for Modify() callbacks. This is still subject to refactoring. Until this gets resolved, new SwClientIter base code should be reduced to the absolute minimum and it also should be wrapped by SwIterator templates that prevent that the code gets polluted by pointer casts (see switerator.hxx). */ // ---------- // SwClient // ---------- class SW_DLLPUBLIC SwClient : ::boost::noncopyable { // avoids making the details of the linked list and the callback method public friend class SwModify; friend class SwClientIter; SwClient *pLeft, *pRight; ///< double-linked list of other clients SwModify *pRegisteredIn; ///< event source // in general clients should not be removed when their SwModify sends out Modify() // notifications; in some rare cases this is necessary, but only the concrete SwClient // sub class will know that; this flag allows to make that known bool mbIsAllowedToBeRemovedInModifyCall; // callbacks received from SwModify (friend class - so these methods can be private) // should be called only from SwModify the client is registered in // mba: IMHO these methods should be pure virtual virtual void Modify( const SfxPoolItem* pOld, const SfxPoolItem *pNew); virtual void SwClientNotify( const SwModify& rModify, const SfxHint& rHint ); protected: // single argument ctors shall be explicit. explicit SwClient(SwModify *pToRegisterIn); // write access to pRegisteredIn shall be granted only to the object itself (protected access) SwModify* GetRegisteredInNonConst() const { return pRegisteredIn; } void SetIsAllowedToBeRemovedInModifyCall( bool bSet ) { mbIsAllowedToBeRemovedInModifyCall = bSet; } public: inline SwClient(); virtual ~SwClient(); // in case an SwModify object is destroyed that itself is registered in another SwModify, // its SwClient objects can decide to get registered to the latter instead by calling this method void CheckRegistration( const SfxPoolItem *pOldValue, const SfxPoolItem *pNewValue ); // controlled access to Modify method // mba: this is still considered a hack and it should be fixed; the name makes grep-ing easier void ModifyNotification( const SfxPoolItem *pOldValue, const SfxPoolItem *pNewValue ) { Modify ( pOldValue, pNewValue ); } void SwClientNotifyCall( const SwModify& rModify, const SfxHint& rHint ) { SwClientNotify( rModify, rHint ); } const SwModify* GetRegisteredIn() const { return pRegisteredIn; } bool IsLast() const { return !pLeft && !pRight; } // needed for class SwClientIter TYPEINFO(); // get information about attribute virtual sal_Bool GetInfo( SfxPoolItem& ) const; }; inline SwClient::SwClient() : pLeft(0), pRight(0), pRegisteredIn(0), mbIsAllowedToBeRemovedInModifyCall(false) {} // ---------- // SwModify // ---------- // class has a doubly linked list for dependencies class SW_DLLPUBLIC SwModify: public SwClient { SwClient* pRoot; // the start of the linked list of clients sal_Bool bModifyLocked : 1; // don't broadcast changes now sal_Bool bLockClientList : 1; // may be set when this instance notifies its clients sal_Bool bInDocDTOR : 1; // workaround for problems when a lot of objects are destroyed sal_Bool bInCache : 1; sal_Bool bInSwFntCache : 1; // mba: IMHO this method should be pure virtual virtual void Modify( const SfxPoolItem* pOld, const SfxPoolItem *pNew); public: SwModify(); // broadcasting: send notifications to all clients void NotifyClients( const SfxPoolItem *pOldValue, const SfxPoolItem *pNewValue ); // the same, but without setting bModifyLocked or checking for any of the flags // mba: it would be interesting to know why this is necessary // also allows to limit callback to certain type (HACK) void ModifyBroadcast( const SfxPoolItem *pOldValue, const SfxPoolItem *pNewValue, TypeId nType = TYPE(SwClient) ); // a more universal broadcasting mechanism void CallSwClientNotify( const SfxHint& rHint ) const; // single argument ctors shall be explicit. explicit SwModify( SwModify *pToRegisterIn ); virtual ~SwModify(); void Add(SwClient *pDepend); SwClient* Remove(SwClient *pDepend); const SwClient* GetDepends() const { return pRoot; } // get information about attribute virtual sal_Bool GetInfo( SfxPoolItem& ) const; void LockModify() { bModifyLocked = sal_True; } void UnlockModify() { bModifyLocked = sal_False; } void SetInCache( sal_Bool bNew ) { bInCache = bNew; } void SetInSwFntCache( sal_Bool bNew ) { bInSwFntCache = bNew; } void SetInDocDTOR() { bInDocDTOR = sal_True; } sal_Bool IsModifyLocked() const { return bModifyLocked; } sal_Bool IsInDocDTOR() const { return bInDocDTOR; } sal_Bool IsInCache() const { return bInCache; } sal_Bool IsInSwFntCache() const { return bInSwFntCache; } void CheckCaching( const sal_uInt16 nWhich ); bool IsLastDepend() { return pRoot && pRoot->IsLast(); } }; // ---------- // SwDepend // ---------- /* * Helper class for objects that need to depend on more than one SwClient */ class SW_DLLPUBLIC SwDepend: public SwClient { SwClient *pToTell; public: SwDepend() : pToTell(0) {} SwDepend(SwClient *pTellHim, SwModify *pDepend); SwClient* GetToTell() { return pToTell; } /** get Client information */ virtual sal_Bool GetInfo( SfxPoolItem & ) const; protected: virtual void Modify( const SfxPoolItem* pOld, const SfxPoolItem *pNewValue ); virtual void SwClientNotify( const SwModify& rModify, const SfxHint& rHint ); }; class SwClientIter { friend SwClient* SwModify::Remove(SwClient *); ///< for pointer adjustments friend void SwModify::Add(SwClient *pDepend); ///< for pointer adjustments const SwModify& rRoot; // the current object in an iteration SwClient* pAct; // in case the current object is already removed, the next object in the list // is marked down to become the current object in the next step // this is necessary because iteration requires access to members of the current object SwClient* pDelNext; // SwClientIter objects are tracked in linked list so that they can react // when the current (pAct) or marked down (pDelNext) SwClient is removed // from its SwModify SwClientIter *pNxtIter; // iterator can be limited to return only SwClient objects of a certain type TypeId aSrchId; public: SW_DLLPUBLIC SwClientIter( const SwModify& ); SW_DLLPUBLIC ~SwClientIter(); const SwModify& GetModify() const { return rRoot; } SwClient* operator++(int); SwClient* GoStart(); SwClient* GoEnd(); // returns the current SwClient object; // in case this was already removed, the object marked down to become // the next current one is returned SwClient* operator()() const { return pDelNext == pAct ? pAct : pDelNext; } // return "true" if an object was removed from a client chain in iteration // adding objects to a client chain in iteration is forbidden // SwModify::Add() asserts this bool IsChanged() const { return pDelNext != pAct; } SW_DLLPUBLIC SwClient* First( TypeId nType ); SW_DLLPUBLIC SwClient* Next(); SW_DLLPUBLIC SwClient* Last( TypeId nType ); SW_DLLPUBLIC SwClient* Previous(); }; #endif /* vim:set shiftwidth=4 softtabstop=4 expandtab: */