Source code of Windows XP (NT5)
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/*
* _M_UNDO.H
*
* Purpose:
* Declares multilevel undo interfaces and classes
*
* Author:
* alexgo 3/25/95
*
* Copyright (c) 1995-2000, Microsoft Corporation. All rights reserved.
*/
#ifndef __M_UNDO_H__
#define __M_UNDO_H__
#include "_callmgr.h"
// Forward declaration to get around dependency cycle
class CTxtEdit;
class IUndoBuilder;
/*
* MergeDataTypes
*
* @enum Tags indicating the different data types that can be
* sent in IAntiEvent::MergeData
*/
enum MergeDataTypes
{
MD_SIMPLE_REPLACERANGE = 1, //@emem a simple replace range;
//usually just typing or backspace
MD_SELECTIONRANGE = 2 //@emem the selection location
};
/*
* SimpleReplaceRange
*
* @stuct SimpleReplaceRange | has the data from a replace range operation
* *except* for any deleted characters. If we don't have to save
* the deleted characters, we don't.
*/
struct SimpleReplaceRange
{
LONG cpMin; //@field cpMin of new text
LONG cpMax; //@field cpMax of new text
LONG cchDel; //@field number of characters deleted
};
/*
* SELAEFLAGS
*
* @enum Flags to control how the selection range info should be treated
*/
enum SELAE
{
SELAE_MERGE = 1,
SELAE_FORCEREPLACE = 2
};
/*
* SelRange
*
* @struct SelRange | has the data for a selection's location _and_ the
* information needed to generate an undo action for the selection
* placement
*
* @comm -1 may be used to NO-OP any field
*/
struct SelRange
{
LONG cp; //@field Active end
LONG cch; //@field Signed extension
LONG cpNext; //@field cp for the inverse of this action
LONG cchNext; //@field Extension for the inverse of this action
SELAE flags; //@field Controls how this info is interpreted
};
/*
* IAntiEvent
*
* Purpose:
* Antievents undo 'normal' events, like typing a character
*/
class IAntiEvent
{
public:
virtual void Destroy( void ) = 0;
// It should be noted that CTxtEdit * here is really just a general
// closure, i.e. it could be expressed by void *. However, since
// this interface is currently just used internally, I've opted
// to use the extra type-checking. alexgo
virtual HRESULT Undo( CTxtEdit *ped, IUndoBuilder *publdr ) = 0;
// This method will let us merge in arbitrary data for things like
// group typing
virtual HRESULT MergeData( DWORD dwDataType, void *pdata) = 0;
// This method is called when antievent is committed to undo stack.
// Allows us to handle re-entrancy better for OLE objects.
virtual void OnCommit(CTxtEdit *ped) = 0;
// These two methods allow antievents to be chained together in
// a linked list
virtual void SetNext(IAntiEvent *pNext) = 0;
virtual IAntiEvent *GetNext() = 0;
protected:
~IAntiEvent() {;}
};
/*
* IUndoMgr
*
* Purpose:
* Interface for managing "stacks" of antievents
*/
class IUndoMgr
{
public:
virtual void Destroy () = 0;
virtual LONG SetUndoLimit (LONG cUndoLim) = 0;
virtual LONG GetUndoLimit () = 0;
virtual HRESULT PushAntiEvent (UNDONAMEID idName, IAntiEvent *pae) = 0;
virtual HRESULT PopAndExecuteAntiEvent (void* pAE) = 0;
virtual UNDONAMEID GetNameIDFromAE (void *pAE) = 0;
virtual IAntiEvent *GetMergeAntiEvent () = 0;
virtual void * GetTopAECookie () = 0;
virtual void ClearAll () = 0;
virtual BOOL CanUndo () = 0;
virtual void StartGroupTyping () = 0;
virtual void StopGroupTyping () = 0;
protected:
~IUndoMgr() {;}
};
/*
* USFlags
*
* @enum
* Flags affecting the behaviour of Undo stacks
*/
enum USFlags
{
US_UNDO = 1, //@emem Regular undo stack
US_REDO = 2 //@emem Undo stack is for REDO functionality
};
/*
* CUndoStack
*
* @class
* Manages a stack of antievents. These antievents are kept in
* a resizable ring buffer. Exports the IUndoMgr interface
*/
class CUndoStack : public IUndoMgr
{
//@access Public Methods
public:
virtual void Destroy(); //@cmember Destroy
virtual LONG SetUndoLimit(LONG cUndoLim);//@cmember Set item limit
virtual LONG GetUndoLimit();
//@cmember Add an AE to stack
virtual HRESULT PushAntiEvent(UNDONAMEID idName, IAntiEvent *pae);
//@cmember Execute most recent
virtual HRESULT PopAndExecuteAntiEvent(void *pAE);// antievent or upto pAE
virtual UNDONAMEID GetNameIDFromAE(void *pAE);//@cmember Get name of given AE
virtual IAntiEvent *GetMergeAntiEvent(); //@cmember Get most recent AE
// of merge state
virtual void * GetTopAECookie(); //@cmember Get cookie for top AE
virtual void ClearAll(); //@cmember Delete all AEs
virtual BOOL CanUndo(); //@cmember Something to undo?
virtual void StartGroupTyping(); //@cmember Starts group typing
virtual void StopGroupTyping(); //@cmember Stops group typing
// Public methods; not part of IUndoMgr
HRESULT EnableSingleLevelMode(); //@cmember RE1.0 undo mode
void DisableSingleLevelMode(); //@cmember Back to RE2.0 mode
//@cmember Are we in 1.0 mode?
BOOL GetSingleLevelMode() {return _fSingleLevelMode;}
CUndoStack(CTxtEdit *ped, LONG &cUndoLim, USFlags flags);
private:
~CUndoStack();
struct UndoAction
{
IAntiEvent * pae;
UNDONAMEID id;
};
void Next(); //@cmember Moves by 1
void Prev(); //@cmember Moves by -1
LONG GetPrev(); //@cmember Get previous index
//@cmember TRUE iff cookie ae is in ae list
BOOL IsCookieInList(IAntiEvent *pae, IAntiEvent *paeCookie);
//@cmember Transfer this object to new stack
void TransferToNewBuffer(UndoAction *prgnew, LONG dwLimNew);
UndoAction *_prgActions; //@cmember List of AEs
LONG _cUndoLim; //@cmember Undo limit
LONG _index; //@cmember Current index
CTxtEdit * _ped; //@cmember Big Papa
DWORD _fGroupTyping :1; //@cmember Group Typing flag
DWORD _fMerge :1; //@cmember Merge flag
DWORD _fRedo :1; //@cmember Stack is the redo stack
DWORD _fSingleLevelMode :1; //@cmember TRUE if single level undo
// mode is on. Valid only for undo,
}; // i.e., not for redo stack
/*
* IUndoBuilder
*
* Purpose:
* Provides a closure for collecting a sequence of antievents (such
* as all of the antievents involved in doing an intraedit drag-move
* operation.
*/
class IUndoBuilder
{
public:
// Names antievent collection
virtual void SetNameID( UNDONAMEID idName ) = 0;
// Adds new antievent to collection
virtual HRESULT AddAntiEvent( IAntiEvent *pae ) = 0;
// Gets topmost antievent in this undo context. This method
// is useful for grouped typing (merging antievents)
virtual IAntiEvent *GetTopAntiEvent() = 0;
// Commits antievent collection
virtual HRESULT Done() = 0;
// Get rid of any antievents that have been collected
virtual void Discard() = 0;
// Notify that a group-typing session should start (forwarded
// to the undo manager)
virtual void StartGroupTyping() = 0;
// Notify that a group-typing session should stop (forwarded
// to the undo manager)
virtual void StopGroupTyping() = 0;
};
/*
* UBFlags
*
* @enum
* Flags affecting the behaviour of Undo builders
*/
enum UBFlags
{
UB_AUTOCOMMIT = 1, //@emem Call IUndoBuilder::Done before delete
UB_REDO = 2, //@emem Undo builder is for REDO functionality
UB_DONTFLUSHREDO = 4 //@emem Don't flush redo stack when adding
// antievents to undo stack
};
/*
* CGenUndoBuilder
*
* @class
* A general purpose undo builder. It can be easily allocated and freed
* on the stack and simply puts new antievents at the beginning of an
* antievent linked list. NO attempt is made to optimize or reorder
* antievents.
*/
class CGenUndoBuilder : public IUndoBuilder, public IReEntrantComponent
{
//@access Public methods
public:
virtual void SetNameID( UNDONAMEID idName ); //@cmember Set the name
virtual HRESULT AddAntiEvent(IAntiEvent *pae); //@cmember Add an AE
virtual IAntiEvent *GetTopAntiEvent( ); //@cmember Get top AE
virtual HRESULT Done(); //@cmember Commit AEs
virtual void Discard(); //@cmember Discard AEs
virtual void StartGroupTyping(); //@cmember Start GT
virtual void StopGroupTyping(); //@cmember Stop GT
CGenUndoBuilder(CTxtEdit *ped, DWORD flags, //@cmember Constructor
IUndoBuilder **ppubldr = NULL);
~CGenUndoBuilder( ); //@cmember Destructor
// IReEntrantComponent methods
virtual void OnEnterContext() {;} //@cmember Reentered notify
//@access Private methods
private:
IUndoBuilder * _publdrPrev; //@cmember Ptr to undobldr
// higher in stack
IUndoMgr * _pundo; //@cmember Ptr to undo mgr
CTxtEdit * _ped; //@cmember Ptr to edit contxt
UNDONAMEID _idName; //@cmember Current name
IAntiEvent * _pfirstae; //@cmember AE list
UINT _fAutoCommit:1; //@cmember AutoCommit on?
UINT _fStartGroupTyping:1; //@cmember GroupTyping on?
UINT _fRedo:1; //@cmember UB destination is
// the redo stack
UINT _fDontFlushRedo:1; //@cmember Don't flush redo
// stack; i.e. we are
// invoking a redo action
UINT _fInactive:1; //@cmember TRUE if undo enabled
};
/*
* CUndoStackGuard
*
* @class
* A stack based class which helps manage reentrancy for the undo stack
*/
class CUndoStackGuard : public IReEntrantComponent
{
//@access Public Methods
public:
virtual void OnEnterContext(); //@cmember reentered notify
CUndoStackGuard(CTxtEdit *ped); //@cmember Constructor
~CUndoStackGuard(); //@cmember Destructor
//@cmember Execute the undo
HRESULT SafeUndo(IAntiEvent *pae, IUndoBuilder *publdr);// actions in <p pae>
BOOL WasReEntered() {return _fReEntered;} //@cmember Return reentered flag
//@access Private Data
private:
CTxtEdit * _ped; //@cmember Edit context
volatile IAntiEvent * _paeNext; //@cmember Antievent loop ptr
volatile HRESULT _hr; //@cmember Cached hr
IUndoBuilder * _publdr; //@cmember Undo/redo context
BOOL _fReEntered; //@cmember Have we been
}; // been reentered?
// Helper Functions.
// Loop through a chain of antievents and destroy them
void DestroyAEList(IAntiEvent *pae);
// Loop through a chain of antievents and call OnCommit
void CommitAEList(CTxtEdit *ped, IAntiEvent *pae);
// Handles merging and/or creation of selection antievent info
HRESULT HandleSelectionAEInfo(CTxtEdit *ped, IUndoBuilder *publdr,
LONG cp, LONG cch, LONG cpNext, LONG cchNext, SELAE flags);
#endif // !__M_UNDO_H__