|
sl@0
|
1 |
/*
|
|
sl@0
|
2 |
* Copyright (c) 2000-2009 Nokia Corporation and/or its subsidiary(-ies).
|
|
sl@0
|
3 |
* All rights reserved.
|
|
sl@0
|
4 |
* This component and the accompanying materials are made available
|
|
sl@0
|
5 |
* under the terms of "Eclipse Public License v1.0"
|
|
sl@0
|
6 |
* which accompanies this distribution, and is available
|
|
sl@0
|
7 |
* at the URL "http://www.eclipse.org/legal/epl-v10.html".
|
|
sl@0
|
8 |
*
|
|
sl@0
|
9 |
* Initial Contributors:
|
|
sl@0
|
10 |
* Nokia Corporation - initial contribution.
|
|
sl@0
|
11 |
*
|
|
sl@0
|
12 |
* Contributors:
|
|
sl@0
|
13 |
*
|
|
sl@0
|
14 |
* Description:
|
|
sl@0
|
15 |
*
|
|
sl@0
|
16 |
*/
|
|
sl@0
|
17 |
|
|
sl@0
|
18 |
|
|
sl@0
|
19 |
#ifndef UNDOSYSTEM_H_
|
|
sl@0
|
20 |
#define UNDOSYSTEM_H_
|
|
sl@0
|
21 |
|
|
sl@0
|
22 |
#include <e32base.h>
|
|
sl@0
|
23 |
|
|
sl@0
|
24 |
namespace UndoSystem
|
|
sl@0
|
25 |
{
|
|
sl@0
|
26 |
class CCommand;
|
|
sl@0
|
27 |
class CSingleCommand;
|
|
sl@0
|
28 |
class CBatchCommand;
|
|
sl@0
|
29 |
class CCommandManager;
|
|
sl@0
|
30 |
class CCommandHistory;
|
|
sl@0
|
31 |
class CCommandStack;
|
|
sl@0
|
32 |
class CSingleCommandStack;
|
|
sl@0
|
33 |
class CDefaultGatekeeper;
|
|
sl@0
|
34 |
|
|
sl@0
|
35 |
/**
|
|
sl@0
|
36 |
Base class for gatekeepers. A Gatekeeper is responsible for finding more
|
|
sl@0
|
37 |
memory during certain out of memory conditions, and for deciding whether
|
|
sl@0
|
38 |
an operation that cannot be undone should be allowed to be excuted.
|
|
sl@0
|
39 |
|
|
sl@0
|
40 |
@since App-frameworks6.1
|
|
sl@0
|
41 |
@internalAll
|
|
sl@0
|
42 |
*/
|
|
sl@0
|
43 |
class MNotUndoableGatekeeper
|
|
sl@0
|
44 |
|
|
sl@0
|
45 |
{
|
|
sl@0
|
46 |
public:
|
|
sl@0
|
47 |
/**
|
|
sl@0
|
48 |
* Tries to find more memory. aNumRetries will be 0 on the first call to
|
|
sl@0
|
49 |
* this function for the processing of a given command. It will increase
|
|
sl@0
|
50 |
* by 1 each time it is called for the same command. The calls will stop
|
|
sl@0
|
51 |
* when either the processing for the command completes successfully, when
|
|
sl@0
|
52 |
* processing for the command fails for some other reason, or when this
|
|
sl@0
|
53 |
* function returns EFalse or leaves.
|
|
sl@0
|
54 |
*
|
|
sl@0
|
55 |
* Default behaviour is to return EFalse always.
|
|
sl@0
|
56 |
*/
|
|
sl@0
|
57 |
IMPORT_C virtual TBool RetryOutOfMemoryL(TInt aNumRetries);
|
|
sl@0
|
58 |
/**
|
|
sl@0
|
59 |
* Decides whether to allow an operation that is undoable.
|
|
sl@0
|
60 |
*
|
|
sl@0
|
61 |
* aReason is the code that the attempt to create an inverse command
|
|
sl@0
|
62 |
* left with.
|
|
sl@0
|
63 |
*
|
|
sl@0
|
64 |
* A return value of EFalse indicates that the command should not be
|
|
sl@0
|
65 |
* executed, and all stored operations should be retained. KErrAbort will
|
|
sl@0
|
66 |
* be returned to the caller of CCommandManager. A return value of ETure
|
|
sl@0
|
67 |
* indicates that the command should be executed, and all stored
|
|
sl@0
|
68 |
* operations deleted. The function may also leave. Any leave will pass
|
|
sl@0
|
69 |
* back to the caller of CCommandManager, leaving the command unexecuted
|
|
sl@0
|
70 |
* and the stored operations intact.
|
|
sl@0
|
71 |
*
|
|
sl@0
|
72 |
* Default behaviour is to return ETrue if aReason is KErrNotSupported,
|
|
sl@0
|
73 |
* and leave with aReason otherwise.
|
|
sl@0
|
74 |
*/
|
|
sl@0
|
75 |
IMPORT_C virtual TBool AllowNotUndoableL(TInt aReason);
|
|
sl@0
|
76 |
};
|
|
sl@0
|
77 |
|
|
sl@0
|
78 |
/**
|
|
sl@0
|
79 |
General undo system. Together with CSingleCommand and CBatchCommand, this
|
|
sl@0
|
80 |
class provides a framework for building undo systems. A bookmark is
|
|
sl@0
|
81 |
maintained so that we can determine if the undo system has returned the
|
|
sl@0
|
82 |
target to a previously bookmarked state. This is useful for determining if
|
|
sl@0
|
83 |
saving is necessary on exit.
|
|
sl@0
|
84 |
|
|
sl@0
|
85 |
@see CSingleCommand, CBatchCommand
|
|
sl@0
|
86 |
@since App-frameworks6.1
|
|
sl@0
|
87 |
@internalAll
|
|
sl@0
|
88 |
*/
|
|
sl@0
|
89 |
class CCommandManager : public CBase
|
|
sl@0
|
90 |
|
|
sl@0
|
91 |
{
|
|
sl@0
|
92 |
public:
|
|
sl@0
|
93 |
/**
|
|
sl@0
|
94 |
* Allows a new owner to share this CCommandManager. Release() will need
|
|
sl@0
|
95 |
* to be called one extra time per call to NewReference().
|
|
sl@0
|
96 |
*/
|
|
sl@0
|
97 |
IMPORT_C void NewReference();
|
|
sl@0
|
98 |
/**
|
|
sl@0
|
99 |
* Allows the caller to finish with this CCommandManager. The caller must
|
|
sl@0
|
100 |
* not access this object after calling Release().
|
|
sl@0
|
101 |
*/
|
|
sl@0
|
102 |
IMPORT_C void Release();
|
|
sl@0
|
103 |
|
|
sl@0
|
104 |
/**
|
|
sl@0
|
105 |
* Creates a new CCommandManager. One call to Release() will be required
|
|
sl@0
|
106 |
* to dispose of this object, unless NewReference() is called, in which case
|
|
sl@0
|
107 |
* one additional call to Release() is required per call to NewReference().
|
|
sl@0
|
108 |
*/
|
|
sl@0
|
109 |
IMPORT_C static CCommandManager* NewL();
|
|
sl@0
|
110 |
|
|
sl@0
|
111 |
/**
|
|
sl@0
|
112 |
* Begins a batch. Commands entered into the batch will be undone and redone
|
|
sl@0
|
113 |
* in one go. If undo is cancelled for one command in the batch, it will be
|
|
sl@0
|
114 |
* considered cancelled for the entire batch.
|
|
sl@0
|
115 |
* End the batch with CleanupStack::PopAndDestroy();
|
|
sl@0
|
116 |
*/
|
|
sl@0
|
117 |
IMPORT_C void BeginBatchLC();
|
|
sl@0
|
118 |
/**
|
|
sl@0
|
119 |
* Returns ETrue iff UndoL() will have an effect.
|
|
sl@0
|
120 |
*/
|
|
sl@0
|
121 |
IMPORT_C TBool CanUndo() const;
|
|
sl@0
|
122 |
/**
|
|
sl@0
|
123 |
* Returns ETrue iff RedoL() will have an effect.
|
|
sl@0
|
124 |
*/
|
|
sl@0
|
125 |
IMPORT_C TBool CanRedo() const;
|
|
sl@0
|
126 |
/**
|
|
sl@0
|
127 |
* Executes a single command, allowing it to be undone later, if
|
|
sl@0
|
128 |
* appropriate.
|
|
sl@0
|
129 |
*/
|
|
sl@0
|
130 |
IMPORT_C TInt ExecuteL(const CSingleCommand&);
|
|
sl@0
|
131 |
/**
|
|
sl@0
|
132 |
* Sets a gatekeper for the undo system. This will be called whenever an
|
|
sl@0
|
133 |
* operation is attempted that cannot be undone for any reason.
|
|
sl@0
|
134 |
* The gatekeeper therefore has an oportunity to suppress execution and
|
|
sl@0
|
135 |
* keep the current undo operations stored.
|
|
sl@0
|
136 |
* NULL may be passed to restore default behaviour.
|
|
sl@0
|
137 |
* Returns previous gatekeeper.
|
|
sl@0
|
138 |
*/
|
|
sl@0
|
139 |
IMPORT_C MNotUndoableGatekeeper* SetGatekeeper(MNotUndoableGatekeeper*);
|
|
sl@0
|
140 |
/**
|
|
sl@0
|
141 |
* Sets limits on the 'undo depth'. This is the number of times that
|
|
sl@0
|
142 |
* successive calls to UndoL() have an effect.
|
|
sl@0
|
143 |
*/
|
|
sl@0
|
144 |
IMPORT_C void SetMaxItems(TInt aMaxItems);
|
|
sl@0
|
145 |
/**
|
|
sl@0
|
146 |
* Undoes one operation or batch of operations. If one operation in the
|
|
sl@0
|
147 |
* middle of a batch leaves, this function will leave, but the underlying
|
|
sl@0
|
148 |
* editor will not necessarily be in the same state as it was in before
|
|
sl@0
|
149 |
* the call. However, all operations will still be stored, and so the
|
|
sl@0
|
150 |
* previous state is still recoverable with a further call to UndoL().
|
|
sl@0
|
151 |
*/
|
|
sl@0
|
152 |
IMPORT_C void UndoL();
|
|
sl@0
|
153 |
/**
|
|
sl@0
|
154 |
* Redoes one operation or batch of operations. If one operation in the
|
|
sl@0
|
155 |
* middle of a batch leaves, this function will leave, but the underlying
|
|
sl@0
|
156 |
* editor will not necessarily be in the same state as it was in before
|
|
sl@0
|
157 |
* the call. However, all operations will still be stored, and so the
|
|
sl@0
|
158 |
* previous state is still recoverable with a further call to RedoL().
|
|
sl@0
|
159 |
*/
|
|
sl@0
|
160 |
IMPORT_C void RedoL();
|
|
sl@0
|
161 |
/**
|
|
sl@0
|
162 |
* Deletes all stored operations. Deletes the bookmark.
|
|
sl@0
|
163 |
*/
|
|
sl@0
|
164 |
IMPORT_C void ResetUndo();
|
|
sl@0
|
165 |
/**
|
|
sl@0
|
166 |
* Sets the bookmark to the current position in the history.
|
|
sl@0
|
167 |
*/
|
|
sl@0
|
168 |
IMPORT_C void SetBookmark();
|
|
sl@0
|
169 |
/**
|
|
sl@0
|
170 |
* Returns true iff we are currently at the bookmarked position.
|
|
sl@0
|
171 |
*/
|
|
sl@0
|
172 |
IMPORT_C TBool IsAtBookmark() const;
|
|
sl@0
|
173 |
|
|
sl@0
|
174 |
private:
|
|
sl@0
|
175 |
|
|
sl@0
|
176 |
TInt ExecuteSingleCommandL(const CSingleCommand& aCommand, CCommandHistory& aUndo);
|
|
sl@0
|
177 |
TInt ExecuteBatchCommandL(CBatchCommand& aCommand, CCommandHistory& aUndo);
|
|
sl@0
|
178 |
void MoveHistoryL(CCommandHistory& aFrom, CCommandHistory& aTo);
|
|
sl@0
|
179 |
TBool CreateAndPrepareToAddInverseL(const CSingleCommand& aCommand,
|
|
sl@0
|
180 |
CCommandHistory& aUndo, CCommand*& aInverse);
|
|
sl@0
|
181 |
|
|
sl@0
|
182 |
CCommandManager();
|
|
sl@0
|
183 |
void ConstructL();
|
|
sl@0
|
184 |
~CCommandManager();
|
|
sl@0
|
185 |
|
|
sl@0
|
186 |
CCommandHistory* iFuture;
|
|
sl@0
|
187 |
CCommandHistory* iPast;
|
|
sl@0
|
188 |
MNotUndoableGatekeeper* iCurrentGatekeeper;
|
|
sl@0
|
189 |
CDefaultGatekeeper* iDefaultGatekeeper;
|
|
sl@0
|
190 |
TInt iRefCount;
|
|
sl@0
|
191 |
};
|
|
sl@0
|
192 |
|
|
sl@0
|
193 |
/**
|
|
sl@0
|
194 |
Abstract base class for all commands that can be stored in the undo system
|
|
sl@0
|
195 |
|
|
sl@0
|
196 |
@since App-frameworks6.1
|
|
sl@0
|
197 |
@internalComponent
|
|
sl@0
|
198 |
*/
|
|
sl@0
|
199 |
class CCommand : public CBase
|
|
sl@0
|
200 |
|
|
sl@0
|
201 |
{
|
|
sl@0
|
202 |
public:
|
|
sl@0
|
203 |
/**
|
|
sl@0
|
204 |
* Casts this CCommand to CSingleCommand* if possible
|
|
sl@0
|
205 |
*/
|
|
sl@0
|
206 |
virtual CSingleCommand* Single() = 0;
|
|
sl@0
|
207 |
/**
|
|
sl@0
|
208 |
* Casts this CCommand to CBatchCommand* if possible
|
|
sl@0
|
209 |
*/
|
|
sl@0
|
210 |
virtual CBatchCommand* Batch() = 0;
|
|
sl@0
|
211 |
};
|
|
sl@0
|
212 |
|
|
sl@0
|
213 |
/**
|
|
sl@0
|
214 |
Abstract base class for all commands. A CSingleCommand is able to be
|
|
sl@0
|
215 |
completed atomically, that is, leave their target unchanged if its
|
|
sl@0
|
216 |
execution leaves.
|
|
sl@0
|
217 |
|
|
sl@0
|
218 |
@since App-frameworks6.1
|
|
sl@0
|
219 |
@internalAll
|
|
sl@0
|
220 |
*/
|
|
sl@0
|
221 |
class CSingleCommand : public CCommand
|
|
sl@0
|
222 |
|
|
sl@0
|
223 |
{
|
|
sl@0
|
224 |
public:
|
|
sl@0
|
225 |
/**
|
|
sl@0
|
226 |
* Executes this command. This function may leave or return an error code.
|
|
sl@0
|
227 |
* in either case, there must have been no effect on its target(s).
|
|
sl@0
|
228 |
*/
|
|
sl@0
|
229 |
virtual TInt ExecuteL() const = 0;
|
|
sl@0
|
230 |
/**
|
|
sl@0
|
231 |
* Prepares to add the inverse of this command to aLastCommand.
|
|
sl@0
|
232 |
* Returns ETrue iff this was possible. Returning ETrue implies that
|
|
sl@0
|
233 |
* a future call to AddInverseToLast with the same parameter will
|
|
sl@0
|
234 |
* succeed without leaving.
|
|
sl@0
|
235 |
* The defualt implementation is to return EFalse.
|
|
sl@0
|
236 |
*/
|
|
sl@0
|
237 |
IMPORT_C virtual TBool PrepareToAddInverseToLastL(CSingleCommand& aLastCommand) const;
|
|
sl@0
|
238 |
|
|
sl@0
|
239 |
/**
|
|
sl@0
|
240 |
* Adds this command's inverse to aLastCommand. This function will
|
|
sl@0
|
241 |
* only be called after PrepareToAddInverseToLastL has been called
|
|
sl@0
|
242 |
* with the same argument, ETrue having been returned.
|
|
sl@0
|
243 |
* Default implementation is to panic.
|
|
sl@0
|
244 |
*/
|
|
sl@0
|
245 |
IMPORT_C virtual void AddInverseToLast(CSingleCommand& aLastCommand) const;
|
|
sl@0
|
246 |
|
|
sl@0
|
247 |
/**
|
|
sl@0
|
248 |
* Creates an inverse of this command.
|
|
sl@0
|
249 |
* A return value of 0 indicates that this command has no effect, and so a
|
|
sl@0
|
250 |
* return is not needed. To indicate that an inverse command cannot be
|
|
sl@0
|
251 |
* created, this function should leave with KErrNotSupported.
|
|
sl@0
|
252 |
* Default implementation is to leave with KErrNotSupported.
|
|
sl@0
|
253 |
*/
|
|
sl@0
|
254 |
IMPORT_C virtual CCommand* CreateInverseL() const;
|
|
sl@0
|
255 |
|
|
sl@0
|
256 |
/**
|
|
sl@0
|
257 |
* Returns a UID for the family of CSingleCommands that this belongs to.
|
|
sl@0
|
258 |
* This would usually be the DLL UID or KNullUid. It can be used to
|
|
sl@0
|
259 |
* determine whether a downcast is safe.
|
|
sl@0
|
260 |
*/
|
|
sl@0
|
261 |
IMPORT_C virtual TUid FamilyUid() const;
|
|
sl@0
|
262 |
/**
|
|
sl@0
|
263 |
* Returns this. Not to be overridden further.
|
|
sl@0
|
264 |
*/
|
|
sl@0
|
265 |
IMPORT_C CSingleCommand* Single();
|
|
sl@0
|
266 |
/**
|
|
sl@0
|
267 |
* Returns 0. Not to be overridden further.
|
|
sl@0
|
268 |
*/
|
|
sl@0
|
269 |
IMPORT_C CBatchCommand* Batch();
|
|
sl@0
|
270 |
};
|
|
sl@0
|
271 |
|
|
sl@0
|
272 |
/**
|
|
sl@0
|
273 |
Batch of commands.
|
|
sl@0
|
274 |
|
|
sl@0
|
275 |
@since App-frameworks6.1
|
|
sl@0
|
276 |
@internalComponent
|
|
sl@0
|
277 |
*/
|
|
sl@0
|
278 |
class CBatchCommand : public CCommand
|
|
sl@0
|
279 |
|
|
sl@0
|
280 |
{
|
|
sl@0
|
281 |
public:
|
|
sl@0
|
282 |
IMPORT_C ~CBatchCommand();
|
|
sl@0
|
283 |
|
|
sl@0
|
284 |
/**
|
|
sl@0
|
285 |
* Creates an empty batch.
|
|
sl@0
|
286 |
*/
|
|
sl@0
|
287 |
IMPORT_C static CBatchCommand* NewL();
|
|
sl@0
|
288 |
/**
|
|
sl@0
|
289 |
* Creates an empty batch on the cleanup stack.
|
|
sl@0
|
290 |
*/
|
|
sl@0
|
291 |
IMPORT_C static CBatchCommand* NewLC();
|
|
sl@0
|
292 |
|
|
sl@0
|
293 |
/**
|
|
sl@0
|
294 |
* Returns 0.
|
|
sl@0
|
295 |
*/
|
|
sl@0
|
296 |
IMPORT_C CSingleCommand* Single();
|
|
sl@0
|
297 |
/**
|
|
sl@0
|
298 |
* Returns this.
|
|
sl@0
|
299 |
*/
|
|
sl@0
|
300 |
IMPORT_C CBatchCommand* Batch();
|
|
sl@0
|
301 |
/**
|
|
sl@0
|
302 |
* Returns the single command that is at the top of the stack. If a batch
|
|
sl@0
|
303 |
* is at the top, then it will be the top of that.
|
|
sl@0
|
304 |
* A return value of 0 indicates that the batch is empty. Some empty
|
|
sl@0
|
305 |
* batches within the batch may be deleted.
|
|
sl@0
|
306 |
*/
|
|
sl@0
|
307 |
IMPORT_C CSingleCommand* Top() const;
|
|
sl@0
|
308 |
/**
|
|
sl@0
|
309 |
* Returns the single command that is at the top of the stack as for Top().
|
|
sl@0
|
310 |
* The ownership of the object is passed to the caller. This method must
|
|
sl@0
|
311 |
* not be called on an empty batch.
|
|
sl@0
|
312 |
*/
|
|
sl@0
|
313 |
IMPORT_C CSingleCommand* Pop();
|
|
sl@0
|
314 |
/**
|
|
sl@0
|
315 |
* Ensures that enough resources to perform a Push(CCommand* aCommand)
|
|
sl@0
|
316 |
* without leaving are allocated. The contents of the batch are unaltered.
|
|
sl@0
|
317 |
*/
|
|
sl@0
|
318 |
IMPORT_C void PrepareToPushL(CCommand* aCommand);
|
|
sl@0
|
319 |
/**
|
|
sl@0
|
320 |
* Pushes the command onto the batch. This command will be executed before
|
|
sl@0
|
321 |
* the commands currently in the batch. This function must only be called
|
|
sl@0
|
322 |
* if PrepareToPushL() has been called successfully since the last call to
|
|
sl@0
|
323 |
* Push() or NewL().
|
|
sl@0
|
324 |
*
|
|
sl@0
|
325 |
* aCommand may not be accessed after this call has completed.
|
|
sl@0
|
326 |
*/
|
|
sl@0
|
327 |
IMPORT_C void Push(CCommand* aCommand);
|
|
sl@0
|
328 |
/**
|
|
sl@0
|
329 |
* Performs PrepareToPushL(aCommand) then Push(aCommand). If it leaves,
|
|
sl@0
|
330 |
* aCommand is destroyed.
|
|
sl@0
|
331 |
*
|
|
sl@0
|
332 |
* @see PrepareToPushL, Push
|
|
sl@0
|
333 |
*/
|
|
sl@0
|
334 |
IMPORT_C void PushL(CCommand* aCommand);
|
|
sl@0
|
335 |
/**
|
|
sl@0
|
336 |
* Returns ETrue iff the batch is empty.
|
|
sl@0
|
337 |
*/
|
|
sl@0
|
338 |
TBool IsEmpty() const
|
|
sl@0
|
339 |
{
|
|
sl@0
|
340 |
if (Top())
|
|
sl@0
|
341 |
return EFalse;
|
|
sl@0
|
342 |
else
|
|
sl@0
|
343 |
return ETrue;
|
|
sl@0
|
344 |
}
|
|
sl@0
|
345 |
|
|
sl@0
|
346 |
private:
|
|
sl@0
|
347 |
CSingleCommandStack* iStack;
|
|
sl@0
|
348 |
CBatchCommand();
|
|
sl@0
|
349 |
void ConstructL();
|
|
sl@0
|
350 |
};
|
|
sl@0
|
351 |
}
|
|
sl@0
|
352 |
|
|
sl@0
|
353 |
#endif // UNDOSYSTEM_H_
|