|
1 /* |
|
2 * Copyright (c) 2000-2009 Nokia Corporation and/or its subsidiary(-ies). |
|
3 * All rights reserved. |
|
4 * This component and the accompanying materials are made available |
|
5 * under the terms of "Eclipse Public License v1.0" |
|
6 * which accompanies this distribution, and is available |
|
7 * at the URL "http://www.eclipse.org/legal/epl-v10.html". |
|
8 * |
|
9 * Initial Contributors: |
|
10 * Nokia Corporation - initial contribution. |
|
11 * |
|
12 * Contributors: |
|
13 * |
|
14 * Description: |
|
15 * |
|
16 */ |
|
17 |
|
18 |
|
19 #ifndef UNDOSYSTEMIMPL_H_ |
|
20 #define UNDOSYSTEMIMPL_H_ |
|
21 |
|
22 #include <e32base.h> |
|
23 #include "UndoSystem.h" |
|
24 |
|
25 namespace UndoSystem |
|
26 { |
|
27 class CCommand; |
|
28 class CSingleCommand; |
|
29 class CBatchCommand; |
|
30 |
|
31 /** |
|
32 * Undo panic codes |
|
33 * |
|
34 * @internalComponent |
|
35 */ |
|
36 enum TPanicCode |
|
37 { |
|
38 /** |
|
39 * CSingleCommand::PrepareToAddInverseToLast() overridden to return ETrue, but |
|
40 * CSingleCommand::AddInverseToLast() not overridden. |
|
41 */ |
|
42 KAddToLastOnlyHalfImplemented = 1, |
|
43 /** |
|
44 * CCommandStack or CSingleCommandStack::Pop() called on an empty stack |
|
45 */ |
|
46 KCommandStackUnderflow, |
|
47 /** |
|
48 * CCommandStack or CSingleCommandStack::Push() called without adequate |
|
49 * space being reserved via PrepareToPushL() |
|
50 */ |
|
51 KCommandStackPushNotPrepared, |
|
52 /** |
|
53 * No shared undo system passed when expected |
|
54 */ |
|
55 KEditorUndoNoCommandManager |
|
56 }; |
|
57 |
|
58 /** |
|
59 * Panic from Undo DLL |
|
60 * |
|
61 * @internalComponent |
|
62 */ |
|
63 void Panic(TPanicCode aCode); |
|
64 |
|
65 /** |
|
66 * Stack of commands. A bookmark is maintianed so that we can tell if the stack |
|
67 * is in the same state it was at a previous time. |
|
68 * |
|
69 * @internalComponent |
|
70 * @since App-frameworks6.1 |
|
71 */ |
|
72 NONSHARABLE_CLASS(CCommandStack) : public CBase |
|
73 { |
|
74 public: |
|
75 static CCommandStack* NewL(); |
|
76 ~CCommandStack(); |
|
77 CCommandStack(); |
|
78 void ConstructL(); |
|
79 |
|
80 CCommand* Top() const; |
|
81 CCommand* Pop(); |
|
82 /** |
|
83 * Allows aNumberOfItems Push()s to be done before the next |
|
84 * call to another non-const member function apart from Push(). |
|
85 * aNumberOfItems must be non-negative. |
|
86 */ |
|
87 void PrepareToPushL(TInt aNumberOfItems); |
|
88 void Push(CCommand* aCommand); |
|
89 void PruneTo(TInt aNumberOfItems); |
|
90 TInt Count() const; |
|
91 /** |
|
92 * Removes all elements from the stack and deletes the bookmark. |
|
93 */ |
|
94 void Reset(); |
|
95 /** |
|
96 * Adds aStack to the top of this CCommandStack, emptying it completely. |
|
97 * Enough items must have been reserved with PrepareToPushL(TInt). |
|
98 */ |
|
99 void Concatenate(CCommandStack& aStack); |
|
100 /** |
|
101 * Sets the current position in the stack as the location of the bookmark. |
|
102 * The bookmark will be lost if the bookmarked object is removed from the |
|
103 * stack. Bookmark begins set at the zero position. |
|
104 */ |
|
105 void SetBookmark(); |
|
106 /** |
|
107 * Returns true iff we are at the current bookmark position. |
|
108 */ |
|
109 TBool IsAtBookmark() const; |
|
110 |
|
111 private: |
|
112 CArrayFix<CCommand*>* iStack; |
|
113 /** |
|
114 * One-past-top element in the array. Less than Count() after a call |
|
115 * to PrepareToPushL() with non-zero argument. |
|
116 */ |
|
117 TInt iEnd; |
|
118 /** |
|
119 * The bookmark into the stack. We are at the bookmark when iEnd == |
|
120 * iBookmark. No bookmark is represented by iBookmark < 0. |
|
121 */ |
|
122 TInt iBookmark; |
|
123 }; |
|
124 |
|
125 /** |
|
126 * Stack of single commands |
|
127 * |
|
128 * @internalComponent |
|
129 * @since App-frameworks6.1 |
|
130 */ |
|
131 class CSingleCommandStack : public CBase |
|
132 { |
|
133 public: |
|
134 static CSingleCommandStack* NewL(); |
|
135 |
|
136 inline CSingleCommand* Top() const; |
|
137 inline CSingleCommand* Pop(); |
|
138 inline void PrepareToPushL(TInt aNumberOfItems); |
|
139 inline void Push(CSingleCommand* aCommand); |
|
140 inline void PruneTo(TInt aNumberOfItems); |
|
141 inline TInt Count() const; |
|
142 inline void Reset(); |
|
143 inline void Concatenate(CSingleCommandStack& aStack); |
|
144 |
|
145 private: |
|
146 CSingleCommandStack() {} |
|
147 |
|
148 CCommandStack iStack; |
|
149 }; |
|
150 |
|
151 /** |
|
152 * A stack of commands supporting batching and a flag for whether a batch |
|
153 * has had its undo option waived. A bookmark is also supported, so that we can |
|
154 * tell whether the history is in the same state as it was at a previous time. |
|
155 * |
|
156 * @internalComponent |
|
157 * @since App-frameworks6.1 |
|
158 */ |
|
159 NONSHARABLE_CLASS(CCommandHistory) : public CBase |
|
160 { |
|
161 public: |
|
162 ~CCommandHistory(); |
|
163 static CCommandHistory* NewL(); |
|
164 |
|
165 /** |
|
166 * Returns the command at the top of the stack. |
|
167 */ |
|
168 CCommand* Top() const; |
|
169 /** |
|
170 * Returns the single command at the top of the stack. |
|
171 */ |
|
172 CSingleCommand* TopSingleCommand() const; |
|
173 /** |
|
174 * Allocates enough resources for one call to AddCommand(CCommand* aCommand). |
|
175 */ |
|
176 void PrepareToAddCommandL(CCommand* aCommand); |
|
177 /** |
|
178 * Adds the command to the top of the stack. PrepareToAddCommandL() must |
|
179 * have been called successfully since the last call to AddCommand or NewL. |
|
180 */ |
|
181 void AddCommand(CCommand*); |
|
182 /** |
|
183 * Returns ETrue iff SetUndoWaived() has been called during this batch. If |
|
184 * there is no batch currently open, this function will always return |
|
185 * EFalse. |
|
186 */ |
|
187 TBool UndoHasBeenWaived() const; |
|
188 /** |
|
189 * Sets a flag to indicated that undo is not required for this current |
|
190 * batch. This function has no effect if there is no batch currently open. |
|
191 * |
|
192 * @see UndoHasBeenWaived |
|
193 */ |
|
194 void SetUndoWaived(); |
|
195 /** |
|
196 * Sets the maximum height of the stack to aMaxItems. If it is exceeded, |
|
197 * the stack is truncated to aPrunedItems. |
|
198 */ |
|
199 void SetMaxItems(TInt aMaxItems); |
|
200 /** |
|
201 * Returns ETrue iff the stack has no elements. |
|
202 */ |
|
203 TBool IsEmpty() const { return Top()? EFalse : ETrue; } |
|
204 /** |
|
205 * Begins a new batch. All commands added subsequently will be exeuted all |
|
206 * at once. Close the batch with CleanupStack::PopAndDestroy(); |
|
207 */ |
|
208 void BeginBatchLC(); |
|
209 /** |
|
210 * Returns ETrue iff there is a batch currently open. |
|
211 */ |
|
212 TBool IsWithinBatch() const; |
|
213 /** |
|
214 * Removes and returns the top element. There must be no batch currently |
|
215 * open before a call to Pop(). |
|
216 */ |
|
217 CCommand* Pop(); |
|
218 /** |
|
219 * Removes all elements from the stack. If a batch is currently open, any |
|
220 * commands added subsequently will not be added to it. Deletes the |
|
221 * bookmark. |
|
222 */ |
|
223 void Reset(); |
|
224 /** |
|
225 * Removes and destroys the top element iff it is an empty batch. Must not |
|
226 * be called if a batch is currently open. |
|
227 */ |
|
228 void Clean(); |
|
229 /** |
|
230 * Sets the bookmark to the current position. |
|
231 */ |
|
232 void SetBookmark(); |
|
233 /** |
|
234 * Returns true iff the bookmark is at the current position. |
|
235 */ |
|
236 TBool IsAtBookmark(); |
|
237 |
|
238 private: |
|
239 |
|
240 CCommandHistory(); |
|
241 void ConstructL(); |
|
242 void Prune(); |
|
243 |
|
244 static void CloseBatch(void* aCCommandHistory); |
|
245 static void DownBatchLevel(void* aCCommandHistory); |
|
246 |
|
247 CCommandStack* iStack; |
|
248 CBatchCommand* iCurrent; // either == 0 or points to the most |
|
249 // recent CBatchCommand within iStack |
|
250 |
|
251 TInt iMaxItems; |
|
252 |
|
253 TBool iBatchUndoHasBeenWaived; |
|
254 }; |
|
255 |
|
256 // |
|
257 // CSingleCommandStack inlines |
|
258 // |
|
259 CSingleCommand* CSingleCommandStack::Top() const |
|
260 { return static_cast<CSingleCommand*>(iStack.Top()); } |
|
261 |
|
262 CSingleCommand* CSingleCommandStack::Pop() |
|
263 { return static_cast<CSingleCommand*>(iStack.Pop()); } |
|
264 |
|
265 void CSingleCommandStack::PrepareToPushL(TInt aNumberOfItems) |
|
266 { iStack.PrepareToPushL(aNumberOfItems); } |
|
267 |
|
268 void CSingleCommandStack::Push(CSingleCommand* aCommand) |
|
269 { iStack.Push(aCommand); } |
|
270 |
|
271 void CSingleCommandStack::PruneTo(TInt aNumberOfItems) |
|
272 { iStack.PruneTo(aNumberOfItems); } |
|
273 |
|
274 TInt CSingleCommandStack::Count() const |
|
275 { return iStack.Count(); } |
|
276 |
|
277 void CSingleCommandStack::Reset() |
|
278 { iStack.Reset(); } |
|
279 |
|
280 void CSingleCommandStack::Concatenate(CSingleCommandStack& aStack) |
|
281 { iStack.Concatenate(aStack.iStack); } |
|
282 |
|
283 } |
|
284 |
|
285 #endif |
|
286 |