sl@0: /*
sl@0: * Copyright (c) 2000-2009 Nokia Corporation and/or its subsidiary(-ies).
sl@0: * All rights reserved.
sl@0: * This component and the accompanying materials are made available
sl@0: * under the terms of "Eclipse Public License v1.0"
sl@0: * which accompanies this distribution, and is available
sl@0: * at the URL "http://www.eclipse.org/legal/epl-v10.html".
sl@0: *
sl@0: * Initial Contributors:
sl@0: * Nokia Corporation - initial contribution.
sl@0: *
sl@0: * Contributors:
sl@0: *
sl@0: * Description: 
sl@0: *
sl@0: */
sl@0: 
sl@0: 
sl@0: #ifndef UNDOSYSTEMIMPL_H_
sl@0: #define UNDOSYSTEMIMPL_H_
sl@0: 
sl@0: #include <e32base.h>
sl@0: #include "UndoSystem.h"
sl@0: 
sl@0: namespace UndoSystem
sl@0: {
sl@0: class CCommand;
sl@0: class CSingleCommand;
sl@0: class CBatchCommand;
sl@0: 
sl@0: /**
sl@0:  * Undo panic codes
sl@0:  *
sl@0:  * @internalComponent
sl@0:  */
sl@0: enum TPanicCode
sl@0: 	{
sl@0: 	/**
sl@0: 	 * CSingleCommand::PrepareToAddInverseToLast() overridden to return ETrue, but
sl@0: 	 * CSingleCommand::AddInverseToLast() not overridden.
sl@0: 	 */
sl@0: 	KAddToLastOnlyHalfImplemented = 1,
sl@0: 	/**
sl@0: 	 * CCommandStack or CSingleCommandStack::Pop() called on an empty stack
sl@0: 	 */
sl@0: 	KCommandStackUnderflow,
sl@0: 	/**
sl@0: 	 * CCommandStack or CSingleCommandStack::Push() called without adequate
sl@0: 	 * space being reserved via PrepareToPushL()
sl@0: 	 */
sl@0: 	KCommandStackPushNotPrepared,
sl@0: 	/**
sl@0: 	 * No shared undo system passed when expected
sl@0: 	 */
sl@0: 	KEditorUndoNoCommandManager
sl@0: 	};
sl@0: 
sl@0: /**
sl@0:  * Panic from Undo DLL
sl@0:  *
sl@0:  * @internalComponent
sl@0:  */
sl@0: void Panic(TPanicCode aCode);
sl@0: 
sl@0: /**
sl@0:  * Stack of commands. A bookmark is maintianed so that we can tell if the stack
sl@0:  * is in the same state it was at a previous time.
sl@0:  *
sl@0:  * @internalComponent
sl@0:  * @since App-frameworks6.1
sl@0:  */
sl@0: NONSHARABLE_CLASS(CCommandStack) : public CBase
sl@0: 	{
sl@0: public:
sl@0: 	static CCommandStack* NewL();
sl@0: 	~CCommandStack();
sl@0: 	CCommandStack();
sl@0: 	void ConstructL();
sl@0: 
sl@0: 	CCommand* Top() const;
sl@0: 	CCommand* Pop();
sl@0: 	/**
sl@0: 	 * Allows aNumberOfItems Push()s to be done before the next
sl@0: 	 * call to another non-const member function apart from Push().
sl@0: 	 * aNumberOfItems must be non-negative.
sl@0: 	 */
sl@0: 	void PrepareToPushL(TInt aNumberOfItems);
sl@0: 	void Push(CCommand* aCommand);
sl@0: 	void PruneTo(TInt aNumberOfItems);
sl@0: 	TInt Count() const;
sl@0: 	/**
sl@0: 	 * Removes all elements from the stack and deletes the bookmark.
sl@0: 	 */
sl@0: 	void Reset();
sl@0: 	/**
sl@0: 	 * Adds aStack to the top of this CCommandStack, emptying it completely.
sl@0: 	 * Enough items must have been reserved with PrepareToPushL(TInt).
sl@0: 	 */
sl@0: 	void Concatenate(CCommandStack& aStack);
sl@0: 	/**
sl@0: 	 * Sets the current position in the stack as the location of the bookmark.
sl@0: 	 * The bookmark will be lost if the bookmarked object is removed from the
sl@0: 	 * stack. Bookmark begins set at the zero position.
sl@0: 	 */
sl@0: 	void SetBookmark();
sl@0: 	/**
sl@0: 	 * Returns true iff we are at the current bookmark position.
sl@0: 	 */
sl@0: 	TBool IsAtBookmark() const;
sl@0: 
sl@0: private:
sl@0: 	CArrayFix<CCommand*>* iStack;
sl@0: 	/**
sl@0: 	 * One-past-top element in the array. Less than Count() after a call
sl@0: 	 * to PrepareToPushL() with non-zero argument.
sl@0: 	 */
sl@0: 	TInt iEnd;
sl@0: 	/**
sl@0: 	 * The bookmark into the stack. We are at the bookmark when iEnd ==
sl@0: 	 * iBookmark. No bookmark is represented by iBookmark < 0.
sl@0: 	 */
sl@0: 	TInt iBookmark;
sl@0: 	};
sl@0: 
sl@0: /**
sl@0:  * Stack of single commands
sl@0:  *
sl@0:  * @internalComponent
sl@0:  * @since App-frameworks6.1
sl@0:  */
sl@0: class CSingleCommandStack : public CBase
sl@0: 	{
sl@0: public:
sl@0: 	static CSingleCommandStack* NewL();
sl@0: 
sl@0: 	inline CSingleCommand* Top() const;
sl@0: 	inline CSingleCommand* Pop();
sl@0: 	inline void PrepareToPushL(TInt aNumberOfItems);
sl@0: 	inline void Push(CSingleCommand* aCommand);
sl@0: 	inline void PruneTo(TInt aNumberOfItems);
sl@0: 	inline TInt Count() const;
sl@0: 	inline void Reset();
sl@0: 	inline void Concatenate(CSingleCommandStack& aStack);
sl@0: 
sl@0: private:
sl@0: 	CSingleCommandStack() {}
sl@0: 
sl@0: 	CCommandStack iStack;
sl@0: 	};
sl@0: 
sl@0: /**
sl@0:  * A stack of commands supporting batching and a flag for whether a batch
sl@0:  * has had its undo option waived. A bookmark is also supported, so that we can
sl@0:  * tell whether the history is in the same state as it was at a previous time.
sl@0:  *
sl@0:  * @internalComponent
sl@0:  * @since App-frameworks6.1
sl@0:  */
sl@0: NONSHARABLE_CLASS(CCommandHistory) : public CBase
sl@0: 	{
sl@0: public:
sl@0: 	~CCommandHistory();
sl@0: 	static CCommandHistory* NewL();
sl@0: 
sl@0: 	/**
sl@0: 	 * Returns the command at the top of the stack.
sl@0: 	 */
sl@0: 	CCommand* Top() const;
sl@0: 	/**
sl@0: 	 * Returns the single command at the top of the stack.
sl@0: 	 */
sl@0: 	CSingleCommand* TopSingleCommand() const;
sl@0: 	/**
sl@0: 	 * Allocates enough resources for one call to AddCommand(CCommand* aCommand).
sl@0: 	 */
sl@0: 	void PrepareToAddCommandL(CCommand* aCommand);
sl@0: 	/**
sl@0: 	 * Adds the command to the top of the stack. PrepareToAddCommandL() must
sl@0: 	 * have been called successfully since the last call to AddCommand or NewL.
sl@0: 	 */
sl@0: 	void AddCommand(CCommand*);
sl@0: 	/**
sl@0: 	 * Returns ETrue iff SetUndoWaived() has been called during this batch. If
sl@0: 	 * there is no batch currently open, this function will always return
sl@0: 	 * EFalse.
sl@0: 	 */
sl@0: 	TBool UndoHasBeenWaived() const;
sl@0: 	/**
sl@0: 	 * Sets a flag to indicated that undo is not required for this current
sl@0: 	 * batch. This function has no effect if there is no batch currently open.
sl@0: 	 *
sl@0: 	 * @see UndoHasBeenWaived
sl@0: 	 */
sl@0: 	void SetUndoWaived();
sl@0: 	/**
sl@0: 	 * Sets the maximum height of the stack to aMaxItems. If it is exceeded,
sl@0: 	 * the stack is truncated to aPrunedItems.
sl@0: 	 */
sl@0: 	void SetMaxItems(TInt aMaxItems);
sl@0: 	/**
sl@0: 	 * Returns ETrue iff the stack has no elements.
sl@0: 	 */
sl@0: 	TBool IsEmpty() const { return Top()? EFalse : ETrue; }
sl@0: 	/**
sl@0: 	 * Begins a new batch. All commands added subsequently will be exeuted all
sl@0: 	 * at once. Close the batch with CleanupStack::PopAndDestroy();
sl@0: 	 */
sl@0: 	void BeginBatchLC();
sl@0: 	/**
sl@0: 	 * Returns ETrue iff there is a batch currently open.
sl@0: 	 */
sl@0: 	TBool IsWithinBatch() const;
sl@0: 	/**
sl@0: 	 * Removes and returns the top element. There must be no batch currently
sl@0: 	 * open before a call to Pop().
sl@0: 	 */
sl@0: 	CCommand* Pop();
sl@0: 	/**
sl@0: 	 * Removes all elements from the stack. If a batch is currently open, any
sl@0: 	 * commands added subsequently will not be added to it. Deletes the
sl@0: 	 * bookmark.
sl@0: 	 */
sl@0: 	void Reset();
sl@0: 	/**
sl@0: 	 * Removes and destroys the top element iff it is an empty batch. Must not
sl@0: 	 * be called if a batch is currently open.
sl@0: 	 */
sl@0: 	void Clean();
sl@0: 	/**
sl@0: 	 * Sets the bookmark to the current position.
sl@0: 	 */
sl@0: 	void SetBookmark();
sl@0: 	/**
sl@0: 	 * Returns true iff the bookmark is at the current position.
sl@0: 	 */
sl@0: 	TBool IsAtBookmark();
sl@0: 
sl@0: private:
sl@0: 
sl@0: 	CCommandHistory();
sl@0: 	void ConstructL();
sl@0: 	void Prune();
sl@0: 
sl@0: 	static void CloseBatch(void* aCCommandHistory);
sl@0: 	static void DownBatchLevel(void* aCCommandHistory);
sl@0: 
sl@0: 	CCommandStack* iStack;
sl@0: 	CBatchCommand* iCurrent;	// either == 0 or points to the most
sl@0: 								// recent CBatchCommand within iStack
sl@0: 
sl@0: 	TInt iMaxItems;
sl@0: 
sl@0: 	TBool iBatchUndoHasBeenWaived;
sl@0: 	};
sl@0: 
sl@0: //
sl@0: // CSingleCommandStack inlines
sl@0: //
sl@0: CSingleCommand* CSingleCommandStack::Top() const
sl@0: 	{ return static_cast<CSingleCommand*>(iStack.Top()); }
sl@0: 
sl@0: CSingleCommand* CSingleCommandStack::Pop()
sl@0: 	{ return static_cast<CSingleCommand*>(iStack.Pop()); }
sl@0: 
sl@0: void CSingleCommandStack::PrepareToPushL(TInt aNumberOfItems)
sl@0: 	{ iStack.PrepareToPushL(aNumberOfItems); }
sl@0: 
sl@0: void CSingleCommandStack::Push(CSingleCommand* aCommand)
sl@0: 	{ iStack.Push(aCommand); }
sl@0: 
sl@0: void CSingleCommandStack::PruneTo(TInt aNumberOfItems)
sl@0: 	{ iStack.PruneTo(aNumberOfItems); }
sl@0: 
sl@0: TInt CSingleCommandStack::Count() const
sl@0: 	{ return iStack.Count(); }
sl@0: 
sl@0: void CSingleCommandStack::Reset()
sl@0: 	{ iStack.Reset(); }
sl@0: 
sl@0: void CSingleCommandStack::Concatenate(CSingleCommandStack& aStack)
sl@0: 	{ iStack.Concatenate(aStack.iStack); }
sl@0: 
sl@0: }
sl@0: 
sl@0: #endif
sl@0: