/*

* Copyright (c) 2000-2009 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description: 

*

*/

#ifndef EDITORUNDO_H_

#define EDITORUNDO_H_

#include "unified_editor.h"

namespace UndoSystem

/**

@internalTechnology

*/

{

class CCommandManager;

class MNotUndoableGatekeeper;

}

class CEditorCommandFactory;

/**

MUnifiedEditor decorator that adds undo functionality.

It passes commands transparently to the editor it is constructed upon, while

storing the operations so that they can be undone and redone. Calling a

non-const method of MUnifiedEditor wipes all 'Redo' operations.

The undo and redo operations are only guaranteed to be accurate if the

underlying editor satisfies certain conditions.

@since App-frameworks6.1

@internalAll

*/

class CEditorWithUndo : public CBase,

	public MUnifiedEditor,

	private MUnifiedEditor::MStyleSupport,

	private MUnifiedEditor::MPictureSupport,

	private MUnifiedEditor::MClipboardSupport

	{

public:

	~CEditorWithUndo();

	/**

	 * Creates a CEditorWithUndo. It does not own the aEditor.

	 */

	IMPORT_C static CEditorWithUndo* NewL(MUnifiedEditor& aEditor);

	/**

	 * Creates a CEditorWithUndo, using the aSharedUndoSystem. This allows

	 * many objects to stay in synchronization when each is accessed

	 * seperately.

	 * The aEditor is not owned.

	 */

	IMPORT_C static CEditorWithUndo* NewL(MUnifiedEditor& aEditor,

		UndoSystem::CCommandManager* aSharedUndoSystem);

	/**

	 * Undoes one operation or batch of operations. If one operation in the

	 * middle of a batch leaves, this function will leave, but the underlying

	 * editor will not necessarily be in the same state as it was in before

	 * the call. However, all operations will still be stored, and so the

	 * previous state is still recoverable with a call to RedoL() or a

	 * further call to UndoL will complete the operation (resource acquisition

	 * permitting).

	 */

	IMPORT_C void UndoL();

	/**

	 * Redoes one operation or batch of operations. If one operation in the

	 * middle of a batch leaves, this function will leave, but the underlying

	 * editor will not necessarily be in the same state as it was in before

	 * the call. However, all operations will still be stored, and so the

	 * previous state is still recoverable with a call to UndoL() or a

	 * further call to RedoL will complete the operation (resource acquisition

	 * permitting).

	 */

	IMPORT_C void RedoL();

	/**

	 * Returns ETrue iff UndoL() would have an effect

	 */

	IMPORT_C TBool CanUndo() const;

	/**

	 * Returns ETrue iff RedoL() would have an effect

	 */

	IMPORT_C TBool CanRedo() const;

	/**

	 * Wipes all undo and redo operations

	 */

	IMPORT_C void ResetUndo();

	/**

	 * Sets limits on the 'undo depth'. This is the numbet of times that

	 * successive calls to UndoL() have an effect. When a depth of

	 * aMaxItems is reached, the undo depth is reset to aMinItems.

	 */

	IMPORT_C void SetMaxItems(TInt aMaxItems);

	/**

	 * Sets a gatekeper for the undo system. This will be called whenever an

	 * operation is attempted that cannot be undone for any reason.

	 * The gatekeeper therefore has an oportunity to suppress execution and

	 * keep the current undo operations stored.

	 * NULL may be passed to restore default behaviour.

	 * Returns the old gatekeeper.

	 */

	IMPORT_C UndoSystem::MNotUndoableGatekeeper*

		SetGatekeeper(UndoSystem::MNotUndoableGatekeeper*);

	// From MUnifiedEditor

	MTmOptionalInterface* Interface(TUint aId);

	void InsertTextL(TInt aPos, const TDesC& aText, const TDesC* aStyle,

		const TTmCharFormatLayer*, const RTmParFormatLayer*);

	void DeleteTextL(TInt aPos,TInt aLength);

	void SetBaseFormatL(const TTmCharFormat&, const RTmParFormat&);

	void SetCharFormatL(TInt aPos, TInt aLength, const TTmCharFormatLayer&);

	void SetParFormatL(TInt aPos, TInt aLength, const RTmParFormatLayer&);

	void DeleteCharFormatL(TInt aPos, TInt aLength);

	void DeleteParFormatL(TInt aPos, TInt aLength);

	TInt DocumentLength() const;

	void GetText(TInt aPos, TPtrC& aText) const;

	void GetBaseFormatL(TTmCharFormat&, RTmParFormat&) const;

	void GetCharFormat(TInt aPos, TFormatLevel aLevel,

		TTmCharFormatLayer& aFormat,TInt& aRunLength) const;

	void GetParFormatL(TInt aPos, TFormatLevel aLevel,

		RTmParFormatLayer& aFormat, TInt& aRunLength) const;

private:

	// from MStyleSupport

	TInt CreateStyleL(const RTmStyle&);

	TInt ChangeStyleL(const RTmStyle&);

	TInt SetStyleL(TInt aPos, TInt aLength, const TDesC&);

	TInt RenameStyleL(const TDesC& aOldName, const TDesC& aNewName);

	TInt DeleteStyleL(const TDesC& aName);

	TInt StyleCount() const;

	void GetStyle(TInt aPos, TPtrC& aName, TInt& aRunLength) const;

	TInt GetStyleByNameL(const TDesC& aName, RTmStyle&) const;

	TInt GetStyleByIndexL(TInt aIndex, RTmStyle&) const;

	// from MPictureSupport

	void InsertPictureL(TInt aPos, const TPictureHeader&);

	void DropPictureL(TInt aPos);

	void Picture(TInt aPos, TPictureHeader&) const;

	// from MClipboardSupport

	void CopyToStoreL(CStreamStore& aStore, CStreamDictionary& aDictionary,

		TInt aPos, TInt aLength) const;

	void PasteFromStoreL(const CStreamStore& aStore,

		const CStreamDictionary& aDictionary, TInt aPos);

	CEditorWithUndo();

	void ConstructL(MUnifiedEditor& aEditorBasedOn,

		UndoSystem::CCommandManager* aSharedUndoSystem);

	CEditorCommandFactory*			iFactory;

	MUnifiedEditor*						iBaseEditor;

	UndoSystem::CCommandManager*	iCommandManager;

	};

#endif	// EDITORUNDO_H_