williamr@2: // Copyright (c) 1999-2009 Nokia Corporation and/or its subsidiary(-ies).
williamr@2: // All rights reserved.
williamr@2: // This component and the accompanying materials are made available
williamr@2: // under the terms of the License "Symbian Foundation License v1.0" to Symbian Foundation members and "Symbian Foundation End User License Agreement v1.0" to non-members
williamr@2: // which accompanies this distribution, and is available
williamr@2: // at the URL "http://www.symbianfoundation.org/legal/licencesv10.html".
williamr@2: //
williamr@2: // Initial Contributors:
williamr@2: // Nokia Corporation - initial contribution.
williamr@2: //
williamr@2: // Contributors:
williamr@2: //
williamr@2: // Description:
williamr@2: //
williamr@2: 
williamr@2: #ifndef __MEDOBSRV_H__
williamr@2: #define __MEDOBSRV_H__
williamr@2: 
williamr@2: #include <e32def.h>
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: class MEditObserver
williamr@2: /** 
williamr@2: Specifies the mixin protocol for a rich text edit observer. 
williamr@2: 
williamr@2: This class is implemented by controls which use a rich text (CRichText) object, 
williamr@2: when it is possible for the text object to be changed from outside of the 
williamr@2: control without the control's knowledge.
williamr@2: 
williamr@2: An edit observer is a callback to the control from the CRichText object which 
williamr@2: it has been set up to observe. The edit observer is set up using CRichText::SetEditObserver(). 
williamr@2: @publishedAll
williamr@2: @released
williamr@2: */
williamr@2: 	{
williamr@2: public:
williamr@2: 	// Observer function called by CRichText to signal changes to the text
williamr@2: 	// buffer within it. A pointer to this function must be passed in to
williamr@2: 	// a CRichText instance by <rich text instance>.SetEditObserver(<ptr>).
williamr@2: 	// aStart is the start position of the edit and aExtent is the number
williamr@2: 	// of characters added or, if negative, deleted after this position.
williamr@2: 	
williamr@2: 	
williamr@2: 	/** Observer function called by the CRichText object when the object is edited 
williamr@2: 	to give notification of changes to its text buffer. In this way, the control 
williamr@2: 	knows how the text object has changed and can reformat and redraw the text 
williamr@2: 	object appropriately.
williamr@2: 	
williamr@2: 	A pointer to the observer object must have been passed in to a CRichText instance 
williamr@2: 	using CRichText::SetEditObserver().
williamr@2: 	
williamr@2: 	@param aStart The start position of the edit. 
williamr@2: 	@param aExtent The number of characters added or, if negative, deleted after 
williamr@2: 	this position. */
williamr@2: 	virtual void EditObserver(TInt aStart, TInt aExtent) = 0;
williamr@2: 	};
williamr@2: 
williamr@2: #endif