/*

* Copyright (c) 2002 - 2006 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: 

*     This class defines the data model interface for CVRButtonPanel.

*

*/

#ifndef __MVRBUTTONPANELMODEL_H__

#define __MVRBUTTONPANELMODEL_H__

// INCLUDES

#include <e32def.h>

// FORWARD DECLARATIONS

class MVRObserver;

// CLASS DEFINITION

/**

* This class defines the data model interface for CVRButtonPanel.

*/

class MVRButtonPanelModel 

	{

	public: // new methods

		/**

		* Returns the number of buttons.

		* @return number of buttons (>=0)

		*/

		virtual TInt ButtonCount() const = 0;

		/**

		* Returns the state of a specific button.

		* @param aButtonId Button identifier

		* @return ENormal or EDimmed

		*/

		virtual TInt ButtonState( TInt aButtonId ) const = 0;

		/**

		* Returns the command id of a specific button.

		* @param aButtonId Button identifier

		* @return One of TVRCommands

		*/

		virtual TInt CommandId( TInt aButtonId ) const = 0;

		/**

		* Returns the id of the button that should have initial focus.

		* @return Button identifier

		*/

		virtual TInt InitialFocusButtonId() const = 0;

		/**

		* Registers an observer for receiving

		* update notifications from this interface.

		* @param aObserver The observer object.

		*/

		virtual void SetButtonPanelObserver( MVRObserver* aObserver ) = 0;

		/**

		* Checks if button panel model needs to reset the focus

		* for example after a state change

		* @return Is reset needed

		*/

		virtual TBool ResetNeeded() = 0;

		/**

		* Returns an ID of the current visual state.

		* @returns Visual state Id.

		*/

		virtual TUint VisualStateId() const = 0; 		

		/**

		* Checks if model is in a state where it can take and handle

		* new commands

		* @return Can model handle new commands

		*/

		virtual TBool CanHandleCommands() const = 0;		

	};

#endif // __MVRBUTTONPANELMODEL_H__