/*

* Copyright (c) 2008-2009 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:    Layout base classes

*

*/

#ifndef __GLXLAYOUT_H__

#define __GLXLAYOUT_H__

#include <e32base.h>

#include <glxlayoutinfo.h>

/**

 * MGlxLayout

 *  

 * Layout base class. Layouts are objects that specify the 

 * renderable values, such as position, size or opacity for the visuals

 * They can be chained to form processing chains, and the chains

 * can also split into several chains (different chain for different 

 * visuals) and combine several chains into one. This allows building

 * complex visual effects by using simple layouts as building blocks.

 */

class MGlxLayout 

	{

	protected:

		/**

		 * Destructor. Dont allow deletion through this interface.

		 */

		~MGlxLayout() { }

	public:

		/**

		 * This method can specify the layout of given visual by setting 

		 * the corresponding fields in the layout info struct.

		 * @param aInfo the layout information to specify

		 */

		virtual void SetLayoutValues( TGlxLayoutInfo& aInfo ) = 0;

		/**

		 * Sets the next layout in the chain.

		 */

		virtual void SetNext( MGlxLayout* aLayout ) = 0;

		/**

		 * Returns the next layout in the chain.

		 */

		virtual MGlxLayout* Next() const = 0;

	};

/**

 * TGlxLayout

 *  

 * Implements the MGlxLayout interface and provides common layout chain functionality.

 *

 * @lib glxlayouts.lib

 */

class TGlxLayout : public MGlxLayout

	{

	public:

		/**

		 * Constructor, resets the object.

		 */

		IMPORT_C TGlxLayout();

		/**

		 * Destructor.

		 */

		IMPORT_C virtual ~TGlxLayout();

		/**

		 * Sets the next layout in the chain.

		 */

		IMPORT_C void SetNext( MGlxLayout* aLayout );

		/**

		 * Returns the next layout in the chain.

		 */

		IMPORT_C MGlxLayout* Next() const;

	public: 	// From MGlxLayout

		/// @ref MGlxLayout::SetLayoutValues

		IMPORT_C void SetLayoutValues( TGlxLayoutInfo& aInfo );

	protected:	// New API, template method pattern

		/**

		 * This method can specify the layout of given visual by setting the corresponding fields

		 * in the layout info struct.

		 * @param aInfo the layout information to specify

		 */

		virtual void DoSetLayoutValues( TGlxLayoutInfo& aInfo );

	private:

		/// Ref: The next layout in chain

		MGlxLayout* iNextLayout;

	public:

		__DEBUG_ONLY( TBuf<50> _iName ); 

	};

/**

 * CGlxLayout

 *  

 * Implements the MGlxLayout interface and provides common layout chain functionality.

 * This class is provided as a base class for CBase deriving layout classes.

 *

 * @lib glxlayouts.lib

 */

class CGlxLayout : public CBase, public MGlxLayout

	{

	public:

		/**

		 * Constructor, resets the object.

		 */

		IMPORT_C CGlxLayout();

		/**

		 * Destructor. Virtual by CBase and MGlxLayout

		 */

		IMPORT_C ~CGlxLayout();

		/**

		 * Sets the next layout in the chain.

		 */

		IMPORT_C void SetNext( MGlxLayout* aLayout );

		/**

		 * Returns the next layout in the chain.

		 */

		IMPORT_C MGlxLayout* Next() const;

	public: 	// From MGlxLayout

		/// @ref MGlxLayout::SetLayoutValues

		IMPORT_C void SetLayoutValues( TGlxLayoutInfo& aInfo );

	protected:	// New API, template method pattern

		/**

		 * This method can specify the layout of given visual by setting the corresponding fields

		 * in the layout info struct.

		 * @param aInfo the layout information to specify

		 */

		virtual void DoSetLayoutValues( TGlxLayoutInfo& aInfo );

	private:

		/// Own: the layout implementation

		TGlxLayout iLayoutImpl;

	public:

		__DEBUG_ONLY( TBuf<50> _iName ); 

	};

#endif // __GLXLAYOUT_H__