/*

* 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:    Utility class for managing the screen size

*

*/

#ifndef __CGLXRESOLUTIONUTILITY_H__

#define __CGLXRESOLUTIONUTILITY_H__

#include <e32cmn.h>                 // for RPointerArray

#include <e32base.h>

// forward declarations

class MGlxResolutionChangeObserver;

class MGlxResolutionSize;

/**

 * Class Description

 * Singleton containing resolution utility methods

 * @author Loughlin

 */        

NONSHARABLE_CLASS (CGlxResolutionUtility) : public CBase

    {

public:    

	/**

	 * Construction of singleton

	 * @return A pointer to the single instance of CGlxResolutionUtility 

	 */

    IMPORT_C static CGlxResolutionUtility* InstanceL();

    /**

	 * Destroys the renderer instance of CGlxResolutionUtility when the 

	 * reference count is zero

     */	

    IMPORT_C void Close();

    /**

	 * Get the screen size

	 * @return The screen size in POSS

     */	

    IMPORT_C TSize ScreenSize() const;

    /**

     * Get the lenght of in POSS

     * @param The lenght in pixels which is to be converted to POSS

     * @return The converted lenght & width in POSS

     */

    IMPORT_C TReal32 PixelsToPoss( const TReal32& aLenPixels ) const;

    /**

     * Get the lenght of in pixels

     * @param The length in POSS which is to be converted to pixels

     * @return The converted size in pixels

     */

    IMPORT_C TReal32 PossToPixels( const TReal32& aSzPoss ) const;

    /**

     * Add a resolution change observer

     * @param The observer that will recieve notification on resolution 

     *           change

     */

    IMPORT_C void AddObserverL( MGlxResolutionChangeObserver& aObserver );

    /**

     * Remove a resolution change observer

     * @param The observer that will no longer recieve notification on 

     *           resolution change

     */

    IMPORT_C void RemoveObserver( MGlxResolutionChangeObserver& aObserver );

public: // not exported

    /**

     * Receives notification of a change in the screen size

     * All resolution observers are notified of the resolution change

     * @param aScreenSize the new screen size

     */

    void SetScreenSizeL( TSize aScreenSize );

private: 

    /**

     * Symbian constructor - used by SingletonStore to create instance

     */

    static CGlxResolutionUtility* NewL();

    /**

     * C++ constructor

     */

    CGlxResolutionUtility();

    /**

     * 2 Phase ctor

     */

    void ConstructL();

    /**

     * Destructor

     */

    ~CGlxResolutionUtility();

private: // class member variables

    // Size of the screen

    TSize iScreenSize;

    // Screen Size aspect ratio - POSS is a unit of measurement 

    // where 1 == the longest screen axis

    TReal32 iOnePossToPixelRatio;

    // The ratio of pixels to poss - stored to save on division 

    TReal32 iPixelToPossRatio;

    // Own: The container for the event observers

	RPointerArray < MGlxResolutionChangeObserver > iObserverList;

    };

#endif //__CGLXRESOLUTIONUTILITY_H__