/*

* Copyright (c) 2007 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:  layoutpreferences implementation class for flowlayoutmanager

*

*/

#ifndef ALFFLOWLAYOUTPREFERENCESIMPL_H

#define ALFFLOWLAYOUTPREFERENCESIMPL_H

#include <osn/osndefines.h>

#include <alf/ialflayoutpreferences.h>

using namespace Alf;

namespace Alf

    {

class AlfFlowLayoutManager;

/**

 * layout preferences implementation for flowlayoutmanager.

 *

 * @lib alfwidgetmodel.lib

 * @since S60 ?S60_version

 */

class AlfFlowLayoutPreferencesImpl : public IAlfLayoutPreferences

    {

public:

    AlfFlowLayoutPreferencesImpl(AlfFlowLayoutManager& aFlowLayoutManager);

public:

// from base class IAlfLayoutPreferences

	/**

	 * Returns the minimum size of the layout by combining the minimum sizes of the

	 * layed out visuals.

	 * 

	 * @param aMinSize The minimum size that the object would like to be laid out to

	 * @return false iff none of the layed out UI elements do not care about minimum size

	 */

	virtual bool getMinimumSize( TAlfXYMetric& aMinSize ) const;

	/**

	 * Returns the maximum size of the layout by combining the maximum sizes of the

	 * layed out visuals.

	 *  

	 * @param aMaxSize The maximum size that the object would like to be laid out to

	 * @return false iff none of the layed out UI elements do not care about maximum size

	 */

	virtual bool getMaximumSize( TAlfXYMetric& aMaxSize ) const;

    /**

     * Returns the size combined by all preferred sizes of child UI elements in this layout 

     * when they are being layed out according to the layout manager rules.

     * 

     * @param aPreferredSize Filled with the referred area occupied by child elements when

     * 						 layed out by layouting rules in this layout manager.

     * @return False if none of the child components report their preferred size. True

     * 		   otherwise.

     */

    virtual bool getPreferredSize(TAlfXYMetric& aPreferredSize) const;

	/**

	 * Set the preferred size into a presentation object.

	 * 

	 * This is not supported on the layout manager. Users should set preferred sizes of the

	 * contained UI elements.

	 */

	virtual void setPreferredSize( const TAlfXYMetric& aPreferredSize );

// from base class IAlfInterfaceBase

    /**

     * Interface getter. 

     * @see IAlfInterfaceBase::makeInterface

     *

     * @since S60 ?S60_version

     * @param aType The type id of the queried interface.

     * @return The queried interface, or NULL if the interface is not

     *         supported or available.

     */    

    virtual IAlfInterfaceBase* makeInterface( const IfId& aType );

protected:

    /** size type to calculate @see calculateChildSizes */

    enum sizeType

        {

        ESizePreferred,

        ESizeMin,

        ESizeMax

        };

	/**

	 * calculate the min-, preferred-, or max- sizes from the children. 

	 * 

	 * @param aSize on return, contains the calculated size.

	 * @param aFlowDirection direction of flow.

	 * @param aSizeType specifies, whether the min-, preferred- or max-size of the

	 *        IAlfLayoutPreferences is used for calculation.

	 */

    bool calculateChildSizes(TAlfXYMetric& aSize,  

        enum IAlfFlowLayoutPolicy::flowDirection aFlowDirection, 

        enum sizeType aSizeType) const;

	/**

	 * fetches the size from the IAlfLayoutPreferences-interface of the aControl.

	 * 

	 * @param aControl control, which preferences-interface to query.

	 * @param aSize on return, contains the size.

	 * @param aSizeType specifies, whether the min-, preferred- or max-size of the

	 *        IAlfLayoutPreferences is returned.

	 */

    bool getSize(CAlfWidgetControl* aControl, 

        TAlfXYMetric& aSize,

        enum sizeType aSizeType) const;

    /**

     * @return the flow layout policy-instance of the layoutmanager.

     *

     */

    const IAlfFlowLayoutPolicy& flowLayoutPolicy() const;

	/**

	 * converts size in metrics to size in pixels. Implementation missing.

	 * 

	 * @param aSize size to convert

	 * @return size in pixels.

	 */

    static TAlfRealSize sizeInPixels(const TAlfXYMetric& aSize);

private:

    AlfFlowLayoutManager &mFlowLayoutManager;

    TAlfXYMetric mPreferredSize;

    };

    } // namespace Alf

#endif // ALFFLOWLAYOUTPREFERENCESIMPL_H