/*

* 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:   Flow layout definition.

*

*/

#ifndef C_ALFFLOWLAYOUT_H

#define C_ALFFLOWLAYOUT_H

#include <alf/alflayout.h> 

/**

 * Flow layout positions children next to each other either horizontally or

 * vertically. The sizes of child visuals are not changed by default.

 *

 * The layout inner padding is used to determine the gap between children.

 *

 * Flow layout takes system wide layout mirroring into consideration by

 * querying the mirroring state through AknLayoutUtils::LayoutMirrored().

 * In western locales the visuals are layed out from left to right whereas

 * in arabic locale for instance the visuals are layed out from right to left.

 * Mirroring is considered only when the flow is horizontal. Vertical flow layout

 * will always lay visuals from top to bottom.

 * Usage:

 * @code

 * 

 *  //create flowlayout

 *  CAlfFlowLayout* flowLayout = CAlfFlowLayout::AddNewL( control );

 *  //Add two child text visuals to flow layout

 *  CAlfTextVisual* text1 = CAlfTextVisual::AddNewL( control, flowLayout );

 *  CAlfTextVisual* text2 = CAlfTextVisual::AddNewL( control, flowLayout );

 *  text1->SetTextL( _L"Text1" );

 *  text2->SetTextL( _L"Text2" );

 * 

 *  //set Flow direction

 *  flowLayout->SetFlowDirection( CAlfFlowLayout::EFlowHorizontal );

 *  flowLayout->UpdateChildrenLayout( 1 );

 * 

 *  // Set Centring

 *  flowLayout->SetCentering( ETrue );

 *  flowLayout->UpdateChildrenLayout(transitionTimeInMilliSeconds);

 * 

 * //Set flow mode

 *  flowLayout->SetMode( CAlfFlowLayout::EModeFitPerpendicular );

 *  flowLayout->UpdateChildrenLayout( 1 );

 * 

 * @endcode

 * @lib alfclient.lib

 * @since S60 v3.2

 */

class CAlfFlowLayout : public CAlfLayout

    {

public:

    /** Flow directions. */

    enum TFlowDirection

        {

        /** 

         * Flow horizontally. System wide layout mirroring is considered

         * to determine whether visuals are layed from left to right

         * or from right to left.

         * @see AknLayoutUtils::LayoutMirrored()

         */

        EFlowHorizontal = 0,

        /** Flow vertically. */

        EFlowVertical

        };

    /** Mode flags that specify how the flow is laid out. */

    enum TMode

        {

        /** Center the children perpendicular to the flow direction.

            For example, if the flow direction is horizontal (left->right)

            this flag will center the children vertically along the flow. */

        EModeCenterPerpendicular = 0x1,

        /** Fit the children perpendicular to the flow direction.

            For example, if the flow direction is horizontal, the children

            will be vertically resized to fit the layout's rectangle. */

        EModeFitPerpendicular = 0x2,

        };        

    /**

     * Two-phased constructor, which attach new object into the control.

     * @param aOwnerControl Control that owns this new obejct.

     * @param aParentLayout If given, the new object is set as child.

     */

    IMPORT_C static CAlfFlowLayout* AddNewL(CAlfControl& aOwnerControl,

                                            CAlfLayout* aParentLayout = 0);

    /**

     * Constructor.

     */

    IMPORT_C CAlfFlowLayout();

    /**

     * Second-phase constructor.

     */

    IMPORT_C void ConstructL(CAlfControl& aOwner);

    /**

     * Destructor.

     */

    IMPORT_C virtual ~CAlfFlowLayout();

    /**

     * Sets the direction of the flow.

     *

     * @param aDirection  Flow direction.

     */

    IMPORT_C void SetFlowDirection(TFlowDirection aDirection);

    /**

     * Sets the centering mode of the flow. This sets/clears the 

     * EModeCenterPerpendicular flag. Calling this is equivalent to calling

     * SetMode() with that flag included or missing from the mode.

     *

     * @param aCentering  <code>ETrue</code> to set the EModeCenterPerpendicular mode.

     *                    <code>EFalse</code> to clear it.

     */    

    IMPORT_C void SetCentering(TBool aCentering);

    /**

     * Sets the mode of the flow. The mode flags determine how the flow layout

     * behaves.

     *

     * @param aMode  Mode flags (OR'd together).

     *

     * @see CAlfFlowLayout::TMode

     */

    IMPORT_C void SetMode(TInt aMode);

    /**

     * Returns the mode flags of the flow.

     *

     * @see CAlfFlowLayout::TMode

     *

     * @return  Returns the current mode flags.

     */

    IMPORT_C TInt Mode() const;

    /**

     * From CAlfVisual

     * @see CAlfVisual

     */

    IMPORT_C void RemoveAndDestroyAllD();

    IMPORT_C void UpdateChildrenLayout(TInt aTransitionTime = 0);

    IMPORT_C CAlfVisual* FindTag(const TDesC8& aTag);

    /** 

     * From CAlfLayout

     * @see CAlfLayout

     */

    IMPORT_C TAlfXYMetric BaseUnit() const; 

protected:

    /**

     * From CAlfVisual

     * @see CAlfVisual

     */

    IMPORT_C void DoRemoveAndDestroyAllD();

    IMPORT_C void PropertyOwnerExtension(const TUid& aExtensionUid, TAny** aExtensionParams);

private:

    struct TFlowLayoutPrivateData;

    TFlowLayoutPrivateData* iFlowLayoutData;

    };

#endif // C_ALFFLOWLAYOUT_H