/*

* 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:  layoutmanager implementation class with focus handling in 1D (next/previous)

*

*/

#include <alf/ialfwidgetcontrol.h>

#include <alf/alfvisual.h>

#include <alf/alfgridlayout.h>

#include "alf/alfwidget.h"

#include <alf/alfvisualfactory.h>

#include <alf/alfexceptions.h>

#include <alf/ialflayoutpreferences.h>

#include <osn/osnnew.h>

//stl

#include <algorithm> //for min & max

#include "alfgridlayoutmanagerimpl.h"

using namespace Alf;

namespace Alf

    {

// ======== MEMBER FUNCTIONS ========

// ---------------------------------------------------------------------------

// layoutmanagerimpl constructor

// ---------------------------------------------------------------------------

//    

AlfGridLayoutManagerImpl::AlfGridLayoutManagerImpl(

    AlfGridLayoutManager& aGridLayoutManager) : 

    mGridLayoutManager(aGridLayoutManager)

    {

    }

// ---------------------------------------------------------------------------

// creates the layout used by the layoutmanager.

// ---------------------------------------------------------------------------

//    

AlfGridLayoutManagerImpl::~AlfGridLayoutManagerImpl()

    {

    }

// ---------------------------------------------------------------------------

// from IAlfLayoutPreferences

// Returns the minimum area that this layout manager can occupy by observing

// the minimum sizes of the child UI elements in the layout

// ---------------------------------------------------------------------------

//

bool AlfGridLayoutManagerImpl::getMinimumSize( TAlfXYMetric& /*aMinSize*/ ) const

	{

	return false;

	}

// ---------------------------------------------------------------------------

// from IAlfLayoutPreferences

// Returns the maximum area that this layout manager can occupy by observing

// the maximum sizes of the child UI elements in the layout

// ---------------------------------------------------------------------------

//

bool AlfGridLayoutManagerImpl::getMaximumSize( TAlfXYMetric& /*aMaxSize*/ ) const

	{

	return false;

	}

// ---------------------------------------------------------------------------

// Combines and returns the preferred sizes of all child UI elements according

// to the layouting rules.

// ---------------------------------------------------------------------------

//

bool AlfGridLayoutManagerImpl::getPreferredSize(TAlfXYMetric& aPreferredSize) const

	{	

	bool hasPreferredSize = false;

	TAlfXYMetric resultSize = TAlfXYMetric(TAlfMetric(0), TAlfMetric(0));

    const CAlfGridLayout& gridlayout = layout();

    const int childCount = mGridLayoutManager.count();

    const int gridColCount = gridlayout.ColumnCount();

    //iterate the columns to calculate the preferred width.

    const int colCount = std::min<int>(gridColCount, childCount);

    for (int i = 0; i < colCount; i++)

        {

        CAlfWidgetControl* childWidgetControl = mGridLayoutManager.getControl(i);

        //getControl may return null, but getLayoutPreferences checks that.

        const IAlfLayoutPreferences* layoutPrefs = 

            mGridLayoutManager.getLayoutPreferences(childWidgetControl);        

        if (layoutPrefs)

            {

            TAlfXYMetric prefSize;

            if (layoutPrefs->getPreferredSize(prefSize))

                {

                if(prefSize.iX.iUnit == EAlfUnitPixel)

                    {

                    resultSize.iX.iMagnitude += prefSize.iX.iMagnitude;

                    hasPreferredSize = true;

                    }

                }

            }

        }

    //iterate the rows to calculate the preferred height  

    if (hasPreferredSize)

        {

        //count rows, that have at least one visual.

        int usedRows = childCount / gridColCount;

        if (childCount % gridColCount)

            {

            //last wor not filled completely, but still valid to get preferred height

            //for this row also.

            usedRows++;

            }

        const int rowCount = std::min<int>(gridlayout.RowCount(), usedRows);

        for (int i = 0; i < rowCount; i+= gridColCount)

            {

            CAlfWidgetControl* childWidgetControl = mGridLayoutManager.getControl(i);

            //getControl may return null, but getLayoutPreferences checks that.

            const IAlfLayoutPreferences* layoutPrefs = 

                mGridLayoutManager.getLayoutPreferences(childWidgetControl);        

            if (layoutPrefs)

                {

                TAlfXYMetric prefSize;

                if (layoutPrefs->getPreferredSize(prefSize))

                    {

                    if(prefSize.iY.iUnit == EAlfUnitPixel)

                        {

                        resultSize.iY.iMagnitude += prefSize.iY.iMagnitude;

                        hasPreferredSize = true;

                        }

                    }

                }

            }

        }

    aPreferredSize = resultSize;

    return hasPreferredSize;

	}

// ---------------------------------------------------------------------------

// from IAlfLayoutPreferences

// At the moment doesn't do anything since preferred size is being queried

// from the child UI elements added to this layout manager.

// ---------------------------------------------------------------------------

//

void AlfGridLayoutManagerImpl::setPreferredSize( const TAlfXYMetric& aPreferredSize)

	{

	TAlfTimedPoint size((float)aPreferredSize.iX.iMagnitude,(float)aPreferredSize.iY.iMagnitude);

	layout().SetSize(size);

	mGridLayoutManager.owner().updateParentLayout();

	}

// ---------------------------------------------------------------------------

// From class IAlfInterfaceBase.

// Getter for interfaces provided by the element.

// ---------------------------------------------------------------------------

//

IAlfInterfaceBase* AlfGridLayoutManagerImpl::makeInterface(const IfId& aType)

    {

    UString param(aType.mImplementationId);

    if (param == IAlfLayoutPreferences::type().mImplementationId)

        {

        return this;

        }      

    return NULL;

    }

// ---------------------------------------------------------------------------

// returns the gridlayout used by the layoutmanager

// ---------------------------------------------------------------------------

//

CAlfGridLayout& AlfGridLayoutManagerImpl::layout() const

    {

    return dynamic_cast<CAlfGridLayout&>(mGridLayoutManager.getLayout());

    }

 } // Alf