/*

 * Copyright (c) 2009 Nokia Corporation.

 */

#include "qaspectratiolayout.h"

QAspectRatioLayout::QAspectRatioLayout(QWidget* parent, int spacing) : QLayout(parent)

{

    init(spacing);

}

QAspectRatioLayout::QAspectRatioLayout(int spacing)

{

    init(spacing);

}

QAspectRatioLayout::~QAspectRatioLayout()

{

    delete item;

    delete lastReceivedRect;

    delete _geometry;

}

void QAspectRatioLayout::init(int spacing)

{

    item = 0;

    lastReceivedRect = new QRect(0, 0, 0, 0);

    _geometry = new QRect(0, 0, 0, 0);

    setSpacing(spacing);

}

/* Adds item if place isn't already taken. */

void QAspectRatioLayout::add(QLayoutItem* item)

{

    if(!hasItem())

    {

        replaceItem(item);

    }

}

/* Adds item if place isn't already taken. */

void QAspectRatioLayout::addItem(QLayoutItem* item)

{

    if(!hasItem())

    {

        replaceItem(item);

    }

}

/* Adds widget if place isn't already taken. */

void QAspectRatioLayout::addWidget(QWidget* widget)

{

    if(!hasItem())

    {

        replaceItem(new QWidgetItem(widget));

    }

}

/* Returns the item pointer and dereferences it here. */

QLayoutItem* QAspectRatioLayout::take()

{

    QLayoutItem* item = 0;

    if(this->hasItem())

    {

        item = this->item;

        this->item = 0;

    }

    return item;

}

/* Returns the item pointer and dereferences it here. */

QLayoutItem* QAspectRatioLayout::takeAt(int index)

{

    if(index != 0)

    {

        return 0;

    }

    return this->take();

}

/* Returns the item pointer. */

QLayoutItem* QAspectRatioLayout::itemAt(int index) const

{

    if(index != 0)

    {

        return 0;

    }

    if(hasItem())

    {

        return this->item;

    }

    return 0;

}

/* Checks if we have an item. */

bool QAspectRatioLayout::hasItem() const

{

    return this->item != 0;

}

/* Returns the count of items which can be either 0 or 1. */

int QAspectRatioLayout::count() const

{

    int returnValue = 0;

    if(hasItem())

    {

        returnValue = 1;

    }

    return returnValue;

}

/* Replaces the item with the new and returns the old. */

QLayoutItem* QAspectRatioLayout::replaceItem(QLayoutItem* item)

{

    QLayoutItem* old = 0;

    if(this->hasItem())

    {

        old = this->item;

    }

    this->item = item;

    setGeometry(*this->_geometry);

    return old;

}

/* Tells which way layout expands. */

Qt::Orientations QAspectRatioLayout::expandingDirections() const

{

    return Qt::Horizontal | Qt::Vertical;

}

/* Tells which size is preferred. */

QSize QAspectRatioLayout::sizeHint() const

{

    return this->item->minimumSize();

}

/* Tells minimum size. */

QSize QAspectRatioLayout::minimumSize() const

{

    return this->item->minimumSize();

}

/*

 * Tells if heightForWidth calculations is handled.

 * It isn't since width isn't enough to calculate

 * proper size.

 */

bool QAspectRatioLayout::hasHeightForWidth() const

{

    return false;

}

/* Replaces lastReceivedRect. */

void QAspectRatioLayout::setLastReceivedRect(const QRect& rect)

{

    QRect* oldRect = this->lastReceivedRect;

    this->lastReceivedRect = new QRect(rect.topLeft(), rect.size());

    delete oldRect;

}

/* Returns geometry */

QRect QAspectRatioLayout::geometry()

{

    return QRect(*this->_geometry);

}

/* Sets geometry to given size. */

void QAspectRatioLayout::setGeometry(const QRect& rect)

{

    /*

     * We check if the item is set and

     * if size is the same previously received.

     * If either is false nothing is done.

     */

    if(!this->hasItem() ||

            areRectsEqual(*this->lastReceivedRect, rect))

    {

        return;

    }

    /* Replace the last received rectangle. */

    setLastReceivedRect(rect);

    /* Calculate proper size for the item relative to the received size. */

    QSize properSize = calculateProperSize(rect.size());

    /* Calculate center location in the rect and with item size. */

    QPoint properLocation = calculateCenterLocation(rect.size(), properSize);

    /* Set items geometry */

    this->item->setGeometry(QRect(properLocation, properSize));

    QRect* oldRect = this->_geometry;

    /* Cache the calculated geometry. */

    this->_geometry = new QRect(properLocation, properSize);

    delete oldRect;

    /* Super classes setGeometry */

    QLayout::setGeometry(*this->_geometry);

}

/* Takes the shortest side and creates QSize

 * with the shortest side as width and height. */

QSize QAspectRatioLayout::calculateProperSize(QSize from) const

{

    QSize properSize;

    if(from.height() * 2 < from.width())

    {

        properSize.setHeight(from.height() - this->margin());

        properSize.setWidth(from.height() * 2 - this->margin());

    }

    else

    {

        properSize.setWidth(from.width() - this->margin());

        properSize.setHeight(from.width() / 2 - this->margin());

    }

    return properSize;

}

/* Calculates center location from the given height and width for item size. */

QPoint QAspectRatioLayout::calculateCenterLocation(QSize from,

        QSize itemSize) const

{

    QPoint centerLocation;

    if((from.width() - itemSize.width()) > 0)

    {

        centerLocation.setX((from.width() - itemSize.width())/2);

    }

    if((from.height() - itemSize.height()) > 0)

    {

        centerLocation.setY((from.height() - itemSize.height())/2);

    }

    return centerLocation;

}

/* Compares if two QRects are equal. */

bool QAspectRatioLayout::areRectsEqual(const QRect& a,

                                       const QRect& b) const

{

    bool result = false;

    if(a.x() == b.x() &&

            a.y() == b.y() &&

            a.height() == b.height() &&

            a.width() == b.width())

    {

        result = true;

    }

    return result;

}