/*

 * 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;

}