/****************************************************************************

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** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).

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** Contact: Nokia Corporation (qt-info@nokia.com)

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** This file is part of the QtGui module of the Qt Toolkit.

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** This file contains pre-release code and may not be distributed.

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** contained in the Technology Preview License Agreement accompanying

** this package.

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** GNU Lesser General Public License Usage

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** General Public License version 2.1 as published by the Free Software

** Foundation and appearing in the file LICENSE.LGPL included in the

** packaging of this file.  Please review the following information to

** ensure the GNU Lesser General Public License version 2.1 requirements

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****************************************************************************/

#include "qglobal.h"

#ifndef QT_NO_GRAPHICSVIEW

#include "qgraphicslayout_p.h"

#include "qgraphicslayout.h"

#include "qgraphicswidget.h"

#include "qapplication.h"

QT_BEGIN_NAMESPACE

/*!

    \internal

    \a mw is the new parent. all items in the layout will be a child of \a mw.

 */

void QGraphicsLayoutPrivate::reparentChildItems(QGraphicsItem *newParent)

{

    Q_Q(QGraphicsLayout);

    int n =  q->count();

    //bool mwVisible = mw && mw->isVisible();

    for (int i = 0; i < n; ++i) {

        QGraphicsLayoutItem *layoutChild = q->itemAt(i);

        if (!layoutChild) {

            // Skip stretch items

            continue;

        }

        if (layoutChild->isLayout()) {

            QGraphicsLayout *l = static_cast<QGraphicsLayout*>(layoutChild);

            l->d_func()->reparentChildItems(newParent);

        } else if (QGraphicsItem *itemChild = layoutChild->graphicsItem()){

            QGraphicsItem *childParent = itemChild->parentItem();

#ifdef QT_DEBUG

            if (childParent && childParent != newParent && itemChild->isWidget() && qt_graphicsLayoutDebug()) {

                QGraphicsWidget *w = static_cast<QGraphicsWidget*>(layoutChild);

                qWarning("QGraphicsLayout::addChildLayout: widget %s \"%s\" in wrong parent; moved to correct parent",

                         w->metaObject()->className(), w->objectName().toLocal8Bit().constData());

            }

#endif

            if (childParent != newParent)

                itemChild->setParentItem(newParent);

        }

    }

}

void QGraphicsLayoutPrivate::getMargin(qreal *result, qreal userMargin, QStyle::PixelMetric pm) const

{

    if (!result)

        return;

    Q_Q(const QGraphicsLayout);

    QGraphicsLayoutItem *parent = q->parentLayoutItem();

    if (userMargin >= 0.0) {

        *result = userMargin;

    } else if (!parent) {

        *result = 0.0;

    } else if (parent->isLayout()) {    // sublayouts have 0 margin by default

        *result = 0.0;

    } else {

        *result = 0.0;

        if (QGraphicsItem *layoutParentItem = parentItem()) {

            if (layoutParentItem->isWidget())

                *result = (qreal)static_cast<QGraphicsWidget*>(layoutParentItem)->style()->pixelMetric(pm, 0);

        }

    }

}

Qt::LayoutDirection QGraphicsLayoutPrivate::visualDirection() const

{

    if (QGraphicsItem *maybeWidget = parentItem()) {

        if (maybeWidget->isWidget())

            return static_cast<QGraphicsWidget*>(maybeWidget)->layoutDirection();

    }

    return QApplication::layoutDirection();

}

static bool removeLayoutItemFromLayout(QGraphicsLayout *lay, QGraphicsLayoutItem *layoutItem)

{

    if (!lay)

        return false;

    for (int i = lay->count() - 1; i >= 0; --i) {

        QGraphicsLayoutItem *child = lay->itemAt(i);

        if (child && child->isLayout()) {

            if (removeLayoutItemFromLayout(static_cast<QGraphicsLayout*>(child), layoutItem))

                return true;

        } else if (child == layoutItem) {

            lay->removeAt(i);

            return true;

        }

    }

    return false;

}

/*!

    \internal

    This function is called from subclasses to add a layout item \a layoutItem 

    to a layout.

    It takes care of automatically reparenting graphics items, if needed.

    If \a layoutItem is a  is already in a layout, it will remove it  from that layout.

*/

void QGraphicsLayoutPrivate::addChildLayoutItem(QGraphicsLayoutItem *layoutItem)

{

    Q_Q(QGraphicsLayout);

    if (QGraphicsLayoutItem *maybeLayout = layoutItem->parentLayoutItem()) {

        if (maybeLayout->isLayout())

            removeLayoutItemFromLayout(static_cast<QGraphicsLayout*>(maybeLayout), layoutItem);

    }    

    layoutItem->setParentLayoutItem(q);

    if (layoutItem->isLayout()) {

        if (QGraphicsItem *parItem = parentItem()) {

            static_cast<QGraphicsLayout*>(layoutItem)->d_func()->reparentChildItems(parItem);

        }

    } else {

        if (QGraphicsItem *item = layoutItem->graphicsItem()) {        

            QGraphicsItem *newParent = parentItem();

            QGraphicsItem *oldParent = item->parentItem();

            if (oldParent == newParent || !newParent)

                return;

#ifdef QT_DEBUG

            if (oldParent && item->isWidget()) {

                QGraphicsWidget *w = static_cast<QGraphicsWidget*>(item);

                qWarning("QGraphicsLayout::addChildLayoutItem: %s \"%s\" in wrong parent; moved to correct parent",

                    w->metaObject()->className(), w->objectName().toLocal8Bit().constData());

            }

#endif

            item->setParentItem(newParent);

        }

    }

}

void QGraphicsLayoutPrivate::activateRecursive(QGraphicsLayoutItem *item)

{

    if (item->isLayout()) {

        QGraphicsLayout *layout = static_cast<QGraphicsLayout *>(item);

        if (layout->d_func()->activated)

            layout->invalidate();

        for (int i = layout->count() - 1; i >= 0; --i) {

            QGraphicsLayoutItem *childItem = layout->itemAt(i);

            if (childItem)

                activateRecursive(childItem);

        }

        layout->d_func()->activated = true;

    }

}

QT_END_NAMESPACE

#endif //QT_NO_GRAPHICSVIEW