source: trunk/src/gui/graphicsview/qgraphicslayout_p.cpp@ 1021

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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)
{