flowlayout.cpp Example File
^{layouts/flowlayout/flowlayout.cpp}

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    **
    ** Copyright (C) 2004-2005 Trolltech AS. All rights reserved.
    **
    ** This file is part of the documentation of the Qt Toolkit.
    **
    ** This file may be used under the terms of the GNU General Public
** License version 2.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of
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    #include <QtGui>

    #include "flowlayout.h"

    FlowLayout::FlowLayout(QWidget *parent, int margin, int spacing)
        : QLayout(parent)
    {
        setMargin(margin);
        setSpacing(spacing);
    }

    FlowLayout::FlowLayout(int spacing)
    {
        setSpacing(spacing);
    }

    FlowLayout::~FlowLayout()
    {
        QLayoutItem *item;
        while ((item = takeAt(0)))
            delete item;
    }

    void FlowLayout::addItem(QLayoutItem *item)
    {
        itemList.append(item);
    }

    int FlowLayout::count() const
    {
        return itemList.size();
    }

    QLayoutItem *FlowLayout::itemAt(int index) const
    {
        return itemList.value(index);
    }

    QLayoutItem *FlowLayout::takeAt(int index)
    {
        if (index >= 0 && index < itemList.size())
            return itemList.takeAt(index);
        else
            return 0;
    }

    Qt::Orientations FlowLayout::expandingDirections() const
    {
        return 0;
    }

    bool FlowLayout::hasHeightForWidth() const
    {
        return true;
    }

    int FlowLayout::heightForWidth(int width) const
    {
        int height = doLayout(QRect(0, 0, width, 0), true);
        return height;
    }

    void FlowLayout::setGeometry(const QRect &rect)
    {
        QLayout::setGeometry(rect);
        doLayout(rect, false);
    }

    QSize FlowLayout::sizeHint() const
    {
        return minimumSize();
    }

    QSize FlowLayout::minimumSize() const
    {
        QSize size;
        QLayoutItem *item;
        foreach (item, itemList)
            size = size.expandedTo(item->minimumSize());

        size += QSize(2*margin(), 2*margin());
        return size;
    }

    int FlowLayout::doLayout(const QRect &rect, bool testOnly) const
    {
        int x = rect.x();
        int y = rect.y();
        int lineHeight = 0;

        QLayoutItem *item;
        foreach (item, itemList) {
            int nextX = x + item->sizeHint().width() + spacing();
            if (nextX - spacing() > rect.right() && lineHeight > 0) {
                x = rect.x();
                y = y + lineHeight + spacing();
                nextX = x + item->sizeHint().width() + spacing();
                lineHeight = 0;
            }

            if (!testOnly)
                item->setGeometry(QRect(QPoint(x, y), item->sizeHint()));

            x = nextX;
            lineHeight = qMax(lineHeight, item->sizeHint().height());
        }
        return y + lineHeight - rect.y();
    }