flowlayout.cpp

qt-x11-opensource-src-4.1.4.tar.gz源码

/****************************************************************************
**
** Copyright (C) 2004-2006 Trolltech ASA. All rights reserved.
**
** This file is part of the example classes 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
** this file.  Please review the following information to ensure GNU
** General Public Licensing requirements will be met:
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**
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** review the following information:
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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();
}