qt-creator/src/plugins/coreplugin/flowlayout.cpp

/**************************************************************************
**
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** Copyright (c) 2011 Nokia Corporation and/or its subsidiary(-ies).
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** contained in the Technology Preview License Agreement accompanying
** this package.
**
** 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
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#include "flowlayout.h"

#include <QRect>
#include <QWidgetItem>

using namespace Core::Internal;

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;
    foreach (QLayoutItem *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;

    foreach (QLayoutItem *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() + margin();
}