qt5base-lts/examples/widgets/layouts/borderlayout/borderlayout.cpp

/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** BSD License Usage
** Alternatively, you may use this file under the terms of the BSD license
** as follows:
**
** "Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
**   * Redistributions of source code must retain the above copyright
**     notice, this list of conditions and the following disclaimer.
**   * Redistributions in binary form must reproduce the above copyright
**     notice, this list of conditions and the following disclaimer in
**     the documentation and/or other materials provided with the
**     distribution.
**   * Neither the name of The Qt Company Ltd nor the names of its
**     contributors may be used to endorse or promote products derived
**     from this software without specific prior written permission.
**
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "borderlayout.h"

BorderLayout::BorderLayout(QWidget *parent, const QMargins &margins, int spacing)
    : QLayout(parent)
{
    setContentsMargins(margins);
    setSpacing(spacing);
}

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


BorderLayout::~BorderLayout()
{
    QLayoutItem *l;
    while ((l = takeAt(0)))
        delete l;
}

void BorderLayout::addItem(QLayoutItem *item)
{
    add(item, West);
}

void BorderLayout::addWidget(QWidget *widget, Position position)
{
    add(new QWidgetItem(widget), position);
}

Qt::Orientations BorderLayout::expandingDirections() const
{
    return Qt::Horizontal | Qt::Vertical;
}

bool BorderLayout::hasHeightForWidth() const
{
    return false;
}

int BorderLayout::count() const
{
    return list.size();
}

QLayoutItem *BorderLayout::itemAt(int index) const
{
    ItemWrapper *wrapper = list.value(index);
    return wrapper ? wrapper->item : nullptr;
}

QSize BorderLayout::minimumSize() const
{
    return calculateSize(MinimumSize);
}

void BorderLayout::setGeometry(const QRect &rect)
{
    ItemWrapper *center = nullptr;
    int eastWidth = 0;
    int westWidth = 0;
    int northHeight = 0;
    int southHeight = 0;
    int centerHeight = 0;
    int i;

    QLayout::setGeometry(rect);

    for (i = 0; i < list.size(); ++i) {
        ItemWrapper *wrapper = list.at(i);
        QLayoutItem *item = wrapper->item;
        Position position = wrapper->position;

        if (position == North) {
            item->setGeometry(QRect(rect.x(), northHeight, rect.width(),
                                    item->sizeHint().height()));

            northHeight += item->geometry().height() + spacing();
        } else if (position == South) {
            item->setGeometry(QRect(item->geometry().x(),
                                    item->geometry().y(), rect.width(),
                                    item->sizeHint().height()));

            southHeight += item->geometry().height() + spacing();

            item->setGeometry(QRect(rect.x(),
                              rect.y() + rect.height() - southHeight + spacing(),
                              item->geometry().width(),
                              item->geometry().height()));
        } else if (position == Center) {
            center = wrapper;
        }
    }

    centerHeight = rect.height() - northHeight - southHeight;

    for (i = 0; i < list.size(); ++i) {
        ItemWrapper *wrapper = list.at(i);
        QLayoutItem *item = wrapper->item;
        Position position = wrapper->position;

        if (position == West) {
            item->setGeometry(QRect(rect.x() + westWidth, northHeight,
                                    item->sizeHint().width(), centerHeight));

            westWidth += item->geometry().width() + spacing();
        } else if (position == East) {
            item->setGeometry(QRect(item->geometry().x(), item->geometry().y(),
                                    item->sizeHint().width(), centerHeight));

            eastWidth += item->geometry().width() + spacing();

            item->setGeometry(QRect(
                              rect.x() + rect.width() - eastWidth + spacing(),
                              northHeight, item->geometry().width(),
                              item->geometry().height()));
        }
    }

    if (center)
        center->item->setGeometry(QRect(westWidth, northHeight,
                                        rect.width() - eastWidth - westWidth,
                                        centerHeight));
}

QSize BorderLayout::sizeHint() const
{
    return calculateSize(SizeHint);
}

QLayoutItem *BorderLayout::takeAt(int index)
{
    if (index >= 0 && index < list.size()) {
        ItemWrapper *layoutStruct = list.takeAt(index);
        return layoutStruct->item;
    }
    return nullptr;
}

void BorderLayout::add(QLayoutItem *item, Position position)
{
    list.append(new ItemWrapper(item, position));
}

QSize BorderLayout::calculateSize(SizeType sizeType) const
{
    QSize totalSize;

    for (int i = 0; i < list.size(); ++i) {
        ItemWrapper *wrapper = list.at(i);
        Position position = wrapper->position;
        QSize itemSize;

        if (sizeType == MinimumSize)
            itemSize = wrapper->item->minimumSize();
        else // (sizeType == SizeHint)
            itemSize = wrapper->item->sizeHint();

        if (position == North || position == South || position == Center)
            totalSize.rheight() += itemSize.height();

        if (position == West || position == East || position == Center)
            totalSize.rwidth() += itemSize.width();
    }
    return totalSize;
}