- Qt 5.5
- Qt Widgets
- Border Layout Example
- borderlayout.cpp Example File
- Qt 5.5.1 Reference Documentation

# borderlayout.cpp Example File

layouts/borderlayout/borderlayout.cpp

    /****************************************************************************
    **
    ** Copyright (C) 2015 The Qt Company Ltd.
    ** Contact: http://www.qt.io/licensing/
    **
    ** This file is part of the examples of the Qt Toolkit.
    **
    ** $QT_BEGIN_LICENSE:BSD$
    ** 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.
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    **     notice, this list of conditions and the following disclaimer in
    **     the documentation and/or other materials provided with the
    **     distribution.
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    **     contributors may be used to endorse or promote products derived
    **     from this software without specific prior written permission.
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    #include "borderlayout.h"

    BorderLayout::BorderLayout(QWidget *parent, int margin, int spacing)
        : QLayout(parent)
    {
        setMargin(margin);
        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);
        if (wrapper)
            return wrapper->item;
        else
            return 0;
    }

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

    void BorderLayout::setGeometry(const QRect &rect)
    {
        ItemWrapper *center = 0;
        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 0;
    }

    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;
    }