- Qt 5.5
- Qt Widgets
- Dynamic Layouts Example
- dialog.cpp Example File
- Qt 5.5.1 Reference Documentation

# dialog.cpp Example File

layouts/dynamiclayouts/dialog.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.
    **   * 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 <QtWidgets>

    #include "dialog.h"

    Dialog::Dialog(QWidget *parent)
        : QDialog(parent)
    {
        createRotableGroupBox();
        createOptionsGroupBox();
        createButtonBox();

        mainLayout = new QGridLayout;
        mainLayout->addWidget(rotableGroupBox, 0, 0);
        mainLayout->addWidget(optionsGroupBox, 1, 0);
        mainLayout->addWidget(buttonBox, 2, 0);
        setLayout(mainLayout);

        mainLayout->setSizeConstraint(QLayout::SetMinimumSize);

        setWindowTitle(tr("Dynamic Layouts"));
    }

    void Dialog::buttonsOrientationChanged(int index)
    {
        mainLayout->setSizeConstraint(QLayout::SetNoConstraint);
        setMinimumSize(0, 0);

        Qt::Orientation orientation = Qt::Orientation(
                buttonsOrientationComboBox->itemData(index).toInt());

        if (orientation == buttonBox->orientation())
            return;

        mainLayout->removeWidget(buttonBox);

        int spacing = mainLayout->spacing();

        QSize oldSizeHint = buttonBox->sizeHint() + QSize(spacing, spacing);
        buttonBox->setOrientation(orientation);
        QSize newSizeHint = buttonBox->sizeHint() + QSize(spacing, spacing);

        if (orientation == Qt::Horizontal) {
            mainLayout->addWidget(buttonBox, 2, 0);
            resize(size() + QSize(-oldSizeHint.width(), newSizeHint.height()));
        } else {
            mainLayout->addWidget(buttonBox, 0, 3, 2, 1);
            resize(size() + QSize(newSizeHint.width(), -oldSizeHint.height()));
        }

        mainLayout->setSizeConstraint(QLayout::SetDefaultConstraint);
    }

    void Dialog::rotateWidgets()
    {
        Q_ASSERT(rotableWidgets.count() % 2 == 0);

        foreach (QWidget *widget, rotableWidgets)
            rotableLayout->removeWidget(widget);

        rotableWidgets.enqueue(rotableWidgets.dequeue());

        const int n = rotableWidgets.count();
        for (int i = 0; i < n / 2; ++i) {
            rotableLayout->addWidget(rotableWidgets[n - i - 1], 0, i);
            rotableLayout->addWidget(rotableWidgets[i], 1, i);
        }
    }

    void Dialog::help()
    {
        QMessageBox::information(this, tr("Dynamic Layouts Help"),
                                   tr("This example shows how to change layouts "
                                      "dynamically."));
    }

    void Dialog::createRotableGroupBox()
    {
        rotableGroupBox = new QGroupBox(tr("Rotable Widgets"));

        rotableWidgets.enqueue(new QSpinBox);
        rotableWidgets.enqueue(new QSlider);
        rotableWidgets.enqueue(new QDial);
        rotableWidgets.enqueue(new QProgressBar);

        int n = rotableWidgets.count();
        for (int i = 0; i < n; ++i) {
            connect(rotableWidgets[i], SIGNAL(valueChanged(int)),
                    rotableWidgets[(i + 1) % n], SLOT(setValue(int)));
        }

        rotableLayout = new QGridLayout;
        rotableGroupBox->setLayout(rotableLayout);

        rotateWidgets();
    }

    void Dialog::createOptionsGroupBox()
    {
        optionsGroupBox = new QGroupBox(tr("Options"));

        buttonsOrientationLabel = new QLabel(tr("Orientation of buttons:"));

        buttonsOrientationComboBox = new QComboBox;
        buttonsOrientationComboBox->addItem(tr("Horizontal"), Qt::Horizontal);
        buttonsOrientationComboBox->addItem(tr("Vertical"), Qt::Vertical);

        connect(buttonsOrientationComboBox, SIGNAL(currentIndexChanged(int)),
                this, SLOT(buttonsOrientationChanged(int)));

        optionsLayout = new QGridLayout;
        optionsLayout->addWidget(buttonsOrientationLabel, 0, 0);
        optionsLayout->addWidget(buttonsOrientationComboBox, 0, 1);
        optionsLayout->setColumnStretch(2, 1);
        optionsGroupBox->setLayout(optionsLayout);
    }

    void Dialog::createButtonBox()
    {
        buttonBox = new QDialogButtonBox;

        closeButton = buttonBox->addButton(QDialogButtonBox::Close);
        helpButton = buttonBox->addButton(QDialogButtonBox::Help);
        rotateWidgetsButton = buttonBox->addButton(tr("Rotate &Widgets"),
                                                   QDialogButtonBox::ActionRole);

        connect(rotateWidgetsButton, SIGNAL(clicked()), this, SLOT(rotateWidgets()));
        connect(closeButton, SIGNAL(clicked()), this, SLOT(close()));
        connect(helpButton, SIGNAL(clicked()), this, SLOT(help()));
    }