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# dialog.cpp Example File

layouts/dynamiclayouts/dialog.cpp

     /****************************************************************************
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     ** Copyright (C) 2015 The Qt Company Ltd.
     ** Contact: http://www.qt.io/licensing/
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     ** This file is part of the examples of the Qt Toolkit.
     **
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     #include <QtGui>

     #include "dialog.h"

     Dialog::Dialog(QWidget *parent)
     #if defined(Q_OS_SYMBIAN) || defined(Q_WS_MAEMO_5) || defined(Q_WS_SIMULATOR)
         : QWidget(parent)
     #else
         : QDialog(parent)
     #endif
     {
         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()));
     }