Window Drag Resize Example - main.cpp

 // Copyright (C) 2025 The Qt Company Ltd.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only

 #include <QApplication>
 #include <QLabel>
 #include <QLatin1String>
 #include <QPushButton>
 #include <QVBoxLayout>
 #include <QWidget>
 #include <QtOhosExtras>
 #include <functional>

 namespace {

 QWidget *createActionButton(QString label, QWidget *parent, std::function<void()> action)
 {
     auto *button = new QPushButton(label, parent);
     QObject::connect(button, &QPushButton::clicked, parent, std::move(action));
     return button;
 }

 QWidget *createDragResizeSettingToggleButton(QWidget *windowToEnableDrag, QWidget *parent)
 {
     auto *enableDragButton = new QPushButton(parent);
     enableDragButton->setCheckable(true);
     enableDragButton->setChecked(false);

     auto updateDragResizable = [enableDragButton, windowToEnableDrag]() {
         auto checked = enableDragButton->isChecked();
         enableDragButton->setText(
             checked
                 ? QLatin1String("Reset window drag resizable")
                 : QLatin1String("Set window drag resizable"));
         QtOhosExtras::setWindowDragResizable(windowToEnableDrag, checked);
     };
     updateDragResizable();

     QObject::connect(
         enableDragButton, &QPushButton::toggled, windowToEnableDrag, std::move(updateDragResizable));

     return enableDragButton;
 }

 QWidget *createDragResizableWindow(const QString& windowName, QWidget *parent)
 {
     auto *window = new QWidget(parent);

     window->setWindowFlags(Qt::Window);
     window->setAttribute(Qt::WA_DeleteOnClose);
     window->resize(800, 200);

     auto *layout = new QVBoxLayout(window);
     layout->addWidget(new QLabel(windowName, window));

     layout->addWidget(
         createDragResizeSettingToggleButton(window, window));

     layout->addWidget(
         createActionButton(
             "Close window", window,
             [window]() {
                 window->close();
             }));

     return window;
 }

 }

 int main(int argc, char *argv[])
 {
     QApplication app(argc, argv);

     QWidget window;
     window.setWindowTitle(QLatin1String("setWindowDragResizable example"));

     auto *layout = new QVBoxLayout(&window);
     layout->addWidget(
         createActionButton(
             "Create new sub window", &window,
             [window = &window]() {
                 auto *newWindow = createDragResizableWindow("Sub window", window);
                 newWindow->show();
             }));

     layout->addWidget(
         createActionButton(
             "Create new float window", &window,
             [window = &window]() {
                 auto *newWindow = createDragResizableWindow("Float window", window);
                 QtOhosExtras::setShowWindowAsFloatWindowHint(newWindow, true);
                 newWindow->show();
             }));

     window.show();
     return app.exec();
 }