screenshot.cpp Example File | Qt Widgets 5.12.11

- Qt 5.12
- Qt Widgets
- Screenshot Example
- screenshot.cpp Example File
- Qt 5.12.11 Reference Documentation

# screenshot.cpp Example File

desktop/screenshot/screenshot.cpp

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     #include <QtWidgets>

     #include "screenshot.h"

     Screenshot::Screenshot()
         :  screenshotLabel(new QLabel(this))
     {
         screenshotLabel->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
         screenshotLabel->setAlignment(Qt::AlignCenter);

         const QRect screenGeometry = QApplication::desktop()->screenGeometry(this);
         screenshotLabel->setMinimumSize(screenGeometry.width() / 8, screenGeometry.height() / 8);

         QVBoxLayout *mainLayout = new QVBoxLayout(this);
         mainLayout->addWidget(screenshotLabel);

         QGroupBox *optionsGroupBox = new QGroupBox(tr("Options"), this);
         delaySpinBox = new QSpinBox(optionsGroupBox);
         delaySpinBox->setSuffix(tr(" s"));
         delaySpinBox->setMaximum(60);

         connect(delaySpinBox, QOverload<int>::of(&QSpinBox::valueChanged),
                 this, &Screenshot::updateCheckBox);

         hideThisWindowCheckBox = new QCheckBox(tr("Hide This Window"), optionsGroupBox);

         QGridLayout *optionsGroupBoxLayout = new QGridLayout(optionsGroupBox);
         optionsGroupBoxLayout->addWidget(new QLabel(tr("Screenshot Delay:"), this), 0, 0);
         optionsGroupBoxLayout->addWidget(delaySpinBox, 0, 1);
         optionsGroupBoxLayout->addWidget(hideThisWindowCheckBox, 1, 0, 1, 2);

         mainLayout->addWidget(optionsGroupBox);

         QHBoxLayout *buttonsLayout = new QHBoxLayout;
         newScreenshotButton = new QPushButton(tr("New Screenshot"), this);
         connect(newScreenshotButton, &QPushButton::clicked, this, &Screenshot::newScreenshot);
         buttonsLayout->addWidget(newScreenshotButton);
         QPushButton *saveScreenshotButton = new QPushButton(tr("Save Screenshot"), this);
         connect(saveScreenshotButton, &QPushButton::clicked, this, &Screenshot::saveScreenshot);
         buttonsLayout->addWidget(saveScreenshotButton);
         QPushButton *quitScreenshotButton = new QPushButton(tr("Quit"), this);
         quitScreenshotButton->setShortcut(Qt::CTRL + Qt::Key_Q);
         connect(quitScreenshotButton, &QPushButton::clicked, this, &QWidget::close);
         buttonsLayout->addWidget(quitScreenshotButton);
         buttonsLayout->addStretch();
         mainLayout->addLayout(buttonsLayout);

         shootScreen();
         delaySpinBox->setValue(5);

         setWindowTitle(tr("Screenshot"));
         resize(300, 200);
     }

     void Screenshot::resizeEvent(QResizeEvent * /* event */)
     {
         QSize scaledSize = originalPixmap.size();
         scaledSize.scale(screenshotLabel->size(), Qt::KeepAspectRatio);
         if (!screenshotLabel->pixmap() || scaledSize != screenshotLabel->pixmap()->size())
             updateScreenshotLabel();
     }

     void Screenshot::newScreenshot()
     {
         if (hideThisWindowCheckBox->isChecked())
             hide();
         newScreenshotButton->setDisabled(true);

         QTimer::singleShot(delaySpinBox->value() * 1000, this, &Screenshot::shootScreen);
     }

     void Screenshot::saveScreenshot()
     {
         const QString format = "png";
         QString initialPath = QStandardPaths::writableLocation(QStandardPaths::PicturesLocation);
         if (initialPath.isEmpty())
             initialPath = QDir::currentPath();
         initialPath += tr("/untitled.") + format;

         QFileDialog fileDialog(this, tr("Save As"), initialPath);
         fileDialog.setAcceptMode(QFileDialog::AcceptSave);
         fileDialog.setFileMode(QFileDialog::AnyFile);
         fileDialog.setDirectory(initialPath);
         QStringList mimeTypes;
         foreach (const QByteArray &bf, QImageWriter::supportedMimeTypes())
             mimeTypes.append(QLatin1String(bf));
         fileDialog.setMimeTypeFilters(mimeTypes);
         fileDialog.selectMimeTypeFilter("image/" + format);
         fileDialog.setDefaultSuffix(format);
         if (fileDialog.exec() != QDialog::Accepted)
             return;
         const QString fileName = fileDialog.selectedFiles().first();
         if (!originalPixmap.save(fileName)) {
             QMessageBox::warning(this, tr("Save Error"), tr("The image could not be saved to \"%1\".")
                                  .arg(QDir::toNativeSeparators(fileName)));
         }
     }

     void Screenshot::shootScreen()
     {
         QScreen *screen = QGuiApplication::primaryScreen();
         if (const QWindow *window = windowHandle())
             screen = window->screen();
         if (!screen)
             return;

         if (delaySpinBox->value() != 0)
             QApplication::beep();

         originalPixmap = screen->grabWindow(0);
         updateScreenshotLabel();

         newScreenshotButton->setDisabled(false);
         if (hideThisWindowCheckBox->isChecked())
             show();
     }

     void Screenshot::updateCheckBox()
     {
         if (delaySpinBox->value() == 0) {
             hideThisWindowCheckBox->setDisabled(true);
             hideThisWindowCheckBox->setChecked(false);
         } else {
             hideThisWindowCheckBox->setDisabled(false);
         }
     }

     void Screenshot::updateScreenshotLabel()
     {
         screenshotLabel->setPixmap(originalPixmap.scaled(screenshotLabel->size(),
                                                          Qt::KeepAspectRatio,
                                                          Qt::SmoothTransformation));
     }