mainwindow.cpp Example File | Qt Widgets 5.12.10

- Qt 5.12
- Qt Widgets
- Tablet Example
- mainwindow.cpp Example File
- Qt 5.12.10 Reference Documentation

# mainwindow.cpp Example File

widgets/tablet/mainwindow.cpp

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     #include <QtWidgets>

     #include "mainwindow.h"
     #include "tabletcanvas.h"

     MainWindow::MainWindow(TabletCanvas *canvas)
       : m_canvas(canvas), m_colorDialog(nullptr)
     {
         createMenus();
         setWindowTitle(tr("Tablet Example"));
         setCentralWidget(m_canvas);
         QCoreApplication::setAttribute(Qt::AA_CompressHighFrequencyEvents);
     }

     void MainWindow::setBrushColor()
     {
         if (!m_colorDialog) {
             m_colorDialog = new QColorDialog(this);
             m_colorDialog->setModal(false);
             m_colorDialog->setCurrentColor(m_canvas->color());
             connect(m_colorDialog, &QColorDialog::colorSelected, m_canvas, &TabletCanvas::setColor);
         }
         m_colorDialog->setVisible(true);
     }

     void MainWindow::setAlphaValuator(QAction *action)
     {
         m_canvas->setAlphaChannelValuator(action->data().value<TabletCanvas::Valuator>());
     }

     void MainWindow::setLineWidthValuator(QAction *action)
     {
         m_canvas->setLineWidthType(action->data().value<TabletCanvas::Valuator>());
     }

     void MainWindow::setSaturationValuator(QAction *action)
     {
         m_canvas->setColorSaturationValuator(action->data().value<TabletCanvas::Valuator>());
     }

     void MainWindow::setEventCompression(bool compress)
     {
         QCoreApplication::setAttribute(Qt::AA_CompressTabletEvents, compress);
     }

     bool MainWindow::save()
     {
         QString path = QDir::currentPath() + "/untitled.png";
         QString fileName = QFileDialog::getSaveFileName(this, tr("Save Picture"),
                                  path);
         bool success = m_canvas->saveImage(fileName);
         if (!success)
             QMessageBox::information(this, "Error Saving Picture",
                                      "Could not save the image");
         return success;
     }

     void MainWindow::load()
     {
         QString fileName = QFileDialog::getOpenFileName(this, tr("Open Picture"),
                                                         QDir::currentPath());

         if (!m_canvas->loadImage(fileName))
             QMessageBox::information(this, "Error Opening Picture",
                                      "Could not open picture");
     }

     void MainWindow::clear()
     {
         if (QMessageBox::question(this, tr("Save changes"), tr("Do you want to save your changes?"),
                                   QMessageBox::Save | QMessageBox::Discard | QMessageBox::Cancel,
                                   QMessageBox::Save) != QMessageBox::Save || save())
             m_canvas->clear();
     }

     void MainWindow::about()
     {
         QMessageBox::about(this, tr("About Tablet Example"),
                            tr("This example shows how to use a graphics drawing tablet in Qt."));
     }

     void MainWindow::createMenus()
     {
         QMenu *fileMenu = menuBar()->addMenu(tr("&File"));
         fileMenu->addAction(tr("&Open..."), this, &MainWindow::load, QKeySequence::Open);
         fileMenu->addAction(tr("&Save As..."), this, &MainWindow::save, QKeySequence::SaveAs);
         fileMenu->addAction(tr("&New"), this, &MainWindow::clear, QKeySequence::New);
         fileMenu->addAction(tr("E&xit"), this, &MainWindow::close, QKeySequence::Quit);

         QMenu *brushMenu = menuBar()->addMenu(tr("&Brush"));
         brushMenu->addAction(tr("&Brush Color..."), this, &MainWindow::setBrushColor, tr("Ctrl+B"));

         QMenu *tabletMenu = menuBar()->addMenu(tr("&Tablet"));
         QMenu *lineWidthMenu = tabletMenu->addMenu(tr("&Line Width"));

         QAction *lineWidthPressureAction = lineWidthMenu->addAction(tr("&Pressure"));
         lineWidthPressureAction->setData(TabletCanvas::PressureValuator);
         lineWidthPressureAction->setCheckable(true);
         lineWidthPressureAction->setChecked(true);

         QAction *lineWidthTiltAction = lineWidthMenu->addAction(tr("&Tilt"));
         lineWidthTiltAction->setData(TabletCanvas::TiltValuator);
         lineWidthTiltAction->setCheckable(true);

         QAction *lineWidthFixedAction = lineWidthMenu->addAction(tr("&Fixed"));
         lineWidthFixedAction->setData(TabletCanvas::NoValuator);
         lineWidthFixedAction->setCheckable(true);

         QActionGroup *lineWidthGroup = new QActionGroup(this);
         lineWidthGroup->addAction(lineWidthPressureAction);
         lineWidthGroup->addAction(lineWidthTiltAction);
         lineWidthGroup->addAction(lineWidthFixedAction);
         connect(lineWidthGroup, &QActionGroup::triggered, this,
                 &MainWindow::setLineWidthValuator);

         QMenu *alphaChannelMenu = tabletMenu->addMenu(tr("&Alpha Channel"));
         QAction *alphaChannelPressureAction = alphaChannelMenu->addAction(tr("&Pressure"));
         alphaChannelPressureAction->setData(TabletCanvas::PressureValuator);
         alphaChannelPressureAction->setCheckable(true);

         QAction *alphaChannelTangentialPressureAction = alphaChannelMenu->addAction(tr("T&angential Pressure"));
         alphaChannelTangentialPressureAction->setData(TabletCanvas::TangentialPressureValuator);
         alphaChannelTangentialPressureAction->setCheckable(true);
         alphaChannelTangentialPressureAction->setChecked(true);

         QAction *alphaChannelTiltAction = alphaChannelMenu->addAction(tr("&Tilt"));
         alphaChannelTiltAction->setData(TabletCanvas::TiltValuator);
         alphaChannelTiltAction->setCheckable(true);

         QAction *noAlphaChannelAction = alphaChannelMenu->addAction(tr("No Alpha Channel"));
         noAlphaChannelAction->setData(TabletCanvas::NoValuator);
         noAlphaChannelAction->setCheckable(true);

         QActionGroup *alphaChannelGroup = new QActionGroup(this);
         alphaChannelGroup->addAction(alphaChannelPressureAction);
         alphaChannelGroup->addAction(alphaChannelTangentialPressureAction);
         alphaChannelGroup->addAction(alphaChannelTiltAction);
         alphaChannelGroup->addAction(noAlphaChannelAction);
         connect(alphaChannelGroup, &QActionGroup::triggered,
                 this, &MainWindow::setAlphaValuator);

         QMenu *colorSaturationMenu = tabletMenu->addMenu(tr("&Color Saturation"));

         QAction *colorSaturationVTiltAction = colorSaturationMenu->addAction(tr("&Vertical Tilt"));
         colorSaturationVTiltAction->setData(TabletCanvas::VTiltValuator);
         colorSaturationVTiltAction->setCheckable(true);

         QAction *colorSaturationHTiltAction = colorSaturationMenu->addAction(tr("&Horizontal Tilt"));
         colorSaturationHTiltAction->setData(TabletCanvas::HTiltValuator);
         colorSaturationHTiltAction->setCheckable(true);

         QAction *colorSaturationPressureAction = colorSaturationMenu->addAction(tr("&Pressure"));
         colorSaturationPressureAction->setData(TabletCanvas::PressureValuator);
         colorSaturationPressureAction->setCheckable(true);

         QAction *noColorSaturationAction = colorSaturationMenu->addAction(tr("&No Color Saturation"));
         noColorSaturationAction->setData(TabletCanvas::NoValuator);
         noColorSaturationAction->setCheckable(true);
         noColorSaturationAction->setChecked(true);

         QActionGroup *colorSaturationGroup = new QActionGroup(this);
         colorSaturationGroup->addAction(colorSaturationVTiltAction);
         colorSaturationGroup->addAction(colorSaturationHTiltAction);
         colorSaturationGroup->addAction(colorSaturationPressureAction);
         colorSaturationGroup->addAction(noColorSaturationAction);
         connect(colorSaturationGroup, &QActionGroup::triggered,
                 this, &MainWindow::setSaturationValuator);

         QAction *compressAction = tabletMenu->addAction(tr("Co&mpress events"));
         compressAction->setCheckable(true);
         connect(compressAction, &QAction::toggled, this, &MainWindow::setEventCompression);

         QMenu *helpMenu = menuBar()->addMenu("&Help");
         helpMenu->addAction(tr("A&bout"), this, &MainWindow::about);
         helpMenu->addAction(tr("About &Qt"), qApp, &QApplication::aboutQt);
     }