mainwindow.cpp Example File

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#include "imagemodel.h" #include "mainwindow.h" #include "pixeldelegate.h" #include <QtWidgets> #if defined(QT_PRINTSUPPORT_LIB) #include <QtPrintSupport/qtprintsupportglobal.h> #if QT_CONFIG(printdialog) #include <QPrinter> #include <QPrintDialog> #endif #endif MainWindow::MainWindow() { currentPath = QDir::homePath(); model = new ImageModel(this); QWidget *centralWidget = new QWidget; view = new QTableView; view->setShowGrid(false); view->horizontalHeader()->hide(); view->verticalHeader()->hide(); view->horizontalHeader()->setMinimumSectionSize(1); view->verticalHeader()->setMinimumSectionSize(1); view->setModel(model); PixelDelegate *delegate = new PixelDelegate(this); view->setItemDelegate(delegate); QLabel *pixelSizeLabel = new QLabel(tr("Pixel size:")); QSpinBox *pixelSizeSpinBox = new QSpinBox; pixelSizeSpinBox->setMinimum(4); pixelSizeSpinBox->setMaximum(32); pixelSizeSpinBox->setValue(12); QMenu *fileMenu = new QMenu(tr("&File"), this); QAction *openAction = fileMenu->addAction(tr("&Open...")); openAction->setShortcuts(QKeySequence::Open); printAction = fileMenu->addAction(tr("&Print...")); printAction->setEnabled(false); printAction->setShortcut(QKeySequence::Print); QAction *quitAction = fileMenu->addAction(tr("E&xit")); quitAction->setShortcuts(QKeySequence::Quit); QMenu *helpMenu = new QMenu(tr("&Help"), this); QAction *aboutAction = helpMenu->addAction(tr("&About")); menuBar()->addMenu(fileMenu); menuBar()->addSeparator(); menuBar()->addMenu(helpMenu); connect(openAction, &QAction::triggered, this, &MainWindow::chooseImage); connect(printAction, &QAction::triggered, this, &MainWindow::printImage); connect(quitAction, &QAction::triggered, qApp, &QCoreApplication::quit); connect(aboutAction, &QAction::triggered, this, &MainWindow::showAboutBox); connect(pixelSizeSpinBox, QOverload<int>::of(&QSpinBox::valueChanged), delegate, &PixelDelegate::setPixelSize); connect(pixelSizeSpinBox, QOverload<int>::of(&QSpinBox::valueChanged), this, &MainWindow::updateView); QHBoxLayout *controlsLayout = new QHBoxLayout; controlsLayout->addWidget(pixelSizeLabel); controlsLayout->addWidget(pixelSizeSpinBox); controlsLayout->addStretch(1); QVBoxLayout *mainLayout = new QVBoxLayout; mainLayout->addWidget(view); mainLayout->addLayout(controlsLayout); centralWidget->setLayout(mainLayout); setCentralWidget(centralWidget); setWindowTitle(tr("Pixelator")); resize(640, 480); } void MainWindow::chooseImage() { QString fileName = QFileDialog::getOpenFileName(this, tr("Choose an image"), currentPath, "*"); if (!fileName.isEmpty()) openImage(fileName); } void MainWindow::openImage(const QString &fileName) { QImage image; if (image.load(fileName)) { model->setImage(image); if (!fileName.startsWith(":/")) { currentPath = fileName; setWindowTitle(tr("%1 - Pixelator").arg(currentPath)); } printAction->setEnabled(true); updateView(); } } void MainWindow::printImage() { #if QT_CONFIG(printdialog) if (model->rowCount(QModelIndex())*model->columnCount(QModelIndex()) > 90000) { QMessageBox::StandardButton answer; answer = QMessageBox::question(this, tr("Large Image Size"), tr("The printed image may be very large. Are you sure that " "you want to print it?"), QMessageBox::Yes | QMessageBox::No); if (answer == QMessageBox::No) return; } QPrinter printer(QPrinter::HighResolution); QPrintDialog dlg(&printer, this); dlg.setWindowTitle(tr("Print Image")); if (dlg.exec() != QDialog::Accepted) { return; } QPainter painter; painter.begin(&printer); int rows = model->rowCount(QModelIndex()); int columns = model->columnCount(QModelIndex()); int sourceWidth = (columns + 1) * ItemSize; int sourceHeight = (rows + 1) * ItemSize;; double xscale = printer.pageRect().width() / double(sourceWidth); double yscale = printer.pageRect().height() / double(sourceHeight); double scale = qMin(xscale, yscale); painter.translate(printer.paperRect().x() + printer.pageRect().width() / 2, printer.paperRect().y() + printer.pageRect().height() / 2); painter.scale(scale, scale); painter.translate(-sourceWidth / 2, -sourceHeight / 2); QStyleOptionViewItem option; QModelIndex parent = QModelIndex(); QProgressDialog progress(tr("Printing..."), tr("Cancel"), 0, rows, this); progress.setWindowModality(Qt::ApplicationModal); float y = ItemSize / 2; for (int row = 0; row < rows; ++row) { progress.setValue(row); qApp->processEvents(); if (progress.wasCanceled()) break; float x = ItemSize / 2; for (int column = 0; column < columns; ++column) { option.rect = QRect(int(x), int(y), ItemSize, ItemSize); view->itemDelegate()->paint(&painter, option, model->index(row, column, parent)); x = x + ItemSize; } y = y + ItemSize; } progress.setValue(rows); painter.restore(); painter.end(); if (progress.wasCanceled()) { QMessageBox::information(this, tr("Printing canceled"), tr("The printing process was canceled."), QMessageBox::Cancel); } #else QMessageBox::information(this, tr("Printing canceled"), tr("Printing is not supported on this Qt build"), QMessageBox::Cancel); #endif } void MainWindow::showAboutBox() { QMessageBox::about(this, tr("About the Pixelator example"), tr("This example demonstrates how a standard view and a custom\n" "delegate can be used to produce a specialized representation\n" "of data in a simple custom model.")); } void MainWindow::updateView() { view->resizeColumnsToContents(); view->resizeRowsToContents(); }

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