mainwindow.cpp Example File
itemviews/pixelator/mainwindow.cpp
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** This file is part of the documentation of the Qt Toolkit.
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#include <QtGui>
#include "imagemodel.h"
#include "mainwindow.h"
#include "pixeldelegate.h"
MainWindow::MainWindow() : QMainWindow()
{
currentPath = QDir::home().absolutePath();
model = new ImageModel(QImage(), this);
QWidget *centralWidget = new QWidget;
view = new QTableView;
view->setShowGrid(false);
view->horizontalHeader()->hide();
view->verticalHeader()->hide();
PixelDelegate *delegate = new PixelDelegate(this);
view->setItemDelegate(delegate);
QLabel *pixelSizeLabel = new QLabel(tr("Pixel size:"));
QSpinBox *pixelSizeSpinBox = new QSpinBox;
pixelSizeSpinBox->setMinimum(1);
pixelSizeSpinBox->setMaximum(32);
pixelSizeSpinBox->setValue(12);
QMenu *fileMenu = new QMenu(tr("&File"), this);
QAction *openAction = fileMenu->addAction(tr("&Open..."));
openAction->setShortcut(QKeySequence(tr("Ctrl+O")));
printAction = fileMenu->addAction(tr("&Print..."));
printAction->setEnabled(false);
printAction->setShortcut(QKeySequence(tr("Ctrl+P")));
QAction *quitAction = fileMenu->addAction(tr("E&xit"));
quitAction->setShortcut(QKeySequence(tr("Ctrl+Q")));
QMenu *helpMenu = new QMenu(tr("&Help"), this);
QAction *aboutAction = helpMenu->addAction(tr("&About"));
menuBar()->addMenu(fileMenu);
menuBar()->addSeparator();
menuBar()->addMenu(helpMenu);
connect(openAction, SIGNAL(triggered()), this, SLOT(chooseImage()));
connect(printAction, SIGNAL(triggered()), this, SLOT(printImage()));
connect(quitAction, SIGNAL(triggered()), qApp, SLOT(quit()));
connect(aboutAction, SIGNAL(triggered()), this, SLOT(showAboutBox()));
connect(pixelSizeSpinBox, SIGNAL(valueChanged(int)),
delegate, SLOT(setPixelSize(int)));
connect(pixelSizeSpinBox, SIGNAL(valueChanged(int)),
this, SLOT(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)) {
ImageModel *newModel = new ImageModel(image, this);
view->setModel(newModel);
delete model;
model = newModel;
if (!fileName.startsWith(":/")) {
currentPath = fileName;
setWindowTitle(tr("%1 - Pixelator").arg(currentPath));
}
printAction->setEnabled(true);
updateView();
}
}
void MainWindow::printImage()
{
if (model->rowCount(QModelIndex())*model->columnCount(QModelIndex())
> 90000) {
int 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 = new QPrintDialog(&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;
painter.save();
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);
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);
}
}
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()
{
for (int row = 0; row < model->rowCount(QModelIndex()); ++row)
view->resizeRowToContents(row);
for (int column = 0; column < model->columnCount(QModelIndex()); ++column)
view->resizeColumnToContents(column);
}
