Qt Reference Documentation

window.cpp Example File

threads/queuedcustomtype/window.cpp
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 #include <QtGui>
 #include "window.h"

 Window::Window()
 {
     thread = new RenderThread();

     label = new QLabel();
     label->setAlignment(Qt::AlignCenter);

     loadButton = new QPushButton(tr("&Load image..."));
     resetButton = new QPushButton(tr("&Stop"));
     resetButton->setEnabled(false);

     connect(loadButton, SIGNAL(clicked()), this, SLOT(loadImage()));
     connect(resetButton, SIGNAL(clicked()), thread, SLOT(stopProcess()));
     connect(thread, SIGNAL(finished()), this, SLOT(resetUi()));
     connect(thread, SIGNAL(sendBlock(Block)), this, SLOT(addBlock(Block)));

     QHBoxLayout *buttonLayout = new QHBoxLayout();
     buttonLayout->addStretch();
     buttonLayout->addWidget(loadButton);
     buttonLayout->addWidget(resetButton);
     buttonLayout->addStretch();

     QVBoxLayout *layout = new QVBoxLayout(this);
     layout->addWidget(label);
     layout->addLayout(buttonLayout);

     setWindowTitle(tr("Queued Custom Type"));
 }

 void Window::loadImage()
 {
     QStringList formats;
     foreach (QByteArray format, QImageReader::supportedImageFormats())
         if (format.toLower() == format)
             formats.append("*." + format);

     QString newPath = QFileDialog::getOpenFileName(this, tr("Open Image"),
         path, tr("Image files (%1)").arg(formats.join(" ")));

     if (newPath.isEmpty())
         return;

     QImage image(newPath);
     if (!image.isNull()) {
         loadImage(image);
         path = newPath;
     }
 }

 void Window::loadImage(const QImage &image)
 {
     QDesktopWidget desktop;
     QImage useImage;
     QRect space = desktop.availableGeometry();
     if (image.width() > 0.75*space.width() || image.height() > 0.75*space.height())
         useImage = image.scaled(0.75*space.width(), 0.75*space.height(),
                                 Qt::KeepAspectRatio, Qt::SmoothTransformation);
     else
         useImage = image;

     pixmap = QPixmap(useImage.width(), useImage.height());
     pixmap.fill(qRgb(255, 255, 255));
     label->setPixmap(pixmap);
     loadButton->setEnabled(false);
     resetButton->setEnabled(true);
     thread->processImage(useImage);
 }

 void Window::addBlock(const Block &block)
 {
     QColor color = block.color();
     color.setAlpha(64);

     QPainter painter;
     painter.begin(&pixmap);
     painter.fillRect(block.rect(), color);
     painter.end();
     label->setPixmap(pixmap);
 }

 void Window::resetUi()
 {
     loadButton->setEnabled(true);
     resetButton->setEnabled(false);
 }