Qt Reference Documentation

# window.cpp Example File

threads/queuedcustomtype/window.cpp

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     ** This file is part of the examples of the Qt Toolkit.
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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);
     }