Qt 5.6 | Qt Core | Queued Custom Type Example | window.cpp Example File

Qt 5.6.2 Reference Documentation

# window.cpp Example File

threads/queuedcustomtype/window.cpp

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      #include <QtWidgets>
      #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);
      }