window.cpp Example File | Qt Mac Extras 5.9

Qt 5.9 | Qt Mac Extras | macOS: Embedded QWindow | window.cpp Example File

Qt 5.9.9 Reference Documentation

# window.cpp Example File

embeddedqwindow/window.cpp

      /****************************************************************************
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      ** Contact: https://www.qt.io/licensing/
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      ** This file is part of the test suite of the Qt Toolkit.
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      #include "window.h"

      #include <private/qguiapplication_p.h>

      #include <QBackingStore>
      #include <QPainter>
      #include <QtWidgets>

      static int colorIndexId = 0;

      QColor colorTable[] =
      {
          QColor("#f09f8f"),
          QColor("#a2bff2"),
          QColor("#c0ef8f")
      };

      Window::Window(QScreen *screen)
          : QWindow(screen)
          , m_backgroundColorIndex(colorIndexId++)
          , m_backingStore(0)
      {
          initialize();
      }

      Window::Window(QWindow *parent)
          : QWindow(parent)
          , m_backgroundColorIndex(colorIndexId++)
          , m_backingStore(0)
      {
          initialize();
      }

      void Window::initialize()
      {
          if (parent())
              setGeometry(QRect(160, 120, 320, 240));
          else {
              setGeometry(QRect(10, 10, 640, 480));

              setSizeIncrement(QSize(10, 10));
              setBaseSize(QSize(640, 480));
              setMinimumSize(QSize(240, 160));
              setMaximumSize(QSize(800, 600));
          }

          setFlags(flags() | Qt::SubWindow); // Don't create a toplevel window.

          create();
          m_backingStore = new QBackingStore(this);

          m_image = QImage(geometry().size(), QImage::Format_RGB32);
          m_image.fill(colorTable[m_backgroundColorIndex % (sizeof(colorTable) / sizeof(colorTable[0]))].rgba());

          m_lastPos = QPoint(-1, -1);
          m_renderTimer = 0;
      }

      void Window::mousePressEvent(QMouseEvent *event)
      {
          m_lastPos = event->pos();
      }

      void Window::mouseMoveEvent(QMouseEvent *event)
      {
          if (m_lastPos != QPoint(-1, -1)) {
              QPainter p(&m_image);
              p.setRenderHint(QPainter::Antialiasing);
              p.drawLine(m_lastPos, event->pos());
              m_lastPos = event->pos();
          }

          scheduleRender();
      }

      void Window::mouseReleaseEvent(QMouseEvent *event)
      {
          if (m_lastPos != QPoint(-1, -1)) {
              QPainter p(&m_image);
              p.setRenderHint(QPainter::Antialiasing);
              p.drawLine(m_lastPos, event->pos());
              m_lastPos = QPoint(-1, -1);
          }

          scheduleRender();
      }

      void Window::exposeEvent(QExposeEvent *)
      {
          scheduleRender();
      }

      void Window::resizeEvent(QResizeEvent *)
      {
          QImage old = m_image;

          //qDebug() << "Window::resizeEvent" << width << height;

          int width = qMax(geometry().width(), old.width());
          int height = qMax(geometry().height(), old.height());

          if (width > old.width() || height > old.height()) {
              m_image = QImage(width, height, QImage::Format_RGB32);
              m_image.fill(colorTable[(m_backgroundColorIndex) % (sizeof(colorTable) / sizeof(colorTable[0]))].rgba());

              QPainter p(&m_image);
              p.drawImage(0, 0, old);
          }

          render();
      }

      void Window::keyPressEvent(QKeyEvent *event)
      {
          switch (event->key()) {
          case Qt::Key_Backspace:
              m_text.chop(1);
              break;
          case Qt::Key_Enter:
          case Qt::Key_Return:
              m_text.append('\n');
              break;
          default:
              m_text.append(event->text());
              break;
          }
          scheduleRender();
      }

      void Window::scheduleRender()
      {
          if (!m_renderTimer)
              m_renderTimer = startTimer(1);
      }

      void Window::timerEvent(QTimerEvent *)
      {
          render();
          killTimer(m_renderTimer);
          m_renderTimer = 0;
      }

      void Window::render()
      {
          if (!m_backingStore)
              return;
          QRect rect(QPoint(), geometry().size());

          m_backingStore->resize(rect.size());

          m_backingStore->beginPaint(rect);

          QPaintDevice *device = m_backingStore->paintDevice();

          QPainter p(device);
          p.drawImage(0, 0, m_image);

          QFont font;
          font.setPixelSize(32);

          p.setFont(font);
          p.drawText(rect, 0, m_text);

          m_backingStore->endPaint();
          m_backingStore->flush(rect);
      }