WidgetUpdate.cpp

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#include "WidgetUpdate.hpp"
#include <QPainter>
#include <QPaintEvent>
#include <QMouseEvent>
#include <QMainWindow>
#include <QApplication>

// The main method of this thread.
void Updater::run() {  // no exec() call = no event handling
  //std::cout << "Other thread " << currentThreadId() << std::endl;
  still_running = true;
  while (still_running) {
#ifdef BUGGY
    widget.updatePosition(1);
    // !!!Feature appears when frequency is high (sleep < 10 ms)!!!
#else
    updatePosRequest(1);
#endif
    msleep(5);  // wait (parameter in milliseconds)
  } // end of while (this thread should run)
} // end of void Updater::run() --------------------------------------

// Draws the position pointed by the mouse. 
// Parameter event  The drawing event, giving the region
//                  which should be redrawn.
void UpdateWidget::paintEvent(QPaintEvent *event) {
  static const int nb_points = 2;
  QPainter     painter(this); 
  const QRect& drawing_rect = event->rect();
  const QPoint *points[nb_points] = {&aimed, &position};
  const Qt::GlobalColor colors[nb_points] = {Qt::green, Qt::blue};

  painter.eraseRect(drawing_rect);  // clean the region
  for(int i = 0; i < nb_points; i++) {  // for each point
    painter.setPen(colors[i]);         // set the border color
    painter.setBrush(colors[i]);       // set the fill color
    painter.drawPie(region(*points[i]), 0, 360 * 16); // fill the disk
  } // end of for (each point)
} // end of void UpdateWidget::paintEvent(QPaintEvent*) --------------

// Moves the drawn position where the mouse is. 
// Parameter event  The mouse event, giving its position.
void UpdateWidget::mouseMoveEvent(QMouseEvent *event) {
  if (event->buttons() & Qt::LeftButton)  // if left button is pressed
    modify( aimed, event->pos() );   // change position and drawing
} // end of void UpdateWidget::mouseMoveEvent(QMouseEvent*) ----------

int main(int argc, char** argv) {
  QApplication app(argc, argv);  // start the Qt main loop
  QMainWindow  mainWindow;
  UpdateWidget centralWidget(&mainWindow);
  centralWidget.setMinimumSize(300,200);
  centralWidget.init();
  mainWindow.setCentralWidget(&centralWidget);
  mainWindow.show();
    
  // stop the Qt main loop when last window (= main window) is closed
  app.connect(&app, SIGNAL(lastWindowClosed()), &app, SLOT(quit()));
  return app.exec();             // return Qt main loop's return value
} // end of int main(int, char**) ------------------------------------