Hi,

I would like to paint on a widget, but every time I call another function, it deletes the old widget content.

I already tried to create an instance of Pixmap with

Qt Code: 
  1. pixmap = QPixmap(pixmap);
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and removed fill() but this doesn't work.

Why is it possible to call

Qt Code: 
  1. pixmap = QPixmap(size());
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but not

Qt Code: 
  1. pixmap = QPixmap(pixmap); ??
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Here is the code snippet:

Qt Code: 
  1. void ClientWindow::paintEvent(QPaintEvent * /* event */)
  2. {
  3.     QStylePainter painter(this);
  4.     painter.drawPixmap(0, 0, pixmap);
  5.  
  6.     if (hasFocus()) {
  8.         option.initFrom(this);
  9.         option.backgroundColor = palette().dark().color();
  10.         //painter.drawPrimitive(QStyle::PE_FrameFocusRect, option);
  11.     }
  12. }
  13.  
  14. void ClientWindow::drawCircle(int x, int y, int width, int height)
  15. {
  16.     pixmap = QPixmap(size());
  17.     pixmap.fill(this, 0, 0);
  18.  
  19.     QPainter painter(&pixmap);
  20.     painter.initFrom(this);
  21.  
  22.     pen.setStyle(Qt::SolidLine);
  23.     pen.setWidth(3);
  24.     pen.setBrush(Qt::green);
  25.     pen.setCapStyle(Qt::RoundCap);
  26.     pen.setJoinStyle(Qt::RoundJoin);
  27.  
  28.     brush.setStyle(Qt::SolidPattern);
  29.  
  30.     painter.setPen(pen);
  31.     //painter.setBrush(brush);
  32.  
  33.     if (antialiased)
  34.         painter.setRenderHint(QPainter::Antialiasing, true);
  35.     painter.drawEllipse(x, y, width, height);
  36.     update();
  37. }
  38.  
  39. void ClientWindow::drawLine(int x1, int y1, int x2, int y2)
  40. {
  41.     pixmap = QPixmap(size());
  42.     pixmap.fill(this, 0, 0);
  43.  
  44.     QPainter painter(&pixmap);
  45.     painter.initFrom(this);
  46.  
  47.  //...
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