CODEWITHSUNDEEP
c++qtqt4
newww0
newww0

Reputation: 181

how to save qwidget as image automatically

i want to draw some rhombuses in a qwidget and save it as image automatically. I use the following code in the paintEvent and get this error "QWidget::repaint: Recursive repaint detected". Problem is that render() seems to call the paintEvent() again, I always get stuck in an infinite, recursive paintEvent call. Is there any way to save the qwidget automatically after drawing. Any advices would be grateful.

 void Dialog::paintEvent(QPaintEvent *e) {
     QPainter painter(this);
     QRect background(0,0,this->geometry().width(),this->geometry().height());
     painter.setBrush( QBrush( Qt::white ) );
     painter.setPen( Qt::NoPen );
     //QBrush bbrush(Qt::black,Qt::SolidPattern);
     painter.drawRect(background);
     int width = this->geometry().width();
     int height = this->geometry().height();


      int rec_size=64;
         int rows=floor((double)height/(double)rec_size);
         int cols=floor((double)width/(double)rec_size);

         QPointF points[4];

         for (int i=0;i<floor(rows);i++){
             for (int j=0;j<floor(cols);j++){
                painter.setBrush( QBrush( colors[rand() % color_size] ) );

                points[0] = QPointF(rec_size*(j),rec_size*(i+0.5));
                points[1] = QPointF(rec_size*(j+0.5),rec_size*(i));
                points[2] = QPointF(rec_size*(j+1),rec_size*(i+0.5));
                points[3] = QPointF(rec_size*(j+0.5),rec_size*(i+1));

                painter.drawPolygon(points, 4);

             }
         }
         QPixmap pixmap(this->size());
         this->render(&pixmap);
         pixmap.save("test.png");

     }

Upvotes: 3

Views: 3250

Answers (2)

damkrat
damkrat

Reputation: 364

Call render() outside of paintevent(), render will repaint widget and save it to pixmap or am i missing something?

If you need to catch paint event itself, then use QObject::installEventFilter() or QObject::event() routines.

Upvotes: 0

Ashot
Ashot

Reputation: 10959

You can have boolean variable as a member in widget. It will control calling render function or not. So you can avoid infinite recursion.

m_callRender is the member variable. If paintEvent is called as a result of render function, render will not called again.

paintevent 
{
    ... // drawing part

    if (m_callRender) {
        m_callRender = false;
        QPixmap pixmap(this->size());
        this->render(&pixmap);
        pixmap.save("test.png");
        m_callRender = true;
    }
}

Upvotes: 3

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