Put in a separate thread a method of a class

Hi to all,
I would put in a separate thread a method of my class that actually blocks the gui.
The method is responsible of drawing an audio waveform into a QWidget in the paint event

So:

Code:

---

void WaveDisplay::paintEvent( QPaintEvent* pe )
{
	// Update the ev->rect area with the wave from the rendered QPixmap here
	if( m_waveCachePixmap.isNull() )
	{
		updateWave();// BLOCK MY GUI
	}
 
	QPainter p( this );
	p.setRenderHint( QPainter::Antialiasing, true );
	QPen pen = QPen( Qt::darkRed, 1 );
 
	// wave
	p.drawPixmap( 0, 0, m_waveCachePixmap );
 
	QWidget::paintEvent(pe);
}

---

AND

Code:

---

// THIS ROUTINE BLOCK MY GUI
void WaveDisplay::updateWave()
{
	int h = this->height();
	int w = this->width();
 
	// I want another width and height here.
	// Also, you might to clear the cache at resize events
	QPixmap temp = QPixmap( w, h );
 
	QPainter p( &temp );
	//p.setRenderHint( QPainter::Antialiasing, true );
	p.fillRect( temp.rect(), bgColor );
 
       ...more code to draw the wave...
}

---

I read about threads and QtConcurrent but I don't know how to adapt my code even because I have to pass the painter
and paint on a specific widget.

I hope to get help.

Regards