How to fill QLabel Circle with color

[arunvv]

I am writing a Qt application, which has MainWindow->groupboxes->labels designed with designer.

I used paintEvent for one of the groupBox to make one of the label as circle. I need to identify the color outside the paintEvent and fill that color to circle.

Can you give me any idea, on how to proceed?

Thanks & Regards,
Arun

[aamer4yu]

I need to identify the color outside the paintEvent and fill that color to circle.

Can u elaborate ? didnt get u

[arunvv]

Normally what we will do to fill the color in widget with paintEvent is by using setPen & setBrush, as shown below.

void paintEvent(QPaintEvent *event)
{
      QPainter p(this);
      p.setPen(QPen(Qt::black, 1, Qt::SolidLine, Qt::RoundCap));
      p.setBrush(QBrush(Qt::black, Qt::SolidPattern));
      p.drawEllipse(0, 0, width() - 1, height() - 1);
      p.end();
      QLabel::paintEvent(event);
}

void paintEvent(QPaintEvent *event)
{
      QPainter p(this);
      p.setPen(QPen(Qt::black, 1, Qt::SolidLine, Qt::RoundCap));
      p.setBrush(QBrush(Qt::black, Qt::SolidPattern));
      p.drawEllipse(0, 0, width() - 1, height() - 1);
      p.end();
      QLabel::paintEvent(event);
}

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Here in the above shown example I am filling circle with black color.

But my problem is I have to fill the circle with random colors taken from some other functionality. I cannot pass that color into this paintEvent function. So I have to do some other things which fills color for the circle outside paintEvent functionality.

So how to fill color for the circle ?

[oob2]

You can have a QColor variable named m_color. Lets say if you have funcA() to set the m_color randomly, then you just need to call update() after that. The paintEvent() will get called and you can then use this m_color in your setPen()/setBrush().

[arunvv]

Ok Thanks for your reply. If I want to fill random colors with solidpattern for 3 circles
how can I do that?

[aamer4yu]

QColor getRandomColor()
{
       int r = rand() % 256;
       int g = rand() % 256;
       int b = rand() % 256;
       return QColor(r,g,b);
}

QColor getRandomColor()
{
       int r = rand() % 256;
       int g = rand() % 256;
       int b = rand() % 256;
       return QColor(r,g,b);
}

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[wysota]

You can also use the palette for this. See QWidget::palette() and QWidget::setPalette(). Adding new variables storing colours is often unnecessary as there already is a container for colours in every widget.