Overlay in QPainter, text needs to be resized as window resizes

Pradeep Kumar

Hi,

I have overlay text in QPainter ,i need to resize the overlay text when the window resizes, right now the text is of same size even if i resize the window.

QPainter painter(this);
    QRect rect(this->m_pQWidget->x(),
               this->m_pQWidget->y(),
               this->m_pQWidget->width(),
               this->m_pQWidget->height());
    painter.fillRect(rect,Qt::black);
    QDateTime dateTimeObject;
    QPen oPen1;
    oPen1.setWidth(1);
    oPen1.setColor("green");
    painter.setPen(oPen1);
    painter.drawText(rect,Qt::AlignBottom | Qt::AlignCenter,
                     dateTimeObject.currentDateTime().toString());

How can i achieve this?.

Thanks,

mrjj

@Pradeep-Kumar
Hi
Use http://doc.qt.io/qt-5/qfontmetrics.html
to know size of text, then use
the font to size it by using a larger point size.

Pradeep Kumar

QFontMetrics fm = painter.fontMetrics();
int width = fm.width(dateTimeObject.currentDateTime().toString());

Is this the way to use QFontMetrics?.

And needs to be updated in paintevent()?.

Thanks,

mrjj

@Pradeep-Kumar
well yes, you can use that information to know
if you should increase or decrease font size.

Pradeep Kumar

Then after i got width from QFontMetrics, we need to add to Qpen setwidth?.

mrjj

@Pradeep-Kumar
No QFont :)
Draw text smaller or bigger
http://doc.qt.io/qt-5/qfont.html#setPointSize