How QTextBrowser highlight line?

[sonichy]

How to create a function to highlight line from the given line number?

QTextBrowser.highlightLine(i);

[VRonin]

You can try something like

QTextCursor coursor(textBrowser->document()->findBlockByLineNumber(i));
QTextBlockFormat frmt = coursor.blockFormat();
frmt.setBackground(QBrush(Qt::yellow));
coursor.setBlockFormat(frmt);

[raven-worx]

@sonichy
you can use setExtraSelections()

[sonichy]

@VRonin
Your method can work, but highlight lines one by one, I need only highlight current line i, I use it to highlight song lyrics.
And can you change the font color but not background color?

[VRonin]

Me and @raven-worx gave you the two solution based on usage. if you want the highlight to change based on user clicking on the line use @raven-worx solution. if you want the highlight as permanent or changing based on a state (a timer, an event, a button click) then you can use my solution

[sonichy]

@VRonin
Clear highlight has been solved.
But how to change to highlight font color not background?
QTextBlockFormat.setForeground(QBrush(Qt::yellow)) has no effort.

// clear
for(int a=0;a<lyrics.size();a++){
    QTextCursor cursor(ui->textBrowser->document()->findBlockByLineNumber(a));
    QTextBlockFormat TBF = cursor.blockFormat();
    TBF.setBackground(QBrush(Qt::transparent));
    cursor.setBlockFormat(TBF);
}
// color it
QTextCursor cursor1(ui->textBrowser->document()->findBlockByLineNumber(i));
QTextBlockFormat TBF1 = cursor1.blockFormat();
TBF1.setBackground(QBrush(Qt::yellow));
cursor.setBlockFormat(TBF1);
ui->textBrowser->setTextCursor(cursor1);