drawText on QGraphicsView::drawForeground

Question

My code is below.

void MyView::drawForeground(QPainter *painter, const QRectF &rect)
{
    Q_UNUSED(rect);

    painter->save();

    QRectF rt = viewport()->rect();
    painter->setWorldMatrixEnabled(false);

    QString strInfo = "test12345";

    painter->setBrush(Qt::NoBrush);
    painter->setPen(Qt::white);

    painter->setFont(QFont("Segoe UI", 200, QFont::Bold));

    QFontMetrics fm(painter->font());
    int fmWidth = fm.width(strInfo, strInfo.length());
    int fmHeight = fm.height();

    painter->drawRect(rt);
    painter->drawText(10, 10, fmWidth, fmHeight, Qt::AlignCenter, strInfo);
    painter->drawRect(10, 10, fmWidth, fmHeight);
    painter->setWorldMatrixEnabled(true);
    painter->restore();
}

result image

QfontMetrics does not seem to return the correct size. What's wrong with my code?

I do not know what to do anymore.

QFontMetrics returns the size of the white rectangle of the attached image, but the actual Text is drawn small.

It works for me correctly: https://imgur.com/a/vsNDQqO with Qt 5.11.1 — eyllanesc, Jul 09 '18 at 12:53
I can not see what went wrong. Are there any other elements related to QPainter :: drawText? — DaeHee.Lim, Jul 09 '18 at 12:58
As I said I used your code and did not find any problem, maybe some part that does not show your code generates that problem, could share your entire project through github or similar — eyllanesc, Jul 09 '18 at 13:00
Thank you for your kind reply. I need to debug again one by one. — DaeHee.Lim, Jul 09 '18 at 13:03
I removed my scene and replaced it with the default QGraphicsScene. It has exactly. Perhaps it is affected by the size of the scene. remove "fitInView", QFontMetrics returns the correct value. — DaeHee.Lim, Jul 09 '18 at 13:17

score 0 · Answer 1 · edited Jul 09 '18 at 14:36

0

Regardless of QPainter::setWorldMatrixEnabled(false), QPainter::drawText() behaves as a scene coordinate.

edited Jul 09 '18 at 14:36

eyllanesc

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answered Jul 09 '18 at 14:11

DaeHee.Lim

1
2

drawText on QGraphicsView::drawForeground

1 Answers1