Minor performance improvement to QLabel with Image

QPixmap::fromImage in QLabel paintEvent should use the rvalue
reference overload for efficiency

[ChangeLog][QtWidgets][QLabel] Minor performance improvement
when painting a label with an image

Change-Id: I8ab9bf427c1efc320907c66538e9f8e4011f5586
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>
This commit is contained in:
Luca Beldi 2018-09-28 19:51:55 +01:00
parent 155ae07b70
commit 98ec8bed19

View File

@ -1098,7 +1098,7 @@ void QLabel::paintEvent(QPaintEvent *)
QImage scaledImage =
d->cachedimage->scaled(scaledSize,
Qt::IgnoreAspectRatio, Qt::SmoothTransformation);
d->scaledpixmap = new QPixmap(QPixmap::fromImage(scaledImage));
d->scaledpixmap = new QPixmap(QPixmap::fromImage(std::move(scaledImage)));
d->scaledpixmap->setDevicePixelRatio(devicePixelRatioF());
}
pix = *d->scaledpixmap;