QWidget::paintEngine: Should no longer be called

Jakob Clausen

I am trying to make a simple widget that can show videos.
I have

#include "video.h"
#include <QVideoWidget>

Video::Video(QWidget* parent, QString videofile) : QVideoWidget(parent)
{
    player = new QMediaPlayer(this);
    player->setMedia(QUrl::fromLocalFile(videofile));
    player->setVolume(50);
    player->setVideoOutput(this);
}

void Video::play()
{
    player->play();
}

Video::~Video()
{
    if (player)
        delete player;
}

And then I get the message:
QWidget::paintEngine: Should no longer be called

What am I doing wrong?

mrjj

Hi
Well it might not be your fault :)

But one thing is wrong
player = new QMediaPlayer(this); << the "this" is a parent

and will delete anything it owns. Most of Qt works this way.

So you very rarely need to delete manually anything you give a parent.

so don't delete the player manually, as your Video class will do it.

This ownership system is explained here
https://doc.qt.io/qt-5/objecttrees.html

Jakob Clausen

Hi.
And thank you.
You make a good point. But I guess that's not the reason.
What do you mean - it might not be your fault?

mrjj

@Jakob-Clausen
"by not your fault" I mean that i see no use of QPainter in the code shown so
it could be QMediaPlayer that does something wrong unless there far more
code to Video , you didnt show.

Jakob Clausen

@mrjj I have shown you everything. Should I just ignore it?

mrjj

@Jakob-Clausen

Yes, then just ignore it for now.

What Qt version and platform are you on ?

This used to be a bug. Didnt track it so not sure it was fixed at some point.

You could try player->stop(); via a button to test if that makes the error go away

Jakob Clausen

@mrjj I am using Qt 5.15 on linux.
I get the error when the widget is shown, so play() is never run.
If it used to be a bug, then I guess it still is.
I will ignore it.

mrjj

@Jakob-Clausen
Oh, so its not even when you close or anything ?
Well, then, i think it's still the same bug as it sounds like how it was reported from other users.
It should be safe to ignore it.

Jakob Clausen

Ok.
Thank you very much for your help.
Have a nice weekend. :-)

mrjj

@Jakob-Clausen
Same to you :)
Also please use the "Topic Tool" button to set this as solved. ( in first post, to the right )