Qt5 QML App not visible when change the resolution ?

Alex_wang

@SGaist
I'm not sure for it to be invisible or move outside of the visible part of the screen.
I have read the eglfs plugin source ,and find that the egl surface or screen or window depending on the resolution is created
by QGuiApplicationPrivate::init -->QGuiApplicationPrivate::createPlatformIntegration().
so ,when my app displays successfully with the resolution 1080P,the egl surface or screen or window is created with the 1080P.
But when I change the resolution to 720P, the egl surface or screen or window has still been depending on the 1080P.
Then my app displays unsuccessfully , is invisible .....

Alex_wang

@SGaist

Does it have an event in Qt5.9.3 that notices the connector resolution changing ?

Devopia53

@Alex_wang

Yes, of course. Read the following document.

QScreen
Screen

like this:

#include <QScreen>
[...]
QScreen     *screen = QApplication::primaryScreen();
QObject::connect(screen, &QScreen::geometryChanged, [](const QRect &geometry){ qDebug() << geometry; });
[...]

Alex_wang

@Devopia53 said in Qt5 QML App not visible when change the resolution ?:

QObject::connect(screen, &QScreen::geometryChanged, [](const QRect &geometry){ qDebug() << geometry; });

Hi, it is not helpful for me.

when I change the resolution, the screen (QApplication::primaryScreen()) is not changed....

jsulm

@Alex_wang Do you mean the QScreen::geometryChanged signal is not emitted?

SGaist

By the way, how are you changing the resolution ?

Alex_wang

@SGaist
change the resolution by an app "drm_modeset":

sudo ./drm_modeset -s 1920x1080@60

Alex_wang

after changed the resolution, the surface or screen or window for qt5 app is still depending on last resolution.
the reason is on four floor

SGaist

See here and the QT_QPA_EGLFS_ALWAYS_SET_MODE environment variable.

Alex_wang

@SGaist
I have got it . It means I still have to relaunch the application.

SGaist

Do you have any other application running on your system ?

Alex_wang

@SGaist
The decoded video is also rendered by DRM, which is running on my system.

SGaist

You have to give more details about your system and what it does.

Michael Chen

@Alex_wang
Have you found a solution? I'm also having the same problem.