Compile QT 5.8 to cross-compile Beaglebone

[Andrey Shmelew]

hi! i have absolutely the same trouble:
i reproduse it with absolutely minimal qml example
When i deploy qt 5.5 application on beaglebone device (arm linux gnueabihf) - then works perfectly
When i deploy qt 5.8 - the error appears:

QQmlApplicationEngine failed to load component
qrc:/main.qml:-1 File not found

// this somehow works but the window is blank
main.cpp:

#include <QGuiApplication>
#include <QQuickView>

int main(int argc, char *argv[])
{
    QGuiApplication app(argc, argv);

    QQuickView view;
    view.setSource(QUrl::fromLocalFile("main.qml"));
    view.show();

    return app.exec();
}

[jsulm]

@Andrey-Shmelew You're using a relative path:

view.setSource(QUrl::fromLocalFile("main.qml"));

Depending from where you start your app the file will not be found.
You should construct an absolute path at runtime using http://doc.qt.io/qt-5/qcoreapplication.html#applicationDirPath

[Andrey Shmelew]

@jsulm
um, should i make something like this?

    QQuickView view;
    view.setSource(QUrl::fromLocalFile("C:/qtqml57/main.qml"));
    view.show();

the output is still

file:///C:/qtqml57/main.qml: File not found

[SGaist]

Because that file is located on your Windows machine.

If you don't want to put it in a Qt resource, then do as @jsulm suggested: build the path at run time.

[jsulm]

@Andrey-Shmelew Something like this:

QString path = QCoreApplication::applicationDirPath() + '/' + "main.qml";
QQuickView view;
view.setSource(QUrl::fromLocalFile(path));
view.show();

[Andrey Shmelew]

@jsulm
thanks, but it don't works for me

file:///usr/main.qml: File not found

note that when i deploy with qt 5.5 kit it enables to deploy without any path stuff

so if i upload main.qml to beaglebone's /usr/ folder then i get :

QQuickView only supports loading of root objects that derive from QQuickItem. 

If your example is using QML 2, (such as qmlscene) and the .qml file you 
loaded has 'import QtQuick 1.0' or 'import Qt 4.7', this error will occur. 

To load files with 'import QtQuick 1.0' or 'import Qt 4.7', use the 
QDeclarativeView class in the Qt Quick 1 module.

[jsulm]

@Andrey-Shmelew "/usr"?!
Where is you app located?

[Andrey Shmelew]

@jsulm
it is located in beaglebone's /usr folder when deployed.

When i develop -main.qml is located on windows C:/qtqml57/main.qml ( qtqml57 is qt 5 project folder)

[jsulm]

@Andrey-Shmelew Quite unusual location.
Can you describe how the layout of your app is?
Is it like this:

/usr/YOUR_APP_EXECUTABLE
/usr/main.qml

?

[Andrey Shmelew]

@jsulm
by default it is:

project:
windows 10, project path C:/qtqml57/

after rebuild it's deployed in Linux /usr/ directory

[jsulm]

@Andrey-Shmelew can you please show how it looks like in /usr? Is it like I asked above? So, how does the deploy directory (/usr in your case) look like?

[Andrey Shmelew]

@jsulm

sorry for annoying

i just added to a .pro file as usual :

target.path  = /usr
INSTALLS    += target
DISTFILES +=

now on my beaglebone /usr/ folder looks like

[jsulm]

@Andrey-Shmelew You should really upload a bigger picture - it is nearly impossible to see anything. I tried hard but could not find main.qml file there. So, where is it?

[jsulm]

@Andrey-Shmelew And you should not pollute /usr with files of your app. It is better to use /opt/YOUR_APP_NAME.

[Andrey Shmelew]

@jsulm

sorry about that, picture is really small

and there is no main.qml in /usr

[jsulm]

@Andrey-Shmelew That's why it is not working

[Andrey Shmelew]

@jsulm
so if i upload main.qml to beaglebone's /usr/ folder then i get :

QQuickView only supports loading of root objects that derive from QQuickItem.

If your example is using QML 2, (such as qmlscene) and the .qml file you
loaded has 'import QtQuick 1.0' or 'import Qt 4.7', this error will occur.

To load files with 'import QtQuick 1.0' or 'import Qt 4.7', use the
QDeclarativeView class in the Qt Quick 1 module.

[jsulm]

@Andrey-Shmelew said in Compile QT 5.8 to cross-compile Beaglebone:

QDeclarativeView

It says what you should do: use QDeclarativeView instead of QQuickView

[Andrey Shmelew]

This post is deleted!

[Andrey Shmelew]

ok, i solved the problem:
put manually main.qml into /usr/ folder

main.cpp

#include <QGuiApplication>
#include <QQmlApplicationEngine>

int main(int argc, char *argv[])
{
    QGuiApplication app(argc, argv);
    QQmlApplicationEngine engine;
    engine.load(QUrl(QStringLiteral("/usr/main.qml")));
    return app.exec();
}