[Solved] display number for device type LinuxFb

sachintm

Hi Guys,

I am running my embedded Qt application with the options specified below, and the application is not displayed on the Linux based hardware.

.\myapplication -qws -display "LinuxFb"

In the "display management":http://harmattan-dev.nokia.com/docs/library/html/qt4/qt-embedded-displaymanagement.html, there is no description for <device> type LinuxFb.

Please suggest, what should I specify for the display number in the options above ?
Which display driver will be loaded and linked with the application in the Linux machine ?

Thanks in advance,
Sachin

SGaist

Hi,

IIRC, device should be something like /dev/ttyX where X is the number of the console where your application should start.

sachintm

Hello SGaist,

The below parameters seems to be working on my device.

.\myapplication -qws -display “LinuxFb:/dev/fb0”

But, I could only see a small arrow on the device screen.
Do I need to set any width and height for the screen ? If yes, How do I set these values ?

Thanks,
Sachin

SGaist

It depends on the screen support you have for your system. You can use the variables described "here":http://qt-project.org/doc/qt-4.8/qt-embedded-envvars.html to set your application environment

sachintm

Hello SGaist,

I tried setting the QWS_SIZE, still the result is same.

This is the simple test code.
@#include <QApplication>
#include <QPushButton>

int main(int argc, char *argv[])
{
QApplication a(argc, argv);
QPushButton button("Hello Emb World");
button.show();
return a.exec();
}@

Thanks,
Sachin

SGaist

What is you screen resolution ?

If you have doubts that Qt uses the right values, you could write a little application that shows the size of a widget when maximized

sachintm

Hello SGaist,

screen resolution is 480x272.

The application is hanging or something when "button.show(); " is called.
So, the debug log which is printed after the show() call, is not coming.

There seems to be some problem with window manager, but I could not find it out.

Thanks,
Sachin

SGaist

You could try to start your application remotely through ssh, that should show you the log while the application is running

sachintm

Hello SGaist,

I am able to see the logs, but the actual problem is in the show() function call.

The application is hanging when the show() is called on the widget.
The same application works fine on the desktop, but when I run the application on the target, it hangs at show() call and in the display, I could see only the image of an arrow.

Thanks,
Sachin

SGaist

Is it hanging or not painting properly ?

sachintm

Hello SGaist,

It was the problem with font I guess.

When I set the font directory path using QT_QWS_FONTDIR and pass "-font unifont" while launching the application, it is launching and working properly.

Thanks for your support.
Sachin

SGaist

You welcome !

Glad you found out :)

Since it's all working now, don't forget to update the thread's title to solved so other forum users may know that a solution has been found :)