Build a Symbian Qt app

examples/qt_app displays a full-screen Qt button. Tapping it closes the application through the Qt event loop and runs the normal application destructors. It uses guest Symbian Qt 4.8.1; the Qt 6 desktop libraries bundled with the emulator serve its host interface and cannot provide guest widgets.

Install the SDK and emulator

Follow Getting started to install symbian-platform into a Python environment. Install the native SDK archive for your host, then install and check the compatible emulator:

symbian emulator install
symbian emulator doctor

Import your firmware and select its local alias. This example requires EKA2 firmware with guest QtCore and QtGui 4.8.1 installed. The SDK and emulator distributions include neither firmware nor guest Qt DLLs. Do not replace the Qt DLLs in another device's firmware with this example's imports.

Prepare the example

The native SDK supplies the original QtCore/QtGui headers, complete import libraries, compatibility settings and allocator hook. It also includes the example source. After installing the SDK at ~/dev/symbian-sdk, build it:

qt_project="$HOME/dev/symbian-sdk/examples/qt_app"
symbian build --project "$qt_project" --output .symbian/qt-app
symbian inspect --format e32 .symbian/qt-app/qt_app.exe

The application build is an ordinary CMake target:

include(SymbianApp)
symbian_add_executable(qt_app app.cc)
target_link_libraries(qt_app PRIVATE Symbian::Runtime Symbian::QtGui)

Symbian::QtGui brings in QtCore. The SDK generates the needed E32 imports from the libraries actually linked; applications need no symbol list or startup files. sdk-location.json can select another installed native SDK. If Symbian::QtGui is unavailable, install a native SDK containing guest Qt support. Older SDK distributions do not provide this target.

The native SDK supplies Clang, LLD, CMake and Ninja on both hosts. From a source checkout, set qt_project="$PWD/examples/qt_app" to use the repository copy instead.

Run the button

Select your imported firmware and launch the application:

symbian app run --project "$qt_project" --firmware my-phone --backend dynarmic

The SDK stages the executable and its application resources, then opens the full-screen button. It reads “Hello from Symbian Qt / Tap to close”; a tap exits the guest application and closes the emulator. --backend dyncom selects the other CPU backend.

To browse the firmware's application list instead, use symbian emu run --project "$qt_project" --firmware my-phone, open Symbian Qt, and close the emulator window when finished.

The application constructs its widgets after QApplication and connects the button's signal to the application slot:

QPushButton button(QString::fromUtf8("Hello from Symbian Qt\nTap to close"));
button.setWindowTitle(QString::fromUtf8("Symbian Qt"));
if (!QObject::connect(&button, SIGNAL(clicked()), &application, SLOT(quit()))) {
  return 3;
}
button.showFullScreen();
return application.exec();

The complete app.cc also selects raster graphics and Plastique, and disables the S60 exit-animation signal. The emulator does not implement the Window Server graphics plugins used by those animations. Keep those settings when adapting this example for the emulator. This is an EKA2 widget example; EKA1, other guest Qt versions, general Qt modules and physical-device operation are outside its tested configuration.

Package the application

The supplied symbian.toml declares the executable, menu caption and package:

symbian package --project "$qt_project" \
  --artifact .symbian/qt-app/qt_app.exe --output .symbian/qt-package
symbian inspect --format sis .symbian/qt-package/qt_app.sis

The package contains your executable and registration resources. It requires the device's existing Qt installation. For signing and transfer, follow the application packaging and device guide.