Function Documentation

[since Qt Quick Ultralite 1.0] void Qul::appMain(const void *arg = NULL)

This function initializes and also acts as a main loop for Qt Quick Ultralite application. This function never exits. arg is not used.

Hardware and Qt Quick Ultralite platform specific components needs to be initialized before calling this function.

This function is called implicitly as part of default entry point implementation if app_target_default_entrypoint is used.

This function was introduced in Qt Quick Ultralite 1.0.

See also initHardware, initPlatform, and Running Qt Quick Ultralite in applications.

[since Qt Quick Ultralite 2.10] void Qul::enableResourceChecksumVerification()

Enable resource data checksum verification

This function enables a resource binary checksum verification to be done during resource initialization, which happens when Qul::initPlatform() or Qul::initResources() is called. The verification computes a CRC32 checksum at runtime, and compares it to the checksum that was computed by the Qt Quick Ultralite resource compiler when the resource binary was originally generated.

If the checksum verification fails, the QulError_Qul_ResourceInitializationFailed assert with parameter ResourceInitializationError::InvalidChecksum will be triggered if Qul::initPlatform() is called with the PlatformInitializationType::InitializePlatformAndResources initialization option. If Qul::initResources() is used, it will return the error code to ResourceInitializationError::InvalidChecksum.

If the resource initialization fails, using any Qt Quick Ultralite API is not supported and may yield undefined behavior.

To have any effect, this function has to be called before Qul::initPlatform() or Qul::initResources() is called.

This function was introduced in Qt Quick Ultralite 2.10.

See also initPlatform and initResources.

[since Qt Quick Ultralite 2.2] const char *errorCodeToString(QulError code)

Returns a pointer to C-string representation of the error code.

On debug build, the function returns a string representation for error range start values and error codes in the Core and Platform range. On release build, it returns a string representation for error range start values and empty string for the rest of error code values.

This function was introduced in Qt Quick Ultralite 2.2.

See also Qul::PlatformInterface::error and Error handling.

[since Qt Quick Ultralite 2.0] void Qul::initHardware()

Initialize hardware required by Qt Quick Ultralite.

This may include clocks, pins, peripherals, buses and memories.

Typically it's called just before Qul::initPlatform(), but developer may also decide not call it all and perform its own hardware initialization.

This function is called implicitly as part of default entry point implementation if app_target_default_entrypoint is used.

This function calls PlatformContext::initializeHardware.

This function was introduced in Qt Quick Ultralite 2.0.

See also appMain, initPlatform, and Running Qt Quick Ultralite in applications.

[since Qt Quick Ultralite 1.0] void Qul::initPlatform(Qul::PlatformInitializationType initializationType = PlatformInitializationType::InitializePlatformAndResources)

Initialize Qt Quick Ultralite platform specific components.

This may include resource preloading and initializing CPU-based fallback drawing engine in Qt Quick Ultralite core.

This function is called implicitly as part of default entry point implementation if app_target_default_entrypoint is used.

This function calls PlatformContext::initializePlatform.

If initializationType is set to PlatformInitializationType::InitializePlatformAndResources, font alpha maps, binary resources image resources and resource caches are also initialized. This is the default behavior.

If initializationType is set to PlatformInitializationType::InitializePlatform, the application should explicitly call initResources() following the call to initPlatform().

This function was introduced in Qt Quick Ultralite 1.0.

See also appMain, initHardware, initResources, and Running Qt Quick Ultralite in applications.

[since Qt Quick Ultralite 2.10] Qul::Status<Qul::ResourceInitializationError> Qul::initResources()

Initialize Qt Quick Ultralite resources.

This function initializes resource font alpha maps, binary resources, image resources, and resource caches. Resource initialization has to happen once at application startup, before calling Application::exec() or Application::update().

Before using this function, Qul::initPlatform() should have been called with Qul::PlatformInitializationType::InitializePlatform.

The return value indicates whether initialization was successful or not.

If the resource initialization fails, using any Qt Quick Ultralite API (including this function itself) is not supported and may yield undefined behavior.

If resource initialization has already been successfully performed, then this function returns true immediately.

This function was introduced in Qt Quick Ultralite 2.10.

See also appMain, initHardware, initPlatform, and Running Qt Quick Ultralite in applications.

[since Qt Quick Ultralite 2.2] QulErrorHandler *Qul::setErrorHandler(QulErrorHandler *handler)

Set error handler to handler. handler is called when error is reported with Qul::PlatformInterface::error.

Passing NULL as argument will restore the default error handling.

Error handler example:

#include <qul/error.h>

void customErrorHandler(enum QulError code, unsigned int lineNumber, int param1, int param2, int param3)
{
    Qul::PlatformInterface::log("Error code: %u, line: %u, params: %i, %i, %i.\r\n",
                                (unsigned int) code,
                                lineNumber,
                                param1,
                                param2,
                                param3);

    while (1) {
    }; // The error handler must not return!
}

The customErrorHandler function is set to handle the errors in the example below.

Qul::initHardware();
Qul::setErrorHandler(customErrorHandler);
Qul::initPlatform();
Qul::Application app;

This function calls Qul::PlatformInterface::setErrorHandler.

Returns a pointer to the previous error handler or NULL when the default handler is in use.

This function was introduced in Qt Quick Ultralite 2.2.

See also Error handling.