different build with Configure commandline macro

[Amarjit123]

Hello All.
I want to create two builds by passing some configure options in command line and add the macro in qml , so that based on that specific build will pick colors and ICON source. Basically, it should be like if I execute a certain command line for build it should fetch the specific color and ICON from qml and application should show the same. its urgent, kindly give some ideas or example programs/ links.

[sierdzio]

There are multiple ways to do this, I'll just pick one to keep this answer simple.

In cmake:

option(SOME_OPTION "Enables different colors" OFF)
if (SOME_OPTION)
  add_definitions(-DSOME_OPTION)
endif()

Then in c++:

#ifdef SOME_OPTION
  qmlEngine->rootContext()->setContextProperty("someOption", true);
#else 
  qmlEngine->rootContext()->setContextProperty("someOption", false);
#endif

This can be improved a lot by using some controller object (a subclass of QObject, maybe a QML_SINGLETON) which will provide good colors and icons to QML based on value of SOME_OPTION). But here, to keep it simple, I'm just passing the property someOption.

Lastly, in QML:

Rectangle {
  color: someOption ? "#ff0000" : "#00ff00"
}

With code prepared like that, you can produce different-looking builds like so:

cmake -S /path/to/source/code -B /build/path -DSOME_OPTION=On

cmake --build /build/path --config Release

Just set the option to On or Off, recompile, and you will get different builds.

[Axel Spoerl]

The bad news is: QML doesn't know preprocessor macros.
The good news is: There are easy workarounds.
I guess your project has a main.cpplaunchning the QML engine.

Suggestion (just from the top of my head, without trying to compile):
Add e.g. -DMYFLAGto the configure arguments.
In main.cppset a context property, based on the macro:

#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <QQmlContext>
/* any other includes needed */

int main(int argc, char *argv[])
{
    QGuiApplication app(argc, argv);
    QQmlApplicationEngine engine;
#ifdef MYFLAG
    const bool myFlag = true;
#elseif
    const bool myFlag = false;
#endif
    engine.rootContext()->setContextProperty("myFlag", QVariant(myFlag));
    const QUrl url(":/path/to/Main.qml");
    engine.load(url);
    return app.exec();

Evaluate the property in QML:

ApplicationWindow {
    Component.onCompleted {
        if (myFlag) {
            // do something
        }
    }
}

[Axel Spoerl]

@sierdzio
Simple minds not only think alike, but also post at the same time :-)
But I must admit, knowing color hex codes by heart exceeds my level!