ScannerFeatureComponent.java

@Component(modules = {
    ScannerFeatureModule.class,
    ScreenNavigationModule.class
    // ScannerFeatureDependencies - api of Scanner feature dependencies
}, dependencies = ScannerFeatureDependencies.class)
@PerFeature
// ScannerFeatureApi - api of Scanner feature
public abstract class ScannerFeatureComponent implements ScannerFeatureApi {

    private static volatile ScannerFeatureComponent sScannerFeatureComponent;

    // classic Singleton
    public static ScannerFeatureApi initAndGet(
        ScannerFeatureDependencies scannerFeatureDependencies) {
        if (sScannerFeatureComponent == null) {
            synchronized (ScannerFeatureComponent.class) {
                if (sScannerFeatureComponent == null) {
                    sScannerFeatureComponent = DaggerScannerFeatureComponent.builder()
                        .scannerFeatureDependencies(scannerFeatureDependencies)
                        .build();
                }
            }
        }
        return sScannerFeatureComponent;
    }

    // this method is used in Scanner module to inject necessary dependencies
    public static ScannerFeatureComponent get() {
        if (sScannerFeatureComponent == null) {
            throw new RuntimeException(
                "You must call 'initAndGet(ScannerFeatureDependenciesComponent 
                 scannerFeatureDependenciesComponent)' method"
            );
        }
        return sScannerFeatureComponent;
    }

    // reset feature Component (when Scanner Activity is destroying)
    public void resetComponent() {
        sScannerFeatureComponent = null;
    }

    public abstract void inject(ScannerActivity scannerActivity);
   
    // more comfortable initializing of Presenters for using in Moxy
    public abstract ScannerScreenComponent scannerScreenComponent();

}