pd2

BindableProperty.kt

fun <T> BaseObservable.bindable(initialValue: T, propertyId: Int): BindableProperty<T> {
    return BindableProperty<T>(initialValue, this)
}

class BindableProperty<T>(initialValue: T,
                          private val observable: BaseObservable) : ObservableProperty<T>(initialValue) {

    private var propertyId: Int = 0

    override fun beforeChange(property: KProperty<*>, oldValue: T, newValue: T): Boolean {
        return oldValue != newValue
    }

    override fun afterChange(property: KProperty<*>, oldValue: T, newValue: T) {
        observable.notifyPropertyChanged(propertyId)
    }

    operator fun provideDelegate(observable: BaseObservable, property: KProperty<*>): BindableProperty<T> {
        propertyId = PropertyMapper.bindableResourceIdForKProperty(property)
        return this
    }
}