Truquis

DatabindingExtensions.kt

import android.databinding.Observable as DataBindingObservable

private inline fun <reified T : DataBindingObservable, R : Any?> T.observe(
        crossinline block: (T) -> R
): Observable<R> = create { subscriber ->
    object : android.databinding.Observable.OnPropertyChangedCallback() {
        override fun onPropertyChanged(observable: DataBindingObservable, id: Int) = try {
            subscriber.onNext(block(observable as T))
        } catch (e: Exception) {
            subscriber.onError(e)
        }
    }.let {
        subscriber.setCancellable { this.removeOnPropertyChangedCallback(it) }
        this.addOnPropertyChangedCallback(it)
    }
}

fun <T : Any> ObservableField<T>.observe() = observe { it() }

operator fun <T : Any?> ObservableField<T>.invoke(): T = get()

//así se usa
val concertList: ObservableField<List<Concert>> = ObservableField(listOf())
compositeDisposable += concertList.observe().subscribe { numberOfResults.set(it.size) }

NumberExtensions.kt

internal val context: Context by lazy { MyCustomApplication.appContext }

val Int.sp: Float
    get() = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, this.toFloat(), context.resources.displayMetrics)

val Int.dp: Float
    get() = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, this.toFloat(), context.resources.displayMetrics)

fun Float.digits(numOfDigits: Int): String {
    return String.format("%.${numOfDigits}f",this)
}

fun Long.fromMillistoDays(): Int {
    return (this/86400000).toInt()
}

fun Long.fromMillisToWeeks(): Int {
    return this.fromMillistoDays() / 7
}

RxBindings.kt

fun TextView.textEvents(): Observable<CharSequence> {
    return Observable.create {
        if (it.isDisposed.not()) {
            this.addTextChangedListener(object : TextWatcher {
                override fun afterTextChanged(s: Editable?) {
                }

                override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {
                }

                override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
                    it.onNext(s)
                }
            })
        }
    }
}