TroyStopera

import android.app.Activity
import android.content.Intent

fun <T : Activity> Activity.startActivity(
    activityClass: KClass<T>, 
    intentBlock: (Intent.() -> Unit)? = null
) {
    val intent = Intent(this, activityClass.java)
    intentBlock?.invoke(intent)
    startActivity(intent)

TroyStopera

import android.view.View

fun View?.setVisibleIf(boolean: Boolean, otherwise: Int = View.GONE) {
    this?.visibility = if (boolean) View.VISIBLE else otherwise
}

fun View?.setVisibleIfNot(boolean: Boolean, otherwise: Int = View.GONE) = setVisibleIf(!boolean, otherwise)

TroyStopera

import java.util.*

fun Date.isSameDay(other: Date, timeZone: TimeZone = TimeZone.getDefault()): Boolean {
    val cal1 = Calendar.getInstance(timeZone).also { it.time = this }
    val cal2 = Calendar.getInstance(timeZone).also { it.time = other }

    return cal1.get(Calendar.DAY_OF_YEAR) == cal2.get(Calendar.DAY_OF_YEAR) &&
            cal1.get(Calendar.YEAR) == cal2.get(Calendar.YEAR)
}

TroyStopera

import android.os.Parcel

fun Parcel.writeBoolean(boolean: Boolean) = writeByte(if (boolean) 1 else 0)

fun Parcel.readBoolean() = readByte() != 0.toByte()

TroyStopera

import androidx.lifecycle.*

fun <T> LiveData<T>.observe(lifecycleOwner: LifecycleOwner, callback: (T) -> Unit): Observer {
  val observer = Observer(callback)
  this.observe(lifecyleOwner, observer)
  return observer
}