Android AdapterView Extension Functions

AdapterExtensions.kt

inline fun <T : Adapter> AdapterView<T>.registerForAdapterEventListener(
    crossinline itemListener: (parent: AdapterView<*>, view: View, position: Int, id: Long) -> Unit,
) = doOnItemSelectedListener(itemListener, {})

inline fun <T : Adapter> AdapterView<T>.registerForAdapterEventListener(
    crossinline itemListener: (parent: AdapterView<*>, view: View, position: Int, id: Long) -> Unit,
    crossinline nothingListener: (parent: AdapterView<*>) -> Unit = {},
) = doOnItemSelectedListener(itemListener, nothingListener)


inline fun <T : Adapter> AdapterView<T>.doOnItemSelectedListener(
    crossinline itemListener: (parent: AdapterView<*>, view: View, position: Int, id: Long) -> Unit,
    crossinline nothingListener: (parent: AdapterView<*>) -> Unit,
): AdapterView.OnItemSelectedListener {
    val listener = object : AdapterView.OnItemSelectedListener {
        override fun onItemSelected(parent: AdapterView<*>, view: View, position: Int, id: Long) {
            itemListener.invoke(parent, view, position, id)
        }

        override fun onNothingSelected(parent: AdapterView<*>) {
            nothingListener.invoke(parent)
        }
    }
    this.onItemSelectedListener = listener
    return listener
}