ArrayAdapter<T>内の全Itemを取得するための拡張メソッド

ArrayAdapterExt.kt

// ArrayAdapter.getItems() with iterator
public class ArrayAdapterIterator<T>(val adapter: ArrayAdapter<T>) {
    private var index = 0

    fun next() = adapter.getItem(index++)
    fun hasNext() = index < adapter.getCount()
}

public fun <T>ArrayAdapter<T>.iterator(): ArrayAdapterIterator<T> = ArrayAdapterIterator(this)

public fun <T>ArrayAdapter<T>.getItems(): List<T> {
    val items = ArrayList<T>(getCount())
    for (item in this) {
        items.add(item)
    }
    return items
}