DialogFragment for Android (SDK 22) in Kotlin 1.0.2

MainActivity.kt

class MainActivity : AppCompatActivity(), SeekDialogFragment.SeekDialogListener {

    companion object {
        private val TAG = MainActivity::class.qualifiedName;
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val view = findViewById(R.id.button)
        view.setOnClickListener {
            SeekDialogFragment.show(this, 0, 0..10)
        }
//        view.setOnTouchListener {
//            view, motionEvent ->
//            SeekDialogFragment.show(this, 0, 0..10)
//            true
//        }
    }

    override fun onChangeSeekValue(value: Int) {
        Log.d(TAG, "$value is selected")
    }
}

seek_dialog.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <SeekBar
        android:id="@+id/seek"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

</LinearLayout>

SeekDialogFragment.kt

import android.app.Activity
import android.app.AlertDialog
import android.app.Dialog
import android.app.DialogFragment
import android.os.Bundle
import android.widget.SeekBar

class SeekDialogFragment : DialogFragment() {

    interface SeekDialogListener {
        fun onChangeSeekValue(value: Int)
    }

    companion object {
        val TAG = SeekDialogFragment::class.qualifiedName
        val ARG_VALUE = "value"
        val ARG_MIN = "min"
        val ARG_MAX = "max"

        fun show(activity: Activity, value: Int, range: IntRange) {
            SeekDialogFragment().apply {
                arguments = Bundle().apply {
                    putInt(ARG_VALUE, value)
                    putInt(ARG_MIN, range.first)
                    putInt(ARG_MAX, range.last)
                }
            }.show(activity.fragmentManager, TAG)
        }
    }

    private var listener: SeekDialogListener? = null

    override fun onAttach(activity: Activity) {
        super.onAttach(activity)
        if (activity is SeekDialogListener) {
            listener = activity
        }
    }

    override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
        val min = arguments.getInt(ARG_MIN)
        val view = activity.layoutInflater.inflate(R.layout.seek_dialog, null)
        val seek = view.findViewById(R.id.seek) as SeekBar
        seek.run {
            max = arguments.getInt(ARG_MAX) - min
            progress = arguments.getInt(ARG_VALUE) - min
        }
        return AlertDialog.Builder(activity)
                .setTitle("Seek")
                .setView(view)
                .setPositiveButton("OK") {
                    dialog, which ->
                    listener?.onChangeSeekValue(seek.progress + min)
                }
                .create()
                .apply {
                    setCanceledOnTouchOutside(false)
                }
    }
}

Why do not use kotlinx.android.synthetic to find seek?
Because that did not work?
I tried that not work.