CustomView.kt

package com.pivincii.blogging

import android.app.Activity
import android.content.Context
import android.content.Intent
import android.util.AttributeSet
import android.widget.Button
import android.widget.FrameLayout
import android.widget.TextView
import com.pivincii.blogging.activityresult.ActivityResultObserver
import com.pivincii.blogging.activityresult.ActivityResultObservable
import android.Manifest.permission.READ_EXTERNAL_STORAGE
import android.support.v4.app.ActivityCompat
import android.content.pm.PackageManager
import android.os.Build


private const val PICKFILE_REQUEST_CODE = 1001

/**
 * TODO: document your custom view class.
 */
class CustomView @JvmOverloads constructor(
        context: Context,
        attrs: AttributeSet? = null,
        defStyleAttr: Int = 0
): FrameLayout(context, attrs, defStyleAttr), ActivityResultObserver {
    override fun onAttachedToWindow() {
        super.onAttachedToWindow()
        (context as ActivityResultObservable).addObserver(this)
    }

    override fun onDetachedFromWindow() {
        super.onDetachedFromWindow()
        (context as ActivityResultObservable).removeObserver(this)
    }

    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
        if (requestCode == PICKFILE_REQUEST_CODE && resultCode == Activity.RESULT_OK) {
            data?.dataString?.run { pathFileTV.text = this }
        }
    }
}