Preset adapter for Equalizer presets

PresetAdapter.kt

import android.content.Context
import android.support.v7.widget.RecyclerView
import android.util.Log
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.CheckBox
import android.widget.CompoundButton
import android.widget.TextView
import kotlinx.android.synthetic.main.item_preset.view.*
import midien.kheldiente.equalizer.R
import midien.kheldiente.equalizer.data.Preset

class PresetAdapter(private val context: Context,
  var presetList: ArrayList<Preset> = ArrayList(0),
  var enabled: Boolean = false,
  var currentPreset: String = "Normal",
  var currentPosition: Int = 0,
  private val listener: (Int, Preset) -> Unit)
  : RecyclerView.Adapter<PresetAdapter.PresetViewHolder>() {

  val TAG = PresetAdapter::class.java.simpleName
  val itemViewList = ArrayList<View>(0)

  override fun onBindViewHolder(holder: PresetViewHolder, position: Int)
    = holder.bind(position = position, preset = presetList[position], listener = listener)

  override fun onCreateViewHolder(parent: ViewGroup, viewType: Int)
    = PresetViewHolder(LayoutInflater.from(context).inflate(R.layout.item_preset, parent, false))

  override fun getItemCount() = presetList.size

  fun checkAll(check: Boolean) {
    itemViewList.forEach {
      val checkBox = it.findViewById<CheckBox>(R.id.cb_preset_selected)
      checkBox.isChecked = check
    }
  }

  fun enableAll(enable: Boolean) {
    itemViewList.forEach {
      val txtName = it.findViewById<TextView>(R.id.txt_preset)
      val checkBox = it.findViewById<CheckBox>(R.id.cb_preset_selected)

      txtName.isEnabled = enable
      checkBox.isEnabled = enable
      it.isEnabled = enable
    }
  }

  fun check(position: Int) {
    itemViewList.forEachIndexed { index, view ->
      val checkBox = view.findViewById<CheckBox>(R.id.cb_preset_selected)
      checkBox.isChecked = index === position
    }
  }

  inner class PresetViewHolder(itemView: View)
    : RecyclerView.ViewHolder(itemView) {

    fun bind(position: Int, preset: Preset, listener: (Int, Preset) -> Unit) = with(itemView) {
      // Save instance for reference
      itemViewList.add(itemView)
      txt_preset.text = preset.name
      itemView.isEnabled = enabled
      txt_preset.isEnabled = enabled
      cb_preset_selected.isEnabled = enabled
      cb_preset_selected.tag = position

      if(preset.name.equals(currentPreset)) {
        currentPosition = position
        cb_preset_selected.isChecked = true
      }

      // Set listeners
      setOnClickListener {
        applyChanges(position, listener, cb_preset_selected, preset)
      }
      cb_preset_selected.setOnCheckedChangeListener { _, _ ->
        // Override and do nothing
      }
    }

    fun applyChanges(position: Int, listener: (Int, Preset) -> Unit,  cb: CompoundButton, preset: Preset) {
      if(currentPosition != position) {
        Log.d(TAG, "applyChanges: $position")
        currentPosition = position
        cb.isChecked = !cb.isChecked
        listener(position, preset)
        forceUncheck(position)
      }
    }

    fun forceUncheck(selected: Int) {
      itemViewList
        .filterIndexed { index, view -> index != selected }
        .forEach {
            val checkBox = it.findViewById<CheckBox>(R.id.cb_preset_selected)
            checkBox.isChecked = false
        }
    }
  }
}