How to create onclick event in adapter using interface android?

Question

How can I create on click event using interface?

In my application I've created view click interface to detect clicking on adapter items into parent activity. After creating interface and method into adapter how I can use this interface to call the view listener ?

Answer 1

Please check this code, It's working fine for me.

First Create Adapter class.

class ChapterAdapter(private val activity: Activity, val mWords: ArrayList<Chapter>, val btnlistener: BtnClickListener) : RecyclerView.Adapter<ChapterAdapter.ViewHolder>() {

        companion object {
            var mClickListener: BtnClickListener? = null
        }

        override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
            val layoutInflater = LayoutInflater.from(parent.context)
            return ViewHolder(layoutInflater.inflate(R.layout.layout_capter_raw, parent, false))
        }

        override fun onBindViewHolder(holder: ViewHolder?, position: Int) {
            mClickListener = btnlistener
            val item = mWords[position]

            holder.layout_chapter_name.setOnClickListener(object : View.OnClickListener {
                override fun onClick(v: View?) {
                    if (mClickListener != null)
                        mClickListener?.onBtnClick(position)
                }
            })
        }

        override fun getItemCount(): Int {
            return mWords.size
        }

        override fun getItemId(position: Int): Long {
            return super.getItemId(position)
        }

        override fun getItemViewType(position: Int): Int {
            return super.getItemViewType(position)
        }

        class ViewHolder(view: View) : RecyclerView.ViewHolder(view) {
            val txt_capter_name = view.txt_capter_name
        }

        open interface BtnClickListener {
            fun onBtnClick(position: Int)
        }
    }

After create and declare adapter in your Activity or Fragment.

listAdapter = ChapterAdapter(activity, _arrChapterList, object : ChapterAdapter.BtnClickListener {
                override fun onBtnClick(position: Int, chapter_id: String, chapter_size: String, chapter_name: String) {
                    toast(chapter_id + " = " + chapter_size, Toast.LENGTH_LONG)
                }
            })