Show how to use extension function to handle recyclerView item and subItem listeners

RecyclerviewListeners

Show how to use extension function to handle recyclerView item and subItem listeners.

There are different ways to handle recyclerView item click listener, today I am going to use kotlin extension function to handle the item click listener and different listeners for sub view in the recycleView cell.

* Using Extenstion fun

• Row (item) click listener
• SubView click listener
• CompoundButton onCheckedChanged listener Code

          //RadioButton, Checkbox, Switch
fun RecyclerView.addOnCheckedChangeListener(onCheckedChangeListener: OnCheckedChangeListener) {
    this.addOnChildAttachStateChangeListener(object : RecyclerView.OnChildAttachStateChangeListener {
        override fun onChildViewAttachedToWindow(view: View) {
            val holder = getChildViewHolder(view)
            for (index in 0 until (view as ViewGroup).childCount) {
                val subview = view.getChildAt(index)
                if(subview is CompoundButton) {
                    subview.setOnCheckedChangeListener { compoundButton, b ->
                        onCheckedChangeListener.onCheckedChanged(compoundButton, b, holder.adapterPosition)
                    }
                }
            }
        }

         override fun onChildViewDetachedFromWindow(view: View) {
            for (index in 0 until (view as ViewGroup).childCount) {
                val subview = view.getChildAt(index)
                if(subview is CompoundButton) {
                    subview.setOnCheckedChangeListener (null)
                }
            }
        }
    })

• RadioGroup onCheckedChanged listener Code

fun RecyclerView.addOnRadioGroupCheckedChangeListener(onRadioGroupCheckedChangeListener: OnRadioGroupCheckedChangeListener) {
    this.addOnChildAttachStateChangeListener(object : RecyclerView.OnChildAttachStateChangeListener {
        override fun onChildViewAttachedToWindow(view: View) {
            val holder = getChildViewHolder(view)
            for (index in 0 until (view as ViewGroup).childCount) {
                val subview = view.getChildAt(index)
                if (subview is RadioGroup) {
                    subview.setOnCheckedChangeListener { group, buttonId ->
                        onRadioGroupCheckedChangeListener.onCheckedChanged(group, buttonId, holder.adapterPosition)
                    }
                }
            }
        }

        override fun onChildViewDetachedFromWindow(view: View) {
            for (index in 0 until (view as ViewGroup).childCount) {
                val subview = view.getChildAt(index)
                if (subview is RadioGroup) {
                    subview.setOnCheckedChangeListener(null)
                }
            }
        }
    })
}

* Using inline fun Full Code

GitHub