Groupie: Item Click Support

[dbof10]

How do you add click listener to a view in a ViewHolder?

[ayonymus]

You would do like this in kotlin:

override fun bind(viewHolder: ViewHolder, position: Int) {
    viewHolder.itemView.setOnClickListener {
        ( your on click logic)
    }
}

[lisawray]

Yes, exactly. Thanks @ayonymus :)

If you want a click listener on the root view of every Item in your adapter, Groupie can do that for you by calling GroupAdapter.setOnClickListener().

If I want a click listener that I set myself (usually on some part of an item and not the whole view), I usually create a meaningful interface, and pass it in the item's constructor. e.g.:

class ProductItem(val product: Product, val heartListener: OnHeartClickedListener) {
    interface OnHeartClickedListener {
        fun onHeartClicked(item: Item, product: Product)
    }

    override fun bind(viewHolder: ViewHolder, position: Int) {
        viewHolder.itemView.heart.setOnClickListener {
            heartListener.onHeartClicked(this@ProductItem, product)
        }
    }
}

[vincent-paing]

You would do like this in kotlin:

override fun bind(viewHolder: ViewHolder, position: Int) {
    viewHolder.itemView.setOnClickListener {
        ( your on click logic)
    }
}

That is not really a efficient way to execute, We should be not be recycling OnClickListener. Instead, pass a single listener object into the ViewHolder, and it should return with adapterPosition to the adapter. Currently, we have to override createViewHolder to make it really efficient.

[FirstSpectr]

The problem is still relevant. I am getting data from the backend and I have to add listeners to the items in a loop.

[Zhuinden]

I solved this issue like so:

class ProductItem(val product: Product, val heartListener: OnHeartClickedListener) {
    interface OnHeartClickedListener {
        fun onHeartClicked(item: Item, product: Product)
    }

    private val onClickListener = OnClickListener {
        heartListener.onHeartClicked(this@ProductItem, product)
    }

    override fun bind(viewHolder: ViewHolder, position: Int) {
        viewHolder.itemView.heart.setOnClickListener(onClickListener)
    }
}