Show dialog on longitemclick of ListAdapter

Question

I have an activity that contains the following List adapter to show some information about github repositories. Now I need to implement that when on a long-press on a list item show a dialog to ask if should go to repository html_url or owner html_url which is then opened in the browser.

What would be the best way to implement this? Should the logic be in the activity or in the ListAdapater/ViewHolder?

RepositoryListAdapter

class RepositoryListAdapter : ListAdapter<Repo, RepositoryListAdapter.RepositoryViewHolder>(
    RepositoryDiffCallback()
) {
    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int) =
        RepositoryViewHolder(
            LayoutInflater.from(parent.context).inflate(
                R.layout.item_repository,
                parent,
                false
            )
        )

    override fun onBindViewHolder(holder: RepositoryViewHolder, position: Int) {
        holder.bind(getItem(position))
    }

    class RepositoryViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView){
        fun bind(repository: Repo) = with(itemView) {
            repositoryName.text = repository.name
            repositoryDescription.text = repository.description
            ownerLogin.text = repository.owner.login
            Glide.with(context)
                .load(repository.owner.avatarUrl)
                .into(imageView)
            if (repository.forksCount > 0) {
                itemView.setBackgroundColor(ContextCompat.getColor(context, R.color.light_green))
            } else {
                itemView.setBackgroundColor(ContextCompat.getColor(context, android.R.color.white))
            }
        }
    }
}

class RepositoryDiffCallback : DiffUtil.ItemCallback<Repo>() {
    override fun areItemsTheSame(oldItem: Repo, newItem: Repo): Boolean {
        return oldItem.id == newItem.id
    }

    override fun areContentsTheSame(oldItem: Repo, newItem: Repo): Boolean {
        return oldItem == newItem
    }
}

Sơn Phan · Accepted Answer · 2020-10-23T15:37:20.043

Let the Activity pass a listener to the adapter to do it.

In your adapter, create a listener interface:

class RepositoryListAdapter(val onItemLongClickListener: OnItemLongClickListener) : ListAdapter<Repo, RepositoryListAdapter.RepositoryViewHolder>(
    RepositoryDiffCallback()
) {
   
    interface OnItemLongClickListener {
        fun onItemLongClick(item: Repo, position: Int)
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int) =
        RepositoryViewHolder(
            LayoutInflater.from(parent.context).inflate(
                R.layout.item_repository,
                parent,
                false
            )
        ).also { vh ->
             vh.itemView.setOnLongClickListener { 
                 val position = vh.adapterPosition
                 if (position != RecyclerView.NO_POSITION) {
                     onItemLongClickListener.onItemLongClick(getItem(position), position)
                 }
                 true
             }
         }

}

Then in your activity where you create the adapter, pass the listener:

class YourActivity : Activity {
    private lateinit var adapter: RepositoryListAdapter

    override fun onCreate(savedInstanceState: Bundle?) {
        ...
        adapter = RepositoryListAdapter(object : OnItemLongClickListener {
            override fun onItemLongClick(item: Repo, position) {
                // Your logic to show the dialog
            }
        })
        ...    
    }
}

score 1 · Answer 2 · answered Oct 23 '20 at 14:10

The best approach is to handle long click popup in adapter and consume the action after user click to fragment/activity

    class RepositoryListAdapter : ListAdapter<Repo, RepositoryListAdapter.RepositoryViewHolder>(
        RepositoryDiffCallback()
    ) {
    
    
        adapter.setPopupListener(object : OnPopupClick {
            override fun goToRepository() {
                //Consume action
            }
    
            override fun goToOwner(){
                //Consume action
            }
        })
    
    
        override fun onCreateViewHolder(parent: ViewGroup, viewType: Int) =
            RepositoryViewHolder(
                LayoutInflater.from(parent.context).inflate(
                    R.layout.item_repository,
                    parent,
                    false
                )
            )
    
        override fun onBindViewHolder(holder: RepositoryViewHolder, position: Int) {
            holder.bind(getItem(position))
        }
    
        //WeakReference to prevent un-wanted gc clean of listener
        private var popupListener: WeakReference<OnPopupClick>? = null
    
        fun setPopupListener(listener: OnPopupClick) {
            popupListener = WeakReference(listener)
        }
    
        interface OnPopupClick {
            fun goToRepository()
            fun goToOwner()
        }
    
        class RepositoryViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView){
            fun bind(repository: Repo) = with(itemView) {
                repositoryName.text = repository.name
                repositoryDescription.text = repository.description
                ownerLogin.text = repository.owner.login
                Glide.with(context)
                    .load(repository.owner.avatarUrl)
                    .into(imageView)
    
    
                itemView.setOnLongClickListener{
                    onLongClick()
                }
    
                if (repository.forksCount > 0) {
                    itemView.setBackgroundColor(ContextCompat.getColor(context, R.color.light_green))
                } else {
                    itemView.setBackgroundColor(ContextCompat.getColor(context, android.R.color.white))
                }
            }
    
            fun onLongClick(){
    
                //MenuAnchor must be added to your item view
                val popup = PopupMenu(view.context, menuAnchor)
    
                popup.inflate(R.menu.yourMenu)  //Customize for user
    
                popup.setOnMenuItemClickListener(object : PopupMenu.OnMenuItemClickListener {
                    override fun onMenuItemClick(item: MenuItem?): Boolean {
                        when (item?.itemId) {
                            R.id.owner -> {
                                popupListener?.get()?.goToOwner()
                                return true
                            }
                            R.id.repo ->{
                                popupListener?.get()?.goToRepository()
                                return true
                            }
                        }
                        return true
                    }
                })
    
                popup.show()
    
            }
        }
    }
    
    class RepositoryDiffCallback : DiffUtil.ItemCallback<Repo>() {
        override fun areItemsTheSame(oldItem: Repo, newItem: Repo): Boolean {
            return oldItem.id == newItem.id
        }
    
        override fun areContentsTheSame(oldItem: Repo, newItem: Repo): Boolean {
            return oldItem == newItem
        }
    }

After that add to your activity/fragment:

  adapter.setPopupListener(object : OnPopupClick {
    override fun goToRepository() {
        //Consume action
    }

    override fun goToOwner(){
        //Consume action
    }
})

score 0 · Answer 3 · answered Oct 23 '20 at 15:06

This is how I did it in the end, in case anyone finds it useful.

RepositoryListAdapter

class RepositoryListAdapter(private val interaction: Interaction? = null) : ListAdapter<Repo, RepositoryListAdapter.RepositoryViewHolder>(
    RepositoryDiffCallback()
) {

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

    override fun onBindViewHolder(holder: RepositoryViewHolder, position: Int) {
        holder.bind(getItem(position))
    }

    class RepositoryViewHolder(itemView: View, private val interaction: Interaction?)
        : RecyclerView.ViewHolder(itemView){
        fun bind(repository: Repo) = with(itemView) {
            repositoryName.text = repository.name
            repositoryDescription.text = repository.description
            ownerLogin.text = repository.owner.login
            Glide.with(context)
                .load(repository.owner.avatarUrl)
                .into(imageView)
            if (repository.forksCount > 0) {
                itemView.setBackgroundColor(ContextCompat.getColor(context, R.color.light_green))
            } else {
                itemView.setBackgroundColor(ContextCompat.getColor(context, android.R.color.white))
            }
            setOnLongClickListener {
                interaction?.onItemLongClick(repository)
                true
            }
        }
    }

    interface Interaction {
        fun onItemLongClick(item: Repo)
    }
}

Activty

class MainActivity : AppCompatActivity(), RepositoryListAdapter.Interaction {
...
    private fun setupListAdapter() {
        repositoryListAdapter = RepositoryListAdapter(this)
     ...
     }

    private fun showDialog(repo: Repo) {
        dialog = AlertDialog.Builder(this)
            .setItems(arrayOf("Repository url", "Owner url")) { _, which ->
                when (which) {
                    0 -> openUrl(repo.htmlUrl)
                    1 -> openUrl(repo.owner.htmlUrl)
                }
            }.show()
    }

    private fun openUrl(url: String?) {
        url?.let {
            startActivity(Intent(Intent.ACTION_VIEW, Uri.parse(url)))
        }
    }

    override fun onItemLongClick(item: Repo) {
        showDialog(item)
    }
...
}

Avoid setting any listener in `onBindViewHolder` since this method will be called over and over again. Check my answer for a more optimized approach. — Sơn Phan, Oct 23 '20 at 15:13
I tried that, but I can't access adapterPosition there :/ is there another way to get the position? — Praveen P., Oct 23 '20 at 15:26
Oops sorry I forgot the `it.` before `adapterPosition`. I edited, check again. If you find it useful please mark accepted. — Sơn Phan, Oct 23 '20 at 15:28
Could you change it to the following? It's taking the second it, so thats why it wan't getting the position. ```.also { viewHolder -> viewHolder.itemView.setOnLongClickListener { val position = viewHolder.adapterPosition if (position != RecyclerView.NO_POSITION) { interaction?.onItemLongClick(getItem(position)) } true } }``` — Praveen P., Oct 23 '20 at 15:34
I still don't get what is the difference between doing it in onCreateViewHolder and onBindViewHolder? — Praveen P., Oct 23 '20 at 15:36
Check out this so [question](https://stackoverflow.com/questions/33845846/why-is-adding-an-onclicklistener-inside-onbindviewholder-of-a-recyclerview-adapt) — Sơn Phan, Oct 23 '20 at 15:39
Like I said above, `onBindViewHolder` will be called over and over again so the `setOnLongClickListener` eventually will be unnecessarily called many times. — Sơn Phan, Oct 23 '20 at 15:42

Show dialog on longitemclick of ListAdapter

3 Answers3