ibrahimyilmaz/kiel

(Published to MavenCentral) Kotlin way of building RecyclerView Adapter 🧩. You do not have to write RecyclerView Adapters again and again and suffer from handling of different view types. Kiel will help you.

Kiel

Kiel is a RecyclerView.Adapter with a minimalistic and convenient Kotlin DSL which provides utility on top of Android's normal RecyclerView.Adapter.

Most of the time:

• We found ourselves repeating same boilerplate code for RecyclerView.Adapter.
• We have difficulty in handling RecyclerView.Adapter when there are many viewTypes.

But now, Kiel may help us to get rid of these problems. You may read the detailed story in this blog post.

Usage:

Basic Usage:

adapterOf

 val recyclerViewAdapter = adapterOf<Text> {
                register(
                    layoutResource = R.layout.adapter_message_text_item,
                    viewHolder = ::TextMessageViewHolder,
                    onViewHolderCreated = { vh->
                       //you may handle your on click listener
                       vh.itemView.setOnClickListener {

                       }
                    },
                    onBindViewHolder = { vh, _, it ->
                        vh.messageText.text = it.text
                        vh.sentAt.text = it.sentAt
                    }
                )
     }

 recyclerView.adapter = recyclerViewAdapter

pagingDataAdapterOf

 val pagingDataAdapterOf = pagingDataAdapterOf<Text> {
                register(
                    layoutResource = R.layout.adapter_message_text_item,
                    viewHolder = ::TextMessageViewHolder,
                    onViewHolderCreated = { vh->
                       //you may handle your on click listener
                       vh.itemView.setOnClickListener {

                       }
                    },
                    onBindViewHolder = { vh, _, it ->
                        vh.messageText.text = it.text
                        vh.sentAt.text = it.sentAt
                    }
                )
     }

 recyclerView.adapter = recyclerViewAdapter

Different View Types:

You may register different ViewHolders to your adapters.

              register(
                    layoutResource = R.layout.adapter_message_text_item,
                    viewHolder = ::TextMessageViewHolder,
                    onBindViewHolder = { vh, _, it ->
                        vh.messageText.text = it.text
                        vh.sentAt.text = it.sentAt
                    }
                )

                register(
                    layoutResource = R.layout.adapter_message_image_item,
                    viewHolder = ::ImageMessageViewHolder,
                    onBindViewHolder = { vh, _, item ->
                        vh.messageText.text = item.text
                        vh.sentAt.text = item.sentAt

                        Glide.with(vh.messageImage)
                            .load(item.imageUrl)
                            .into(vh.messageImage)
                    }
                )

Handling Events:

As ViewHolder instance is accessible in:

• onViewHolderCreated
• onBindViewHolder
• onBindViewHolderWithPayload

You can handle the events in the same way how you did it before.

 val recyclerViewAdapter = adapterOf<Text> {
                register(
                    layoutResource = R.layout.adapter_message_text_it,
                    viewHolder = ::TextMessageViewHolder,
                    onViewHolderCreated = { vh->
                       vh.itemView.setOnClickListener {

                       }
                       vh.messageText.addTextChangedListener{text ->

                       }
                    },
                    onBindViewHolder = { vh, _, it ->
                        vh.messageText.text = it.text
                        vh.sentAt.text = it.sentAt
                    }
                )
 }

recyclerView.adapter = recyclerViewAdapter

View Binding:

As ViewHolder instance is accessible in:

• onViewHolderCreated
• onBindViewHolder
• onBindViewHolderWithPayload

You may define your ViewBinding in your ViewHolder class and you can easily reach it:

class TextMessageViewHolder(view: View) : RecyclerViewHolder<Text>(view) {
    val binding = AdapterTextItemBinding.bind(view)
}

val recyclerViewAdapter = adapterOf<Text> {
                register(
                    layoutResource = R.layout.adapter_message_text_it,
                    viewHolder = ::TextMessageViewHolder,
                    onViewHolderCreated = { vh->
                       vh.binding.
                    },
                    onBindViewHolder = { vh, _, it ->
                       vh.binding.messageText.text = it.text
                       vh.binding.sentAt.text = it.sentAt
                    }
                )
 }

DiffUtil:

val recyclerViewAdapter = adapterOf<MessageViewState> {
                diff(
                    areContentsTheSame = { old, new -> old == new },
                    areItemsTheSame = { old, new -> old.message.id == new.message.id },
                    getChangePayload = { oldItem, newItem ->
                        val diffBundle = Bundle()

                        if (oldItem.selectionState != newItem.selectionState) {
                            diffBundle.putParcelable(
                                TextMessageViewHolder.KEY_SELECTION,
                                newItem.selectionState
                            )
                        }

                        if (diffBundle.isEmpty) null else diffBundle
                    }
                )
                register (
                    layoutResource = R.layout.adapter_message_text_item,
                    viewHolder = ::TextMessageViewHolder,
                    onBindViewHolder = { vh, _, it ->
                        vh.messageText.text = it.message.text
                        vh.sentAt.text = it.message.sentAt
                    }
                )

Download

implementation 'io.github.ibrahimyilmaz:kiel:latestVersion'

latestVersion = 1.2.1

License

Copyright 2020 Ibrahim Yilmaz

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.