Easier and more flexible to create multiple types for Android RecyclerView.
Easier and more flexible to create multiple types for Android RecyclerView.
Previously, when we need to develop a complex RecyclerView / ListView, it is difficult and troublesome work. We should override the
getItemViewType()of
RecyclerView.Adapter, add some types, and create some
ViewHolders relating to those types. Once we need to add a new item type, we have to go to the original adapter file and modify some old codes carefully, and these adapter classes will get more complicated.
Nowadays, I created a new intuitive and flexible way to easily create complex RecyclerViews, with the MultiType library, we could insert a new item type without changing any old adapter codes and make them more readable.
In your
build.gradle:
MultiType has been rebuilt based on AndroidX. If you are still using the android support library, please use
me.drakeet.multitype:multitype:3.4.4and
me.drakeet.multitype:multitype-kotlin:3.4.4.
In addition, since 4.0.0 we have migrated to fully build with Kotlin. If you don't want to use Kotlin, you can use the last stable version
me.drakeet.multitype:multitype:3.5.0and see 3.x.
dependencies { implementation 'com.drakeet.multitype:multitype:4.2.0' }
classor
data class, for example:
data class Foo( val value: String )
ItemViewDelegate, for example:
class FooViewDelegate: ItemViewDelegate() {override fun onCreateViewHolder(context: Context, parent: ViewGroup): ViewHolder { // If you want a LayoutInflater parameter instead of a Context, // you can use ItemViewBinder as the parent of this class. return ViewHolder(FooView(context)) }
override fun onBindViewHolder(holder: ViewHolder, item: Foo) { holder.fooView.text = item.value Log.d("ItemViewDelegate API", "position: ${getPosition(holder)}") Log.d("ItemViewDelegate API", "items: $adapterItems") Log.d("ItemViewDelegate API", "adapter: $adapter") Log.d("More", "Context: ${holder.itemView.context}") }
class ViewHolder(itemView : View): RecyclerView.ViewHolder(itemView) { val fooView: TextView = itemView.findViewById(R.id.foo) } }
ViewDelegate:
The
ViewDelegateis a simpleItemViewDelegatethat does not require to declare and provide aRecyclerView.ViewHolder.
class FooViewDelegate : ViewDelegate() {override fun onCreateView(context: Context): FooView { return FooView(context).apply { layoutParams = LayoutParams(MATCH_PARENT, WRAP_CONTENT) } }
override fun onBindView(view: FooView, item: Foo) { view.imageView.setImageResource(item.imageResId) view.textView.text = item.text // Or bind the data in the FooView by calling view.setFoo(item) } }
RichViewDelegate&
RichViewexamples for more details)
registeryour types and setup your
RecyclerView, for example:
class SampleActivity : AppCompatActivity() {private val adapter = MultiTypeAdapter() private val items = ArrayList()
override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_list) val recyclerView = findViewById(R.id.list)
adapter.register(TextItemViewDelegate()) adapter.register(ImageItemViewDelegate()) adapter.register(RichItemViewDelegate()) recyclerView.adapter = adapter val textItem = TextItem("world") val imageItem = ImageItem(R.mipmap.ic_launcher) val richItem = RichItem("小艾大人赛高", R.drawable.img_11) for (i in 0..19) { items.add(textItem) items.add(imageItem) items.add(richItem) } adapter.items = items adapter.notifyDataSetChanged()
} }
That's all, you're good to go!
One to many:
adapter.register(Data::class).to( DataType1ViewDelegate(), DataType2ViewDelegate() ).withKotlinClassLinker { _, data -> when (data.type) { Data.TYPE_2 -> DataType2ViewDelegate::class else -> DataType1ViewDelegate::class } }
See
OneDataToManyActivity,
OneToManyFlowand
OneToManyEndpointfor more details.
More methods that you can override from ItemViewDelegate:
open fun onBindViewHolder(holder: VH, item: T, payloads: List) open fun getItemId(item: T): Long open fun onViewRecycled(holder: VH) open fun onFailedToRecycleView(holder: VH): Boolean open fun onViewAttachedToWindow(holder: VH) open fun onViewDetachedFromWindow(holder: VH)
An intellij idea plugin for Android to generate
MultiType
Itemand
ItemViewDelegateeasily.
Pages created with MultiType:
Copyright (c) 2016-present. Drakeet XuLicensed 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.