abstract class SimpleAbstractAdapter<T>(private var items: ArrayList<T> = arrayListOf()) : RecyclerView.Adapter<SimpleAbstractAdapter.VH>() {
protected var listener: OnViewHolderListener<T>? = null
private val filter = ArrayFilter()
private val lock = Any()
protected abstract fun getLayout(): Int
protected abstract fun bindView(item: T, viewHolder: VH)
protected abstract fun getDiffCallback(): DiffCallback<T>?
private var onFilterObjectCallback: OnFilterObjectCallback? = null
private var constraint: CharSequence? = ""
override fun onBindViewHolder(vh: VH, position: Int) {
getItem(position)?.let { bindView(it, vh) }
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): VH {
return VH(parent, getLayout())
}
override fun getItemCount(): Int = items.size
protected abstract class DiffCallback<T> : DiffUtil.Callback() {
private val mOldItems = ArrayList<T>()
private val mNewItems = ArrayList<T>()
fun setItems(oldItems: List<T>, newItems: List<T>) {
mOldItems.clear()
mOldItems.addAll(oldItems)
mNewItems.clear()
mNewItems.addAll(newItems)
}
override fun getOldListSize(): Int {
return mOldItems.size
}
override fun getNewListSize(): Int {
return mNewItems.size
}
override fun areItemsTheSame(oldItemPosition: Int, newItemPosition: Int): Boolean {
return areItemsTheSame(
mOldItems[oldItemPosition],
mNewItems[newItemPosition]
)
}
abstract fun areItemsTheSame(oldItem: T, newItem: T): Boolean
override fun areContentsTheSame(oldItemPosition: Int, newItemPosition: Int): Boolean {
return areContentsTheSame(
mOldItems[oldItemPosition],
mNewItems[newItemPosition]
)
}
abstract fun areContentsTheSame(oldItem: T, newItem: T): Boolean
}
class VH(parent: ViewGroup, @LayoutRes layout: Int) : RecyclerView.ViewHolder(LayoutInflater.from(parent.context).inflate(layout, parent, false))
interface OnViewHolderListener<T> {
fun onItemClick(position: Int, item: T)
}
fun getItem(position: Int): T? {
return items.getOrNull(position)
}
fun getItems(): ArrayList<T> {
return items
}
fun setViewHolderListener(listener: OnViewHolderListener<T>) {
this.listener = listener
}
fun addAll(list: List<T>) {
val diffCallback = getDiffCallback()
when {
diffCallback != null && !items.isEmpty() -> {
diffCallback.setItems(items, list)
val diffResult = DiffUtil.calculateDiff(diffCallback)
items.clear()
items.addAll(list)
diffResult.dispatchUpdatesTo(this)
}
diffCallback == null && !items.isEmpty() -> {
items.clear()
items.addAll(list)
notifyDataSetChanged()
}
else -> {
items.addAll(list)
notifyDataSetChanged()
}
}
}
fun add(item: T) {
items.add(item)
notifyDataSetChanged()
}
fun add(position:Int, item: T) {
items.add(position,item)
notifyItemInserted(position)
}
fun remove(position: Int) {
items.removeAt(position)
notifyItemRemoved(position)
}
fun remove(item: T) {
items.remove(item)
notifyDataSetChanged()
}
fun clear(notify: Boolean=false) {
items.clear()
if (notify) {
notifyDataSetChanged()
}
}
fun setFilter(filter: SimpleAdapterFilter<T>): ArrayFilter {
return this.filter.setFilter(filter)
}
interface SimpleAdapterFilter<T> {
fun onFilterItem(contains: CharSequence, item: T): Boolean
}
fun convertResultToString(resultValue: Any): CharSequence {
return filter.convertResultToString(resultValue)
}
fun filter(constraint: CharSequence) {
this.constraint = constraint
filter.filter(constraint)
}
fun filter(constraint: CharSequence, listener: Filter.FilterListener) {
this.constraint = constraint
filter.filter(constraint, listener)
}
fun getFilter(): Filter {
return filter
}
interface OnFilterObjectCallback {
fun handle(countFilterObject: Int)
}
fun setOnFilterObjectCallback(objectCallback: OnFilterObjectCallback) {
onFilterObjectCallback = objectCallback
}
inner class ArrayFilter : Filter() {
private var original: ArrayList<T> = arrayListOf()
private var filter: SimpleAdapterFilter<T> = DefaultFilter()
private var list: ArrayList<T> = arrayListOf()
private var values: ArrayList<T> = arrayListOf()
fun setFilter(filter: SimpleAdapterFilter<T>): ArrayFilter {
original = items
this.filter = filter
return this
}
override fun performFiltering(constraint: CharSequence?): Filter.FilterResults {
val results = Filter.FilterResults()
if (constraint == null || constraint.isBlank()) {
synchronized(lock) {
list = original
}
results.values = list
results.count = list.size
} else {
synchronized(lock) {
values = original
}
val result = ArrayList<T>()
for (value in values) {
if (constraint!=null && constraint.trim().isNotEmpty() && value != null) {
if (filter.onFilterItem(constraint, value)) {
result.add(value)
}
} else {
value?.let { result.add(it) }
}
}
results.values = result
results.count = result.size
}
return results
}
override fun publishResults(constraint: CharSequence, results: Filter.FilterResults) {
items = results.values as? ArrayList<T> ?: arrayListOf()
notifyDataSetChanged()
onFilterObjectCallback?.handle(results.count)
}
}
class DefaultFilter<T> : SimpleAdapterFilter<T> {
override fun onFilterItem(contains: CharSequence, item: T): Boolean {
val valueText = item.toString().toLowerCase()
if (valueText.startsWith(contains.toString())) {
return true
} else {
val words = valueText.split(" ".toRegex()).dropLastWhile { it.isEmpty() }.toTypedArray()
for (word in words) {
if (word.contains(contains)) {
return true
}
}
}
return false
}
}
}
请扩展抽象适配器并实现方法
TasksAdapter.kt
import android.annotation.SuppressLint
import kotlinx.android.synthetic.main.task_item_layout.view.*
class TasksAdapter(private val listener:TasksListener? = null) : SimpleAbstractAdapter<Task>() {
override fun getLayout(): Int {
return R.layout.task_item_layout
}
override fun getDiffCallback(): DiffCallback<Task>? {
return object : DiffCallback<Task>() {
override fun areItemsTheSame(oldItem: Task, newItem: Task): Boolean {
return oldItem.id == newItem.id
}
override fun areContentsTheSame(oldItem: Task, newItem: Task): Boolean {
return oldItem.items == newItem.items
}
}
}
@SuppressLint("SetTextI18n")
override fun bindView(item: Task, viewHolder: VH) {
viewHolder.itemView.apply {
val position = viewHolder.adapterPosition
val customer = item.customer
val customerName = if (customer != null) customer.name else ""
tvTaskCommentTitle.text = customerName + ", #" + item.id
tvCommentContent.text = item.taskAddress
ivCall.setOnClickListener {
listener?.onCallClick(position, item)
}
setOnClickListener {
listener?.onItemClick(position, item)
}
}
}
interface TasksListener : SimpleAbstractAdapter.OnViewHolderListener<Task> {
fun onCallClick(position: Int, item: Task)
}
}
初始化适配器
mAdapter = TasksAdapter(object : TasksAdapter.TasksListener {
override fun onCallClick(position: Int, item:Task) {
}
override fun onItemClick(position: Int, item:Task) {
}
})
rvTasks.adapter = mAdapter
并填充
mAdapter?.addAll(tasks)
mAdapter?.setFilter(object : SimpleAbstractAdapter.SimpleAdapterFilter<MoveTask> {
override fun onFilterItem(contains: CharSequence, item:Task): Boolean {
return contains.toString().toLowerCase().contains(item.id?.toLowerCase().toString())
}
})
筛选数据
mAdapter?.filter("test")
建议更新到这里的androidx库,其中包括implementation androidx.recyclerview:recyclerview:....
https://developer.android.com/jetpack/androidx/releases/recyclerview
布局文件中的小部件XML标签必须更新为:androidx.recyclerview.widget.RecyclerViewimport android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.TextView
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import androidx.constraintlayout.widget.ConstraintLayout
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.RecyclerView
class ModelDownloaderActivity : AppCompatActivity() {
val items = (1..50).toList().map { "Item #$it" }
inner class ItemHolder(view: View, var textField: TextView = view.findViewById(android.R.id.text1)) : RecyclerView.ViewHolder(view)
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
// Create recycler view, or find it in Activity's XML file if you prefer
val myLayoutResource: Int? = null // Replace with R.layout.activity_model_downloader if you want to use an XML layout with a recycler view in it
val recyclerView = myLayoutResource?.let {
setContentView(it)
findViewById(R.id.modelRecyclerView) // Replace with ID of your recycler view in layout
} ?: RecyclerView(this).also { setContentView(ConstraintLayout(this).apply { addView(it) }) }
// Bind controls to it.
recyclerView.layoutManager = LinearLayoutManager(this)
recyclerView.adapter = object : RecyclerView.Adapter<ItemHolder>() {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int) =
ItemHolder(LayoutInflater.from(parent.context).inflate(android.R.layout.simple_list_item_1, parent, false))
override fun getItemCount() = items.size
override fun onBindViewHolder(holder: ItemHolder, position: Int) {
holder.textField.text = items[position]
holder.textField.setOnClickListener {
Toast.makeText(this@ModelDownloaderActivity, "Clicked $position", Toast.LENGTH_SHORT).show()
}
}
}
}
}