Kotlin / Android Custom RecyclerView issue - android

I was trying to make a custom RecyclerView with Adapter which takes a HashMap as parameter, I succeeded but now only 1 item is showing in recyclerView list and I have no idea why.
Here my code snippet:
Custom RecyclerAdapter:
class ProductsRecyclerAdapter(private val dataSet: HashMap<Int, ProductEntry>) : RecyclerView.Adapter<ProductsRecyclerAdapter.ViewHolder>() {
class ViewHolder(val linearLay: LinearLayout) : RecyclerView.ViewHolder(linearLay)
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int) : ProductsRecyclerAdapter.ViewHolder {
val linearLay = LayoutInflater.from(parent.context).inflate(R.layout.test_text_view, parent, false) as LinearLayout
return ViewHolder(linearLay)
}
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
holder.linearLay.textView.text = dataSet[position]?.pName
holder.linearLay.textView2.text = dataSet[position]?.pExpiry
}
override fun getItemCount(): Int {
return dataSet.size
}
}
Initialization:
// Setup RecyclerView
val prod1 = ProductEntry("Milk", "04/06/1996")
val prod2 = ProductEntry("Bread", "04/01/2012")
val testArray : HashMap<Int, ProductEntry> = hashMapOf(1 to prod1, 2 to prod2)
viewManager = LinearLayoutManager(this)
viewAdapter = ProductsRecyclerAdapter(testArray)
recyclerView = findViewById<RecyclerView>(R.id.productsRecyclerView).apply {
setHasFixedSize(true)
layoutManager = viewManager
adapter = viewAdapter
}
And finally, custom XML for row:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/linearLay"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="#+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="TextView" />
<TextView
android:id="#+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="40dp"
android:layout_weight="1"
android:text="TextView" />
Despite everything seems to be OK, I get only 1 row showing "milk".
Thanks for all help!

position in override fun onBindViewHolder(holder: ViewHolder, position: Int) starts at index 0.
So in your case, it will be [0, 1] and your map keys are [1, 2]. Only key "1" will be displayed correctly.
try:
val testArray : HashMap<Int, ProductEntry> = hashMapOf(0 to prod1, 1 to prod2)
But no need to use a map here! Just use a simple list of ProductEntry.

Related

Android: RelativeLayout measures child width incorrectly

What I want to do:
My idea is simple:
I have RecyclerView in RelativeLayout
When data loaded I set first item's text to TextView for pinned message
On scroll I take first visible item and set this item's text to header (TextView)
So I have:
RelativeLayout + RecyclerView + TextView for pinned message + TextView for header
I update header on scroll, it looks like sticky header for list.
It is my layout:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<TextView
android:id="#+id/pin"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#ebebeb"
android:gravity="center"
android:padding="24dp"/>
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/list"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="#+id/pin"/>
<androidx.appcompat.widget.AppCompatTextView
android:id="#+id/header"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignTop="#id/list"
android:layout_alignEnd="#id/list"
android:background="#33ff0000"
android:gravity="center"
android:padding="24dp"/>
</RelativeLayout>
And it is my Activity:
class CustomAdapter() :
RecyclerView.Adapter<CustomAdapter.ViewHolder>() {
var data: List<UUID> = listOf()
class ViewHolder(view: View) : RecyclerView.ViewHolder(view) {
val textView: TextView
init {
textView = view.findViewById(R.id.text)
}
}
override fun onCreateViewHolder(viewGroup: ViewGroup, viewType: Int): ViewHolder {
val view = LayoutInflater.from(viewGroup.context)
.inflate(R.layout.list_item, viewGroup, false)
return ViewHolder(view)
}
override fun onBindViewHolder(viewHolder: ViewHolder, position: Int) {
viewHolder.textView.text = data[position].toString()
}
override fun getItemCount() = data.size
}
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val adapter = CustomAdapter()
val header = findViewById<TextView>(R.id.header)
findViewById<RecyclerView>(R.id.list).apply {
this.adapter = adapter
layoutManager = LinearLayoutManager(this#MainActivity, LinearLayoutManager.VERTICAL, false)
addOnScrollListener(object : RecyclerView.OnScrollListener() {
override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
val position = recyclerView.topChildPosition() ?: return
if (position >= 0) {
header.text = adapter.data[position].toString().substring(0, 10)
Log.w("MainActivity", header.text.toString())
} else {
header.text = null
}
}
})
}
/**
* SIMULATE DATA LOADING
*/
Handler(Looper.getMainLooper()).postDelayed({
adapter.data = List(100) {
UUID.randomUUID()
}
findViewById<TextView>(R.id.pin).text = adapter.data[0].toString()
adapter.notifyDataSetChanged()
}, 1000L)
}
private fun RecyclerView.topChildPosition(): Int? {
layoutManager.let { layoutManager ->
if (layoutManager != null && layoutManager is LinearLayoutManager) {
return if (!layoutManager.reverseLayout) layoutManager.findFirstVisibleItemPosition()
else layoutManager.findLastVisibleItemPosition()
} else {
val topChild: View = getChildAt(0) ?: return null
return getChildAdapterPosition(topChild)
}
}
}
}
And what I have:
RelativeLayout measured views, header has text = null, so header's width = padding only
Data loaded (see "SIMULATE DATA LOADING" in the activity code), I call notifyDataSetChanged and I set text to header. Header (TextView) calls requestLayout() on set text, but RelativeLayout doesn't measured new width (actually, RelativeLayout calls header's onMeasure with widthMode == MeasureSpec.EXACTLY and pass old width)
When I scroll RecyclerView header remeasured successfully.
I can reproduce it on Android 26-33
What I can do with this.
I can change layout:
from this:
<androidx.appcompat.widget.AppCompatTextView
android:id="#+id/header"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignTop="#id/list"
android:layout_alignEnd="#id/list"
android:background="#33ff0000"
android:gravity="center"
android:padding="24dp"/>
to this:
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignTop="#id/list"
android:layout_alignEnd="#id/list">
<androidx.appcompat.widget.AppCompatTextView
android:id="#+id/header"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="end"
android:background="#33ff0000"
android:gravity="center"
android:padding="24dp"/>
</FrameLayout>
But actually I can't, because really my TextView in custom view extends from TextView and it is part of library. I don't know how it will be used in layouts.
I can call requestLayout() after data loading like this:
adapter.notifyDataSetChanged()
header.doOnNextLayout { header.post { header.requestLayout() } }
But it is ugly.
So, finally my questions:
Do you know how to fix it without layout changing?
Do you know bug or some documented RelativeLayout behavior
Thanks for any help!

how to add views in onBindViewHolder?

I'm using RecyclerView to display a list of items.
Dependent on the specific item, i want to show additional views in the cell.
I know the viewholder should be static, but how do i achieve a cell design that depends on the properties of the item?
Minified example, which gives me weird results:
class CustomAdapter internal constructor() :
RecyclerView.Adapter<CustomAdapter.ViewHolder>() {
private var dataSet = emptyList()
inner class ViewHolder(v: View) : RecyclerView.ViewHolder(v) {
val title: TextView
val linearLayout: LinearLayout
init {
title = v.findViewById(R.id.textView)
linearLayout = v.findViewById(R.id.linearLayout)
}
}
override fun onCreateViewHolder(viewGroup: ViewGroup, viewType: Int): ViewHolder {
val v = LayoutInflater.from(viewGroup.context)
.inflate(R.layout.cardview, viewGroup, false)
return ViewHolder(v)
}
override fun onBindViewHolder(viewHolder: ViewHolder, position: Int) {
viewHolder.title.text = dataSet[position].name
for (i in 0 until 5) {
viewHolder.linearLayout.addView(ImageView())
}
}
internal fun setItems(items: List<T>) {
this.dataSet = items
notifyDataSetChanged()
}
}
<androidx.cardview.widget.CardView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center_vertical">
<TextView
android:id="#+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginStart="22dp"
android:layout_marginEnd="12dp"
android:text="Title"
android:textSize="18sp"
android:textStyle="bold" />
<LinearLayout
android:id="#+id/linearLayout"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal">
</LinearLayout>
</androidx.cardview.widget.CardView>
You can't add an ImageView directly as shown in your example. Try this:
override fun onBindViewHolder(viewHolder: ViewHolder, position: Int) {
viewHolder.title.text = dataSet[position].name
for (i in 0 until 5) {
val holder = viewHolder
val context = holder.itemView.context
val imagebyCode = ImageView(context)
imagebyCode.setImageResource(R.drawable.exampleImage)
val params : LinearLayout.LayoutParams = LinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,LinearLayout.LayoutParams.WRAP_CONTENT);
imagebyCode.layoutParams = params
val myLayout : LinearLayout = holder.itemView.findViewById(R.id.linearLayout)
myLayout.addView(imagebyCode)
}
}
You can add views to the xml for the recycler view row and keep the visibility hidden.
In onBindViewHolder you can check the condition and make the View visible.
override fun onBindViewHolder(viewHolder: ViewHolder, position: Int) {
viewHolder.title.text = dataSet[position].name
for (i in 0 until 5) {
viewHolder.linearLayout.view.visibility = View.VISIBLE //Set visibility here
}
}

How to update editText for data object in recycle view Kotlin

I am new to android studio and just starter 1 month ago for learning it.
I currently try to written the app that has list of data class with name, price, quantity and unit cost.
I have done the recycle view and i am facing the problem that how to update the editText value whenever the user input the quantity in the data classs
Below are my data class code
data class food (val food: String, val price: Int, var quantity: Int, var cost: Int = price*quantity)
object ABC {
var food_List = listOf<food>(
ABC ("A", 28 ,5) ,
ABC ("B", 28, 0)
)}
Below are my recycle view adaptor
class customAdaptor (val context: Context, val food_List:List<food>):RecyclerView.Adapter<customAdaptor.ViewHolder>() {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
val v = LayoutInflater.from(context).inflate(R.layout.list_layout,parent, false)
return ViewHolder(v)
}
override fun getItemCount(): Int {
return food_List.size
}
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
val listused= food_List[position]
holder.setData(listused,position)
}
inner class ViewHolder (itemView: View): RecyclerView.ViewHolder(itemView) {
fun setData(listused: food?, pos: Int) {
itemView.listFoodName.text = listused!!.food
itemView.listUnitPrice.text =listused.price.toString()
itemView.listUnitTotalPrice.text=listused.cost.toString()
}
}}
Below are my mainactivity
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_page_budget)
val layoutManager = LinearLayoutManager(this)
layoutManager.orientation = LinearLayoutManager.VERTICAL
recyclerview.layoutManager = layoutManager
val adapter = customAdaptor(this, ABC.food_List)
recyclerview.adapter = adapter}
Below are my layout for card view.
<androidx.cardview.widget.CardView
android:id="#+id/cardView"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<TextView
android:layout_width="270dp"
android:layout_height="wrap_content"
android:textAlignment="center"
android:id="#+id/listFoodName"/>
<TextView
android:layout_width="50dp"
android:layout_height="wrap_content"
android:textAlignment="center"
android:id="#+id/listUnitPrice"/>
<EditText
android:layout_width="50dp"
android:layout_height="wrap_content"
android:textAlignment="center"
android:inputType="numberDecimal"
android:id="#+id/listQuantity"/>
<TextView
android:layout_width="50dp"
android:layout_height="wrap_content"
android:textAlignment="center"
android:id="#+id/listUnitTotalPrice"/> -->
</LinearLayout>
</androidx.cardview.widget.CardView>
Then i didnt know how to write the editText for the update.
Please help. Thank you very much.
You should use this:
editText.afterTextChanged{doSomethingWithText(it)}
Your code would be something like:
fun setData(listused: food?, pos: Int) {
itemView.listFoodName.text =listused!!.food
itemView.listUnitPrice.text =listused.price.toString()
itemView.listUnitTotalPrice.text=listused.cost.toString()
itemView.listQuantity.afterTextChanged {
listused?.quantity = it.toInt()
itemView.listUnitTotalPrice.text=listused.cost.toString()
}
}

RecyclerView shows just one item from Firebase

I know there are few questions about this problem. But none of them didn't solve my problem especially my code is in Kotlin and new working with Fragments. Don't rush to say my question is duplicated.
My problem is exactly what title said, my RecyclerView is populated just with one item(child) from Firebase in my Fragment.
Adapter:
class NewsList(private val userList: List<News>) : RecyclerView.Adapter<NewsList.ViewHolder>() {
private val Context = this
override fun onBindViewHolder(p0: ViewHolder?, p1: Int) {
val news: News = userList[p1]
p0?.mesajTextView?.text = news.text
val time = news.time
val getTimeAgo = GetTimeAgo()
val lastMsg = getTimeAgo.getTimeAgo(time, Context)
p0?.timeNewsTextView!!.text = lastMsg
}
override fun onCreateViewHolder(p0: ViewGroup?, p1: Int): ViewHolder {
val v = LayoutInflater.from(p0?.context).inflate(R.layout.news_layout, p0, false)
return ViewHolder(v)
}
override fun getItemCount(): Int {
return userList.size
}
class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
val mesajTextView = itemView.findViewById(R.id.mesajTextView) as TextView
val timeNewsTextView = itemView.findViewById(R.id.timeNewsTextView) as TextView
}
}
My fragment where ReyclerView is populated:
override fun onActivityCreated(savedInstanceState: Bundle?) {
newsRecyclerView.layoutManager = LinearLayoutManager(context, LinearLayoutManager.VERTICAL, false)
}
private fun populalteQuestionsList() {
val mChatDatabaseReference = FirebaseDatabase.getInstance().reference.child(Constants.NEWS)
mListenerPopulateList = mChatDatabaseReference.addValueEventListener(object : ValueEventListener {
override fun onDataChange(dataSnapshot: DataSnapshot) {
for (convSnapshot in dataSnapshot.children) {
val news = ArrayList<News>()
val conv = convSnapshot.getValue(News::class.java)
news.add(conv!!)
val adapter = NewsList(news)
newsRecyclerView!!.adapter = adapter
adapter.notifyDataSetChanged()
}
}
override fun onCancelled(databaseError: DatabaseError) {
}
})
mChatDatabaseReference.addListenerForSingleValueEvent(mListenerPopulateList)
}
Layout for items:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<android.support.v7.widget.CardView
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:id="#+id/card_view"
android:layout_gravity="center"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_margin="5dp"
card_view:cardCornerRadius="2dp"
card_view:contentPadding="10dp"
card_view:cardElevation="10dp">
<RelativeLayout
android:id="#+id/relativeLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingBottom="10dp"
android:paddingLeft="10dp"
android:paddingRight="10dp"
android:paddingTop="10dp">
<TextView
android:id="#+id/mesajTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_marginStart="64dp"
android:textAppearance="?android:attr/textAppearanceLarge"
tools:text="Mesaj" />
<TextView
android:id="#+id/timeNewsTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_marginEnd="16dp"
android:layout_marginTop="4dp"
android:maxLength="15"
android:maxLines="1"
android:textAppearance="?android:attr/textAppearanceSmall"
tools:text="14:20" />
</RelativeLayout>
</android.support.v7.widget.CardView>
</LinearLayout>
Hope you understand, please help me I really need to finish this app.
You are creating new list with having single element in loop and passing it to adapter so it has only one element to show so
Move this outside loop
val adapter = NewsList(news)
newsRecyclerView!!.adapter = adapter
adapter.notifyDataSetChanged()
and initialise list outside for loop
val news = ArrayList<News>()
for (convSnapshot in dataSnapshot.children) {
val conv = convSnapshot.getValue(News::class.java)
news.add(conv!!)
}
val adapter = NewsList(news)
newsRecyclerView!!.adapter = adapter
adapter.notifyDataSetChanged()
Note : fill_parent has been deprecated so us match_parent
You're recreating the dataset at every iteration, so it will always have the last added item, move the instantiation of the datasource to outside the loop. Also, try not adding the values for the adapter at every iteration. When you're done adding items to the datasource, then you should add them to the adapter and set the adapter in the recyclerview. :
val news = ArrayList<News>()
for (convSnapshot in dataSnapshot.children) {
val conv = convSnapshot.getValue(News::class.java)
news.add(conv!!)
}
val adapter = NewsList(news)
newsRecyclerView!!.adapter = adapter
adapter.notifyDataSetChanged()

RecyclerView is not showing data

I'm currently trying to create a dynamic header with a recyclerView. I have written the ListAdapter aswell as the ViewHolder. The custom list elements are added, and also the numer of the elements within the list is correct, but somehow it's not showing the object data, but only the dummyText that was added at the layoutdesign.
HeaderlistAdapter:
class HeaderListAdapter(val context: Context, val headers: List<CustomHeader>) : RecyclerView.Adapter<HeaderViewHolder>() {
override fun onCreateViewHolder(parent: ViewGroup?, viewType: Int): HeaderViewHolder {
val view = LayoutInflater.from(context).inflate(R.layout.ui_basic_custom_list_element_header, parent, false)
return HeaderViewHolder(view)
}
override fun getItemCount(): Int {
return headers.size
}
override fun onBindViewHolder(holder: HeaderViewHolder?, position: Int) {
holder?.bindHeader(headers[position])
}
fun setFocus(step:UIStep)
{
for(header in headers)
header.Active=header.MainContent==step
notifyDataSetChanged()
}
}
HeaderViewHolder:
class HeaderViewHolder:RecyclerView.ViewHolder{
#Bind(R.id.ui_adapter_main) var mainText:TextView?=null
#Bind(R.id.ui_adapter_additional) var additionalText:TextView?=null
#Bind(R.id.ui_adapter_layout) var layout:LinearLayout?=null
constructor(itemView: View): super(itemView){
ButterKnife.bind(this,itemView)
}
fun bindHeader(header:CustomHeader){
if(header.Active) {
mainText?.text = header.MainContent.description
additionalText?.text=header.AdditionalText
layout?.setBackgroundColor(R.color.colorBackgroundActive.toInt())
}
else{
mainText?.text=header.MainContent.number.toString()
additionalText?.text=""
layout?.setBackgroundColor(R.color.colorBackgroundInactive.toInt())
}
}
}
Here is, how the listAdapter looks within the view
<android.support.v7.widget.RecyclerView
android:id="#+id/ui_basic_lv_header"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
android:background="#color/colorBackgroundInactive"
android:layout_weight="1" />
Below here you se the xml of the custom element
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:orientation="horizontal"
android:background="#color/colorBackgroundInactive"
android:textColor="#color/colorHeaderFont"
android:id="#+id/ui_adapter_layout">
<TextView
android:id="#+id/ui_adapter_main"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:text="Main Info"
android:textSize="36sp"/>
<TextView
android:id="#+id/ui_adapter_additional"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:text="additional"
android:gravity="center_vertical"/>
Looks like there was something wrong with the
#Bind
I replaced that by using findViewById within the binHeader function:
fun bindHeader(header:CustomHeader){
val mainText = itemView.findViewById<TextView>(R.id.ui_adapter_main)
val additionalText = itemView.findViewById<TextView>(R.id.ui_adapter_additional)
val layout = itemView.findViewById<LinearLayout>(R.id.ui_adapter_layout)
if(header.Active) {
mainText?.text = header.MainContent.description
additionalText?.text=header.AdditionalText
layout?.setBackgroundColor(R.color.colorBackgroundActive.toInt())
}
else{
mainText?.text=header.MainContent.number.toString()
additionalText?.text=""
layout?.setBackgroundColor(R.color.colorBackgroundInactive.toInt())
}
}
contentList may be null ,if contentList is Null, the method following '?' will not execute . and after setting the adapter can not call notifyDataSetChanged ;
You should set layout manager for recyclerview
myRecyclerView.setLayoutManager(linearLayoutManagerVertical);

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