I'm trying to play a sound outside of #Copmosable because of my application structure.
I have a validation routine which is in my viewmodel and based on the result I would like to trigger a sound but I cannot seem to get context working outside of #Composable
I get the following error in the MasterViewModel:
None of the following functions can be called with the arguments supplied.
create(Context!, Uri!) defined in android.media.MediaPlayer
create(Context!, Int) defined in android.media.MediaPlayer
Any pointers would be great thanks!!
package com.example.soundtest
import android.os.Bundle
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.compose.material.MaterialTheme
import androidx.compose.material.Surface
import androidx.compose.material.Text
import androidx.compose.runtime.Composable
import androidx.compose.ui.tooling.preview.Preview
import com.example.soundtest.ui.theme.SoundTestTheme
class MainActivity : ComponentActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContent {
SoundTestTheme {
// A surface container using the 'background' color from the theme
Surface(color = MaterialTheme.colors.background) {
Greeting()
}
}
}
}
}
#Composable
fun Greeting(mastVM: MasterViewModel = MasterViewModel()) {
Text("Play a sound...")
mastVM.playSound()
}
and the MasterViewModel
package com.example.soundtest
import android.media.MediaPlayer
class MasterViewModel {
fun playSound() {
val mp: MediaPlayer = MediaPlayer.create(this, R.raw.correct)
}
}
I have correct.mp3 save under res->raw-correct.mp3
MasterViewModel Error
I got it working!!!
I just include
#Composable
fun Greeting(mastVM: MasterViewModel = MasterViewModel()) {
val context = LocalContext.current
Text("Play a sound...")
mastVM.playSound(context: context)
}
and then in the MasterViewModel like this
fun playSound(context: Context) {
val mp: MediaPlayer = MediaPlayer.create(context, R.raw.correct)
}
Related
Trying to add an onclicklistener to the items in my recycler view, that will use an intent to open another activity. I've tried finding examples, but I can only find examples using Java or Kotlin examples that aren't using viewbinding.
package com.truuce.anotherrvtest
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import androidx.recyclerview.widget.GridLayoutManager
import com.truuce.anotherrvtest.databinding.ActivityHeroBinding
class HeroActivity : AppCompatActivity() {
var binding: ActivityHeroBinding? = null
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding = ActivityHeroBinding.inflate(layoutInflater)
setContentView(binding?.root)
val adapter = CardAdapter(HeroList.heroList)
binding?.heroRV?.adapter = adapter
binding?.heroRV?.layoutManager = GridLayoutManager(applicationContext, 3)
}
override fun onDestroy() {
super.onDestroy()
binding = null
}
}
package com.truuce.anotherrvtest
import android.content.Context
import android.content.Intent
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.ImageView
import android.widget.TextView
import androidx.recyclerview.widget.RecyclerView
import com.truuce.anotherrvtest.databinding.HeroCardBinding
class CardAdapter(val heroList: List<Hero>) : RecyclerView.Adapter<CardAdapter.MainViewHolder>() {
inner class MainViewHolder(val heroBinding: HeroCardBinding) :
RecyclerView.ViewHolder(heroBinding.root) {
fun bindHero(hero: Hero){
heroBinding.heroNameTV.text = hero.heroName
heroBinding.heroIV.setImageResource(hero.image)
}
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MainViewHolder {
return MainViewHolder(HeroCardBinding.inflate(LayoutInflater.from(parent.context), parent, false))
}
override fun onBindViewHolder(holder: MainViewHolder, position: Int) {
val hero = heroList[position]
holder.bindHero(hero)
}
override fun getItemCount() = heroList.size
}
tried adding View.OnClickListener to MainViewHolder, then implemented a member. OnClick(p0: View){}, but no idea how to get it working.
You should add a functional property for a click listener in your adapter.
The Activity can set the item click listener behavior.
class CardAdapter(
val heroList: List<Hero>,
val itemClickListener: (Hero)->Unit
) : RecyclerView.Adapter<CardAdapter.MainViewHolder>() {
inner class MainViewHolder(val heroBinding: HeroCardBinding) :
RecyclerView.ViewHolder(heroBinding.root) {
fun bindHero(hero: Hero) = with(heroBinding) {
heroNameTV.text = hero.heroName
heroIV.setImageResource(hero.image)
root.setOnClickListener { itemClickListener(hero) }
}
}
//...
}
// In Activity:
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding = ActivityHeroBinding.inflate(layoutInflater)
setContentView(binding?.root)
val adapter = CardAdapter(HeroList.heroList) { hero ->
// do something with hero item when it's clicked
}
binding?.heroRV?.adapter = adapter
binding?.heroRV?.layoutManager = GridLayoutManager(applicationContext, 3)
}
I'm struggling with both a dilemma and an issue here. The dilemma is that I want to keep the ManagerUsers screen simple, but Google is pushing fragments. I can see a use for fragments for this screen later on, but for now, it seems like overkill. Should I use them anyway?
Second, if I do avoid fragments for now, I am struggling to finish setting up the ClickListener to simply change the name of the user in the ListView. Kotlin seems to have at least 6 different methods for doing most things, making it confusing to figure this out. Google's tutorials force you to use fragments, and others' tutorials don't really cover what I'm trying to do. When I navigate to the Manage Users activity, the app crashes. LogCat shows that userSelect needs to be initialized. I have no idea how to do that.
UserListAdapter.kt
package com.neillbarrett.debitsandcredits
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.TextView
import androidx.recyclerview.widget.DiffUtil
import androidx.recyclerview.widget.ListAdapter
import androidx.recyclerview.widget.RecyclerView
import com.neillbarrett.debitsandcredits.database.UsersTable
import com.neillbarrett.debitsandcredits.databinding.ActivityManageUsersBinding
class UserListAdapter(private val userSelect: (UsersTable?) -> Unit) :
ListAdapter<UsersTable, UserListAdapter.UserViewHolder>(UsersComparator()) {
override fun onBindViewHolder(holder: UserViewHolder, position: Int) {
val current = getItem(position)
holder.bind(current, userSelect)
}
class UserViewHolder(private val binding: ActivityManageUsersBinding) : RecyclerView.ViewHolder(binding.root) {
fun bind(usersTable: UsersTable?, userSelect: (UsersTable?) -> Unit) {
binding.root.setOnClickListener( View.OnClickListener {
userSelect(usersTable)
binding.etEditName.setText(R.layout.activity_list_of_users.toString())
})
}
companion object {
fun create(parent: ViewGroup) : UserViewHolder {
val view: View = LayoutInflater.from(parent.context)
.inflate(R.layout.activity_manage_users, parent, false)
return UserViewHolder(ActivityManageUsersBinding.bind(view))
}
}
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): UserViewHolder {
val view = LayoutInflater.from(parent.context)
.inflate(R.layout.activity_manage_users, parent, false)
return UserViewHolder.create(parent)
}
class UsersComparator : DiffUtil.ItemCallback<UsersTable>() {
override fun areItemsTheSame(oldItem: UsersTable, newItem: UsersTable): Boolean {
return oldItem == newItem
}
override fun areContentsTheSame(oldItem: UsersTable, newItem: UsersTable): Boolean {
return oldItem.userName == newItem.userName
}
}
}
ManageUsers.kt
package com.neillbarrett.debitsandcredits
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.text.TextUtils
import android.widget.Button
import android.widget.EditText
import android.widget.Toast
import androidx.activity.viewModels
import androidx.lifecycle.Observer
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.RecyclerView
import com.neillbarrett.debitsandcredits.database.CreditsAndDebitsApp
import com.neillbarrett.debitsandcredits.database.UsersTable
import com.neillbarrett.debitsandcredits.databinding.ActivityManageUsersBinding
class ManageUsers : AppCompatActivity() {
lateinit var binding: ActivityManageUsersBinding
lateinit var recyclerView: RecyclerView
lateinit var editTextAddUser: EditText
lateinit var editTextChangeUser: EditText
lateinit var newUser: String
lateinit var userSelect: ((UsersTable?) -> Unit)
var position: Long = 0
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding = ActivityManageUsersBinding.inflate(layoutInflater)
val view = binding.root
setContentView(view)
//setContentView(R.layout.activity_manage_users)
val userViewModel: UserViewModel by viewModels {
UserViewModelFactory((application as CreditsAndDebitsApp).repository)
}
recyclerView = findViewById(R.id.rec_view_userList)
editTextAddUser = findViewById(R.id.et_UserName)
editTextChangeUser = findViewById(R.id.et_Edit_Name)
val adapter = UserListAdapter(userSelect)
binding.recViewUserList.adapter = adapter
recyclerView.adapter = adapter
recyclerView.layoutManager = LinearLayoutManager(this)
userViewModel.allUsers.observe(this, Observer() {user ->
user?.let { adapter.submitList(it) }
})
val btnAddUser = findViewById<Button>(R.id.btn_AddUser)
btnAddUser.setOnClickListener {
if (TextUtils.isEmpty(editTextAddUser.text)) {
Toast.makeText(this, "User name cannot be empty", Toast.LENGTH_SHORT).show()
} else {
newUser = editTextAddUser.text.toString()
userViewModel.insertUser(UsersTable(0, newUser))
}
}
val btnChangeUser = findViewById<Button>(R.id.btn_ChangeUserName)
btnChangeUser.setOnClickListener {
if (recyclerView.getChildAdapterPosition(it) == -1) {
Toast.makeText(this, "Select a name.", Toast.LENGTH_SHORT).show()
} else {
if (editTextChangeUser.text.toString() == recyclerView.adapter.toString()) {
Toast.makeText(this, "Name has not been changed.", Toast.LENGTH_SHORT).show()
} else {
Toast.makeText(this, "Name would have been changed.", Toast.LENGTH_SHORT).show()
/*val rvItemRecId: Long
rvItemRecId = adapter.getItemId(position.toInt())
userViewModel.updateUser(UsersTable(rvItemRecId.toInt(), adapter.toString()))*/
}
}
}
}
}
UserViewModel.kt
package com.neillbarrett.debitsandcredits
import androidx.lifecycle.*
import com.neillbarrett.debitsandcredits.database.UsersTable
import kotlinx.coroutines.launch
import java.lang.IllegalArgumentException
class UserViewModel(private val repository: UserRepository) : ViewModel() {
val allUsers: LiveData<List<UsersTable>> = repository.allUsers.asLiveData()
fun insertUser(user: UsersTable) = viewModelScope.launch {
repository.insertUser(user)
}
fun updateUser(user: UsersTable) = viewModelScope.launch {
repository.updateUser(user)
}
fun deleteUser(user: UsersTable) = viewModelScope.launch {
repository.deleteUser(user)
}
}
class UserViewModelFactory(private val repository: UserRepository) : ViewModelProvider.Factory{
override fun <T : ViewModel> create(modelClass: Class<T>): T {
if (modelClass.isAssignableFrom(UserViewModel::class.java)) {
#Suppress("UNCHECKED_CAST")
return UserViewModel(repository) as T
}
throw IllegalArgumentException("Unknown ViewModel class")
}
}
If you check your ManageUsers activity implementation
lateinit var userSelect: ((UsersTable?) -> Unit)
userSelect is lateinit and it must be initialised before you pass the reference to UserListAdapter adapter. Something like this
userSelect = {
// do something
}
before passing to adapter, or
val userSelect: ((UsersTable?) -> Unit) = {
}
at the time of declaration.
I'm trying to read a text file using Kotlin from my Assets folder and display it to a Compose text widget. Android Studio Arctic Fox 2020.3
The following code runs successfully and displays the text file to the Output console, however I can't figure out how to get the text file and pass it to a Compose text widget.
You'll notice that I have 2 text() calls inside ReadDataFile(). The first text() is outside of try{} and it works fine, but the text() inside the try{} causes an error: "Try catch is not supported around composable function invocations"
How can I make this work?
Thanks!
package com.learning.kotlinreadfile
import android.os.Bundle
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.compose.material.MaterialTheme
import androidx.compose.material.Surface
import androidx.compose.material.Text
import androidx.compose.runtime.Composable
import androidx.compose.ui.platform.LocalContext
import com.learning.kotlinreadfile.ui.theme.KotlinReadFileTheme
import java.io.InputStream
import java.io.IOException
class MainActivity : ComponentActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContent {
KotlinReadFileTheme {
// A surface container using the 'background' color from the theme
Surface(color = MaterialTheme.colors.background) {
ReadDataFile()
}
}
}
}
}
#Composable
fun ReadDataFile() {
println("Read Data File")
Text("Read Data File")
val context = LocalContext.current
try {
val inputStream: InputStream = context.assets.open("data.txt")
val size: Int = inputStream.available()
val buffer = ByteArray(size)
inputStream.read(buffer)
var string = String(buffer)
println(string)
//Text(string) // ERROR: Try catch is not supported around composable function invocations
} catch (e: IOException) {
e.printStackTrace()
println("Error")
}
}
Caution
File read (I/O) operations can be long, so it is not recommended to use the UI scope to read files. But that's not what's causing the problem, I'm just warning you that if it reads very large files, it can make your app crash because it does a very long processing in the UI thread. I recommend checking this link if you're not familiar with this type of problem.
Problem solving following best practices
Fortunately Jetpack compose works very well with reactive programming, so we can take advantage of that to write reactive code that doesn't face the aforementioned problems.
I made an example very similar to yours, I hope you can understand:
UiState file
As stated earlier, reading a file can be a long process, so let's imagine 3 possible states, "loading", "message successful" and "error". In the case of "successful message" we will have a possibly null string that will no longer be null when the message is actually read from the txt file:
package com.example.kotlinreadfile
data class UiState(
val isLoading: Boolean,
val isOnError: Boolean,
val fileMessage: String?
)
MainActivity.kt file
Here will be just our implementation of the UI, in your case the text messages arranged in the application. As soon as we want to read these messages on the screen we will make a request to our ViewModel:
package com.example.kotlinreadfile
import android.os.Bundle
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.activity.viewModels
import androidx.compose.foundation.layout.*
import androidx.compose.material.CircularProgressIndicator
import androidx.compose.material.MaterialTheme
import androidx.compose.material.Surface
import androidx.compose.material.Text
import androidx.compose.runtime.Composable
import androidx.compose.ui.Modifier
import androidx.compose.ui.platform.LocalContext
import androidx.compose.ui.unit.dp
import com.example.kotlinreadfile.ui.theme.KotlinReadFileTheme
class MainActivity : ComponentActivity() {
private val viewModel: MainViewModel by viewModels()
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContent {
KotlinReadFileTheme {
// A surface container using the 'background' color from the theme
Surface(color = MaterialTheme.colors.background) {
val context = LocalContext.current
viewModel.loadData(context)
ScreenContent(viewModel.uiState.value)
}
}
}
}
#Composable
fun ScreenContent(uiState: UiState) {
Column(
modifier = Modifier
.fillMaxWidth()
.padding(16.dp)
) {
Text(text = "Read Data File")
Spacer(modifier = Modifier.height(8.dp))
when {
uiState.isLoading -> CircularProgressIndicator()
uiState.isOnError -> Text(text = "Error when try load data from txt file")
else -> Text(text = "${uiState.fileMessage}")
}
}
}
}
MainViewModel.kt file
If you are unfamiliar with the ViewModel class I recommend this official documentation link.
Here we will focus on "our business rule", what we will actually do to get the data. Since we are dealing with an input/output (I/O) operation we will do this in an appropriate scope using viewModelScope.launch(Dispatchers.IO):
package com.example.kotlinreadfile
import android.content.Context
import androidx.compose.runtime.State
import androidx.compose.runtime.mutableStateOf
import androidx.lifecycle.ViewModel
import androidx.lifecycle.viewModelScope
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.launch
import java.io.IOException
import java.io.InputStream
class MainViewModel : ViewModel() {
private val _uiState = mutableStateOf(
UiState(
isLoading = true,
isOnError = false,
fileMessage = null
)
)
val uiState: State<UiState> = _uiState
fun loadData(context: Context) {
viewModelScope.launch(Dispatchers.IO) {
try {
val inputStream: InputStream = context.assets.open("data.txt")
val size: Int = inputStream.available()
val buffer = ByteArray(size)
inputStream.read(buffer)
val string = String(buffer)
launch(Dispatchers.Main) {
_uiState.value = uiState.value.copy(
isLoading = false,
isOnError = false,
fileMessage = string
)
}
} catch (e: IOException) {
e.printStackTrace()
launch(Dispatchers.Main) {
_uiState.value = uiState.value.copy(
isLoading = false,
isOnError = true,
fileMessage = null
)
}
}
}
}
}
jetpack compose by state refresh, please try
#Preview
#Composable
fun ReadDataFile() {
var dataText by remember {
mutableStateOf("asd")
}
println("Read Data File")
Column {
Text("Read Data File")
Text(dataText)
}
val context = LocalContext.current
LaunchedEffect(true) {
kotlin.runCatching {
val inputStream: InputStream = context.assets.open("data.txt")
val size: Int = inputStream.available()
val buffer = ByteArray(size)
inputStream.read(buffer)
String(buffer)
}.onSuccess {
it.logE()
dataText = it
}.onFailure {
dataText = "error"
}
}
}
I am attempting to make a function :
In recyclerView
when you click the user image ,navigate to the userActivity,
and when you click the "gift" icon ,navigate to otherActivity .
As follow is my Adapter.kt :
package Users.UserReceiveGiftItem
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.recyclerview.widget.RecyclerView
import com.gearsrun.www.R
import com.squareup.picasso.Picasso
import kotlinx.android.synthetic.main.user_receive_gift_item.view.*
class UserReceiveGiftAdapter(val userList : List<UserReceiveGiftItem>) : RecyclerView.Adapter<UserReceiveGiftAdapter.UserHolder>(){
private lateinit var mListener :onItemClickListener
interface onItemClickListener{
fun onItemClick(view:View,position: Int)
}
fun setOnItemClickListener(listener: onItemClickListener){
mListener = listener
}
override fun onCreateViewHolder(
parent: ViewGroup,
viewType: Int
): UserHolder {
val layoutInflater = LayoutInflater.from(parent.context)
return UserHolder(layoutInflater.inflate(R.layout.user_receive_gift_item,parent,false),mListener)
}
override fun onBindViewHolder(holder: UserReceiveGiftAdapter.UserHolder, position: Int) {
holder.render(userList[position])
}
override fun getItemCount(): Int = userList.size
class UserHolder(val view : View,listener:onItemClickListener) : RecyclerView.ViewHolder(view){
fun render(userList: UserReceiveGiftItem){
Picasso.get().load(userList.user_img).into(view.user_img)
view.user_name.text = userList.user_name
view.time.text = userList.time
view.userId.text = userList.userId
view.giftImg.setImageResource(userList.giftImg)
}
init {
view.setOnClickListener {
listener.onItemClick(it,absoluteAdapterPosition)
}
}
}
}
And I use in the Activity :
package com.gearsrun.www.UI.Receive
import Users.UserReceiveGiftItem.UserReceiveGiftAdapter
import Users.UserReceiveGiftItem.UserReceiveGiftItem
import android.content.Intent
import android.graphics.drawable.ColorDrawable
import android.os.Build
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.util.Log
import android.view.View
import android.widget.ImageView
import android.widget.Toast
import androidx.appcompat.app.ActionBar
import androidx.core.content.ContextCompat
import androidx.recyclerview.widget.LinearLayoutManager
import com.gearsrun.www.R
import com.gearsrun.www.UI.Gift.AwaitingToUnwrapActivity
import com.gearsrun.www.UI.Sunflower.SunflowerAvailableActivity
import com.gearsrun.www.UI.User.UserDetailActivity
import kotlinx.android.synthetic.main.activity_who_receive_gift.*
import kotlinx.android.synthetic.main.user_receive_gift_item.view.*
class ReceiveActivity : AppCompatActivity() {
val userList : List<UserReceiveGiftItem> = listOf(
UserReceiveGiftItem(
"https://i.pinimg.com/564x/63/85/68/63856877880614e0dab080071513156f.jpg",
"Sharry",
"10 mins ago",
"517ddY",
R.drawable.donut
),
)
lateinit var gift_unwrap : ImageView
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_receive)
changeColor(R.color.font_green)
initRecycler()
gift_unwrap = findViewById(R.id.gift_unwrap)
gift_unwrap.setOnClickListener {
}
}
private fun changeColor(resourseColor: Int) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
window.statusBarColor = ContextCompat.getColor(applicationContext, resourseColor)
}
val bar: ActionBar? = supportActionBar
if (bar != null) {
bar.setBackgroundDrawable(ColorDrawable(resources.getColor(resourseColor)))
}
}
fun initRecycler(){
rvUser.layoutManager = LinearLayoutManager(this)
val adapter = UserReceiveGiftAdapter(userList)
rvUser.adapter = adapter
adapter.setOnItemClickListener(object:UserReceiveGiftAdapter.onItemClickListener{
override fun onItemClick(view: View, position: Int) {
view.user_img.setOnClickListener {
val intent = Intent(this#ReceiveActivity,UserDetailActivity::class.java)
startActivity(intent)
}
view.giftImg.setOnClickListener {
val intent =Intent(this#ReceiveActivity,SunflowerAvailableActivity::class.java)
startActivity(intent)
}
}
})
}
}
It is a bit rare that it is able to navigate successfully ,however ,it dosen't react for the first click ..Could you please take a look my code ?Thank you guys in advance !!
You are using the click listener of the list item to add more click listeners to its children. So the first time you click it, the children don't have listeners yet and won't do anything. It is also error prone that a parent and its children both have click listeners, because it's undefined what will happen if you change the click listener as you are clicking it.
Instead, you should define your interface in the adapter to handle both types of clicks. In the ViewHolder, set click listeners only on the relevant children to be clicked.
Also, I think you're misusing lateinit. I would make the property nullable. And it is redundant to have a setter function for a property's value.
If you make the ViewHolder class inner, then you don't have to pass instances of the listener to the view holder instances, which will cause problems if you ever change the Adapter's listener.
Finally, personally I think the listener should return the list item, not the specific view and position in the list. Those are implementation details that the outer class doesn't need to know about.
class UserReceiveGiftAdapter(val userList : List<UserReceiveGiftItem>) : RecyclerView.Adapter<UserReceiveGiftAdapter.UserHolder>(){
var onItemClickListener: OnItemClickListener? = null
interface OnItemClickListener{
fun onUserClick(item: UserReceiveGiftItem)
fun onGiftClick(item: UserReceiveGiftItem)
}
override fun onCreateViewHolder(
parent: ViewGroup,
viewType: Int
): UserHolder {
val layoutInflater = LayoutInflater.from(parent.context)
return UserHolder(layoutInflater.inflate(R.layout.user_receive_gift_item,parent,false))
}
override fun onBindViewHolder(holder: UserReceiveGiftAdapter.UserHolder, position: Int) {
holder.render(userList[position])
}
override fun getItemCount(): Int = userList.size
inner class UserHolder(val view : View) : RecyclerView.ViewHolder(view){
fun render(userList: UserReceiveGiftItem){
Picasso.get().load(userList.user_img).into(view.user_img)
view.user_name.text = userList.user_name
view.time.text = userList.time
view.userId.text = userList.userId
view.giftImg.setImageResource(userList.giftImg)
}
init {
view.user_img.setOnClickListener {
onItemClickListener?.onUserClick(userList[absoluteAdapterPosition])
}
view.giftImg.setOnClickListener {
onItemClickListener?.onGiftClick(userList[absoluteAdapterPosition])
}
}
}
}
In Activity or Fragment:
adapter.onItemClickListener = object: UserReceiveGiftAdapter.OnItemClickListener {
override fun onUserClick(item: UserReceiveGiftItem) {
val intent = Intent(this#ReceiveActivity, UserDetailActivity::class.java)
startActivity(intent)
}
override fun onGiftClick(item: UserReceiveGiftItem) {
val intent = Intent(this#ReceiveActivity, SunflowerAvailableActivity::class.java)
startActivity(intent)
}
}
What I think after looking your code is, that you are setting adapter to your recyclerview first and then you are injecting a click listener to adapter.
What happens here is that some items from recycler view are loaded and they wouldn't have the click listener at that time,
for example if you scroll down, the newly appeared items on the screen will have proper click listeners, now if you scroll up, the previous one's will also have listener attached.
What to do to get rid of this problem:
Change your initRecycler() method as below:
fun initRecycler(){
rvUser.layoutManager = LinearLayoutManager(this)
val adapter = UserReceiveGiftAdapter(userList)
adapter.setOnItemClickListener(object:UserReceiveGiftAdapter.onItemClickListener{
override fun onItemClick(view: View, position: Int) {
view.user_img.setOnClickListener {
val intent = Intent(this#ReceiveActivity,UserDetailActivity::class.java)
startActivity(intent)
}
view.giftImg.setOnClickListener {
val intent =Intent(this#ReceiveActivity,SunflowerAvailableActivity::class.java)
startActivity(intent)
}
}
})
//set adapter after setting click listener to your adapter.
rvUser.adapter = adapter
}
I am currently building an app with a main activity which hosts a navHostFragment, and 3 fragments that are connected by a bottom navigation bar. My goal is to have each fragment use a Recycler View. I am using a Room database with an Adapter and LiveData for the "data". When I launch the app, I want to go to the Wallet fragment and see a vertical list of textViews. Because I am new and just starting out with this, I just wanted to have a very simple database of just text and then lay it out in a vertical format. Nothing too crazy yet. Any help would be greatly appreciated.
MainActivity
package com.example.android.pointmax
import android.os.Bundle
import com.google.android.material.bottomnavigation.BottomNavigationView
import androidx.appcompat.app.AppCompatActivity
import androidx.navigation.findNavController
import androidx.navigation.ui.AppBarConfiguration
import androidx.navigation.ui.setupActionBarWithNavController
import androidx.navigation.ui.setupWithNavController
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.RecyclerView
import timber.log.Timber
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
// Plant tree to enable Debugging with Timber
Timber.plant(Timber.DebugTree())
// Find the bottomNavigation bar
val navView: BottomNavigationView = findViewById(R.id.nav_view)
// Find the fragment that will host the different fragments
val navController = findNavController(R.id.nav_host_fragment)
// Passing each menu ID as a set of Ids because each
// menu should be considered as top level destinations.
val appBarConfiguration = AppBarConfiguration(
setOf(
R.id.navigation_home, R.id.navigation_wallet, R.id.navigation_recommended
)
)
setupActionBarWithNavController(navController, appBarConfiguration)
navView.setupWithNavController(navController)
}
}
WalletFragment
package com.example.android.pointmax.ui.wallet
import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.fragment.app.Fragment
import androidx.lifecycle.Observer
import androidx.lifecycle.ViewModelProvider
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.RecyclerView
import com.example.android.pointmax.CardAdapter
import com.example.android.pointmax.R
class WalletFragment : Fragment() {
private lateinit var viewManager: RecyclerView.LayoutManager
private lateinit var viewAdapter: RecyclerView.Adapter<*>
private lateinit var recyclerView: RecyclerView
private lateinit var viewModel: WalletViewModel
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
val rootView = inflater.inflate(R.layout.fragment_wallet, container, false)
recyclerView = rootView.findViewById(R.id.wallet_recyclerview)
viewModel = ViewModelProvider(
this
).get(WalletViewModel::class.java)
val linearLayoutManager = LinearLayoutManager(context, RecyclerView.VERTICAL, false)
viewManager = linearLayoutManager
// Observe the ViewModel
viewModel.allCards.observe(viewLifecycleOwner, Observer { cards ->
viewAdapter = CardAdapter(cards)
})
return rootView
}
}
WalletViewModel
package com.example.android.pointmax.ui.wallet
import android.app.Application
import androidx.lifecycle.*
import com.example.android.pointmax.database.Card
import com.example.android.pointmax.database.CardRepository
import com.example.android.pointmax.database.CardRoomDatabase
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.launch
class WalletViewModel(application: Application) : AndroidViewModel(application) {
private val repository: CardRepository
// Using LiveData and caching what getAlphabetizedWords returns has several benefits:
// - We can put an observer on the data (instead of polling for changes) and only update the
// the UI when the data actually changes.
// - Repository is completely separated from the UI through the ViewModel.
val allCards: LiveData<List<Card>>
init {
val cardsDao = CardRoomDatabase.getDatabase(application, viewModelScope).cardDao()
repository = CardRepository(cardsDao)
allCards = repository.allCards
}
/**
* Launching a new coroutine to insert the data in a non-blocking way
*/
fun insert(card: Card) = viewModelScope.launch(Dispatchers.IO) {
repository.insert(card)
}
}
CardAdapter
package com.example.android.pointmax
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.TextView
import androidx.recyclerview.widget.RecyclerView
import com.example.android.pointmax.database.Card
class CardAdapter internal constructor(
private var cards: List<Card>
) : RecyclerView.Adapter<CardAdapter.CardViewHolder>() {
inner class CardViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
val cardItemView: TextView = itemView.findViewById(R.id.textView)
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): CardViewHolder {
val itemView = LayoutInflater.from(parent.context)
.inflate(R.layout.recyclerview_item, parent, false)
return CardViewHolder(itemView)
}
override fun onBindViewHolder(holder: CardViewHolder, position: Int) {
val current = cards[position]
holder.cardItemView.text = current.toString()
}
internal fun setWords(cards: List<Card>) {
this.cards = cards
notifyDataSetChanged()
}
override fun getItemCount() = cards.size
}
CardRepository
package com.example.android.pointmax.database
import androidx.lifecycle.LiveData
// Declares the DAO as a private property in the constructor. Pass in the DAO
// instead of the whole database, because you only need access to the DAO
class CardRepository(private val cardDao: CardDao) {
// Room executes all queries on a separate thread.
// Observed LiveData will notify the observer when the data has changed.
val allCards: LiveData<List<Card>> = cardDao.getCards()
suspend fun insert(card: Card) {
cardDao.insert(card)
}
}
CardRoomDatabase
package com.example.android.pointmax.database
import android.content.Context
import androidx.room.Database
import androidx.room.Room
import androidx.room.RoomDatabase
import androidx.sqlite.db.SupportSQLiteDatabase
import kotlinx.coroutines.CoroutineScope
import kotlinx.coroutines.launch
// Annotates class to be a Room Database with a table (entity) of the Word class
#Database(entities = arrayOf(Card::class), version = 1, exportSchema = false)
public abstract class CardRoomDatabase : RoomDatabase() {
abstract fun cardDao(): CardDao
companion object {
// Singleton prevents multiple instances of database opening at the
// same time.
#Volatile
private var INSTANCE: CardRoomDatabase? = null
fun getDatabase(
context: Context,
scope: CoroutineScope
): CardRoomDatabase {
val tempInstance = INSTANCE
if (tempInstance != null) {
return tempInstance
}
synchronized(this) {
val instance = Room.databaseBuilder(
context.applicationContext,
CardRoomDatabase::class.java,
"card_database"
).addCallback(CardDatabaseCallback(scope)).build()
INSTANCE = instance
return instance
}
}
private class CardDatabaseCallback(
private val scope: CoroutineScope
) : RoomDatabase.Callback() {
override fun onOpen(db: SupportSQLiteDatabase) {
super.onOpen(db)
INSTANCE?.let { database ->
scope.launch {
populateDatabase(database.cardDao())
}
}
}
suspend fun populateDatabase(cardDao: CardDao) {
// Delete all content here.
cardDao.deleteAll()
// Add sample words.
var card = Card("Petal Credit Card")
cardDao.insert(card)
card = Card("Discover IT")
cardDao.insert(card)
}
}
}
}
Card
package com.example.android.pointmax.database
import androidx.room.ColumnInfo
import androidx.room.Entity
import androidx.room.PrimaryKey
#Entity(tableName = "card_table")
data class Card(
#PrimaryKey
#ColumnInfo(name = "cardName")
var card: String
)
CardDao
package com.example.android.pointmax.database
import androidx.lifecycle.LiveData
import androidx.room.Dao
import androidx.room.Insert
import androidx.room.OnConflictStrategy
import androidx.room.Query
#Dao
interface CardDao {
#Query("SELECT * from card_table")
fun getCards(): LiveData<List<Card>>
#Insert(onConflict = OnConflictStrategy.REPLACE)
suspend fun insert(card: Card)
#Query("DELETE FROM card_table")
suspend fun deleteAll()
}
I can launch the application but as soon as I go to the Wallet fragment, the application crashes with the following:
2020-04-23 19:24:18.676 5048-5048/com.example.android.pointmax E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.android.pointmax, PID: 5048
java.lang.RuntimeException: Cannot create an instance of class com.example.android.pointmax.ui.wallet.WalletViewModel
at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.java:275)
at androidx.lifecycle.SavedStateViewModelFactory.create(SavedStateViewModelFactory.java:106)
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.java:185)
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.java:150)
at com.example.android.pointmax.ui.wallet.WalletFragment.onCreateView(WalletFragment.kt:31)
at androidx.fragment.app.Fragment.performCreateView(Fragment.java:2698)
at androidx.fragment.app.FragmentStateManager.createView(FragmentStateManager.java:320)
at androidx.fragment.app.FragmentManager.moveToState(FragmentManager.java:1187)
at androidx.fragment.app.FragmentManager.addAddedFragments(FragmentManager.java:2224)
at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:1997)
at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:1953)
at androidx.fragment.app.FragmentManager.execPendingActions(FragmentManager.java:1849)
at androidx.fragment.app.FragmentManager$4.run(FragmentManager.java:413)
at android.os.Handler.handleCallback(Handler.java:883)
at android.os.Handler.dispatchMessage(Handler.java:100)
at android.os.Looper.loop(Looper.java:214)
at android.app.ActivityThread.main(ActivityThread.java:7356)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Constructor.newInstance0(Native Method)
at java.lang.reflect.Constructor.newInstance(Constructor.java:343)
at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.java:267)
at androidx.lifecycle.SavedStateViewModelFactory.create(SavedStateViewModelFactory.java:106)
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.java:185)
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.java:150)
at com.example.android.pointmax.ui.wallet.WalletFragment.onCreateView(WalletFragment.kt:31)
at androidx.fragment.app.Fragment.performCreateView(Fragment.java:2698)
at androidx.fragment.app.FragmentStateManager.createView(FragmentStateManager.java:320)
at androidx.fragment.app.FragmentManager.moveToState(FragmentManager.java:1187)
at androidx.fragment.app.FragmentManager.addAddedFragments(FragmentManager.java:2224)
at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:1997)
at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:1953)
at androidx.fragment.app.FragmentManager.execPendingActions(FragmentManager.java:1849)
at androidx.fragment.app.FragmentManager$4.run(FragmentManager.java:413)
at android.os.Handler.handleCallback(Handler.java:883)
at android.os.Handler.dispatchMessage(Handler.java:100)
at android.os.Looper.loop(Looper.java:214)
at android.app.ActivityThread.main(ActivityThread.java:7356)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)
Caused by: java.lang.RuntimeException: cannot find implementation for com.example.android.pointmax.database.CardRoomDatabase. CardRoomDatabase_Impl does not exist
at androidx.room.Room.getGeneratedImplementation(Room.java:94)
at androidx.room.RoomDatabase$Builder.build(RoomDatabase.java:952)
at com.example.android.pointmax.database.CardRoomDatabase$Companion.getDatabase(CardRoomDatabase.kt:37)
at com.example.android.pointmax.ui.wallet.WalletViewModel.(WalletViewModel.kt:20)
The most essential part of your stack trace is here
`Caused by: java.lang.RuntimeException: cannot find implementation for com.example.android.pointmax.database.CardRoomDatabase. CardRoomDatabase_Impl does not exist at androidx.room.Room.getGeneratedImplementation(Room.java:94) at androidx.room.RoomDatabase$Builder.build(RoomDatabase.java:952) at com.example.android.pointmax.database.CardRoomDatabase$Companion.getDatabase(CardRoomDatabase.kt:37) at com.example.android.pointmax.ui.wallet.WalletViewModel.(WalletViewModel.kt:20)`
So the problem is Room couldn't generate class CardRoomDatabase_Impl (implementation of your abstract class CardRoomDatabase). Since you use Room annotation correctly, the only reason of your problem I could guess - you haven't included annotation processor in your build.gradle (app level). Check if it is in dependencies-section:
kapt "androidx.room:room-compiler:2.2.5"