I am working with recycler view, but it was behaving differently now.
The issue is when we scroll from top to bottom all things work okay, but when scrolling bottom to top it not working as expected.
I am loading arround 450 Items.
Please find more details in the attached video (Last Few Seconds Very Important).
Video : https://www.dropbox.com/s/rb7y52av6wwcq3q/RecyclerViewIssue.mp4?dl=0
Gradle dependencies
implementation 'androidx.appcompat:appcompat:1.5.1'
implementation 'com.google.android.material:material:1.6.1'
implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
//RecyclerView
implementation 'androidx.recyclerview:recyclerview:1.2.1'
//Other dependencies
XML Code
<androidx.constraintlayout.widget.ConstraintLayout 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=".ui.home.HomeActivity">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/rcvJobList"
android:layout_width="match_parent"
android:layout_height="#dimen/_400sdp"
android:background="#drawable/box2"
android:clipChildren="false"
android:paddingTop="#dimen/_5sdp"
android:paddingBottom="#dimen/_5sdp"
tools:itemCount="20"
tools:listitem="#layout/item_job" />
</androidx.constraintlayout.widget.ConstraintLayout>
Activity Code
class HomeActivity : BaseActivity<HomeViewModel, ActivityHomeBinding, HomeRepository>(),
RcvJobListAdapter.AdapterListener {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
// Other Code
ViewModel.jobList.observe(this, jobListObserver)
}
// Live data observer code
val jobListObserver = Observer<List<Job>> {
Log.e("HomeActivity", "Job List Observer Invoked Size : ${it.size}");
var tempList = arrayListOf<Job>()
tempList.addAll(it)
var adapter = RcvJobListAdapter(tempList, this#HomeActivity)
binding.rcvJobList.adapter = adapter
}
}
Adapter Code
class RcvJobListAdapter : RecyclerView.Adapter<RcvJobListAdapter.ViewHolder> {
var jobList: List<Job> = emptyList()
private lateinit var callback: AdapterListener
constructor(
jobList: List<Job>,
callback: AdapterListener,
) : super() {
this.jobList = jobList
this.callback = callback
}
class ViewHolder(var itemView: View) : RecyclerView.ViewHolder(itemView)
{
var binding = ItemJobBinding.bind(itemView)
init {
binding.root.setBackgroundColor(Color.WHITE)
}
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
return ViewHolder(
LayoutInflater.from(parent.context).inflate(R.layout.item_job,parent,false)
)
}
var prevPosition : Int = -1
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
Log.e("Adapter","Bind Pos : ${holder.bindingAdapterPosition}, Absolute : ${holder.absoluteAdapterPosition} , Last ${prevPosition}")
var job = jobList.get(holder.bindingAdapterPosition)
holder.binding.tvJobText.setText("${holder.bindingAdapterPosition}\n${job.getCombainedString()}")
holder.binding.tvJobText.setOnClickListener {
if(prevPosition!=-1)
{
var temp = prevPosition
prevPosition = -1;
notifyItemChanged(temp)
if(temp == holder.bindingAdapterPosition)
{
return#setOnClickListener
}
}
prevPosition = holder.bindingAdapterPosition
holder.binding.root.setBackgroundColor(Color.parseColor("#BCF1C9"))
}
if(prevPosition == holder.bindingAdapterPosition)
{
holder.binding.root.setBackgroundColor(Color.parseColor("#BCF1C9"))
}
else
{
holder.binding.root.setBackgroundColor(Color.WHITE)
}
}
override fun getItemCount(): Int = jobList.size
open interface AdapterListener {
fun jobItemClick(position: Int, job: Job);
}
}
i am calling data from API to display it to use but in my case i want to display the latest 4 images of the API, i don't want to call all of them
so what is the correct way to do this?
Here is my code:
Interface:
interface facebookInterface {
#GET(" ")
fun getServices(): Call<List<facebookData>>
companion object Factory {
fun create(): facebookInterface {
val retrofit = Retrofit.Builder()
.addConverterFactory(GsonConverterFactory.create())
.baseUrl("API_URL")
.build()
return retrofit.create(facebookInterface::class.java)
}
}
}
Adapter:
class facebookAdapter(var countryList: List<facebookData>, var activity: MainActivity): RecyclerView.Adapter<facebookAdapter.ViewHolder>(){
lateinit var context: Context
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): facebookAdapter.ViewHolder {
context = parent.context!!
val view = LayoutInflater.from(context).inflate(R.layout.facebook_list_item, parent, false)
return ViewHolder(view)
}
override fun getItemCount(): Int {
return countryList.size
}
override fun onBindViewHolder(holder: facebookAdapter.ViewHolder, position: Int) {
holder.name.text = countryList[position].source
holder.capital.text = countryList[position].imageLink
Picasso.get()
.load(countryList[position].imageUrl)
.memoryPolicy(MemoryPolicy.NO_CACHE, MemoryPolicy.NO_STORE)
.networkPolicy(NetworkPolicy.NO_CACHE, NetworkPolicy.NO_STORE)
.into(holder.thumbnailUrl)
}
class ViewHolder(itemView: View): RecyclerView.ViewHolder(itemView){
val name: TextView = itemView.findViewById(R.id.country_name)
val capital: TextView = itemView.findViewById(R.id.country_capital)
val thumbnailUrl: ImageView = itemView.findViewById(R.id.country_flag)
}
}
list_item.xml
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout 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/frame_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<androidx.cardview.widget.CardView
android:id="#+id/list_card"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:cardCornerRadius="4dp"
app:contentPadding="8dp">
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/list_constraint"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="#+id/country_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:fontFamily="monospace"
android:text="TextView"
android:textSize="24sp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="#+id/country_capital"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:layout_marginTop="8dp"
android:fontFamily="monospace"
android:text="TextView"
android:textSize="18sp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/country_name" />
<ImageView
android:id="#+id/country_flag"
android:layout_width="100dp"
android:layout_height="100dp"
android:layout_marginTop="8dp"
android:layout_marginEnd="8dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.cardview.widget.CardView>
</FrameLayout>
Activity:
val recyclerView: RecyclerView = findViewById(R.id.list_recycler4)
recyclerView.layoutManager = LinearLayoutManager(this)
val facebookInterface = facebookInterface.Factory.create()
val facebok: Call<List<facebookData>> = facebookInterface.getServices()
facebok.enqueue(object : Callback<List<facebookData>> {
override fun onFailure(call: Call<List<facebookData>>, t: Throwable) {
Log.d("xxxx", t.toString())
Toast.makeText(this#MainActivity, t.message, Toast.LENGTH_SHORT).show()
}
override fun onResponse(
call: Call<List<facebookData>>,
response: Response<List<facebookData>>
) {
Log.d("xxxx", response.body().toString())
val list = response.body()!!
recyclerView.adapter = facebookAdapter(list, this#MainActivity)
}
})
data class:
data class facebookData (
val imageUrl : String,
val imageLink: String,
val source: String
)
i am getting the data and i can see it on the device but is there a way to display only the latest 4 images from API?
and how to link the url of each image so the user can go to the url of each image
"English is not my mother tongue, i will explain more if you didn't understand me"
As Teo said, you are better of applying a filter directly to your API call, but if that is not possible, you can trim off the list you receive.
There are mainly two methods I can think of, that can get you what you want, first is to make a sublist and then assign the adapter as follows.
val trimmedList = if(list.size > 4){
list.subList(fromIndex = 0, toIndex = 3)
} else {
list
}
recyclerView.adapter = facebookAdapter(trimmedList , this#MainActivity)
Second way to override the itemCount method inside the Recycler View Adapter, same logic shall apply there. It will be as follows.
override fun getItemCount(): Int {
return if(countryList.size > 4) {
4
} else {
countryList.size
}
}
For second part of your answer, I am adding the following code for your reference, but I still believe it is better for you to understand what is happening.
To open the url in browser, firstly you need a callback from your Adapter to your MainActivity.
Your adapter will be modified as the following.
class facebookAdapter(var countryList: List<facebookData>,
private val facebookAdapterCallback: FacebookAdapterCallback)
: RecyclerView.Adapter<facebookAdapter.ViewHolder>(){
lateinit var context: Context
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): facebookAdapter.ViewHolder {
context = parent.context!!
val view = LayoutInflater.from(context).inflate(R.layout.facebook_list_item, parent, false)
return ViewHolder(view)
}
override fun getItemCount(): Int {
return countryList.size
}
override fun onBindViewHolder(holder: facebookAdapter.ViewHolder, position: Int) {
holder.name.text = countryList[position].source
holder.capital.text = countryList[position].imageLink
holder.thumbnailUrl.setOnClickListener {
facebookAdapterCallback.onFacebookAdapterItemClick(countryList[position])
}
Picasso.get()
.load(countryList[position].imageUrl)
.memoryPolicy(MemoryPolicy.NO_CACHE, MemoryPolicy.NO_STORE)
.networkPolicy(NetworkPolicy.NO_CACHE, NetworkPolicy.NO_STORE)
.into(holder.thumbnailUrl)
}
class ViewHolder(itemView: View): RecyclerView.ViewHolder(itemView){
val name: TextView = itemView.findViewById(R.id.country_name)
val capital: TextView = itemView.findViewById(R.id.country_capital)
val thumbnailUrl: ImageView = itemView.findViewById(R.id.country_flag)
}
interface FacebookAdapterCallback{
fun onFacebookAdapterItemClick(data: facebookData)
}
}
Next we will have to modify your activity as follows to implement the above interface inside it
class MainActivity : AppCompatActivity(), facebookAdapter.FacebookAdapterCallback {
override fun onFacebookAdapterItemClick(data: facebookData) {
openLinkInBrowser(this#MainActivity, data.imageLink)
}
fun openLinkInBrowser(context: Context, url: String) {
try {
val url = if (Uri.parse(url).scheme == null || !url.startsWith("https://") && !url.startsWith("http://")) {
"https://$url"
} else url
val webPage: Uri = Uri.parse(url)
val intent = Intent(Intent.ACTION_VIEW, webPage)
if (intent.resolveActivity(context.packageManager) != null) {
context.startActivity(intent)
} else {
Toast.makeText(context, "No App Available for this action", Toast.LENGTH_SHORT).show()
}
} catch (e: Exception) {
e.printStackTrace()
}
}
}
I have also added a helper method to open the link in browser, it uses the default Android Intents and checks for apps available in which this action can be performed.
We also check if the URL has http or https appended else we add it.
While I have provided you the code, I would still recommend you to understand what is happening before doing it.
I have A Bottom Navigation Bar Using Navigation Components It Contain 3 Fragments let Say A(Home), B And C. When I Moved From B To C Fragment B Destroys And Similarly C To B C Destroys. When I Re-Select A It Again Makes Network Call Fetches The Data and Display. I Don't Want To Make A Network Request Again And Again When Fragment Destroys Or Re-Selected.
I'm Using ViewModel, Retrofit, LiveData, Coroutines And Kotlin.
Please Help Me To Fix This Problem
Base Fragment
abstract class BaseFragment<VM: ViewModel, VB: ViewBinding, R: BaseRepository>:Fragment() {
private var _viewBinding: VB? = null
protected val viewBinding
get() = _viewBinding!!
protected lateinit var viewModel: VM
protected lateinit var userTokenData: UserTokenData
protected lateinit var remoteDataStore: RemoteDataSource
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
remoteDataStore = RemoteDataSource()
userTokenData = UserTokenData(requireContext())
_viewBinding = getFragmentBinding(inflater, container)
val factory = ViewModelFactory(getRepository())
viewModel = ViewModelProvider(this, factory).get(getViewModelClass())
lifecycleScope.launch {
userTokenData.token.first()
}
return viewBinding.root
}
abstract fun getViewModelClass():Class<VM>
abstract fun getFragmentBinding(inflater: LayoutInflater, container: ViewGroup?): VB
abstract fun getRepository(): R
override fun onDestroyView() {
super.onDestroyView()
Log.d(MyTAG, "onDestroyView")
_viewBinding = null
}
Home Fragment
class HomeFragment : BaseFragment<HomeViewModel, FragmentHomeBinding, UserRepository>() {
override fun getViewModelClass() = HomeViewModel::class.java
override fun getFragmentBinding(
inflater: LayoutInflater,
container: ViewGroup?
) = FragmentHomeBinding.inflate(inflater, container, false)
override fun getRepository(): UserRepository {
val token = runBlocking { userTokenData.token.first() }
return UserRepository(remoteDataStore.buildApi(UserApi::class.java, token))
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
viewBinding.progressBar.visible(true)
viewModel.user.observe(viewLifecycleOwner, Observer {
when(it){
is Resources.Success -> {
updateUI(it.value.user)
}
is Resources.Loading -> {
viewBinding.progressBar.visible(true)
}
}
})
}
fun updateUI(user: User){
viewBinding.progressBar.visible(false)
viewBinding.email.text = user.email
viewBinding.name.text = user.name
}
}
In each Fragment, put this before onCreate
private val myViewModel: MyViewModel by activityViewModels()
Also, in order to do that, you will need to have this dependency:
implementation "androidx.fragment:fragment-ktx:1.2.5"
To understand it better read this :
First game :
Skate QuestionMark
Archery QuestionMark
Swim QuestionMark
---------------------------
Water Bow Wheel
If user drags Water to Skate or Archery QuestionMark it will animate to the list (because it is not correct)
If user drags twice incorrect (it will mark the one that is correct from the answer list)
If user still fail in the third try it will drag to the incorrect one and then it will highlight or just change the color doesn't matter to red.
If user drags to the correct one it will highlight green and replace QuestionMark with the correct one (I do not want to be draggable anymore that image)
------
Game 2 (is more or less the same...)
There's no QuestionMark column, there's only :
Skate
Swim
Archery
--------------
(Lot of answers)
Now the way to play is the same (about the fails and etc) the thing is now when I drag any answer to the correct one it won't replace the correct one, it will just disappear and if it fails instead of highlighting all the corrects one it will highlight the correct answer (for instance; if I drag wheel to Swim once, it doesn't happen anything just animate to the place where it was, if I do it twice it will highlight the Skate one, and if it fails at third one it just drag wherever he did and highlight with red)
I'm planning to build an app that does a simple check, I'm calling an endpoint and I'll get some params, and then I'll know how many ImageView are going to be displayed in the screen.
This is like a puzzle, and it would look like this :
So I have different options, which contains only one correct answer, I'm planing the way to achieve this, could be able to drag "Bow" to the questionmark infront of "skateboarding" and then says that is not correct, then drag it to the "archery" one and replace the questionmark for the ImageView from the bottom that contains the word "Arrow".
Layout should contain one column for Question (this should be the sports) then another one in front of the Question one and should be the Answer one, then below them should contain the Options one.
Was it clear? Otherwise let me know and I'll try to explain it a little bit with more details.
EDIT
What I thought is having like a class that contains a list of Answers or just create like :
RightList : (id:1,id:2,id:3)
LeftList : (id:1, id:2, id:3)
DownList : (Bow = id:2),(Skate = id:1), (Ball = id:3)
Then doing the drag and drop thing when the DragEvent.ACTION_DROP or DragEvent.ACTION_DRAG_ENDEDI do not know which one, check (Pseudocode below)
if(imageDragged.id==location.id) then replace the question mark image for imageDragged
else animate the image to the place where it comes
I do not know if creating a class that implements onDragListener() or something like that, I'd like to have it generic so I can use it on different games like for instance :
SKATE(id:1) ARCHERY(id:2) FOOTBALL(id:3)
Answers : TABLE(C.A. id:1) BOW(C.A. id:2) GRASS(C.A. id:3) GOAL(C.A. id:3) BALL(C.A. id:3) ARROW(C.A. id:2) AXES(C.A. id:1) WHEELS(C.A. id:1)
So if I drag and drop for instance BOW to FOOTBALL then it should display that is bad, otherwise say that it's good.
EXAMPLE 1/3
Just for reference and summarize everything. Here is one 100 lines code, within single Activity and imports, representing all this behavior even with simple animation.
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
bind()
}
private fun bind() {
addQuestions()
addAnswers()
}
#SuppressLint("InflateParams")
private fun addQuestions() {
val inflater = getSystemService(
Context.LAYOUT_INFLATER_SERVICE
) as LayoutInflater
for (i in 1..8) {
val view = inflater.inflate(R.layout.item_question, null)
view.setOnDragListener(DragListener())
questionContainer.addView(view)
}
}
#SuppressLint("InflateParams")
private fun addAnswers() {
val inflater = getSystemService(
Context.LAYOUT_INFLATER_SERVICE
) as LayoutInflater
for (i in 1..8) {
val view = inflater.inflate(R.layout.item_answer, null)
view.setOnTouchListener(DragItemTouchListener())
answerContainer.addView(view)
}
}
private inner class DragItemTouchListener : OnTouchListener {
override fun onTouch(view: View, motionEvent: MotionEvent): Boolean {
return if (motionEvent.action == MotionEvent.ACTION_DOWN) {
dragMultiple(view)
true
} else {
false
}
}
private fun dragMultiple(view : View) {
val data = ClipData.newPlainText("", "")
val shadowBuilder = DragShadowBuilder(
view
)
val parent = view.parent as ViewGroup
view.startDragAndDrop(data, shadowBuilder, view, 0)
parent.removeView(view)
}
}
private inner class DragListener : OnDragListener {
override fun onDrag(v: View, event: DragEvent): Boolean {
when (event.action) {
DragEvent.ACTION_DRAG_STARTED -> {
}
DragEvent.ACTION_DRAG_ENTERED -> {
}
DragEvent.ACTION_DRAG_EXITED -> {
}
DragEvent.ACTION_DROP -> {
animateDropEffect(v as ViewGroup, event.localState as View)
}
DragEvent.ACTION_DRAG_ENDED -> {
}
else -> {
}
}
return true
}
private fun animateDropEffect(into: ViewGroup, view: View) {
into.addView(view)
val params = (view.layoutParams as FrameLayout.LayoutParams)
.apply {
gravity = Gravity.END
}
view.layoutParams = params
}
}
}
All Xmls used. Below xml for all examples below.
/* activity_main.xml */
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
android:id="#+id/mainContainer"
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".MainActivity">
<ScrollView
android:layout_width="match_parent"
android:layout_height="500dp"
android:animateLayoutChanges="true">
<LinearLayout
android:id="#+id/questionContainer"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:animateLayoutChanges="true"
android:orientation="vertical">
</LinearLayout>
</ScrollView>
<HorizontalScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:animateLayoutChanges="true">
<LinearLayout
android:id="#+id/answerContainer"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:animateLayoutChanges="true"
android:orientation="horizontal">
</LinearLayout>
</HorizontalScrollView>
</LinearLayout>
</FrameLayout>
/* item_question.xml */
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:animateLayoutChanges="true"
android:padding="5dp">
<View
android:layout_width="100dp"
android:layout_height="100dp"
android:layout_gravity="start"
android:background="#android:color/holo_blue_bright">
</View>
<View
android:id="#+id/questionView"
android:layout_width="100dp"
android:layout_height="100dp"
android:layout_gravity="end"
android:background="#android:color/holo_orange_light">
</View>
</FrameLayout>
/* item_answer.xml */
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
android:padding="5dp"
android:tag="Test">
<LinearLayout
android:layout_width="100dp"
android:layout_height="100dp"
android:layout_gravity="center"
android:background="#android:color/darker_gray">
</LinearLayout>
</FrameLayout>
EXAMPLE 2/3
It's not a problem to make dragging for few elements following with a the same approach. Here is a little crappy, but simple example.
Modified code for second example. Xml stay the same.
class MainActivity : AppCompatActivity() {
var activeOneDrag : Boolean = false
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
bind()
}
private fun bind() {
addQuestions()
addAnswers()
}
fun getRandomColor(): Int {
return Color.argb(255, Random.nextInt(255),
Random.nextInt(255), Random.nextInt(255))
}
#SuppressLint("InflateParams")
private fun addQuestions() {
val inflater = getSystemService(
Context.LAYOUT_INFLATER_SERVICE
) as LayoutInflater
for (i in 1..8) {
val view = inflater.inflate(R.layout.item_question, null)
view.setOnDragListener(DragListener())
questionContainer.addView(view)
}
}
#SuppressLint("InflateParams")
private fun addAnswers() {
val inflater = getSystemService(
Context.LAYOUT_INFLATER_SERVICE
) as LayoutInflater
for (i in 1..8) {
val view = inflater.inflate(R.layout.item_answer, null)
(view as ViewGroup).getChildAt(0).setBackgroundColor(getRandomColor())
view.setOnTouchListener(DragItemTouchListener())
answerContainer.addView(view)
}
}
private inner class DragItemTouchListener : OnTouchListener {
override fun onTouch(view: View, motionEvent: MotionEvent): Boolean {
return if (motionEvent.action == MotionEvent.ACTION_DOWN) {
dragMultiple(view)
true
} else {
false
}
}
private fun dragMultiple(view : View) {
val parent = view.parent as ViewGroup
parent.removeView(view)
/**
* Some other logic with selective multiple View.
* Just getting neighbor in our case
*/
var anotherView : View? = null
if (!activeOneDrag) {
anotherView = parent.getChildAt(
parent.indexOfChild(view) + 1)
parent.removeView(anotherView)
}
activeOneDrag = !activeOneDrag
/**
* As you can see, there is postDelay here.
* But only for our case with animateLayoutChanges,
* with delays removing View! In your samples, you could remove it
* with listener on your own animation, if any!
*/
parent.postDelayed({
val layout = LinearLayout(this#MainActivity)
val params = FrameLayout.LayoutParams(
FrameLayout.LayoutParams.WRAP_CONTENT,
FrameLayout.LayoutParams.WRAP_CONTENT)
params.gravity = Gravity.BOTTOM
layout.layoutParams = params
layout.orientation = LinearLayout.HORIZONTAL
layout.addView(view)
if (anotherView != null) {
layout.addView(anotherView)
}
layout.visibility = INVISIBLE
mainContainer.addView(layout)
parent.post {
layout.startDragAndDrop(
ClipData.newPlainText("", ""),
DragShadowBuilder(layout), layout, 0)
}
}, 400)
}
}
private inner class DragListener : OnDragListener {
override fun onDrag(v: View, event: DragEvent): Boolean {
when (event.action) {
DragEvent.ACTION_DRAG_STARTED -> {
}
DragEvent.ACTION_DRAG_ENTERED -> {
}
DragEvent.ACTION_DRAG_EXITED -> {
}
DragEvent.ACTION_DROP -> {
val view = event.localState as View
(view.parent as ViewGroup).removeView(view)
view.visibility = VISIBLE
animateDropEffect(v as ViewGroup, event.localState as View)
}
DragEvent.ACTION_DRAG_ENDED -> {
}
else -> {
}
}
return true
}
private fun animateDropEffect(into: ViewGroup, view: View) {
into.addView(view)
val params = (view.layoutParams as FrameLayout.LayoutParams)
.apply {
gravity = Gravity.END
}
view.layoutParams = params
}
}
}
EXAMPLE 3/3
As I see, it's not clear, how to change simple actions with animation or Drag listening area. Here is another simple example of doing all actions
class MainActivity : AppCompatActivity() {
#Volatile
var state : State = State.INACTIVE
enum class State {
ACTIVE, INACTIVE, HANDLED
}
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
bind()
}
private fun bind() {
addQuestions()
addAnswers()
}
private fun getRandomColor(): Int {
return Color.argb(255, Random.nextInt(255),
Random.nextInt(255), Random.nextInt(255))
}
#SuppressLint("InflateParams")
private fun addQuestions() {
val inflater = getSystemService(
Context.LAYOUT_INFLATER_SERVICE
) as LayoutInflater
for (i in 1..8) {
val view = inflater.inflate(R.layout.item_question, null)
view.findViewById<View>(R.id.questionView)
.setOnDragListener(DragListener())
questionContainer.addView(view)
}
}
#SuppressLint("InflateParams")
private fun addAnswers() {
val inflater = getSystemService(
Context.LAYOUT_INFLATER_SERVICE
) as LayoutInflater
for (i in 1..8) {
val view = inflater.inflate(R.layout.item_answer, null)
(view as ViewGroup).getChildAt(0).setBackgroundColor(getRandomColor())
view.setOnTouchListener(DragItemTouchListener())
answerContainer.addView(view)
}
}
private inner class DragItemTouchListener : OnTouchListener {
val ITEM_INDEX_D = "Index-From"
override fun onTouch(view: View, motionEvent: MotionEvent): Boolean {
return if (motionEvent.action == MotionEvent.ACTION_DOWN) {
createDrag(view)
true
} else {
false
}
}
private fun createDrag(view : View) {
val parent = view.parent as ViewGroup
view.tag = Pair(ITEM_INDEX_D,
parent.indexOfChild(view))
view.startDragAndDrop(ClipData.newPlainText("", ""),
DragShadowBuilder(view), view, 0)
parent.removeView(view)
parent.setBackgroundColor(Color.WHITE)
}
}
private inner class DragListener : OnDragListener {
override fun onDrag(parent: View, event: DragEvent): Boolean {
val view = event.localState as View
when (event.action) {
DragEvent.ACTION_DRAG_STARTED -> {
state = State.ACTIVE
}
DragEvent.ACTION_DRAG_ENTERED -> {
}
DragEvent.ACTION_DRAG_EXITED -> {
}
DragEvent.ACTION_DROP -> {
state = State.HANDLED
animateDropEffect(parent, view)
return true
}
DragEvent.ACTION_DRAG_ENDED -> {
if (state == State.ACTIVE) {
state = State.INACTIVE
animateMoveBack(view,
(view.tag as Pair<*, *>).second as Int)
}
return true
}
else -> {
}
}
return true
}
private fun animateMoveBack(view: View, index : Int) {
answerContainer.addView(view, index)
}
private fun animateDropEffect(into: View, view: View) {
val parent = (into.parent as ViewGroup)
parent.addView(view)
val params = (view.layoutParams as FrameLayout.LayoutParams)
.apply {
gravity = Gravity.END
}
view.layoutParams = params
checkIsCorrect(parent)
}
private fun checkIsCorrect(parent : ViewGroup) {
val correct = Random.nextBoolean()
val colorFrom = Color.WHITE
val colorTo : Int = if (correct) 0x8000ff00.toInt() else 0x80ff0000.toInt()
ObjectAnimator.ofObject(
parent,
"backgroundColor",
ArgbEvaluator(),
colorFrom,
colorTo
)
.setDuration(1000)
.start()
}
}
}
UPDATE
The last update from the comments sections. I think it's enough, and of course you would need you changes. So just change two "if" statement to align with your requirements and animation.
class MainActivity : AppCompatActivity() {
enum class State {
ACTIVE, INACTIVE, HANDLED
}
var state : State = State.INACTIVE
var failsCount = 0
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
bind()
}
private fun bind() {
addQuestions()
addAnswers()
}
private fun getRandomColor(): Int {
return Color.argb(255, Random.nextInt(255),
Random.nextInt(255), Random.nextInt(255))
}
#SuppressLint("InflateParams")
private fun addQuestions() {
val inflater = getSystemService(
Context.LAYOUT_INFLATER_SERVICE
) as LayoutInflater
for (i in 1..3) {
val view = inflater.inflate(R.layout.item_question, null)
view.findViewById<View>(R.id.questionView)
.setOnDragListener(DragListener())
questionContainer.addView(view)
}
}
#SuppressLint("InflateParams")
private fun addAnswers() {
val inflater = getSystemService(
Context.LAYOUT_INFLATER_SERVICE
) as LayoutInflater
for (i in 1..3) {
val view = inflater.inflate(R.layout.item_answer, null)
(view as ViewGroup).getChildAt(0).setBackgroundColor(getRandomColor())
view.setOnTouchListener(DragItemTouchListener())
answerContainer.addView(view)
}
}
private inner class DragItemTouchListener : OnTouchListener {
val ITEM_INDEX_D = "Index-From"
override fun onTouch(view: View, motionEvent: MotionEvent): Boolean {
return if (motionEvent.action == MotionEvent.ACTION_DOWN) {
createDrag(view)
true
} else {
false
}
}
private fun createDrag(view : View) {
val parent = view.parent as ViewGroup
view.tag = Pair(ITEM_INDEX_D,
parent.indexOfChild(view))
view.startDragAndDrop(ClipData.newPlainText("", ""),
DragShadowBuilder(view), view, 0)
parent.removeView(view)
parent.setBackgroundColor(Color.WHITE)
}
}
private inner class DragListener : OnDragListener {
val ANIM_DURATION_LONG = TimeUnit.SECONDS.toMillis(1)
val ANIM_DURATION_SHORT = TimeUnit.MILLISECONDS.toMillis(500)
val GREEN_ALPHA = 0x8000ff00.toInt()
val RED_ALPHA = 0x80ff0000.toInt()
val ANIM_COLOR = "backgroundColor"
override fun onDrag(parent: View, event: DragEvent): Boolean {
val view = event.localState as View
when (event.action) {
DragEvent.ACTION_DRAG_STARTED -> {
state = State.ACTIVE
}
DragEvent.ACTION_DRAG_ENTERED -> {
}
DragEvent.ACTION_DRAG_EXITED -> {
}
DragEvent.ACTION_DROP -> {
state = State.HANDLED
animateDropEffect(parent, view)
return true
}
DragEvent.ACTION_DRAG_ENDED -> {
if (state == State.ACTIVE) {
state = State.INACTIVE
animateMoveBack(view,
(view.tag as Pair<*, *>).second as Int)
}
return true
}
else -> {
}
}
return true
}
private fun animateMoveBack(view: View, index : Int) {
answerContainer.addView(view, index)
}
private fun animateDropEffect(into: View, view: View) {
val parent = (into.parent as ViewGroup)
parent.addView(view)
val params = (view.layoutParams as FrameLayout.LayoutParams)
.apply {
gravity = Gravity.END
}
view.layoutParams = params
checkIsCorrect(parent)
}
private fun checkIsCorrect(parent : ViewGroup) {
val correct = false
if (correct) {
animateColorChange(parent, true)
return
}
if (++failsCount > Companion.MAX_FAIL_COUNT) {
animateColorChange(parent, false)
return
}
animateWrongAttempt(parent)
}
private fun animateWrongAttempt(parent: ViewGroup) {
val questionMark = parent.findViewById<View>(R.id.questionView)
questionMark.setBackgroundColor(Color.RED)
val va = ValueAnimator.ofFloat(1f, 1.1f)
va.interpolator = BounceInterpolator()
va.duration = ANIM_DURATION_SHORT
va.addUpdateListener { animation ->
questionMark.scaleX = animation.animatedValue as Float
questionMark.scaleY = animation.animatedValue as Float
}
va.start()
}
private fun animateColorChange(parent : ViewGroup, right : Boolean) {
val colorFrom = Color.WHITE
ObjectAnimator
.ofObject(parent, ANIM_COLOR,
ArgbEvaluator(), colorFrom,
if (right) GREEN_ALPHA else RED_ALPHA)
.setDuration(ANIM_DURATION_LONG)
.start()
}
}
companion object {
const val MAX_FAIL_COUNT = 2
}
}
And new xml.
/* activity_main.xml */
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
android:id="#+id/mainContainer"
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".MainActivity">
<ScrollView
android:layout_width="match_parent"
android:layout_height="500dp"
android:animateLayoutChanges="true">
<LinearLayout
android:id="#+id/questionContainer"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:animateLayoutChanges="true"
android:orientation="vertical">
</LinearLayout>
</ScrollView>
<HorizontalScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:animateLayoutChanges="true">
<LinearLayout
android:id="#+id/answerContainer"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:animateLayoutChanges="true"
android:orientation="horizontal">
</LinearLayout>
</HorizontalScrollView>
</LinearLayout>
</FrameLayout>
/* item_question.xml */
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:animateLayoutChanges="true"
android:paddingTop="10dp">
<View
android:layout_width="100dp"
android:layout_height="100dp"
android:layout_gravity="start"
android:layout_margin="5dp"
android:background="#android:color/holo_blue_bright">
</View>
<View
android:id="#+id/questionView"
android:layout_width="100dp"
android:layout_height="100dp"
android:layout_gravity="end"
android:layout_margin="5dp"
android:background="#android:color/holo_orange_light">
</View>
</FrameLayout>
/* item_answer.xml */
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
android:padding="5dp"
android:tag="Test">
<LinearLayout
android:layout_width="100dp"
android:layout_height="100dp"
android:layout_gravity="center"
android:background="#android:color/darker_gray">
</LinearLayout>
</FrameLayout>
I think, there are various ways to do it. For me, seems nice, to split the screen into two main sections. a) To have single vertical list with Items and connections to "Question mark", refer to the image below.
Single row in a vertical list
So it's easy to change size to the item list, which you are retrieving from Server, by dynamically adding and removing simple View. Once correct tile would be places on the top of "Question mark" you will change new View on the top of this View. b) To create bottom list with possible "Answers" there will be Horizontal list, with this items. As you mentioned in our question.
Bottom horizontal list
Description
a) I really do't like implementation of such kind of task with Android widgets like RecyclerView. With small list of items, we could bring a lot of customization. For the first list I would use VerticalScrollView with LinearLayout and View (with any your layout).
Note. Your last layout could be ConstraintLayout. Ex. 1. In this case your dragged items would stick on exact places, where you live it. And In case it's stick on specific row with more than half size, you could change view for it (to green or red). Ex 2. Maybe even better way would be animate moving from place where live the tiles, to the nearest "Question mark" with "Property Animation"
b) To create bottom list I would use the same structure with `HorizontalListView". This will help to use "Property Animation" and not just animate dragging, but also move an object with your grading trajectory. Using dynamically added items in the containers with simple views will reflect on changes in bottom, or top lists.
Implementation
1) Initial listeners for each your "Answer" tiles.
// Assign the touch listener to your view which you want to move
findViewById(R.id.myimage1).setOnTouchListener(new MyTouchListener());
// This defines your touch listener
private final class MyTouchListener implements OnTouchListener {
public boolean onTouch(View view, MotionEvent motionEvent) {
if (motionEvent.getAction() == MotionEvent.ACTION_DOWN) {
ClipData data = ClipData.newPlainText("", "");
DragShadowBuilder shadowBuilder = new View.DragShadowBuilder(
view);
view.startDrag(data, shadowBuilder, view, 0);
view.setVisibility(View.INVISIBLE);
return true;
} else {
return false;
}
}
}
2) Define each of your target Views in the top list.
findViewById(R.id.bottomright).setOnDragListener(new MyDragListener());
class MyDragListener implements OnDragListener {
Drawable enterShape = getResources().getDrawable(
R.drawable.shape_droptarget);
Drawable normalShape = getResources().getDrawable(R.drawable.shape);
#Override
public boolean onDrag(View v, DragEvent event) {
int action = event.getAction();
switch (event.getAction()) {
case DragEvent.ACTION_DRAG_STARTED:
// do nothing
break;
case DragEvent.ACTION_DRAG_ENTERED:
v.setBackgroundDrawable(enterShape);
break;
case DragEvent.ACTION_DRAG_EXITED:
v.setBackgroundDrawable(normalShape);
break;
case DragEvent.ACTION_DROP:
// Dropped, reassign View to ViewGroup
View view = (View) event.getLocalState();
ViewGroup owner = (ViewGroup) view.getParent();
owner.removeView(view);
LinearLayout container = (LinearLayout) v;
container.addView(view);
view.setVisibility(View.VISIBLE);
break;
case DragEvent.ACTION_DRAG_ENDED:
v.setBackgroundDrawable(normalShape);
default:
break;
}
return true;
}
}
3) That is it you need to create dragging. Just to make another setup in the Activity and View changes.
However you could check few other examples of drag and drop implementation. But since you were using simple Views and Scrollable containers, you can align every sample to work with your lists.
I have two activities. Activity A contains a recycler view of card view elements with images in them. On selecting an element in Activity A. The full landscape version of the image is displayed in Activity B.
The layout file for Activity B is a follows:
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<androidx.appcompat.widget.AppCompatImageView
android:id="#+id/imageView"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
/>
</androidx.constraintlayout.widget.ConstraintLayout>
The codebase for Activity B is as follows:
class PosterViewActivity : AppCompatActivity()
{
private lateinit var imageView: AppCompatImageView
override fun onCreate(savedInstanceState: Bundle?)
{
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_poster_view)
init()
}
private fun init()
{
findViewsByID()
getBundle()
toggleHide()
}
private fun getBundle()
{
if (intent != null)
{
var imageUrl = intent.getStringExtra(ARG_IMAGE_URL)
if (imageUrl != null)
{
Glide.with(this).load(imageUrl).centerInside().into(imageView)
}
}
}
private fun findViewsByID()
{
imageView = findViewById(R.id.imageView)
}
override fun onOptionsItemSelected(item: MenuItem): Boolean
{
if (item.itemId == android.R.id.home)
{
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)
}
return super.onOptionsItemSelected(item)
}
override fun onBackPressed()
{
super.onBackPressed()
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)
}
override fun onWindowFocusChanged(hasFocus: Boolean)
{
super.onWindowFocusChanged(hasFocus)
}
private fun toggleHide()
{
val uiOptions = window.decorView.systemUiVisibility
var newUiOptions = uiOptions
val isImmersiveModeEnabled = uiOptions or View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY == uiOptions
if (isImmersiveModeEnabled)
{
Log.i("PosterViewActivity", "Turning immersive mode mode off. ")
}
else
{
Log.i("PosterViewActivity", "Turning immersive mode mode on.")
}
if (Build.VERSION.SDK_INT >= 14)
{
newUiOptions = newUiOptions xor View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
}
// Status bar hiding: Backwards compatible to Jellybean
if (Build.VERSION.SDK_INT >= 16)
{
newUiOptions = newUiOptions xor View.SYSTEM_UI_FLAG_FULLSCREEN
}
if (Build.VERSION.SDK_INT >= 18)
{
newUiOptions = newUiOptions xor View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY
}
window.decorView.systemUiVisibility = newUiOptions
}
}
However, when I press the back button on the device instead of returning to Activity A. The status and navigation buttons are displayed and hidden and it takes 4 presses of the back button to return to Activity A. I have checked the Back stack and two activities are in the stack namely A and B
You should just have to do something similar to this in your PosterViewActivity:
//link instance of menu_main
val mainToolbar = findViewById<androidx.appcompat.widget.Toolbar>(R.id.toolbar)
setSupportActionBar(mainToolbar)
//Enable Up Button to return you to home page
val actionBar = supportActionBar
actionBar?.title = null
actionBar?.setDisplayHomeAsUpEnabled(true)