I am making a simple App which holds a list of timers and allows the user to scroll between these timers via ViewPager. Android Architecture Component principles are in effect here: the ViewModel holds the state of the app, and Fragments/Activities just handle UI interactions.
In this case, a custom ViewPager and FragmentStatePagerAdapter has been made. My question is, what is the best way to have the ViewPager/adapter respond to changes in the ViewModel?
The current code below works fine, but is there a better way to do this? Currently, both the ViewPager and Adapter require reference to the ViewModel and this feels contrary to what MVVM should implement.
ViewPager
class VerticalTimerViewPager(context: Context, attributeSet: AttributeSet): ViewPager(context, attributeSet){
var homeViewModel: HomeViewModel?=null
init {
setPageTransformer(true, VerticalPageTransformer())
}
override fun onInterceptTouchEvent(ev: MotionEvent?): Boolean {
ev ?: return false
val intercepted = super.onInterceptTouchEvent(swapXYOnMotionEvent(ev))
swapXYOnMotionEvent(ev)
return intercepted
}
override fun onTouchEvent(ev: MotionEvent?): Boolean {
homeViewModel ?: throwNoViewModelException()
when(ev?.action){
MotionEvent.ACTION_DOWN -> homeViewModel?.onSwipeDown()
MotionEvent.ACTION_UP -> homeViewModel?.onSwipeUp()
}
return super.onTouchEvent(swapXYOnMotionEvent(ev ?: return false))
}
private fun swapXYOnMotionEvent(motionEvent: MotionEvent): MotionEvent{
with(motionEvent){
val newX = (y/height)*width
val newY = (x/width) * height
setLocation(newX, newY)
}
return motionEvent
}
private fun throwNoViewModelException():Boolean{
throw RuntimeException("${this.javaClass.simpleName}: HomeViewModel must be set by setting the variable homeViewModel")
}
}
FragmentStatePagerAdapter
class VerticalTimerViewPager(context: Context, attributeSet: AttributeSet): ViewPager(context, attributeSet){
var homeViewModel: HomeViewModel?=null
init {
setPageTransformer(true, VerticalPageTransformer())
}
override fun onInterceptTouchEvent(ev: MotionEvent?): Boolean {
ev ?: return false
val intercepted = super.onInterceptTouchEvent(swapXYOnMotionEvent(ev))
swapXYOnMotionEvent(ev)
return intercepted
}
override fun onTouchEvent(ev: MotionEvent?): Boolean {
homeViewModel ?: throwNoViewModelException()
when(ev?.action){
MotionEvent.ACTION_DOWN -> homeViewModel?.onSwipeDown()
MotionEvent.ACTION_UP -> homeViewModel?.onSwipeUp()
}
return super.onTouchEvent(swapXYOnMotionEvent(ev ?: return false))
}
private fun swapXYOnMotionEvent(motionEvent: MotionEvent): MotionEvent{
with(motionEvent){
val newX = (y/height)*width
val newY = (x/width) * height
setLocation(newX, newY)
}
return motionEvent
}
private fun throwNoViewModelException():Boolean{
throw RuntimeException("${this.javaClass.simpleName}: HomeViewModel must be set by setting the variable homeViewModel")
}
}
Instantiation Method called in Activity onCreate()
private fun setupPagerAdapter() {
val pagerAdapter = TimerSlidePagerAdapter(viewModel = viewModel, fragmentManager = supportFragmentManager)
with(pager){
adapter = pagerAdapter
homeViewModel = viewModel
}
}
Looks like you're using ViewModel to communicate for onTouchEvent(ev: MotionEvent?) from your adapter & view pager, if you want to make your adapter & view pager independent form ViewModel i would suggest you following way:
Make one interface having methods onSwipeDown() & onSwipeUp() (or make any N numbers of method you want to have for ViewModel)
Take this interface object instead of ViewModel in your view pager & adapter.
Implement this interface to your ViewModel (which will expose methods of interface in ViewModel).
Cast your interface to ViewModel where you're passing ViewModel to adapter and view pager.
Voila! you've made your adapter & view pager independent to ViewModel's direct reference.
The Answer from Jeel Vankhede was marked as a solution and implemented. For future reference, the solution code will be pasted below to show the specifics of how the ViewPager and Adapter were successfully made independent of the ViewModel:
ViewPager:
notice we now have an Interface object. When the ViewPager is swiped, if there is no interface object, an exception is thrown.
//Overriding default touch events and swapping x/y coordinates prior to handling
class VerticalTimerViewPager(context: Context, attributeSet: AttributeSet): ViewPager(context, attributeSet){
var timerViewPagerEventListener: TimerViewPagerEvent? = null
init {
setPageTransformer(true, VerticalPageTransformer())
}
override fun onInterceptTouchEvent(ev: MotionEvent?): Boolean {
ev ?: return false
val intercepted = super.onInterceptTouchEvent(swapXYOnMotionEvent(ev))
swapXYOnMotionEvent(ev)
return intercepted
}
override fun onTouchEvent(ev: MotionEvent?): Boolean {
timerViewPagerEventListener ?: throwInterfaceExeption()
when(ev?.action){
MotionEvent.ACTION_DOWN -> timerViewPagerEventListener?.onViewPagerSwipeDown()
MotionEvent.ACTION_UP -> timerViewPagerEventListener?.onViewPagerSwipeUp()
}
return super.onTouchEvent(swapXYOnMotionEvent(ev ?: return false))
}
private fun throwInterfaceExeption():Boolean {
throw RuntimeException("${this.javaClass.simpleName}: Parent Activity must implement TimerViewPagerEvent interface" )
}
private fun swapXYOnMotionEvent(motionEvent: MotionEvent): MotionEvent{
with(motionEvent){
val newX = (y/height)*width
val newY = (x/width) * height
setLocation(newX, newY)
}
return motionEvent
}
interface TimerViewPagerEvent{
fun onViewPagerSwipeUp()
fun onViewPagerSwipeDown()
}
}
Adapter: Now takes a list of objects (Timers in this case)
class TimerSlidePagerAdapter(fragmentManager: FragmentManager, private val timers: List<TimerEntity>?):
FragmentStatePagerAdapter(fragmentManager){
override fun getItem(position: Int): Fragment {
if (count > 0) {
return makeTimerFragment(position)
}
return NoDataFragment()
}
override fun getCount(): Int = timers?.size ?: 0
//Internal Functions
private fun makeTimerFragment(position: Int): Fragment {
timers ?: return NoDataFragment()
val timeInMS = timers[position].timeInMS
return if (timeInMS > 0) {
TimerFragment.newInstance(timeInMS)
} else {
NoDataFragment()
}
}
}
Activity Implementation:
private fun setupPagerAdapter() {
val pagerAdapter = TimerSlidePagerAdapter(
fragmentManager = supportFragmentManager,
timers = viewModel?.timers?.value)
with(pager){
adapter = pagerAdapter
timerViewPagerEventListener = this#MainActivity
}
}
private fun observeTimers(){
viewModel.timers.observe(this, Observer {timerList->
timerList ?: Log.e(this.javaClass.simpleName, "List of timers is null")
.also {return#Observer}
setupPagerAdapter()
})
}
Related
So, I am creating a cocktail app, based on the https://www.thecocktaildb.com/ api. Thus far, I have only created a screen to display options based on the ingredient I put in the search bar (search bar is not done yet). Yet when I run the app, only the first entry is displayed
By putting Log.e("TAG", "$position") inside of my onBindViewHolder, of the adapter, I saw that the position variable never increases from 0
class CocktailsAdapter: RecyclerView.Adapter<CocktailsAdapter.CocktailsViewHolder>() {
inner class CocktailsViewHolder(val binding: ItemCocktailPreviewBinding) :
RecyclerView.ViewHolder(binding.root)
private val differCallback = object : DiffUtil.ItemCallback<CocktailsByBaseDto>() {
override fun areItemsTheSame( oldItem: CocktailsByBaseDto, newItem: CocktailsByBaseDto): Boolean {
return oldItem.drinks[0].idDrink == newItem.drinks[0].idDrink
}
override fun areContentsTheSame(oldItem: CocktailsByBaseDto, newItem: CocktailsByBaseDto): Boolean {
return oldItem.drinks[0] == newItem.drinks[0]
}
}
val differ = AsyncListDiffer(this, differCallback)
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): CocktailsViewHolder {
return CocktailsViewHolder(
ItemCocktailPreviewBinding.inflate(
LayoutInflater.from(parent.context),
parent,
false
)
)
}
override fun onBindViewHolder(holder: CocktailsViewHolder, position: Int) {
val binding = holder.binding
val cocktail = differ.currentList[position]
holder.itemView.apply {
Glide.with(this).load(cocktail.drinks[position].strDrinkThumb).into(binding.imgCocktailsMainRecyclerViewImage)
binding.tvCocktailsMainRecyclerViewTitle.text = cocktail.drinks[position].strDrink
Log.e("TAG", "$position")
setOnClickListener {
onItemClickListener?.let { it(cocktail) }
}
}
}
override fun getItemCount(): Int {
return differ.currentList.size
}
private var onItemClickListener: ((CocktailsByBaseDto) -> Unit)? = null
fun setOnItemClickListener(listener: (CocktailsByBaseDto) -> Unit) {
onItemClickListener = listener
}
I have tried both position and 0 (which makes more sense) inside val cocktail = differ.currentList[position], but neither gave me a different result
Fixed it by changing the class I had passed to DiffUtil.ItemCallback
I use ListAdapter as the source of a RecyclerView, it will display a list of MVoice. You can see Code B.
I think I can get the position of a MVoice in ListAdapter, so I can scroll to the position of the item in RecyclerView, just like Code A
Is there a way to get the position of a Movice?
Code A
binding.recyclerViewVoice.adapter = myAdapter
mHomeViewModel.listVoiceBySort.observe(this.viewLifecycleOwner) {
myAdapter.submitList(it)
}
//val position=myAdapter.getPostionByItem(aMovice)
//binding.recyclerViewVoice.scrollToPosition(position)
Code B
class VoiceAdapters (private val aHomeViewModel: HomeViewModel, private val mPlay: PlayInterface):
ListAdapter<MVoice, VoiceAdapters.VoiceViewHolder>(MVoiceDiffCallback()) {
private lateinit var mContext: Context
private lateinit var mLifecycleOwner:LifecycleOwner
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): VoiceViewHolder {
mContext = parent.context
mLifecycleOwner = mContext as LifecycleOwner
return VoiceViewHolder(
LayoutVoiceItemBinding.inflate(LayoutInflater.from(parent.context), parent, false).also {
it.lifecycleOwner = mLifecycleOwner
it.aHomeViewModel = aHomeViewModel
}
)
}
override fun onBindViewHolder(holder: VoiceViewHolder, position: Int) {
val inputMVoice = getItem(position)
holder.bind(inputMVoice)
}
inner class VoiceViewHolder (private val binding: LayoutVoiceItemBinding):
RecyclerView.ViewHolder(binding.root) {
fun bind(inputMVoice: MVoice) {
binding.amVoice = inputMVoice
binding.executePendingBindings()
}
}
}
class MVoiceDiffCallback : DiffUtil.ItemCallback<MVoice>() {
override fun areItemsTheSame(oldItem: MVoice, newItem: MVoice): Boolean {
return oldItem.id == newItem.id
}
override fun areContentsTheSame(oldItem: MVoice, newItem: MVoice): Boolean {
return oldItem == newItem
}
}
You can get a reference to the list currently displayed with currentList, and use indexOf() to get the position
fun getPositionByItem(aMovice: MVoice) = currentList.indexOf(aMovice)
Add a ItemClick Listener in fun bind(), then pass the MVoice.getPosition in Toast.
Thus you would able to see the position of item in your toast.
I am working with MVP for the first time and I believe I get the idea of it but I am not sure about the RecyclerView. As far as I can say, MVP is about making views as passive as possible so all business logic goes to the Presenter but how can this be achieved for the Recycler View?
Here is my code so far:
Contract
public interface PhotosContract {
// View
interface View {//: IBaseActivity {
fun showPhotos(photos: ArrayList<Photo>)
fun showText(message: String)
}
// Presenter
interface Presenter {//: IBasePresenter<View> {
fun getPhotos()
}
}
Presenter
public class PhotosPresenter(var view: PhotosContract.View) :PhotosContract.Presenter {
var dataList = ArrayList<Photo>()
override fun getPhotos() {
//call for endpoint
val call : Call<ArrayList<Photo>> = ApiClient.getClient.getPhotos()
call.enqueue(object: Callback<ArrayList<Photo>> {
override fun onFailure(call: Call<ArrayList<Photo>>, t: Throwable) {
Log.d("FAIL","FAILED")
}
override fun onResponse(
call: Call<ArrayList<Photo>>,
response: Response<ArrayList<Photo>>
)
{
Log.d("SUCCESS","SUCCESSED")
dataList.addAll(response!!.body()!!)
Log.d("SIZELIST",dataList.size.toString())
view.showPhotos(dataList)
view.showText("SUCCESS")
}
})
}
}
RecyclerViewAdapter
class PhotosAdapter(private var dataList: List<Photo>, private val context: Context) : RecyclerView.Adapter<PhotosAdapter.PhotosViewHolder>() {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): PhotosAdapter.PhotosViewHolder {
return PhotosViewHolder(LayoutInflater.from(this.context).inflate(R.layout.list_item_home, parent, false))
}
override fun getItemCount(): Int {
return dataList.size
}
override fun onBindViewHolder(holder: PhotosAdapter.PhotosViewHolder, position: Int) {
val dataModel = dataList[position]
holder.titleTextView.text = dataModel.title
}
class PhotosViewHolder(itemLayoutView: View) : RecyclerView.ViewHolder(itemLayoutView){
var titleTextView: TextView = itemLayoutView.tv_title
}
}
Activity
class PhotosActivity : AppCompatActivity(),PhotosContract.View {
private lateinit var presenter: PhotosPresenter
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_photos)
presenter = PhotosPresenter(this)
presenter.getPhotos()
}
override fun showPhotos(photos: ArrayList<Photo>) {
photosRecyclerView.layoutManager = LinearLayoutManager(this)
photosRecyclerView.adapter = PhotosAdapter(photos,this)
photosRecyclerView.adapter?.notifyDataSetChanged()
}
override fun showText(message: String) {
Toast.makeText(this,message,Toast.LENGTH_LONG).show()
}
}
Here's how I did it when I used MVP. In your contract, define an additional view named ItemView. The way I do it, each item view holder is a MVP view. The view is dumb, so it just calls the presenter whenever something happens, and the presenter calls it back.
interface MyContract {
interface View {
fun setTitle(title: String)
}
// Add this interface here
interface ItemView {
fun bindItem(item: Item)
}
interface Presenter {
fun attach(view: View)
fun detach()
val itemCount: Int
fun onItemClicked(pos: Int)
fun onBindItemView(itemView: ItemView, pos: Int)
}
}
The adapter is also dumb. When it needs to bind an item view holder, it calls the presenter to do it.
class MyAdapter : RecyclerView.Adapter<ViewHolder>() {
// How many items do we have? We don't know, ask the presenter.
override fun getItemCount() = presenter?.itemCount ?: 0
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
// How to bind the item if we only have position? We don't know, ask the presenter.
presenter?.onBindItemView(holder, position)
}
// ...
}
The ViewHolder implements the MyContract.ItemView interface. Again, it's just a view so it has no responsibility by itself. It just delegates to the presenter.
class MyViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView), MyContract.ItemView {
private val txv: TextView = view.findViewById(R.id.text_view)
init {
view.setOnClickListener {
// What to do here, we only have the item's position? Call the presenter.
presenter?.onItemClicked(adapterPosition)
}
}
override fun bindItem(item: Item) {
txv.text = item.text
}
}
And finally the presenter:
class MyPresenter : MyContract.Presenter {
private var view: View? = null
private val items = mutableListOf<Item>()
override fun attach(view: View) {
this.view = view
// ...
}
override fun detach() {
view = null
}
override val itemCount: Int
get() = items.size
override fun onItemClicked(pos: Int) {
val item = items[pos]
// ...
}
override fun onBindItemView(itemView: ItemView, pos: Int) {
itemView.bindItem(items[pos])
}
// ...
}
The view for completeness, but nothing new here:
class MyView : Fragment(), MyContract.View {
private var presenter: Presenter? = null
override fun onViewCreated(view: View) {
// Attach presenter
presenter = MyPresenter()
presenter?.attach(this)
}
override fun onDestroyView() {
super.onDestroyView()
// Detach the presenter
presenter?.detach()
presenter = null
}
// ...
}
That's just one way to do it, I'm sure there are a lot of others. I just like this one because all the responsibility belongs to the presenter, there's no business logic anywhere else.
Eventually, you'll want to make changes to your list and notify the adapter. For this, add a couple methods in your View contract like notifyItemInserted(pos: Int) and call them when needed from the presenter. Or, better yet, use DiffUtil so you don't have to manage it yourself!
Once you have a good understanding of MVP though, I strongly suggest you move to MVVM as it is the official architecture promoted by Google. Most people also find it a lot more convenient than MVP.
If you have any questions don't hesitate.
I've done this successfully with a normal ViewAdapter but I can't seem to get it working with a ListAdapter.
Here is my Fragment that does most of the work:
class CrimeListFragment: Fragment() {
//Required interface for hosting activities
interface Callbacks {
fun onCrimeSelected(crimeId: UUID)
}
private var callbacks: Callbacks? = null
private lateinit var crimeRecyclerView: RecyclerView
private val crimeListViewModel: CrimeListViewModel by lazy {
ViewModelProviders.of(this).get(CrimeListViewModel::class.java)
}
override fun onAttach(context: Context) {
super.onAttach(context)
callbacks = context as Callbacks?
}
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
val view = inflater.inflate(R.layout.fragment_crime_list, container, false)
crimeRecyclerView =
view.findViewById(R.id.crime_recycler_view) as RecyclerView
crimeRecyclerView.layoutManager = LinearLayoutManager(context)
crimeRecyclerView.adapter = CrimeListAdapter(emptyList())
return view
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
crimeListViewModel.crimeListLiveData.observe(
viewLifecycleOwner,
Observer { crimes ->
crimes?.let {
Log.i(TAG, "Got crimes ${crimes.size}")
updateUI(crimes)
}
}
)
}
override fun onDetach() {
super.onDetach()
callbacks = null
}
private fun updateUI(crimes: List<Crime>) {
crimeRecyclerView.adapter = CrimeListAdapter(crimes)
}
companion object {
fun newInstance(): CrimeListFragment {
return CrimeListFragment()
}
}
private inner class CrimeHolder(view: View)
: RecyclerView.ViewHolder(view), View.OnClickListener {
private lateinit var crime: Crime
private val titleTextView = itemView.findViewById<TextView>(R.id.crime_title)
private val dateTextView = itemView.findViewById<TextView>(R.id.crime_date)
private val solvedImageView = itemView.findViewById<ImageView>(R.id.crime_solved)
init {
itemView.setOnClickListener(this)
}
fun bind(crime: Crime) {
this.crime = crime
titleTextView.text = crime.title
dateTextView.text = crime.date.toString()
solvedImageView.visibility = if(crime.isSolved) {
View.VISIBLE
} else {
View.GONE
}
}
override fun onClick(v: View) {
callbacks?.onCrimeSelected(crime.id)
}
}
private inner class CrimeListAdapter(var crimes: List<Crime>)
: ListAdapter<Crime, CrimeHolder>(DiffCallback()) {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): CrimeHolder {
val view =
layoutInflater.inflate(R.layout.list_item_crime, parent, false)
return CrimeHolder(view)
}
override fun onBindViewHolder(holder: CrimeHolder, position: Int) {
holder.bind(crimes[position])
}
}
private inner class DiffCallback: DiffUtil.ItemCallback<Crime>() {
override fun areItemsTheSame(oldItem: Crime, newItem: Crime): Boolean {
return oldItem.id == newItem.id
}
override fun areContentsTheSame(oldItem: Crime, newItem: Crime): Boolean {
return oldItem == newItem
}
}
}
And here is the fragment's viewmodel:
class CrimeListViewModel: ViewModel() {
private val crimeRepository = CrimeRepository.get()
val crimeListLiveData = crimeRepository.getCrimes() //returns LiveData<List<Crime>>
}
Android documentation has this regarding ListAdapter:
While using a LiveData is an easy way to provide data to the adapter, it isn't required - you can use submitList(List) when new lists are available.
I'm supposed to submit a new list instead of creating a new ListAdapter object each time I update the UI. But crimeRecyclerView.adapter has no .submitList() function. So how do I pass on the new list?
LiveData is still new to me so I'm not quite clear on this. I already observe a LiveData stored in my viewmodel. So what do I observe this time? Or do I just add code to my existing Observer?
Finally when I run the code in this state, phone shows an empty RecyclerView. Only UpdateUI() gets called, none of CrimeListAdapter's functions get called. I'm not sure if this is a real problem or just the consequence of the above.
1.I'm supposed to submit a new list instead of creating a new ListAdapter object each time I update the UI. But
crimeRecyclerView.adapter has no .submitList() function. So how do I
pass on the new list?
crimeRecyclerView.adapter return RecyclerView.Adapter type
submitList() is a method of ListAdapter, a sub-class of RecyclerView.Adapter
You need to cast from super to sub class before calling that method, like this.
(crimeRecyclerView.adapter as CrimeListAdapter).submitList(crimes)
2.LiveData is still new to me so I'm not quite clear on this. I already observe a LiveData stored in my viewmodel. So what do I
observe this time? Or do I just add code to my existing Observer?
Your code for this part is good, no need to do more.
3.Finally when I run the code in this state, phone shows an empty RecyclerView. Only UpdateUI() gets called, none of CrimeListAdapter's
functions get called. I'm not sure if this is a real problem or just
the consequence of the above.
The best part of using ListAdapter is you do not need to provide a list of data (crimes in your case) to constructor.
Back to your code, you need to change 3 things.
// crimeRecyclerView.adapter = CrimeListAdapter(emptyList())
crimeRecyclerView.adapter = CrimeListAdapter()
and
// crimeRecyclerView.adapter = CrimeListAdapter(crimes)
(crimeRecyclerView.adapter as CrimeListAdapter).submitList(crimes)
and
//private inner class CrimeListAdapter(var crimes: List<Crime>) :
// ListAdapter<Crime, CrimeHolder>(DiffCallback()) {
//
// override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): CrimeHolder {
// val view = layoutInflater.inflate(R.layout.list_item_crime, parent, false)
// return CrimeHolder(view)
// }
//
// override fun onBindViewHolder(holder: CrimeHolder, position: Int) {
// holder.bind(crimes[position])
// }
//}
private inner class CrimeListAdapter : ListAdapter<Crime, CrimeHolder>(DiffCallback()) {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): CrimeHolder {
val view = layoutInflater.inflate(R.layout.list_item_crime, parent, false)
return CrimeHolder(view)
}
override fun onBindViewHolder(holder: CrimeHolder, position: Int) {
holder.bind(getItem(position))
}
}
I make bottom sheet fragment like this:
val bottomSheet = PictureBottomSheetFragment(fragment)
bottomSheet.isCancelable = true
bottomSheet.setListener(pictureListener)
bottomSheet.show(ac.supportFragmentManager, "PictureBottomSheetFragment")
But its not dismiss when I touch outside. and dismiss or isCancelable not working.
try this
behavior.setState(BottomSheetBehavior.STATE_HIDDEN));
You can override method and indicate, for example, in onViewCreated what you need:
class ModalDialogSuccsesDataPatient : ModalDialog() {
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
isCancelable = false //or true
}
}
Let's try to design reusable functions to solve this problem and similar ones if the need arises.
We can create extension functions on View that tell whether a point on the screen is contained within the View or not.
fun View.containsPoint(rawX: Int, rawY: Int): Boolean {
val rect = Rect()
this.getGlobalVisibleRect(rect)
return rect.contains(rawX, rawY)
}
fun View.doesNotContainPoint(rawX: Int, rawY: Int) = !containsPoint(rawX, rawY)
Now we can override the dispatchTouchEvent(event: MotionEvent) method of Activity to know where exactly the user clicked on the screen.
private const val SCROLL_THRESHOLD = 10F // To filter out scroll gestures from clicks
private var downX = 0F
private var downY = 0F
private var isClick = false
override fun dispatchTouchEvent(event: MotionEvent): Boolean {
when (event.action and MotionEvent.ACTION_MASK) {
MotionEvent.ACTION_DOWN -> {
downX = event.x
downY = event.y
isClick = true
}
MotionEvent.ACTION_MOVE -> {
val xThreshCrossed = abs(downX - event.x) > SCROLL_THRESHOLD
val yThreshCrossed = abs(downY - event.y) > SCROLL_THRESHOLD
if (isClick and (xThreshCrossed or yThreshCrossed)) {
isClick = false
}
}
MotionEvent.ACTION_CANCEL, MotionEvent.ACTION_UP -> {
if (isClick) onScreenClick(event.rawX, event.rawY)
}
else -> { }
}
return super.dispatchTouchEvent(event)
}
private fun onScreenClick(rawX: Float, rawY: Float) { }
Now, you can simply use the above-defined functions to achieve the required result
private fun onScreenClick(rawX: Float, rawY: Float) {
if (bottomSheet.doesNotContainPoint(rawX.toInt(), rawY.toInt())) {
// Handle bottomSheet state changes
}
}
What more? If you have a BaseActivity which is extended by all your Activities then you can add the click detection code to it. You can make the onScreenClick an protected open method so that it can be overridden by the sub-classes.
protected open fun onScreenClick(rawX: Float, rawY: Float) { }
Usage:
override fun onScreenClick(rawX: Float, rawY: Float) {
super.onScreenClick(rawX, rawY)
if (bottomSheet.doesNotContainPoint(rawX.toInt(), rawY.toInt())) {
// Handle bottomSheet state changes
}
}