android - implementing a ChipGroup with adapter pattern

Question

My fragment contains a ChipGroup with the chips being added dynamically based on the users choice. What I wish to accomplish is an adapter pattern where a list is exposed to the adapter from which chips are being created user gets to add/remove the elements to and from the list.

I couldn't find any way to do that and right now, whenever the user interacts with the list, all the chips are recreated.

Code has been clipped for the sake of brevity

XML file

// capturing the user's choice
      <RadioGroup
          android:id="@+id/vehicles_radio_group"
          android:onCheckedChanged="@{vehicleViewModel::radioCheckedChanged}">

ViewModel

fun radioCheckedChanged(radioGroup: RadioGroup, checkedId: Int) {

        //validating the user's choice
            if (condition) {
                //code for adding the choice to a List
                vehicleDispatched(selectedVehicle, checkedId)   
            } else {
                selectionError()
            }
    }

    // adding the user's choice to the list
    // _dispatchingUnits is a LiveData

    private fun vehicleDispatched(selectedVehicle: DomainVehicle, checkedId: Int) {
  
     // appending the selected choice to the list(Type : List<Pair<Vehicle,Planet>>)
        _dispatchingUnits.value =
            _dispatchingUnits.value?.plus(selectedVehicle to _currentPlanet.value!!)
                ?: listOf(selectedVehicle to _currentPlanet.value!!)
    }

Fragment

// register an observer and take action

        myViewModel.dispatchingUnits.observe(viewLifecycleOwner) { allPairs ->
            allPairs?.apply {

                with(binding) {
                   // remove the existing chips if any
                    if (selectedPairChipGroup.isNotEmpty()) {
                        selectedPairChipGroup.removeAllViews()
                    }
                  // create new chips
                    allPairs.forEach { chipPair ->
                        createChips(chipPair)
                    }
                }
            }
        }

Expecting something like,

// In fragment class
val adapter = ChipAdapter()
binding.chipGroup.setAdapter(adapter)


// In bindingUtils file
@BindingAdapter("fill_data")
fun RecyclerChipGroup.setData(list : MyListType){
val adapter = this.adapter as ChipAdapter
adapter.submitChipList(list)
}

//XML File
<RecyclerChipGroup
....
app:fill_data = "@{viewModel.dispatchingUnits}"
....
/>

how to go on with it?

question from:https://stackoverflow.com/questions/65651888/implementing-a-chipgroup-with-adapter-pattern

Answer 1

If you want to achieve adapter based list of chips and more controls than ChipGroup then you can use RecyclerView with chips as an item and to arrange chips in Left-to-Right or Right-to-Left order, you can create a custom LayoutManager.

For more details, you can visit https://github.com/BelooS/ChipsLayoutManager. This library provides support for ChipsLayoutManager.