Which base fragment prefer to use and why?
In this implementation layoutRes is abstract field.
abstract class BaseFragment1 : Fragment() {
abstract val layoutRes: Int
override fun onCreateView(inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View {
return inflater.inflate(layoutRes, container, false)
}
}
And in this implementation layoutRes is passing through constructor
abstract class BaseFragment2(#LayoutRes private val layoutRes: Int) : Fragment() {
override fun onCreateView(inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View {
return inflater.inflate(layoutRes, container, false)
}
}
I want to know which implementation is better to use? If you have another solution you can share it.
Example of implementations:
class FramgnetA : BaseFragment1() {
override val layuotRes = R.layout.layout
}
class FragmentB : BaseFragment2(R.layout.layout)
Like in Best practice for instantiating a new Android Fragment - for parameters that can be supplied from the outside you can use a Bundle and Fragment#setArguments(Bundle)
E.g.
class DynamicContentFragment : Fragment() {
companion object {
private const val KEY_LAYOUT_ID = "layoutId"
fun instance(#LayoutRes layoutRes: Int) =
DynamicContentFragment().apply {
arguments = Bundle().apply { putInt(KEY_LAYOUT_ID, layoutRes) }
}
}
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View {
val layout = arguments!!.getInt(KEY_LAYOUT_ID)!!
return inflater.inflate(layout, container, false)
}
}
class UseCase {
fun test(fm: FragmentManager) {
fm.beginTransaction()
.replace(R.id.container, DynamicContentFragment.instance(R.layout.main))
}
}
Otherwise your solutions are fine but it require a new class per parameter. Classes are cheap to write in kotlin so it's preference I guess.
Recently google added this overload of the fragment constructors. I think now, everything very obvious.
Related
Hello i am using a recyclerView to swipe and call for a Dialog fragment
The the idea is that when i dismiss the dialog Fragment the raw come back to the original place
but the problem is that it return, just after the dialog is opened.
So i do not how to call notifyItemChanged inside the dialogFragment, or implement the dialogFragment.setOnDismissListener because when i override i dont know how to pass to the function the adapter to call notifyItemChanged i
This is my code
class Fragmento : Fragment(), RecyclerAdapter.ClickListener {
// TODO: Rename and change types of parameters
private lateinit var adapter :RecyclerAdapter
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
arguments?.let {
}
}
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?): View? {
// Inflate the layout for this fragment
val view =inflater.inflate(R.layout.fragment_fragmento, container,false)
initRecyclerView(view)
return view
}
private fun initRecyclerView(view: View) {
val recyclerView = view.findViewById<RecyclerView>(R.id.recyclerView)
recyclerView.layoutManager=LinearLayoutManager(activity)
adapter = RecyclerAdapter()
recyclerView.adapter=adapter
val itemSwipe=object:ItemTouchHelper.SimpleCallback(0,ItemTouchHelper.LEFT){
override fun onMove(
recyclerView: RecyclerView,
viewHolder: RecyclerView.ViewHolder,
target: RecyclerView.ViewHolder
): Boolean {
return false
}
override fun onSwiped(viewHolder: RecyclerView.ViewHolder, direction: Int) {
showDialog(viewHolder as RecyclerAdapter.ViewHolder)
var dialog = DialogFragment()
dialog.show(childFragmentManager,"dialog")
adapter.notifyItemChanged(viewHolder.adapterPosition)
}
}
val swap =ItemTouchHelper(itemSwipe)
swap.attachToRecyclerView(recyclerView)
}
private fun showDialog(viewHolder: RecyclerAdapter.ViewHolder){
val builder= AlertDialog.Builder(activity)
builder.setTitle("DeleteItem")
}
companion object {
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
*/
// TODO: Rename and change types and number of parameters
#JvmStatic
fun newInstance() =
Fragmento().apply {
arguments = Bundle().apply {
}
}
}
}
and for the DialogFragment
class DialogFragment: DialogFragment(){
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
var rootView: View = inflater.inflate(R.layout.dialog_fragment_noticias, container, false)
return rootView
}
override fun onDismiss(dialog: DialogInterface) {
super.onDismiss(dialog)
}
}
If I have understand the problem here is that you want to call notifyItemChanged() when your dialog is dismiss without setOnDismissListener.
If you want to do that you can simply add a callback on your DialogFragment and use it in your recyclerView.
class DialogFragment(dismiss: () -> Unit): DialogFragment(){
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
var rootView: View = inflater.inflate(R.layout.dialog_fragment_noticias, container, false)
return rootView
}
override fun onDismiss(dialog: DialogInterface) {
super.onDismiss(dialog)
dismiss()
}
}
When you are creating the DialogFragment you can use the callback :
override fun onSwiped(viewHolder: RecyclerView.ViewHolder, direction: Int) {
showDialog(viewHolder as RecyclerAdapter.ViewHolder)
var dialog = DialogFragment() {
//here you are notified when the dialog is dismiss
adapter.notifyItemChanged(viewHolder.adapterPosition)
}
dialog.show(childFragmentManager,"dialog")
adapter.notifyItemChanged(viewHolder.adapterPosition)
}
I have a method onBind() that I want to use with a scope of binding, is there a way to achieve this?
Currently, I have a variable (“binding: T”) and an abstract function onBind() in BaseBindableFragment, and in my implementation I use with(binding){} to scope onBind(). I want to avoid using with(binding) and make it so that in implementation I get onBind() { this: T -> }
My abstract class
abstract class BaseBindableFragment<T : ViewDataBinding> : Fragment() {
protected lateinit var binding: T
private set
protected abstract val layout: Int
#LayoutRes get
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
binding = DataBindingUtil.inflate(inflater, layout, container, false)
// Wrap with(binding){onBind()} in a way that `onBind` executes with `binding` as `this`
onBind()
return binding.root
}
protected abstract fun onBind()
}
And then in my implementation
override fun onBind() = with(binding) { // <- I want to avoid this "= with(binding)" line
lifecycleOwner = viewLifecycleOwner
viewModel = myViewModel
}
protected abstract fun T.onBind()
and
binding = DataBindingUtil.inflate(inflater, layout, container, false)
binding.onBind()
return binding.root
The implementation becomes
override protected fun T.onBind() {
lifecycleOwner = viewLifecycleOwner
viewModel = myViewModel
}
(or e.g. MyBinding.onBind() if your class extends BaseBindableFragment<MyBinding>)
Im new in programming, and i got stuck with adding onClickListener in my FragmentHome.kt
i added this code to my existing activity:
val exc = this.findViewById<Button>(R.id.execute)
exc.setOnClickListener {
Toast.makeText(this, "You clicked me.", Toast.LENGTH_SHORT).show()
}
I tried set onClicklistener on a blank activity and it worked, but when i added it to an existing
Fragment activity it does nothing (it should display a toast with some text)
I see no error messages so i don't know where the problem could be.
Thank you for your responses.
enter code here
public class FragmentHome : Fragment() {
public class HomeFragmentElements : AppCompatActivity() {
private lateinit var spinView: Spinner
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.fragment_home)
val exc = this.findViewById<Button>(R.id.execute)
exc.setOnClickListener {
Toast.makeText(this, "You clicked me.", Toast.LENGTH_SHORT).show()
}
spinView = findViewById(R.id.spinner)
spinView.onItemSelectedListener = object : AdapterView.OnItemSelectedListener {
override fun onItemSelected(
parent: AdapterView<*>?,
view: View?,
position: Int,
id: Long
) {
TODO("Not yet implemented")
}
override fun onNothingSelected(parent: AdapterView<*>?) {
TODO("Not yet implemented")
}
}
}
}
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_home, container, false)
}
}
enter code here
Try to put your code into "onViewCreated":
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
val exc = this.findViewById<Button>(R.id.execute)
exc.setOnClickListener {
Toast.makeText(this, "You clicked me.", Toast.LENGTH_SHORT).show()
}
}
onViewCreated is executed after "onCreateView". View bindings and initializations should be into onViewCreated
change the following in your onCreateView
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
// Inflate the layout for this fragment
val view: View = inflater.inflate(R.layout.fragment_home, container, false)
collectId(view)
return view
}
fun collectId(view: view){
val exc = view.findViewById<Button>(R.id.execute)
exc.setOnClickListener {
Toast.makeText(this, "You clicked me.", Toast.LENGTH_SHORT).show()
}
}
You can consider viewBinding instead of findViewById
It looks like you have defined an AppCompatActivity subclass inside your Fragment class's definition, kind of like this:
class MyFragment: Fragment {
class MyActivity: AppCompatActivity() {
//...
}
}
The ability to define a non-inner class in a nested way is purely a code organization tool. There is absolutely no connection between your Fragment and Activity classes here. The code above is no different than if you did this, with each class in a completely different file:
class MyFragment: Fragment {
}
class MyActivity: AppCompatActivity() {
}
It also doesn't make sense to think of an Activity as a child of a Fragment. A Fragment is a piece of an Activity, so it's the other way around.
All the code that you have in this Activity's onCreate should be put in the Fragment's onViewCreated() function, except for the call to setContentView(), because that's what your overriding of onCreateView() does. And remove the unused nested Activity class.
Also, you don't need to override onCreateView if you're simply inflating a layout and returning it. You can put the layout directly in the super-constructor call like this:
public class FragmentHome : Fragment(R.layout.fragment_home) {
private lateinit var spinView: Spinner
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
// your view setup code
}
}
In the following code:
class LobbyFragment : Fragment() {
#Inject
lateinit var lobbyFragmentHelloService: LobbyFragmentHelloService
#BindView(R.id.lobby_fragment_hello)
lateinit var lobbyFragmentHelloTextView: TextView
lateinit var unbinder: Unbinder
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
val view = inflater.inflate(R.layout.lobby_fragment, container, false)
unbinder = ButterKnife.bind(this, view)
return view
}
override fun onViewCreated(view: View?, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
sayFragmentHello()
}
override fun onAttach(context: Context?) {
AndroidInjection.inject(this)
super.onAttach(context)
}
override fun onDestroyView() {
super.onDestroyView()
unbinder.unbind()
}
private fun sayFragmentHello() {
lobbyFragmentHelloTextView.text = lobbyFragmentHelloService.sayHello()
}
}
lobbyFragmentHelloTextView is never initialized. Butterknife is used to initialize this variable. Why is not initialized by the time sayFramentHello is called?
I'm not really sure what went wrong but to fix the issue, you can consider using kotlin built in synthetic binding and just get rid of butterknife. It's more efficient.
explained here
I am working kotlin. I have a fragment on my Activity . l want when click on button inside of fragment activity go to another activity .
this code my used in fragment class
class fragment_Arr :Fragment(), View.OnClickListener {
override fun onClick(v: View?) {
val intent = Intent(activity, FlightDeatilasDep::class.java)
startActivity(intent)
}
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
return inflater.inflate(R.layout.fragment_arrivel,container,false)
loadmorefilghtsbeforday.setOnClickListener{this}
}
}
when l debug app and click on button no event happening !
loadmorefilghtsbeforday.setOnClickListener{} body of the lambda is empty - nothing happen.
Please register your listener by
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
val view = inflater.inflate(R.layout.fragment_arrivel,container,false)
loadmorefilghtsbeforday.setOnClickListener(this)
return view
}
or if you prefer using lambdas
loadmorefilghtsbeforday.setOnClickListener{ onClick(null) } could be called but then your fragment don't need to implements View.OnClickListener.
and class names in Kotlin/java should start from capital later: FragmentArr.
_ is not recommended