Kotlin: How do I add an actionbar menu on a tabbed activity? - kotlin

I have a tabbed activity with fragments. Now I just need to add an actionbar menu. I am guessing I add the action bar in the mainactivity. How can I do this?
I have tried adding an action bar for each fragment but looks like that cannot be done in kotlin. I am new to android development but I was able to perform this task with java. I am converting my small projects to Kotlin which is supposed to be easier than java.
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val sectionsPagerAdapter = SectionsPagerAdapter(this, supportFragmentManager)
val viewPager: ViewPager = findViewById(R.id.view_pager)
viewPager.adapter = sectionsPagerAdapter
val tabs: TabLayout = findViewById(R.id.tabs)
tabs.setupWithViewPager(viewPager)
val fab: FloatingActionButton = findViewById(R.id.fab)
fab.setOnClickListener { view ->
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show()
}
fun onCreateOptionsMenu(menu: Menu): Boolean {
menuInflater.inflate(R.menu.mainmenu, menu)
return true
}
}
}

Actually figured it out. My question was basically senseless. It should have been how to add a menu in an AppBarLayout. My app is using a tabbed activity.
All I had to do was under my main activity layout, I needed to add a toolbar under the Appbarlayout.
then under the Main activity Oncreate, I added
setSupportActionBar(toolbar)
val actionBar = supportActionBar
Then call the oncreateoptionsmenu
override fun onCreateOptionsMenu(menu: Menu): Boolean {
// Inflate the menu to use in the action bar
val inflater = menuInflater
inflater.inflate(R.menu.mainmenu, menu)
return super.onCreateOptionsMenu(menu)
}

Related

how to navigate to fragment inside recycler view?

I have an activity that is controlled with a navigation component, it has few fragments, inside one of these fragments there is a recyclerView that has some items, when I click on an Item I want it to navigate me to another fragment that has additional information about the item, I don't know how to use navigation component inside a recycelerView, when I type findNavController it has some parameters that am not sure what to put in or if its even the right function, I also tried to do it by code like this:
val fm = (context as AppCompatActivity).supportFragmentManager
fm.beginTransaction()
.replace(R.id.fragmentContainer, fragment)
.addToBackStack(null)
.commit()
by the way this is the code that asks for other parameters:
// it asks for a (fragment) or (activity, Int)
findNavController().navigate(R.id.action_settingsFragment_to_groupUnits)
the problem is when I navigate out of this fragment or use the drawer navigation (nav component for the other fragments), this fragment that I navigated to stays displayed in the screen, I see both fragments at the same time, I assume its a fragment backStack issue but I don't know how to solve it, thanks for the help and your time in advance
You do not need to navigate from RecyclerView item click to AdditionalDetails fragment directly.
You can do this same thing by help of interface.
Steps:
Create an interface with a method declaration.
Extend Interface from the fragment where you are using your RecyclerView and Implement interface method.
Pass this interface with the adapter.
Using the interface from adapter you just pass object when click on item.
Finally from your fragment you just navigate to AdditionalDetails fragment with argument.
Lets see sample code from my current project:
Interface
interface ChatListClickListener {
fun onChatListItemClick(view:View, user: User)
}
Adapter Class
class UserAdapter(val Users: List<User>, val chatListClickListener: ChatListClickListener) : RecyclerView.Adapter<UserAdapter.UserViewHolder>() {
inner class UserViewHolder(
val recyclerviewUsersBinding: RecyclerviewChatlistBinding
) : RecyclerView.ViewHolder(recyclerviewUsersBinding.root)
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): UserViewHolder {
val vh = UserViewHolder(
DataBindingUtil.inflate(
LayoutInflater.from(parent.context),
R.layout.recyclerview_chatlist,
parent,
false
)
)
return vh
}
override fun onBindViewHolder(holder: UserViewHolder, position: Int) {
holder.recyclerviewUsersBinding.user = Users[position]
holder.recyclerviewUsersBinding.root.setOnClickListener{
chatListClickListener.onChatListItemClick(it,Users[position])
}
}
override fun getItemCount(): Int {
return Users.size
}
}
My fragment
class FragmentChatList : Fragment(), ChatListClickListener {
lateinit var binding: FragmentChatListBinding
lateinit var viewModel: ChatListViewModel
lateinit var listener: ChatListClickListener
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
}
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
val args: FragmentChatListArgs by navArgs()
binding = FragmentChatListBinding.inflate(layoutInflater, container, false)
val factory = ChatListFactory(args.user)
viewModel = ViewModelProvider(this, factory).get(ChatListViewModel::class.java)
binding.viewModel = viewModel
listener = this
lifecycleScope.launch {
viewModel.addUserWhenUserConnect()
}
viewModel.userList.observe(viewLifecycleOwner, Observer { data ->
binding.rvChatList.apply {
layoutManager = LinearLayoutManager(requireContext())
setHasFixedSize(true)
adapter = UserAdapter(data, listener)
}
})
return binding.root
}
override fun onChatListItemClick(view: View, user: User) {
Toast.makeText(requireContext(), user.name + "", Toast.LENGTH_SHORT).show()
// here you navigate to your fragment....
}
}
I guess this will be helpful.

How to View Bind multiple layouts in Kotlin

I'm trying to migrate from Kotlin synthetics to View Binding. How should I View bind from two different layouts. I'm trying to connect a button from fragment Main layout and from custom dialog layout. Right now I can connect button id from fragment main layout.Example code below:
class MainFragment: Fragment(R.layout.fragment_main) {
private var fragmentMainBinding: FragmentMainBinding? = null
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
// Main fragment viewbinding
val binding = FragmentMainBinding.bind(view)
fragmentMainBinding = binding
// FAB button onClick Listener
binding.fabAddItem.setOnClickListener {
// Inflate add_item_dialog.xml custom view
val dialogView = LayoutInflater.from(activity).inflate(R.layout.add_item_dialog, null)
// Add AlertDialog Builder
val dialogBuilder = AlertDialog.Builder(activity)
.setView(dialogView)
//Show custom dialog
val customAlertDialog = dialogBuilder.show()
binding.btnClose.setOnClickListener {
customAlertDialog.dismiss()
}
}
}
}
If you want to get a hold of dialog binding you can do the following
val dialogBinding = AddItemDialogBinding.bind(dialogView)

Kotlin OnItemClickListener for a RecyclerView inside a Fragment

The problem is related to the fact that I don't manage to implement a OnItemClick listener for a RecyclerView that is located in a "mainFragment" by implementing the OnClickListener in the Adapter.
I would like my application (kotlin) to launch another fragment ("deletePage" in the code bellow) everytime an itemView (an ImageView) from the RecyclerView is clicked, this fragment would display the same photo in big.
My Adapter code is the following one:
class MyAdapter : RecyclerView.Adapter<MyAdapter.MyViewHolder>() {
private var photo = emptyList<Photo>()
inner class MyViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView)
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyViewHolder {
return MyViewHolder(
LayoutInflater.from(parent.context).inflate(R.layout.row_layout, parent, false)
)
}
override fun getItemCount(): Int {
return photo.size
}
override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
holder.itemView.longitude.text = photo[position].latitude
holder.itemView.latitude.text = photo[position].longitude
holder.itemView.imageView.load(photo[position].photo)
}
fun setData(photo: List<Photo>) {
this.photo = photo
notifyDataSetChanged()
}
}
And my mainFragment code is the following one:
class MainFragment : Fragment(){
private lateinit var myView: MyViewModel
private val adapter by lazy { MyAdapter() }
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
// Inflate the layout for this fragment
val view = inflater.inflate(R.layout.fragment_main, container, false)
//Recyclerview
val adapter = MyAdapter()
val recyclerView = view.recycler_view
recyclerView.adapter = adapter
recyclerView.layoutManager = LinearLayoutManager(requireContext())
myView = ViewModelProvider(this).get(MyViewModel::class.java)
myView.readPhoto.observe(viewLifecycleOwner, Observer {photo ->
adapter.setData(photo)
})
setHasOptionsMenu(true)
return view
}
override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
inflater.inflate(R.menu.menu_database, menu)
}
override fun onOptionsItemSelected(item: MenuItem): Boolean {
when {
item.itemId == R.id.deleteAll -> findNavController().navigate(R.id.deletePage)
item.itemId == R.id.refresh -> {
Toast.makeText(activity, "yep", Toast.LENGTH_SHORT).show()
instertDataToDatabase()
}
}
if (item.itemId == R.id.deleteAll) {
}
return super.onOptionsItemSelected(item)
}
}
The objective is that when you click on an item of the RecyclerView the "findNavController().navigate(R.id.deletePage)" fragment is displayed but everytime I try to implement a solution the application crashes when clicking at an item of the RecyclerView. Right now the navigation works by the click on a button in the Menu at the toolbar but is not the ideal solution.
Any sort of help or advice would be very much appreciated!
Firstly you need to give click listener of your itemView in onBindViewHolder
override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
holder.itemView.longitude.text = photo[position].latitude
holder.itemView.latitude.text = photo[position].longitude
holder.itemView.imageView.load(photo[position].photo)
holder.itemView.setOnClickListener { navigateToFragment() }
}
For the navigation somehow you should have a context instance.
Here is the possible solutions that came up to my mind:
Give navigator instance to adapter
class Navigator(fragment: Fragment) {
private val fragmentRef = WeakReference(fragment)
fun navigate(){
// make your navigations here with using fragmentRef.get()
}
}
In your fragment:
private val navigator = Navigator(this)
...
val adapter = MyAdapter(navigator)
In your adapter:
class MyAdapter(private val navigator: Navigator) : RecyclerView.Adapter<MyAdapter.MyViewHolder>() {
fun navigateToFragment(){
navigator.navigate()
}
Make interface for callback
2.1. Implement that interface in fragment and give adapter the interface instance
interface Navigable{
fun navigate()
}
In your fragment:
class MainFragment : Fragment(), Navigable{
...
override fun navigate(){
// make your navigation
}
val adapter = MyAdapter(navigator)
In your adapter:
class MyAdapter(private val navigable: Navigable) : RecyclerView.Adapter<MyAdapter.MyViewHolder>() {
fun navigateToFragment(){
navigable.navigate()
}
2.2. Make the interface, but do not pass reference, use findFragment in adapter
In your adapter: override onAttachedToRecyclerView to find fragment
private lateinit var navigable: Navigable
override fun onAttachedToRecyclerView(recyclerView: RecyclerView) {
super.onAttachedToRecyclerView(recyclerView)
navigable = recyclerView.findFragment<Fragment>() as Navigable
}
fun navigateToFragment(){
navigable.navigate()
}

New to coding; Can't get button to link to new activity in Kotlin

It opens the first activity on the emulator, but fails on button click. I created the second activity (AddProductActivity), so maybe I did something wrong there. I've tried all the variables I could find online to change how the button operates.
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.content_main)
val button = findViewById<Button>(R.id.goToAddProduct)
button.setOnClickListener {
val intent = Intent(this, AddProductActivity::class.java)
startActivity(intent)
}
}
}
class AddProductActivity: AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.add_product)
}
}
on content_main.xml:
<Button
android:id="#+id/goToAddProduct"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/add_to_inventory"/>
Make sure you have registered your new activity in the manifest. This is a common mistake by newcomers.
If that is not the case before you click on the button open your logcat view in android studio. Once you click on the button please investigate the crash issue from here.

Issue overriding onDrawerOpened() - Kotlin

I'm working on a Kotlin coded app using the Navigation Drawer Layout with a list of items. When I open the drawer using the icon at the top left I want it to notifyDataSetChanged so that the list is updated from outside the MainActivity. This includes pressing the back button, swiping open the drawer, or clicking the stacked lines icon at the top left
Here's a simplified version of my code, but it's essentially a Navagation Drawer Activity with a recyclerView for the context of my question:
class MainActivity : AppCompatActivity() {
lateinit var drawerLayout: DrawerLayout
lateinit var navView: NavigationView
lateinit var toolbar: Toolbar
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
toolbar = findViewById(R.id.app_bar_toolbar)
setSupportActionBar(toolbar)
drawerLayout = findViewById(R.id.drawer_layout)
navView = nav_view
val toggle = ActionBarDrawerToggle(this, drawerLayout, toolbar,
R.string.navigation_drawer_open, R.string.navigation_drawer_close)
drawerLayout.addDrawerListener(toggle)
toggle.syncState()
}
I've spent several hours trying anything I can, but primarily I can't get this to work:
override fun onDrawerOpen(view:View){
... myAdapter.notifyDataSetChanged()
super.onDrawerOpen(view)
}
it gives me the hint "overrides nothing" or "unused", and if I try to add it to any of my code in onCreate it states "Modifier 'override' not applicable to local function.
What am I doing wrong? Is there a better way to notify a data change when the drawer is opened?
The Question is old, but to whom has the same problem:
Just Create new class that implements DrawerListener and write your logic inside appropriate method:
private inner class MyDrawerListener(): DrawerListener {
override fun onDrawerSlide(drawerView: View, slideOffset: Float) {
}
override fun onDrawerOpened(drawerView: View) {
}
override fun onDrawerClosed(drawerView: View) {
}
override fun onDrawerStateChanged(newState: Int) {
}
}
Now add listener as:
drawerLayout.addDrawerListener(MyDrawerListener())