Develop Reference

Navigation up clicked

Previously I used onCreateOptionsMenu and onSupportNavigationUp.
Now I use MenuProvide. To check if navigation up was clicked I check id - "android.R.id.home". While it works, I'm not sure this is the right approach?
override fun onCreate(savedInstanceState: Bundle?) {
WindowCompat.setDecorFitsSystemWindows(window, false)
super.onCreate(savedInstanceState)
binding = ActivityMainBinding.inflate(layoutInflater)
setContentView(binding.root)
setSupportActionBar(binding.toolbar)
val navController = findNavController(R.id.nav_host_fragment_content_main)
appBarConfiguration = AppBarConfiguration(navController.graph)
setupActionBarWithNavController(navController, appBarConfiguration)
addMenuProvider(object : MenuProvider {
override fun onCreateMenu(menu: Menu, menuInflater: MenuInflater) {
menuInflater.inflate(R.menu.menu_main, menu)
}
override fun onMenuItemSelected(menuItem: MenuItem): Boolean {
Log.d(TAG, "onMenuItemSelected: {${menuItem.itemId}}")
return when (menuItem.itemId) {
android.R.id.home -> {
navController.navigateUp(appBarConfiguration)
}
else -> {
true
}
}
}
})
}

Is it possible to have databinding for action menu with searchView?

I have a SearchFragment
and here is my code of onCreateOptionMenu in SearchFragment
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setHasOptionsMenu(true)
}
override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
inflater.inflate(R.menu.search_menu, menu)
val searchItem = menu.findItem(R.id.action_search)
val searchManager = activity?.getSystemService(Context.SEARCH_SERVICE) as? SearchManager
searchView = searchItem?.actionView as? SearchView
searchView?.setSearchableInfo(searchManager?.getSearchableInfo(activity?.componentName))
queryTextListener = object : SearchView.OnQueryTextListener {
override fun onQueryTextChange(newText: String): Boolean {
return true
}
override fun onQueryTextSubmit(query: String): Boolean {
viewModel.loadSearchResults(query)
return true
}
}
searchView?.setOnQueryTextListener(queryTextListener)
super.onCreateOptionsMenu(menu, inflater)
}
I would like to know is it possible to have databinding for SearchView of menu so in the case I wouldn't like to have SearchView.OnQueryTextListener in Fragment and I can connect viewModel with menu and listen searchView changes in ViewModel
android:text="#={viewModel.query}"

Have you tried to move your listener to the viewModel directly?
class ViewModel: ViewModel() {
interface ViewModelListener {
fun onQueryTextChange(newText: String)
fun onQueryTextSubmit(newQuery: String)
}
var listener: ViewModelListener? = null
var query = ObservableField<String>()
val queryTextListener = object : SearchView.OnQueryTextListener {
override fun onQueryTextChange(newText: String): Boolean {
listener?.onQueryTextChange(newText: String)
return true
}
override fun onQueryTextSubmit(newQuery: String): Boolean {
listener?.onQueryTextSubmit(newQuery: String)
query.set(newQuery)
return true
}
}
}
And assign it in your onViewCreated like searchView?.setOnQueryTextListener(viewModel.queryTextListener)
Also you can add listener viewModel.listener = this

How to switch viewpager Tab with button Click in Kotlin?

I want to switch Fragments by button click inside the fragment itself. I have have created viewpager + tablayout, everything worked until i made an interface to communicate with my activity where i can set different Page for Viewpager. I am pretty new to Kotlin and I do not understand why I am catching NullPointer :(
I probably initialized my button poorly too, but I am not sure
Here is my MainActivity code
class MainActivity : AppCompatActivity()
, MyFragment1.buttonClick {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
tablayout.addTab(tablayout.newTab().setIcon(R.drawable.ic_fragment1))
tablayout.addTab(tablayout.newTab().setIcon(R.drawable.ic_fragment_2))
tablayout.addTab(tablayout.newTab().setIcon(R.drawable.ic_fragment3))
tablayout.tabGravity = TabLayout.GRAVITY_FILL
val adapter = MyAdapter(this, supportFragmentManager, tablayout.tabCount)
viewpager!!.adapter = adapter
viewpager.addOnPageChangeListener(TabLayout.TabLayoutOnPageChangeListener(tablayout))
val tabStrip = tablayout.getChildAt(0) as LinearLayout
for (i in 0 until tabStrip.childCount) {
tabStrip.getChildAt(i).setOnTouchListener { v, event -> true }
}
}
override fun buttonClicked(view: View) {
viewpager.currentItem = 2
}
fun selectIndex(index: Int) {
viewpager.currentItem = index
}
override fun onBackPressed() {
val currentPos = viewpager.currentItem
if (currentPos != 0) {
viewpager.currentItem = 0
} else {
super.onBackPressed()
}
}
}
**And a code for my Fragment**
class MyFragment1 : Fragment() {
private var click: buttonClick? = null
interface buttonClick {
fun buttonClicked(view: View)
}
var currentPage: Int = 0
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
val view: View = inflater.inflate(R.layout.fragment_my_fragment1, container, false)
val btn: Button = view?.findViewById(R.id.btn_next)
btn.setOnClickListener {
Toast.makeText(context, "test", Toast.LENGTH_LONG).show()
click?.buttonClicked(it)
}
return view
}
}

Have you initialized your click variable?
private var click: buttonClick? = null
override fun onAttach(context: Context?) {
super.onAttach(context)
click = context as? buttonClick
}
override fun onDetach() {
super.onDetach()
click = null
}

Unable to use setOnClickListener on button in fragment

I have tried to add an setOnClickListener in my Fragment. But both methods i tried didnt work. There is no readction to my button press in the App.
class LoginFragment: Fragment(), View.OnClickListener {
//AuthVariable for global use
private lateinit var myAuth: FirebaseAuth
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
var view = inflater.inflate(R.layout.content_login, container, false)
view?.login_button?.setOnClickListener(this)
return view
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
}
override fun onClick(p0: View?) {
Log.i("BUTTON123","TEST")
loginUser()
}
}
Activity:
class MainActivity : AppCompatActivity(), NavigationView.OnNavigationItemSelectedListener {
//AuthVariable for global use
private lateinit var myAuth : FirebaseAuth
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
setSupportActionBar(toolbar)
val toggle = ActionBarDrawerToggle(
this, drawer_layout, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close)
drawer_layout.addDrawerListener(toggle)
toggle.syncState()
nav_view.setNavigationItemSelectedListener(this)
//Initializing FirebaseAuth Instance
myAuth = FirebaseAuth.getInstance()
var user = myAuth.currentUser
if(user != null){
updateUI(user)
}else{
val test = supportFragmentManager
val frag = LoginFragment()
test.beginTransaction().replace(R.id.placeholder,frag).addToBackStack(null).commit()
}
}
override fun onBackPressed() {
if (drawer_layout.isDrawerOpen(GravityCompat.START)) {
drawer_layout.closeDrawer(GravityCompat.START)
} else {
super.onBackPressed()
}
}
override fun onCreateOptionsMenu(menu: Menu): Boolean {
// Inflate the menu; this adds items to the action bar if it is present.
menuInflater.inflate(R.menu.main, menu)
return true
}
override fun onOptionsItemSelected(item: MenuItem): Boolean {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
when (item.itemId) {
R.id.action_settings -> return true
else -> return super.onOptionsItemSelected(item)
}
}
override fun onNavigationItemSelected(item: MenuItem): Boolean {
// Handle navigation view item clicks here.
when (item.itemId) {
R.id.nav_addShop -> {
//Activity to Add your Shop
val addshopIntent = Intent(this,AddShopActivity::class.java)
startActivity(addshopIntent)
}
R.id.nav_searchShop -> {
//SearchFragment
val test = supportFragmentManager
val frag = test()
test.beginTransaction().replace(R.id.placeholder,frag).addToBackStack(null).commit()
}
R.id.nav_shopMap -> {
//MapActivity
val mapintent = Intent(this, ShopMap::class.java)
startActivity(mapintent)
}
R.id.nav_manage -> {
}
R.id.nav_share -> {
}
R.id.nav_logout -> {
myAuth.signOut()
updateUI(myAuth.currentUser)
}
}
drawer_layout.closeDrawer(GravityCompat.START)
return true
}
}

Did you forget the onClick() method in LoginFragment?
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
val view: View = inflater.inflate(R.layout.content_login, container, false)
view.login_button.setOnClickListener {
Log.i("BUTTON123","TEST")
loginUser()
}
return view
}

Fragment in kotlin

i'm stuck in my application because i have to do a fragment with the navigation drawer in kotlin.. can anyone help? I have search a lot of things in web but i didn't find anything yet...
Down here is two items that i have do in main activity and i want that is present in the fragment too.
override fun onNavigationItemSelected(item: MenuItem): Boolean {
// Handle navigation view item clicks here.
when (item.itemId) {
R.id.home -> {
}
R.id.subjects -> {
val intent = Intent(this, SubjectsActivity::class.java)
startActivity(intent)
}
}
drawer_layout.closeDrawer(GravityCompat.START)
return true
}

You can use this to replace your frame with HomeFragment()
mainDisplayFrame should be replace by your FrameID
var fragmentTransaction = supportFragmentManager.beginTransaction()
fragmentTransaction.replace(R.id.mainDisplayFrame,HomeFragment()).commit()
mDrawerLayout!!.closeDrawers()

You can download the source link from here(Navigation Drawer In Android Kotlin)
MainActivity.kt:
class MainActivity : AppCompatActivity(), View.OnClickListener {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
init()
}
private fun init() {
tv_home.setText("Home Tab")
tv_title.setText("Home")
ll_about.setOnClickListener(this)
ll_home.setOnClickListener(this)
ll_bookmark.setOnClickListener(this)
ll_help.setOnClickListener(this)
rl_menu.setOnClickListener(this)
rl_header.setOnClickListener(this)
tv_link.setLinkTextColor(Color.parseColor("#000000"));
Linkify.addLinks(tv_link, Linkify.ALL)
}
override fun onBackPressed() {
if (drawer_layout.isDrawerOpen(GravityCompat.START)) {
drawer_layout.closeDrawer(GravityCompat.START)
} else {
super.onBackPressed()
}
}
override fun onClick(p0: View?) {
when (p0?.id) {
R.id.ll_home -> {
drawer_layout.closeDrawer(GravityCompat.START)
tv_home.setText("Home Tab")
tv_title.setText("Home")
}
R.id.ll_about -> {
val browserIntent = Intent(Intent.ACTION_VIEW, Uri.parse("http://deepshikhapuri.blogspot.in/"))
startActivity(browserIntent)
}
R.id.ll_help -> {
drawer_layout.closeDrawer(GravityCompat.START)
tv_home.setText("Help Tab")
tv_title.setText("Help")
}
R.id.ll_bookmark -> {
drawer_layout.closeDrawer(GravityCompat.START)
tv_home.setText("Bookmark Tab")
tv_title.setText("Bookmark")
}
R.id.rl_header -> {
}
R.id.rl_menu -> {
if (drawer_layout.isDrawerOpen(GravityCompat.START)) {
drawer_layout.closeDrawer(GravityCompat.START)
} else {
drawer_layout.openDrawer(GravityCompat.START)
}
}
}
}
Thanks!

Is something like this? #NongthonbamTonthoi
class NavViewFragment : AppCompatActivity(),
NavigationView.OnNavigationItemSelectedListener {
fun AppCompatActivity.addFragment(fragment: Fragment, frameId: Int){
supportFragmentManager.inTransaction { add(frameId, fragment) }
}
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_nav_view_fragment)
setSupportActionBar(toolbar)
nav_view.setNavigationItemSelectedListener(this)
}
override fun onBackPressed() {
if (drawer_layout.isDrawerOpen(GravityCompat.START)) {
drawer_layout.closeDrawer(GravityCompat.START)
} else {
super.onBackPressed()
}
}
override fun onCreateOptionsMenu(menu: Menu): Boolean {
// Inflate the menu; this adds items to the action bar if it is present.
menuInflater.inflate(R.menu.nav_view, menu)
return true
}
override fun onOptionsItemSelected(item: MenuItem): Boolean {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
when (item.itemId) {
R.id.action_settings -> return true
else -> return super.onOptionsItemSelected(item)
}
}
override fun onNavigationItemSelected(item: MenuItem): Boolean {
// Handle navigation view item clicks here.
when (item.itemId) {
R.id.home -> {
}
R.id.subjects -> {
val intent = Intent(this, SubjectsActivity::class.java)
startActivity(intent)
}
}
drawer_layout.closeDrawer(GravityCompat.START)
return true
}
inline fun FragmentManager.inTransaction(func: FragmentTransaction.() -> Unit) {
val fragmentTransaction = beginTransaction()
fragmentTransaction.func()
fragmentTransaction.commit()
}
}