Develop Reference

Android scrollbars appear inside views after opening preferencescreen

I use navigation architecture component and if I navigate to the settings page and then I go back then lines and scrollbars appear on views. The PreferenceScreen is very simple only contains a ListPreference.
SettingsFragment:
class SettingsFragment : PreferenceFragmentCompat() {
override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {
setPreferencesFromResource(R.xml.root_preferences, rootKey)
init()
}
private fun init() {
(activity as AppCompatActivity?)?.supportActionBar?.show()
activity?.fab?.visibility = View.GONE
(activity as AppCompatActivity?)?.nav_view?.visibility = View.GONE
activity?.app_bar?.setExpanded(true, true)
val toolbarParams = activity?.toolbar?.layoutParams as AppBarLayout.LayoutParams
toolbarParams.scrollFlags = 0
} }
xml:
<PreferenceScreen xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:android="http://schemas.android.com/apk/res/android">
<PreferenceCategory app:title="General">
<ListPreference
app:key="app_theme_color"
app:title="Theme"
app:defaultValue="black"
app:entries="#array/color_entries"
app:entryValues="#array/color_values"
app:useSimpleSummaryProvider="true" />
</PreferenceCategory>

Android: Navigation Component - How to connect Toolbar menu to the fragments?

Iv been stuck in trying to add the Navigation Component to my app. Specifically to my toolbar menu items.
I have been following the navigation migrate documentation on Android's site but I am getting a but confused on how it works or even to set it up.
This is a single-activity multi-fragment architecture.
The app would start in the MainFragment and then when tapping the menu items in the toolbar, such as Main Frag to Search Movie Frag. The user would be able to navigate using the menu items from anywhere in the app (e.g. if they click the home icon, they should be sent to the home screen form anywhere in the app. Still thinking if thats how it should be done).
The main thing is I don't know how to properly attach the Navigation Component to the menu items.
App
Nav Graph
nav_graph.xml
<?xml version="1.0" encoding="utf-8"?>
<navigation xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/nav_graph"
app:startDestination="#id/mainFragment">
<fragment
android:id="#+id/mainFragment"
android:name="com.example.movieapp.ui.main.MainFragment"
android:label="MainFragment">
<action
android:id="#+id/action_mainFragment_to_searchMovieFragment"
app:destination="#id/searchMovieFragment" />
</fragment>
<fragment
android:id="#+id/searchMovieFragment"
android:name="com.example.movieapp.ui.search.SearchMovieFragment"
android:label="SearchMovieFragment" />
</navigation>
main_activity.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".activity.MainActivity">
<include
layout="#layout/appbar"
android:id="#+id/mainToolBar"/>
<androidx.fragment.app.FragmentContainerView
android:id="#+id/nav_host_fragment"
android:name="androidx.navigation.fragment.NavHostFragment"
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="#id/mainToolBar"
app:layout_constraintBottom_toBottomOf="parent"
app:defaultNavHost="true"
app:navGraph="#navigation/nav_graph" />
</androidx.constraintlayout.widget.ConstraintLayout>
MainActivity.kt
class MainActivity : AppCompatActivity() {
private lateinit var toolbar: Toolbar
private val navController by lazy {
(supportFragmentManager.findFragmentById(R.id.nav_host_fragment) as NavHostFragment).navController
}
private lateinit var appBarConfiguration: AppBarConfiguration
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.main_activity)
toolbar = findViewById(R.id.mainToolBar)
setSupportActionBar(toolbar)
appBarConfiguration = AppBarConfiguration(navController.graph, null)
setupActionBarWithNavController(navController, appBarConfiguration)
}
override fun onCreateOptionsMenu(menu: Menu?): Boolean {
val inflater: MenuInflater = menuInflater
inflater.inflate(R.menu.main_menu_bar, menu)
return true
}
override fun onSupportNavigateUp(): Boolean {
return navController.navigateUp(appBarConfiguration) || super.onSupportNavigateUp()
}
}
MainFragment.kt
class MainFragment : Fragment() {
companion object {
fun newInstance() = MainFragment()
}
private lateinit var viewModel: MainViewModel
private lateinit var binding: MainFragmentBinding
private lateinit var navController: NavController
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View {
binding = DataBindingUtil.inflate(inflater, R.layout.main_fragment, container, false)
setHasOptionsMenu(true)
return binding.root
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
navController = Navigation.findNavController(view)
// navController.navigate(R.id.action_mainFragment_to_searchMovieFragment)
}
override fun onActivityCreated(savedInstanceState: Bundle?) {
super.onActivityCreated(savedInstanceState)
viewModel = ViewModelProvider(this).get(MainViewModel::class.java)
binding.viewModel = viewModel
// TODO: Use the ViewModel
}
}
main_fragment.xml
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools">
<data>
<variable
name="viewModel"
type="com.example.movieapp.ui.main.MainViewModel" />
</data>
<LinearLayout
android:orientation="vertical"
android:id="#+id/main_fragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".ui.main.MainFragment">
<TextView
android:id="#+id/message"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="MainFragment1" />
</LinearLayout>
</layout>

The id for a menu item in your file main_menu_bar.xml needs to match the id for the destination(fragment) specified in your navigation graph (nav_graph.xml).
Your main_menu_bar.xml should look something like this:
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
tools:showIn="navigation_view">
<group android:checkableBehavior="single">
<item
android:id="#id/searchMovieFragment"
android:icon="#drawable/search"
android:title="#string/menu_search" />
<item
android:id="#id/mainFragment"
android:icon="#drawable/ic_menu_camera"
android:title="#string/menu_home" />
</group>
</menu>
Also, you need to override the onOptionsItemSelected(MenuItem) method and associate your menu items with destinations. Like so:
override fun onOptionsItemSelected(item: MenuItem): Boolean {
val navController = findNavController(R.id.nav_host_fragment)
return item.onNavDestinationSelected(navController) || super.onOptionsItemSelected(item)
}
Reference

You can add a Toolbar on top of the most basic FragmentContainerView, access this toolbar from other fragments, and change the toolbar I created separately according to the fragment in it while opening the relevant fragment as follows.
toolbar = requireActivity().findViewById(R.id.toolbar_base)
toolbar?.menu?.clear()
toolbar?.title = ""
val toolbarFlowFragment = context?.let { getInflateLayout(it, R.layout.toolbar_profile) }
toolbar?.addView(toolbarFlowFragment)

I have a gap on top of my preferences fragment, dunno what causes it

I followed this guide https://developer.android.com/guide/topics/ui/settings to create my preferences page, but when I navigate to my settings page, I get an empty row in my settings fragment just before the preferencescreen items, like in the picture https://imgur.com/a/KbVrIHr
This is my code;
class SettingsActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
supportFragmentManager
.beginTransaction()
.replace(R.id.settings_container, SettingsFragment())
.commit()
}
}
class SettingsFragment : PreferenceFragmentCompat() {
override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {
addPreferencesFromResource(R.xml.preferences)
}
}
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/settings_container"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".ui.actionbar.settings.SettingsActivity">
</LinearLayout>
<?xml version="1.0" encoding="utf-8"?>
<androidx.preference.PreferenceScreen
xmlns:app="http://schemas.android.com/apk/res-auto">
<PreferenceCategory
app:iconSpaceReserved="false"
app:title="Theme">
<SwitchPreferenceCompat
app:iconSpaceReserved="false"
app:key="switch"
app:summary="Enable dark theme."
app:title="Dark Theme" />
</PreferenceCategory>
</androidx.preference.PreferenceScreen>

How to add bottom navigation listeners to fragments

I used to have a single activity that included the navigation host and the BottomNavigationView that allowed switching views between the 3 fragments. I recently changed my design so that the initial activity now represents a single new fragment, and there exists a button that allows the user to navigate to another fragment which should hold the aforementioned 3 tabbed bottom navigation.
I've managed to implement the initial activity and the first fragment. But the issue that I am having is that when I navigate to the second fragment with the 3 tabbed bottom navigation bar, I don't know how to implement the onClickListener on the tabs. It used to be fairly straightforward when I had the bottom navigation inside the AppCompatActivity. I'm guessing that fragments are not supposed to be used for this case. I could easily use another activity class but I wanted to build a single activity application and wondered if there was another solution to this.
In the original method using an activity class, I was able to implement the bottom navigation like below:
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
setSupportActionBar(toolbar)
val navController = Navigation.findNavController(this, R.id.nav_host_fragment)
setupBottomNavMenu(navController)
setupActionBar(navController)
}
override fun onCreateOptionsMenu(menu: Menu?): Boolean {
menuInflater.inflate(R.menu.menu_toolbar, menu)
return true
}
override fun onOptionsItemSelected(item: MenuItem?): Boolean {
val navController = Navigation.findNavController(this, R.id.nav_host_fragment)
val navigated = NavigationUI.onNavDestinationSelected(item!!, navController)
return navigated || super.onOptionsItemSelected(item)
}
override fun onSupportNavigateUp(): Boolean {
return NavigationUI.navigateUp(Navigation.findNavController(this, R.id.nav_host_fragment), drawer_layout)
}
private fun setupBottomNavMenu(navController: NavController) {
bottom_nav?.let {
NavigationUI.setupWithNavController(it, navController)
}
}
private fun setupActionBar(navController: NavController) {
NavigationUI.setupActionBarWithNavController(this, navController, drawer_layout)
}
}
<?xml version="1.0" encoding="utf-8"?>
<layout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:background="#color/colorMintCream"
tools:context=".activity.MainActivity">
<androidx.appcompat.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="?colorPrimary"
android:theme="#style/ToolbarTheme"/>
<fragment
android:id="#+id/nav_host_fragment"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:name="androidx.navigation.fragment.NavHostFragment"
app:navGraph="#navigation/main_nav_graph"
app:defaultNavHost="true"/>
<com.google.android.material.bottomnavigation.BottomNavigationView
android:id="#+id/bottom_nav"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:menu="#menu/menu_navigation"/>
</LinearLayout>
</layout>
The navigation looks like follows:
<?xml version="1.0" encoding="utf-8"?>
<navigation xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto" android:id="#+id/mobile_navigation.xml"
app:startDestination="#id/destination_profile">
<fragment
android:id="#+id/destination_profile"
android:name="com.example.project.profile.ProfileFragment"
android:label="Profile" />
<fragment
android:id="#+id/destination_achievements"
android:name="com.example.project.fragments.AchievementsFragment"
android:label="Achievements" />
<fragment
android:id="#+id/destination_logs"
android:name="com.example.project.fragments.LogsFragment"
android:label="Logs" />
<fragment
android:id="#+id/destination_settings"
android:name="com.example.project.fragments.SettingsFragment"
android:label="Settings" />
</navigation>
And finally the menu:
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
<item
android:id="#+id/destination_profile"
android:icon="#drawable/ic_person_black_24dp"
android:title="#string/profile"/>
<item
android:id="#+id/destination_logs"
android:icon="#drawable/ic_fitness_center_black_24dp"
android:title="#string/logs"/>
<item
android:id="#+id/destination_achievements"
android:icon="#drawable/ic_star_black_24dp"
android:title="#string/achievements"/>
</menu>
Similarly I tried to apply this on a fragment like below:
class MainFragment : Fragment() {
override fun onCreateView(inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?): View? {
var binding: FragmentMainBinding = DataBindingUtil.inflate(
inflater,
R.layout.fragment_main,
container,
false
)
val application = requireNotNull(this.activity).application
val dataSource = UserProfileDatabase.getInstance(application).userProfileDao
val viewModelFactory = MainViewModelFactory(dataSource, application)
val navController = this.findNavController()
NavigationUI.setupWithNavController(binding.bottomNav, navController)
return binding.root
}
override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
super.onCreateOptionsMenu(menu, inflater)
inflater.inflate(R.menu.menu_toolbar, menu)
}
override fun onOptionsItemSelected(item: MenuItem): Boolean {
val navController = this.findNavController()
val navigated = NavigationUI.onNavDestinationSelected(item, navController)
return navigated || super.onOptionsItemSelected(item)
}
companion object {
fun newInstance(): MainFragment = MainFragment()
}
}
The xml is almost exactly the same as the one for activity.
I expected to invoke onOptionsItemSelected() when I clicked on the tab elements, but I wasn't able to do so. How can I implement the listeners on those tab elements so that I can navigate to the correct fragment destinations?

Why don't you keep your first implementation for your BottomNavigationView which is good and combine it with your new implementation by using addOnDestinationChangedListener.
Your FirstFragment that hold the button will hide the BottomNavigationView and the SecondFragment with the 3 tabbed bottom navigation will show it.
For example :
navController.addOnDestinationChangedListener { _, destination, _ ->
if(destination.id == R.id.first_fragment) {
// your intro fragment will hide your bottomNavigationView
bottomNavigationView.visibility = View.GONE
} else if (destination.id == R.id.second_fragment){
// your second fragment will show your bottomNavigationView
bottomNavigationView.visibility = View.VISIBLE
}
}
in that way you keep the control in your Activity instead of Fragment and by that interact better with your listeners and your NavController.

Keep your menu item's id same as your graph id and simply use 1 line code i.e
val navHostFragment =childFragmentManager.findFragmentById(R.id.fragmentContainerView) as NavHostFragment
val navController = navHostFragment.navController
binding.bottomNavBar.setupWithNavController(navController)

Error: No view found for id androidx(Jetpack) Preference library

I was following the instructions on docs to use Android Jetpack preference library, but I am getting the following error
java.lang.RuntimeException: Unable to start activity ComponentInfo{ ... activity.SettingsActivity}: java.lang.IllegalArgumentException: No view found for id 0x7f090111 (... :id/settings_container) for fragment SettingsFragment
...
Caused by: java.lang.IllegalArgumentException: No view found for id 0x7f090111 (... :id/settings_container) for fragment SettingsFragment
as I think this usually happens when there is no container to mount the fragment, but in my case there is a container(settings_container).
My code looks like below
SettingsActivity
class SettingsActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
supportFragmentManager
.beginTransaction()
.replace(R.id.settings_container, SettingsFragment())
.commit()
}
}
SettingsFragment
class SettingsFragment : PreferenceFragmentCompat() {
override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {
setPreferencesFromResource(R.xml.pref_main, rootKey)
}
activity_settings.xml
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/settings_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".activities.SettingsActivity">
</FrameLayout>
pref_main.xml (shortened)
<?xml version="1.0" encoding="utf-8"?>
<androidx.preference.PreferenceScreen
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:android="http://schemas.android.com/apk/res/android">
<PreferenceCategory
app:key="data_sync_category"
app:title="#string/pref_data_sync_category">
<SwitchPreferenceCompat app:key="data_sync_status"
app:title="#string/pref_data_sync_status_title"
app:summary="#string/pref_data_sync_status_summary"
android:defaultValue="true"
/>
<ListPreference app:key="what_data_sync"
app:title="#string/pref_sync_frequency_title"
app:summary="#string/pref_sync_frequency_summary"
android:entries="#array/pref_sync_frequency_titles"
android:entryValues="#array/pref_sync_frequency_values"
android:defaultValue="30"
android:negativeButtonText="#null"
android:positiveButtonText="#null"
/>
</PreferenceCategory>
</androidx.preference.PreferenceScreen>
As you can see code is almost identical to the code in documentation.
I tried invalidate and restart, did not work.
Please help

No, there isn't a container.
You never use setContentView() in your Activity, so that layout doesn't exist. tools:context is an IDE-only feature.
You need to use
setContentView(R.layout.activity_settings)
right after calling super.onCreate(savedInstanceState).

java.lang.RuntimeException: Unable to start activity ComponentInfo{ ... activity.SettingsActivity}: java.lang.IllegalArgumentException: No view found for id 0x7f090111 (... :id/settings_container) for fragment SettingsFragment
...
Caused by: java.lang.IllegalArgumentException: No view found for id 0x7f090111 (... :id/settings_container) for fragment SettingsFragment
according your code you did't set layout for activity
you are giving reference of settings_container but its not found in activity layout because they dont have layout file so you need to setContentView for your activity
setContentView(R.layout.name)
public void setContentView (int layoutResID)
Set the activity content from a layout resource. The resource will be inflated, adding all top-level views to the activity.
Replace your activity kt file with
class SettingsActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_settings)
supportFragmentManager
.beginTransaction()
.replace(R.id.settings_container, SettingsFragment())
.commit()
}
}