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Problem with android toolbar using navigation drawer

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I'm developing an app using a navigation drawer and navigation components and I'm facing two issues:
I settled specifically each toolbar title where it is supposed to be, but every time I change the fragments, in the toolbar, for an instant, I can see the previous name from the fragment, which is the fragment name itself. So, it quickly changes from MySpecificFragment to MyFragmentName and I would like it to not happen. I've settled the title even onCreateView or onViewCreated. It didn't matter, still happening.
How could I decide the direction in which the back button of the fragment goes? I would like to create a standard position where the back button arrow goes, always the same. But it just travels back to the previous fragment (which is not a real problem, but I would like to improve its behavior)
Sorry for the lack of code, I don't know what I am supposed to display since I'm going against the standard android behavior.
P.S.: Using android studio and kotlin

Regarding the first issue, one way to avoid the brief display of the previous fragment name in the toolbar is to set the toolbar title in the parent activity and then update it from the fragment's onResume() method. This ensures that the toolbar title is set correctly when the fragment is resumed after being pushed onto the back stack. Here's an example code snippet:
In your activity:
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
setSupportActionBar(toolbar)
}
fun setToolbarTitle(title: String) {
supportActionBar?.title = title
}
}
In your fragment:
class MySpecificFragment : Fragment() {
override fun onResume() {
super.onResume()
(activity as? MainActivity)?.setToolbarTitle("MySpecificFragment")
}
}
Regarding the second issue, you can customize the back button behavior by using a custom NavController.OnDestinationChangedListener. In the listener, you can set the back button icon and its behavior based on the current and previous destinations. Here's an example code snippet:
class MyNavigationController(activity: AppCompatActivity, navController: NavController) {
init {
navController.addOnDestinationChangedListener(
activity, object : NavController.OnDestinationChangedListener {
override fun onDestinationChanged(
controller: NavController,
destination: NavDestination,
arguments: Bundle?
) {
if (destination.id == R.id.my_fragment) {
activity.supportActionBar?.setDisplayHomeAsUpEnabled(false)
} else {
activity.supportActionBar?.setDisplayHomeAsUpEnabled(true)
activity.supportActionBar?.setHomeAsUpIndicator(R.drawable.ic_arrow_back)
activity.supportActionBar?.setHomeActionContentDescription(R.string.back)
activity.supportActionBar?.setHomeAsUpIndicator(R.drawable.ic_arrow_back)
activity.supportActionBar?.setDisplayShowHomeEnabled(true)
}
}
})
}
}
Here, you can adjust the back button icon and behavior based on the current and previous destinations by setting setDisplayHomeAsUpEnabled, setHomeAsUpIndicator, and setHomeActionContentDescription.

Android Kotlin - How execute an animation only when app opens?

I would like that animation on MainActivity to be exhibited only when the user opens the app, but remains static if the user comes from another Activity/Fragment (e.g. by using BottomNavigationMenu), so as not to pollute the window too much.
I think it can be solved by using onCreate, onStart, onResume but I am unable to set it properly (still learning).
The only answer I found is here: https://www.tutorialspoint.com/how-to-launch-activity-only-once-when-android-app-is-opened-for-the-first-time
but it is not what I want since I still would like the animation to be exhibited every time the app opens.
Thank you in advance.
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
// execute animation here??
}
override fun onStart() {
super.onStart()
setContentView(R.layout.activity_main)
// logic part (buttons) is executed here??
}

Once the Main activity is loaded then you have to finish() from other Activity/Fragment then onResume() override method Main Activity will be called. Do not start Main activity every time if the user comes from another Activity/Fragment.
For fragments:
activity.finish()
For Activity:
finish()
Rather then:
Intent startIntent = new Intent(context, MainActivity.class);
startIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(startIntent);

How can I use button in one activity to do something in second activity?

I got a question. I have two activities in my app. In first one, when I click the button, I need something to happen in the second one. How can I do it? If that button would be in the second activity I would just do it by:
button.setOnClickListener {}
But how can I do it when button is in the other activity? It's worth adding that code, that tells what should happen, must be in that second activity, just like it was in that "setOnClickListener". Sorry, I'm starting with Android development.

You could communicate between two activities via broadcast or intent.
But it make logic more complex.
So I suggest use two fragments instead two activities.
If you use two fragment in one activity, you can easy communicate between two fragments.
You can look more detailed information about fragment from this URL.
https://developer.android.com/guide/fragments

To achieve the intended flow you may try the below approach,
Start activity 2 on button click from activity 1.
On activity 2 place your code in onCreate so, once activity 2 loads up your code will fire up.
Activity 1:
button.setOnClickListener{
val intent = Intent(this, second::class.java)
startActivity(intent)
}
Activity 2:
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
CallDefinedFunctionHere();
}

You cannot be sure that both activities are present at the same moment since the system might destroy inactive one therefore you cannot trigger any code from activity A inside activity B.
What you can do you can start activity B with an intent and some parameters describing what should happen inside activity B.
or
You can communicate by writing something down to a persistent storage (like SharedPreferences) and then when the other activity is resumed (active again) reading it, reacting to it and then removing it from the storage (to make sure you do not handle it twice).

You can pass data in the intent that opens the second activity.
// In first activity:
buttonX.setOnClickListner {
val intent = Intent(MySecondActivity::class.java).apply {
putExtra("wasFromButtonX", true)
}
startActivity(intent)
}
// In second activity:
fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
val wasLaunchedFromButtonX = intent.getBooleanExtra("wasFromButtonX", false)
// Above line uses false as default, so it will only be true if you explicitly
// put the extra in the Intent that started this Activity.
if (wasLaunchedFromButtonX) {
// do alternate setup here
}
}
How to pass information between Activities is explained in the introductory documentation here.

Create a function in class where 2nd activity are defined like this.
public void refresh(){}
Now Call that in your 1st activity where you want to call 1st after any action.
button.setOnClickListener {((MainActivity) Objects.requireNonNull(getActivity())).refresh();}

Android WebView becomes not responsive after finishing previous activity 🤔

I've bumped into a strange issue - WebView becomes unresponsive when I finish the activity that started the activity with the WebView BUT it doesn't happen on the first launch, only on the consecutive ones and it also happens on Android 6 and 7, newer Android versions seem to handle that gently.
The full project which reproduces this can be found here
I have two activities Launcher
class LauncherActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
startActivity(Intent(this, MainActivity::class.java))
finish()
}
}
And MainActivity with the WebView
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val webView = findViewById<WebView>(R.id.oauthWebView)
webView.loadUrl("https://semantic-ui.com/examples/login.html")
}
}
When I start the app the first time everything seems okay, but the second time when I open it,
WebView becomes unresponsive, the keyboard is not showing and it happens right after Launcher onDestroy
If I'm not calling finish in the LauncherActivity everything is fine.
It looks like finishing LauncherActivity has some impact on WebView loading or some other process that's happening under the hood.
It's pretty weird, Logcat is not very helpful either.
Maybe any of you can provide some hint what might be the reason for such behaviour?
Side note:
I'm not looking for answers on how to architect my navigation better, I know it can be done differently - I'm curious why WebView is behaving so weird.

Can you try this?
val webView = findViewById<WebView>(R.id.oauthWebView)
webView.getSettings().setJavaScriptEnabled(true);
webView.loadUrl("https://semantic-ui.com/examples/login.html")

Kotlin: Load/initialize next activity in the background

I have an initialization activity in my app which displays the logo, then I show my next activity using
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState) // Call the parent class function
setContentView(R.layout.activity_launcher)
// This starts a new co-routine
// it is important to do it this way, in order to show the UI _before_
// all the initialization happens, otherwise launcher is pointless
GlobalScope.launch {
...
[initialization]
...
startActivity(ActivityTwo)
}
}
The transition takes about three seconds because of all the code that is running inside onCreate belonging to ActivityTwo. Is there a way to "create" the second activity behind the scenes, and then show it. I don't mind if the app stays on the initialization screen for those 3 seconds, but the white transition looks really ugly.

onCreate method is actually creating your activity. You must be doing some heavy computation if your activity is janking while rendering. If you are not satisfied with the transition between the two activities, then apply an animation between them.