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Unwanted Blank screen showing on app start up android jetpack compose - android studio chipmunk.-How to remove it?

I just created an empty project and run it on device. On the app start up it shows a default blank screen on start up(app launch) before the first activity. I went through many answers and didn't find an exact answer or the root cause from where it is showing up. Many answers told to add
<item name="android:windowDisablePreview">true</item>
in themes.xml. Even after adding I still see the blank screen appearing.
Also in some other answer they told about new splash screen api, but I didn't feel it much customizable for doing server calls and other operations in splash screens. Also its available in below 12 versions.
What is right solution to handle this unwanted glitches during app startup?
Your help is highly appreciated.
<resources>
<style name="Theme.Owl" parent="#style/Theme.Material.DayNight.NoActionBar">
<item name="android:colorPrimary">#ff00ff</item>
<item name="android:colorAccent">#ff00ff</item>
<item name="android:statusBarColor">#color/immersive_sys_ui</item>
<item name="android:navigationBarColor">#color/nav_bar</item>
<item name="android:windowDisablePreview">true</item>
</style>
<style name="Theme.Material.DayNight.NoActionBar" parent="#android:style/Theme.Material.Light.NoActionBar" />
</resources>

Is there any SafeArea Widget for Native Android development?

I am trying to occupy as much space as available on notched android devices. In Flutter development, there is widget called SafeArea which automatically adjusts your view depending on whether the device has a notch or not. Even in iOS development whenever we add constraints using storyboard, we can add it according to SafeArea.
But I couldn't find anything similar to it in Native Android development.
In my styles.xml for v28 I have added something as follows
<style name="TPAFTheme" parent="#style/Theme.AppCompat.Light.NoActionBar">
<item name="android:windowNoTitle">true</item>
<item name="android:windowActionBar">false</item>
<item name="android:windowFullscreen">true</item>
<item name="android:windowContentOverlay">#null</item>
<item name="colorAccent">#color/colorAccent</item>
<item name="android:windowLayoutInDisplayCutoutMode">shortEdges</item>
<item name="android:windowTranslucentStatus">true</item>
<item name="android:windowTranslucentNavigation">true</item>
</style>
But is it possible to detect whether device has Notch or not in layout file itself and adjust the layout according.
I am using Constraintlayout in my App. As my app has image at the top it gets cropped if the device has notch at the top.
Any help would be appreciated.

I finally found the answer. Just use android:fitsSystemWindows="true" in your ConstraintLayout or any other top level Layout which you're using

I think the right option is to use CoordinatorLayout as a parent for your ConstraintLayout. CoordinatorLayout does lots of things and handling the system area is one of them (which I'd say isn't obvious...). It internally sets OnApplyWindowInsetsListener which is called by the system with information about sizes of system elements. CoordinatorLayout handles this calls and sets the right padding for its children. So, in Android it's more complicated than in iOS, you'll have to get used to it...
I'd recommend this video: https://www.youtube.com/watch?v=_mGDMVRO3iE

Unity android "freezes" with splash image

I have added a custom theme with background image to serve as "splash" image to make the app look nicer while unity player is loading.
That's the theme definition I have
<?xml version="1.0" encoding="utf-8"?>
<resources>
<style name="Theme.Test" parent="#android:style/Theme.Light.NoTitleBar.Fullscreen">
<item name="android:windowBackground">#drawable/launchimage</item>
<item name="android:windowContentOverlay">#null</item>
<item name="android:windowNoTitle">true</item>
<item name="android:backgroundDimEnabled">false</item>
</style>
</resources>
Now, when I refer to this theme in AndroidManifest.xml like:
<activity android:name="com.unity3d.player.UnityPlayerActivity" android:theme="#style/Theme.Test" ... ></activity>
the game just "freezes" – it's hard to tell in fact, because it just displays the splash image and ... that's it. Logcat doesn't show any warnings/errors either.
Removing the theme OR changing android:windowBackground property to a solid color make the game work, but window background appears black until the game is launched.
What is the correct way to set activity background to make Unity happy?

When your image is too large this issue happen. change your image with smaller and set centerCrop attribute may fixed this issue. (usually this show skip frame in your log)
Also if you use Android studio 2.0 there is newly issue with that you can find it here.

How to remove white screen before loading of first activity in android?

Whenever i launch my app, a white screen appears in the beginning with the title bar. I don't want this screen to be appear in my app. I have read previous questions, but answers are not clear to me.
I'm also using splash screen, but white screen appears before that.
I don't want to change the theme style, because it either increases the minimum sdkVersion or changes the style of edittext, buttons, checkboxes etc
Please help me to keep me out of this.
Thank you.

Preface: For questions like this you should post your starting activities xml and the onCreate() and associated methods.
When android starts your application it will typically use a black view to indicate that it is launching, this my change to white with your theme/style selected. If you are loading the view correctly then you should only see this blank (white or black) page for 50-200 ms (I can't find the google document for this right now). If you are doing a lot of work in your onCreate method then it will take longer.
Typically to make my views display faster I will simply do the majority of the linking work after it has loaded. ex:
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.initial_activity_layout);
//We use a handler so that the activity starts very fast
new Handler().postDelayed(new Runnable() {
#Override
public void run() {
delayedInit();
}
}, 100);
}
Additionally, mobile applications should typically not have a splash screen unless they take quite a while to load the contents (e.g. games, first time launch files, etc.) and should not be used just to brand your application, or display your company name.
Update (July 31, 2015)
Google apps are now moving in the direction of having splash screens (see drive, GMail, etc.)
Additionally, You shouldn't be doing any work other than de-referencing views in the onCreate() method. Any long running operations such as retrieving information from memory (database, prefs, etc.) should be done in an AsyncTaskLoader or AsyncTask.

If you are using AppCompatActivity then create below theme in style.xml :
<style name="Theme.Transparent" parent="Theme.AppCompat.Light.NoActionBar">
<item name="android:windowNoTitle">true</item>
<item name="android:windowActionBar">false</item>
<item name="android:windowFullscreen">true</item>
<item name="android:windowContentOverlay">#null</item>
<item name="android:windowIsTranslucent">true</item>
</style>
And in manifest file for SplashActivity add theme :
android:theme="#style/Theme.Transparent"

Add below line in your Theme of splash screen as you wrote you are using splash screen
<item name="android:windowFullscreen">true</item>
<item name="android:windowContentOverlay">#null</item>
<item name="android:windowIsTranslucent">true</item>

1- Make windowDisablePreview false in your style.xml
<item name="android:windowDisablePreview">false</item>
2- Add windowBackground in your style.xml.
<item name="android:windowBackground">#drawable/your_background</item>

How to set the background screen as Wallpaper all the time?

Currently, I'm using this to show my application background as phone wallpaper.
getWindow().setFlags(WindowManager.LayoutParams.FLAG_SHOW_WALLPAPER,
WindowManager.LayoutParams.FLAG_SHOW_WALLPAPER);
But for some reason when I start my application by pressing the icon. It just shows the activity screen with the icons on the home screen. I didn't use dialog but it looks like a dialog because layout is just set that way. So I just want to show the wallpaper whenever this activity is running. But it only shows the wallpaper only after the next event occurs such as switching to different activity. I already put that code on onCreate() and whenever I do setContentView()..... Is there way to do such thing or there is just no way?

For users of AppCompat, just use the following in your styles.xml, no need for code:
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat">
<item name="android:windowBackground">#android:color/transparent</item>
<item name="android:colorBackgroundCacheHint">#null</item>
<item name="android:windowShowWallpaper">true</item>
<item name="android:windowTranslucentNavigation">true</item>
<item name="android:windowTranslucentStatus">true</item>
</style>

After long search and trial and error. I've found the solution to what I wanted. It was just creating separate themes.xml file and just tweak the Theme.Dialog which is already defined in default android themes.xml. All I did was change the Animation part. Originally in android themes.xml the line looks like this.
<item name="android:windowAnimationStyle">#android:style/Animation.Dialog</item>
but since modifying in android themes.xml doesn't take the effect. I just created my own themes.xml as I said above and just set parent as android:Theme.Dialog. And added a line like this.
<item name="android:windowAnimationStyle">#android:style/Animation</item>
Thanks for the help and I hope this solution helps others.

Use following code -
rl = (RelativeLayout)findViewById(R.id.someid);
//relative layout is my root node in main.xml (yours may be linearlayout)
WallpaperManager wm = WallpaperManager.getInstance(this);
Drawable d = wm.peekDrawable();
rl.setBackgroundDrawable(d);// You can also use rl.setBackgroundDrawable(getWallpaper);