Android splashscreen remove white and black flashing

Manatee

Hi everybody, in my app I want to remove the splashscreen because I already use an image in my stackView as splashscreen with visibility time and other stuff that I can control instead of using AndroidManifest and then the "iOS manifest".
I copy paste my code to a better understanding.
At first the Init.qml will be called and use as first item MainMini also a Loader load my custom Splashscreen

    StackView
    {
        id: stackView        
        initialItem: MainMini {}
        anchors.fill: parent
   }

    Loader
    {
        id: loaderSplash
        anchors.fill: parent
        active: false
        sourceComponent:
        Splash
        {
            id: splashItem
            anchors.fill: parent
            onSplashTimeout:
            {
                console.log("[Init.qml] Timeout disabling Splashscreen");
                loaderSplash.active = false;
            }
        }
    }

This is my splash Item

Rectangle
{
    id: splashInit
    signal splashTimeout()

    property string qwe: "#F5F5F5"
    property string asd: "#C05656"
    property string fgh: "#565656"

    color: "white"    

    Image
    {
        id: splashscreen
        anchors.centerIn: parent
        width: parent.width * 0.4
        height: splashscreen.width / 1.172
        source: "assets/splashscreen/splashscreen_app_1280x1920_hor.png"

        mipmap: true
    }



    MText {
        id: name
        anchors.horizontalCenter: splashInit.horizontalCenter
        anchors.bottom: parent.bottom
        bottomPadding: splashInit.height * 0.03

        color: "grey"

        font.pointSize: parent.height * 0.021
        font.family: "Titillium Web"
        font.weight: Font.Light

        text: "Version " + Qt.application.version
    }

    Timer
    {
        id: timerInit
        interval: 2000
        running: true
        repeat: false
        onTriggered:
        {
            timerInit.stop();
            timerInit.running = false;
            console.log("[Splash.qml] Time's up, emitting...");
            splashTimeout();
        }
    }
}

Here seems all ok this is my Android stuff:

package my_package;

import android.content.Context;
import android.content.Intent;
import android.provider.Settings;
import android.os.Bundle;
import android.widget.Toast;
import android.util.Log;
import java.util.Timer;
import java.util.TimerTask;

//URL from intent
import android.net.Uri;

//VIBE
import android.os.VibrationEffect;
import android.os.Vibrator;

//FCM
import androidx.annotation.NonNull;
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.iid.FirebaseInstanceId;
import com.google.firebase.iid.InstanceIdResult;
import com.google.firebase.messaging.FirebaseMessaging;

//class CustomSending
//{
//    public static native void sendFibonaciResult(int n);
//}

public class MainActivity extends org.qtproject.qt5.android.bindings.QtActivity
{
    public static native void nativeUrlReceived(String url);

    public static native void sendFibonaciResult(int n);

    public static native void callAndroid(int n);
    public static native void functionCppCalledFromAndroid(String a);

    private static final String TAG = "MainActivity";

    public static MainActivity mInstance;
    private static Context mContext;
    private static String mFCMToken = "";
    private static String androidId = "";
    private static String encodedData;

    public MainActivity()
    {      
        mInstance = this;
        mContext = this;
    }

    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        Log.d(TAG, "ANDROID 1");
        super.onCreate(savedInstanceState);

        Log.d(TAG, "ANDROID 2");
        //sendFibonaciResult(47);

        androidId = Settings.Secure.getString(getContentResolver(), Settings.Secure.ANDROID_ID);

        Log.d(TAG, "ANDROID 3");
        //GET FCM TOKEN
        FirebaseInstanceId.getInstance().getInstanceId()
            .addOnCompleteListener(new OnCompleteListener<InstanceIdResult>()
            {
                @Override
                public void onComplete(@NonNull Task<InstanceIdResult> task) {
                    if (!task.isSuccessful()) {
                        Log.w(TAG, "getInstanceId failed", task.getException());
                        return;
                    }

                    // Get new Instance ID token
                    String token = task.getResult().getToken();
                    mFCMToken = token;
                    // Log and toast
                    Log.d(TAG, "FirebaseInstance token = " + token);
                    //Toast.makeText(MainActivity.this, token, Toast.LENGTH_SHORT).show();
                }
            });

        Log.d(TAG, "ANDROID 4");
        getSchemeUrl(getIntent());
    }
    
    @Override
    protected void onNewIntent(Intent intent) {
        Log.d(TAG, "ANDROID onNewIntent called");
        super.onNewIntent(intent);
        getSchemeUrl(intent);
    }
}

And here the Manifest

<?xml version="1.0"?>
<manifest package="my_package" xmlns:android="http://schemas.android.com/apk/res/android" android:versionName="1.0.17.100" android:versionCode="32" android:installLocation="auto">
    <uses-sdk android:minSdkVersion="25" android:targetSdkVersion="29"/>

    <!-- The following comment will be replaced upon deployment with default permissions based on the dependencies of the application.
         Remove the comment if you do not require these default permissions. -->
    <!-- %%INSERT_PERMISSIONS -->

    <!-- The following comment will be replaced upon deployment with default features based on the dependencies of the application.
         Remove the comment if you do not require these default features. -->
    <!-- %%INSERT_FEATURES -->

    <supports-screens android:largeScreens="true" android:normalScreens="true" android:anyDensity="true" android:smallScreens="true"/>

    <application android:hardwareAccelerated="true" android:name="org.qtproject.qt5.android.bindings.QtApplication" android:label="myAppName" android:extractNativeLibs="true" android:icon="@drawable/icon">
        <activity android:configChanges="orientation|uiMode|screenLayout|screenSize|smallestScreenSize|locale|fontScale|keyboard|keyboardHidden|navigation|mcc|mnc|density" android:name="my_Package.MainActivity" android:label="myAppName" android:screenOrientation="portrait" android:launchMode="singleTop">
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>
                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
            <intent-filter>
                <action android:name="android.intent.action.VIEW"/>
                <category android:name="android.intent.category.BROWSABLE"/>
                <category android:name="android.intent.category.DEFAULT"/>
                <data android:scheme="myAppName"/>
            </intent-filter>
            <!-- Application arguments -->
            <!-- meta-data android:name="android.app.arguments" android:value="arg1 arg2 arg3"/ -->
            <!-- Application arguments -->
            <meta-data android:name="android.app.lib_name" android:value="-- %%INSERT_APP_LIB_NAME%% --"/>
            <meta-data android:name="android.app.qt_sources_resource_id" android:resource="@array/qt_sources"/>
            <meta-data android:name="android.app.repository" android:value="default"/>
            <meta-data android:name="android.app.qt_libs_resource_id" android:resource="@array/qt_libs"/>
            <meta-data android:name="android.app.bundled_libs_resource_id" android:resource="@array/bundled_libs"/>
            <!-- Deploy Qt libs as part of package -->
            <meta-data android:name="android.app.bundle_local_qt_libs" android:value="-- %%BUNDLE_LOCAL_QT_LIBS%% --"/>
            <!-- Run with local libs -->
            <meta-data android:name="android.app.use_local_qt_libs" android:value="-- %%USE_LOCAL_QT_LIBS%% --"/>
            <meta-data android:name="android.app.libs_prefix" android:value="/data/local/tmp/qt/"/>
            <meta-data android:name="android.app.load_local_libs_resource_id" android:resource="@array/load_local_libs"/>
            <meta-data android:name="android.app.load_local_jars" android:value="-- %%INSERT_LOCAL_JARS%% --"/>
            <meta-data android:name="android.app.static_init_classes" android:value="-- %%INSERT_INIT_CLASSES%% --"/>
            <!-- Used to specify custom system library path to run with local system libs -->
            <!-- <meta-data android:name="android.app.system_libs_prefix" android:value="/system/lib/"/> -->
            <!--  Messages maps -->
            <meta-data android:value="@string/ministro_not_found_msg" android:name="android.app.ministro_not_found_msg"/>
            <meta-data android:value="@string/ministro_needed_msg" android:name="android.app.ministro_needed_msg"/>
            <meta-data android:value="@string/fatal_error_msg" android:name="android.app.fatal_error_msg"/>
            <meta-data android:value="@string/unsupported_android_version" android:name="android.app.unsupported_android_version"/>
            <!--  Messages maps -->
            <!-- Splash screen -->
            <!-- Orientation-specific (portrait/landscape) data is checked first. If not available for current orientation,
                 then android.app.splash_screen_drawable. For best results, use together with splash_screen_sticky and
                 use hideSplashScreen() with a fade-out animation from Qt Android Extras to hide the splash screen when you
                 are done populating your window with content. -->
            <!-- meta-data android:name="android.app.splash_screen_drawable_portrait" android:resource="@drawable/logo_portrait" / -->
            <!-- meta-data android:name="android.app.splash_screen_drawable_landscape" android:resource="@drawable/logo_landscape" / -->
            <!-- meta-data android:name="android.app.splash_screen_drawable" android:resource="@drawable/logo"/ -->
            <!-- meta-data android:name="android.app.splash_screen_sticky" android:value="true"/ -->
            <!-- Splash screen -->
            <!-- Background running -->
            <!-- Warning: changing this value to true may cause unexpected crashes if the
                          application still try to draw after
                          "applicationStateChanged(Qt::ApplicationSuspended)"
                          signal is sent! -->
            <meta-data android:name="android.app.background_running" android:value="false"/>
            <!-- Background running -->
            <!-- auto screen scale factor -->
            <meta-data android:name="android.app.auto_screen_scale_factor" android:value="false"/>
            <!-- auto screen scale factor -->
            <!-- extract android style -->
            <!-- available android:values :
                * default - In most cases this will be the same as "full", but it can also be something else if needed, e.g., for compatibility reasons
                * full - useful QWidget & Quick Controls 1 apps
                * minimal - useful for Quick Controls 2 apps, it is much faster than "full"
                * none - useful for apps that don't use any of the above Qt modules
                -->
            <meta-data android:name="android.app.extract_android_style" android:value="default"/>
            <!-- extract android style -->
        </activity>
        <!-- For adding service(s) please check: https://wiki.qt.io/AndroidServices -->
        <service android:name="my_package.MyFirebaseMessagingService">
            <meta-data android:name="android.app.lib_name" android:value="-- %%INSERT_APP_LIB_NAME%% --"/>
        </service>
    </application>

    <uses-permission android:name="android.permission.VIBRATE"/>
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
</manifest>

Finally when I opened the app I visualize for 1 second a white screen, then a black screen for 1 second again then my Splash.qml item.
How could I remove these white and black screen at the beginning of the app?

EDIT: I discovered that changing the image size in KB change the time that the black screen stay up on display (700KB 2 seconds~, 400KB a flash of 100 millisecond)
Here a link to the bug: https://drive.google.com/file/d/107STvnrNsYd-6GHJQDmWrBOj7XQPK-Fb/view?usp=sharing (in this case the image is in low res and the black flash last milliseconds)

Thanks to everybody that want to help

IntruderExcluder

On Android Qt application isn't a real application, its just a set of libs, that loaded after when initial activity starts. And this may take time, depending on different devices, this time may vary. So, as a result, you will see always an empty activity for a short period of time. The true way is to use system splash screen.
You can play with QtAndroid::hideSplashScreen and splash screen 'life-time' to achieve different effects.