QML Application Shows Blank Screen After Background Termination on Android 15

NatureYellow

Description:
My QML-based Android app works normally when launched, but if it stays in the background for an extended period (e.g., 30+ minutes), reopening it results in a blank screen. The UI components disappear entirely, and only a white/black background is visible. This issue occurs on Android 15 devices.

Key Observations:

The app uses QtFullscreenActivity with the following manifest configuration:

<activity
    android:name="org.qtproject.qt.android.bindings.QtFullscreenActivity"
    android:configChanges="orientation|uiMode|screenLayout|screenSize|smallestScreenSize|layoutDirection|locale|fontScale|keyboard|keyboardHidden|navigation|mcc|mnc|density"
    android:launchMode="singleTask"
    android:screenOrientation="portrait">
</activity>

Logs show OpenGL context destruction when entering the background:

D/HWUI    : RenderThread::destroyRenderingContext: this=0xb400007591894480
D/HWUI    : SkiaOpenGLPipeline::onContextDestroyed: this=0xb40000768a718d00
D/HWUI    : EglManager::destroy: mEglDisplay=0xb40000768a716500, mEglContext=0xb40000768a48f900, mCurrentSurface=0x0

Although there is a crash report when running in Qt Creator, the QML engine can restore the UI state. However, when running independently on the phone and the application is in the background for too long, the QML engine cannot restore the UI state, leaving only a blank space when entering again.

Request for Guidance:

How can I enforce state persistence for QML components (e.g., StackView navigation history)?
Are there manifest flags or Qt-specific configurations to prevent OpenGL context destruction?
Should I replace QtFullscreenActivity with a custom lifecycle-aware Activity?
Full Manifest:

//AndroidManifest.xml
<?xml version="1.0"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
    package="org.ChengWang.YellowTown" 
    android:installLocation="auto"
    android:versionCode="1" 
    android:versionName="0.2.1">
    
    <supports-screens 
        android:anyDensity="true" 
        android:largeScreens="true" 
        android:normalScreens="true" 
        android:smallScreens="true"/>
    
    <application 
        android:name="org.qtproject.qt.android.bindings.QtApplication" 
        android:hardwareAccelerated="true" 
        android:label="城网" 
        android:requestLegacyExternalStorage="true" 
        android:allowBackup="true" 
        android:fullBackupOnly="false" 
        android:icon="@drawable/icon">
        
        <activity 
            android:name="org.qtproject.qt.android.bindings.QtFullscreenActivity" 
            android:configChanges="orientation|uiMode|screenLayout|screenSize|smallestScreenSize|layoutDirection|locale|fontScale|keyboard|keyboardHidden|navigation|mcc|mnc|density" 
            android:launchMode="singleTask" 
            android:screenOrientation="portrait" 
            android:exported="true" 
            android:label="城网">
            
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>
                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
            
            <meta-data 
                android:name="android.app.lib_name" 
                android:value="-- %%INSERT_APP_LIB_NAME%% --"/>
            <meta-data 
                android:name="android.app.arguments" 
                android:value="-- %%INSERT_APP_ARGUMENTS%% --"/>
        </activity>
        
        <provider 
            android:name="androidx.core.content.FileProvider" 
            android:authorities="${applicationId}.qtprovider" 
            android:exported="false" 
            android:grantUriPermissions="true">
            <meta-data 
                android:name="android.support.FILE_PROVIDER_PATHS" 
                android:resource="@xml/qtprovider_paths"/>
        </provider>
    </application>
    
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
</manifest>

//QtFullscreenActivity.java
package  org.qtproject.qt.android.bindings;

import android.content.Context;
import android.content.Intent;
import android.app.PendingIntent;
import android.util.Log;
import android.os.Bundle;
import android.os.Build;
import android.graphics.Color;
import android.view.WindowManager;
import android.view.View;

// 继承 QtActivity 类
public class QtFullscreenActivity extends org.qtproject.qt.android.bindings.QtActivity {
    private final static String TAG = "QtFullscreen";
    private static Context context;

    @Override
    // 重写 onCreate 方法
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // 去除标题导航栏
        context = getApplicationContext();
        // 设置状态栏全透明
        this.setStatusBarFullTransparent();
    }

    // 全局获取Context
    public static Context getContext() {
        return context;
    }

    // 全透状态栏
    private void setStatusBarFullTransparent() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS); // 透明状态栏
            // 状态栏字体设置为深色，SYSTEM_UI_FLAG_LIGHT_STATUS_BAR 为SDK23增加
            getWindow().getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN | View.SYSTEM_UI_FLAG_LIGHT_STATUS_BAR);

            // 部分机型的statusbar会有半透明的黑色背景
            getWindow().addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
            getWindow().clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
            getWindow().setStatusBarColor(Color.TRANSPARENT); // SDK21
        }
    }

    // 非全透,带颜色的状态栏,需要指定颜色
    private void setStatusBarColor(String color) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            // 需要安卓版本大于5.0以上
            getWindow().addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
            getWindow().setStatusBarColor(Color.parseColor(color));
        }
    }
}

pypi

I had a similar looking problem (Qt app displaying blank screen after being backgrounded). Maybe you just need to update the Qt version you are using?

https://bugreports.qt.io/browse/QTBUG-132085

zvoopz

My android built app suffers the same issue with blank screen after being backgrounded.
qmake, OS Android 13 Qt version - 6.8.2

Michel de Boer

Interesting, I received complaints from some users that this happens with and Android app I developed. They experience a grey screen on Android 15 (Qt 6.8.3) on Pixel phones. I have not experienced this myself on Android 14 on a Samsung Galaxy S22.