Hey there, let's tackle this issue you're facing with your Migraine Relief: Green Dimmer app on Android 12+. The problem you described—being unable to interact with your device after minimizing the app—usually stems from changes in how Android 12+ handles TYPE_APPLICATION_OVERLAY windows, especially around touch event routing and window lifecycle constraints.

Root Cause Analysis #

Your current flag combination (FLAG_NOT_TOUCH_MODAL | FLAG_NOT_TOUCHABLE | FLAG_NOT_FOCUSABLE) should theoretically make the floating window ignore touch events, but Android 12 (API 31) introduced stricter rules for overlay windows. Full-screen overlays can sometimes inadvertently intercept touch input even with these flags, especially when the app moves to the background.

Step-by-Step Fixes #

1. Adjust WindowManager Layout Parameters

First, update your window parameters to align with Android 12+ requirements. We'll tweak the flags and add some API-specific settings to ensure the window doesn't block touch events:

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) { 
    params = new WindowManager.LayoutParams( 
        WindowManager.LayoutParams.MATCH_PARENT, 
        WindowManager.LayoutParams.MATCH_PARENT, 
        WindowManager.LayoutParams.TYPE_APPLICATION_OVERLAY, 
        // Simplify and prioritize flags that prevent touch interception
        WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE | 
        WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE | 
        WindowManager.LayoutParams.FLAG_LAYOUT_IN_SCREEN | 
        WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS, 
        PixelFormat.TRANSLUCENT
    ); 

    // Add Android 12+ specific adjustments
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
        // Disable inset handling to avoid unexpected touch area conflicts
        params.setFitInsetsTypes(0);
        // Optional: Prevent screen recording from capturing the overlay if needed
        params.flags |= WindowManager.LayoutParams.FLAG_SECURE;
    }
}

• FLAG_LAYOUT_NO_LIMITS ensures the window properly covers the entire screen without being constrained by system UI boundaries, which can prevent unintended touch interception.
• setFitInsetsTypes(0) tells the system not to adjust the window for system bars, reducing the chance of touch event misrouting.

2. Manage Window Lifecycle with App State

Android 12+ restricts overlay window behavior when the hosting app is in the background. To avoid the window blocking input, update its state when your app moves to the background:

Option A: Update window flags when the app pauses

@Override
protected void onPause() {
    super.onPause();
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S && params != null && floatingView != null) {
        // Explicitly enforce the window is not touchable when in background
        params.flags |= WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE;
        windowManager.updateViewLayout(floatingView, params);
    }
}

Option B: Remove the window when the app stops, re-add when it resumes
If you don't need the overlay to stay active when the app is minimized, this is a more reliable approach:

private WindowManager windowManager;
private View floatingView;

@Override
protected void onStop() {
    super.onStop();
    if (floatingView != null && windowManager != null) {
        windowManager.removeView(floatingView);
        floatingView = null;
    }
}

@Override
protected void onStart() {
    super.onStart();
    if (floatingView == null && hasOverlayPermission()) {
        // Recreate and attach the floating window
        createFloatingWindow();
    }
}

// Helper method to check overlay permission
private boolean hasOverlayPermission() {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        return Settings.canDrawOverlays(this);
    }
    return true;
}

3. Verify Overlay Permissions

Double-check that your app properly requests the SYSTEM_ALERT_WINDOW permission and that users have granted it. Even if the app works initially, Android 12+ may revoke implicit access when the app moves to the background.

Why This Works #

These changes ensure your green overlay window behaves as a non-interactive layer, even on Android 12+. By aligning with the platform's updated overlay rules and managing the window's lifecycle alongside your app, you prevent the system from treating the overlay as a blocking interactive element.

内容的提问来源于stack exchange，提问作者Bhavin