Android: hide system bars via WindowInsetsController on API 30+

The immersive-fullscreen code hid the status and navigation bars with the
deprecated View.setSystemUiVisibility() flags plus FLAG_FULLSCREEN. On
Android 15+ (API 35), edge-to-edge is enforced for apps targeting SDK 35+
and those flags are ignored, so the bars never hide (e.g. on a Samsung
S25). Android 14 and below still honour them, which is why older devices
were unaffected.

Hide/show the system bars with WindowInsetsController on API 30+ (using
BEHAVIOR_SHOW_TRANSIENT_BARS_BY_SWIPE for sticky-immersive), keeping the
legacy setSystemUiVisibility() path for API < 30. The minimum supported
version is unchanged.

android-project/app/src/main/java/org/libsdl/app/SDLActivity.java

@@ -38,6 +38,8 @@ import android.view.Surface;
 import android.view.View;
 import android.view.ViewGroup;
 import android.view.Window;
+import android.view.WindowInsets;
+import android.view.WindowInsetsController;
 import android.view.WindowManager;
 import android.view.inputmethod.BaseInputConnection;
 import android.view.inputmethod.EditorInfo;
@@ -773,21 +775,45 @@ public class SDLActivity extends Activity implements View.OnSystemUiVisibilityCh
                         Window window = ((Activity) context).getWindow();
                         if (window != null) {
                             if ((msg.obj instanceof Integer) && ((Integer) msg.obj != 0)) {
-                                int flags = View.SYSTEM_UI_FLAG_FULLSCREEN |
-                                        View.SYSTEM_UI_FLAG_HIDE_NAVIGATION |
-                                        View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY |
-                                        View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN |
-                                        View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION |
-                                        View.SYSTEM_UI_FLAG_LAYOUT_STABLE | View.INVISIBLE;
-                                window.getDecorView().setSystemUiVisibility(flags);
-                                window.addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
-                                window.clearFlags(WindowManager.LayoutParams.FLAG_FORCE_NOT_FULLSCREEN);
+                                if (Build.VERSION.SDK_INT >= 30 /* Android 11 (R) */) {
+                                    // The legacy setSystemUiVisibility() flags are ignored on
+                                    // Android 15+ (API 35+), where edge-to-edge is enforced for
+                                    // apps targeting that SDK, so the status/navigation bars
+                                    // would never hide. Use WindowInsetsController instead.
+                                    window.setDecorFitsSystemWindows(false);
+                                    final WindowInsetsController controller = window.getInsetsController();
+                                    if (controller != null) {
+                                        controller.hide(WindowInsets.Type.systemBars());
+                                        // Sticky-immersive (replaces SYSTEM_UI_FLAG_IMMERSIVE_STICKY):
+                                        // a swipe shows the bars transiently, then they auto-hide.
+                                        controller.setSystemBarsBehavior(
+                                                WindowInsetsController.BEHAVIOR_SHOW_TRANSIENT_BARS_BY_SWIPE);
+                                    }
+                                } else {
+                                    int flags = View.SYSTEM_UI_FLAG_FULLSCREEN |
+                                            View.SYSTEM_UI_FLAG_HIDE_NAVIGATION |
+                                            View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY |
+                                            View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN |
+                                            View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION |
+                                            View.SYSTEM_UI_FLAG_LAYOUT_STABLE | View.INVISIBLE;
+                                    window.getDecorView().setSystemUiVisibility(flags);
+                                    window.addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
+                                    window.clearFlags(WindowManager.LayoutParams.FLAG_FORCE_NOT_FULLSCREEN);
+                                }
                                 SDLActivity.mFullscreenModeActive = true;
                             } else {
-                                int flags = View.SYSTEM_UI_FLAG_LAYOUT_STABLE | View.SYSTEM_UI_FLAG_VISIBLE;
-                                window.getDecorView().setSystemUiVisibility(flags);
-                                window.addFlags(WindowManager.LayoutParams.FLAG_FORCE_NOT_FULLSCREEN);
-                                window.clearFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
+                                if (Build.VERSION.SDK_INT >= 30 /* Android 11 (R) */) {
+                                    window.setDecorFitsSystemWindows(true);
+                                    final WindowInsetsController controller = window.getInsetsController();
+                                    if (controller != null) {
+                                        controller.show(WindowInsets.Type.systemBars());
+                                    }
+                                } else {
+                                    int flags = View.SYSTEM_UI_FLAG_LAYOUT_STABLE | View.SYSTEM_UI_FLAG_VISIBLE;
+                                    window.getDecorView().setSystemUiVisibility(flags);
+                                    window.addFlags(WindowManager.LayoutParams.FLAG_FORCE_NOT_FULLSCREEN);
+                                    window.clearFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
+                                }
                                 SDLActivity.mFullscreenModeActive = false;
                             }
                             if (Build.VERSION.SDK_INT >= 28 /* Android 9 (Pie) */) {
@@ -1623,7 +1649,13 @@ public class SDLActivity extends Activity implements View.OnSystemUiVisibilityCh
     private final Runnable rehideSystemUi = new Runnable() {
         @Override
         public void run() {
-            if (Build.VERSION.SDK_INT >= 19 /* Android 4.4 (KITKAT) */) {
+            if (Build.VERSION.SDK_INT >= 30 /* Android 11 (R) */) {
+                final WindowInsetsController controller =
+                        SDLActivity.this.getWindow().getInsetsController();
+                if (controller != null) {
+                    controller.hide(WindowInsets.Type.systemBars());
+                }
+            } else if (Build.VERSION.SDK_INT >= 19 /* Android 4.4 (KITKAT) */) {
                 int flags = View.SYSTEM_UI_FLAG_FULLSCREEN |
                         View.SYSTEM_UI_FLAG_HIDE_NAVIGATION |
                         View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY |