feat(ios): opt-out new tab bar under iPadOS 18+

apidoc/Titanium/UI/TabGroup.yml

@@ -415,6 +415,19 @@ properties:
     default: True if tab group is opened on top of the root activity. False otherwise.
     type: Boolean
 
+  - name: forceBottomPosition
+    summary: Force tab bar to bottom position.
+    description: |
+        A new floating tab bar was introduced in iPadOS 18.
+        It is displayed without tab icons and at the top of the screen.
+        This property forces the tab bar to be displayed in the old style with icons and at the bottom of the screen (as on iPhone).
+    type: Boolean
+    default: false
+    availability: creation
+    osver: {ios: {min: "18.0"}}
+    platforms: [ipad]
+    since: 13.1.0
+
   - name: swipeable
     summary: |
         Boolean value indicating if tab navigation can be done by swipes, in addition to tab clicks.

iphone/Classes/TiUITabGroup.m

@@ -49,6 +49,14 @@ - (UITabBarController *)tabController
       appearance.backgroundColor = UIColor.clearColor;
       controller.tabBar.scrollEdgeAppearance = appearance;
     }
+
+    // force tab bar to bottom position (as before iPadOS 18 and on iPhone)
+    if ([TiUtils isIOSVersionOrGreater:@"18.0"] && [TiUtils isIPad]) {
+      BOOL forceBottomPosition = [TiUtils boolValue:[self.proxy valueForUndefinedKey:@"forceBottomPosition"] def:NO];
+      if (forceBottomPosition) {
+        controller.traitOverrides.horizontalSizeClass = UIUserInterfaceSizeClassCompact;
+      }
+    }
   }
   return controller;
 }