Defer focus until attached (#54309)

Summary:
Pull Request resolved: #54309

We can encounter cases where something is rendered by React but not yet attached to Android at the point focus is called.

If we defer focus until the View is attached to the window, we can avoid apps needing to add annoying timeouts or other creative mechanisms to wait for native mount before calling imperative focus.

The only caveat here is that if you call imperative focus on something offscreen initially that is attached later (e.g., due to clipping), apps could encounter undesirable bugs where focus jumps at the point the previously detached view is now attached. One might also argue it's  bug prone to call focus on something that is far offscreen / you don't plan to mount onscreen immediately.

## Changelog

[Android][Fixed] Defers focus until View is attached

Reviewed By: sbuggay

Differential Revision: D85727424

fbshipit-source-id: 677834aa2d9ba2d3247d1e71b3fe0cdd9a6ec4aa

Author: rozele

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/views/view/ReactViewGroup.kt

@@ -153,6 +153,8 @@ public open class ReactViewGroup public constructor(context: Context?) :
   private var accessibilityStateChangeListener:
       AccessibilityManager.AccessibilityStateChangeListener? =
       null
+  private var focusOnAttach = false
+  private var hasAttachedToWindowForFocus = false
 
   init {
     initView()
@@ -212,6 +214,10 @@ public open class ReactViewGroup public constructor(context: Context?) :
     updateBackgroundDrawable(null)
 
     resetPointerEvents()
+
+    // In case a focus was attempted but the view never attached, reset to false
+    focusOnAttach = false
+    hasAttachedToWindowForFocus = false
   }
 
   private var _drawingOrderHelper: ViewGroupDrawingOrderHelper? = null
@@ -417,10 +423,17 @@ public open class ReactViewGroup public constructor(context: Context?) :
   }
 
   internal fun requestFocusFromJS() {
-    super.requestFocus(FOCUS_DOWN, null)
+    // We need a local variable here as opposed to the View.isAttachedToWindow check
+    // since the value is not updated until after the Fabric commit.
+    if (hasAttachedToWindowForFocus) {
+      super.requestFocus(FOCUS_DOWN, null)
+    } else {
+      focusOnAttach = true
+    }
   }
 
   internal fun clearFocusFromJS() {
+    focusOnAttach = false
     super.clearFocus()
   }
 
@@ -572,6 +585,12 @@ public open class ReactViewGroup public constructor(context: Context?) :
     if (_removeClippedSubviews) {
       updateClippingRect()
     }
+
+    hasAttachedToWindowForFocus = true
+    if (focusOnAttach) {
+      requestFocusFromJS()
+      focusOnAttach = false
+    }
   }
 
   private fun customDrawOrderDisabled(): Boolean {