fix(Android, Tabs): fix flickering tab bar height & contents when entering on ScreenStackFragment

android/src/main/java/com/swmansion/rnscreens/ScreenStack.kt

@@ -76,6 +76,13 @@ class ScreenStack(
     }
 
     override fun endViewTransition(view: View) {
+        require(view is ScreensCoordinatorLayout) {
+            "[RNScreens] Expected children of type: ${ScreensCoordinatorLayout::class.java.simpleName}"
+        }
+        if (view.blockFrameworkTransitionFinalization) {
+            return
+        }
+
         super.endViewTransition(view)
 
         disappearingTransitioningChildren.remove(view)
@@ -89,10 +96,17 @@ class ScreenStack(
         }
     }
 
-    fun onViewAppearTransitionEnd() {
+    internal fun onViewTransitionEnd(view: ScreensCoordinatorLayout) {
         if (!removalTransitionStarted) {
             dispatchOnFinishTransitioning()
         }
+
+        if (view.needsTransitionFinalization) {
+            check(!view.blockFrameworkTransitionFinalization) {
+                "[RNScreens] Attempt to finalize transition on view that blocks the action!"
+            }
+            endViewTransition(view)
+        }
     }
 
     /**

android/src/main/java/com/swmansion/rnscreens/ScreenStackFragment.kt

@@ -148,19 +148,17 @@ class ScreenStackFragment :
 
     override fun onViewAnimationEnd() {
         super.onViewAnimationEnd()
-
-        // Rely on guards inside the callee to detect whether this was indeed appear transition.
-        notifyViewAppearTransitionEnd()
-
-        // Rely on guards inside the callee to detect whether this was indeed removal transition.
-        screen.endRemovalTransition()
+        notifyViewTransitionEnd()
     }
 
-    private fun notifyViewAppearTransitionEnd() {
+    private fun notifyViewTransitionEnd() {
         val screenStack = view?.parent
         if (screenStack is ScreenStack) {
-            screenStack.onViewAppearTransitionEnd()
+            screenStack.onViewTransitionEnd(coordinatorLayout)
         }
+
+        // Rely on guards inside the callee to detect whether this was indeed removal transition.
+        screen.endRemovalTransition()
     }
 
     /**

android/src/main/java/com/swmansion/rnscreens/gamma/tabs/host/TabsHost.kt

@@ -128,14 +128,17 @@ class TabsHost(
         @Suppress("SENSELESS_COMPARISON") // layoutCallback can be null here since this method can be called in init
         if (!isLayoutEnqueued && layoutCallback != null) {
             isLayoutEnqueued = true
-            // we use NATIVE_ANIMATED_MODULE choreographer queue because it allows us to catch the current
-            // looper loop instead of enqueueing the update in the next loop causing a one frame delay.
-            ReactChoreographer
-                .getInstance()
-                .postFrameCallback(
-                    ReactChoreographer.CallbackType.NATIVE_ANIMATED_MODULE,
-                    layoutCallback,
-                )
+            post {
+                layoutCallback.doFrame(0)
+            }
+//            // we use NATIVE_ANIMATED_MODULE choreographer queue because it allows us to catch the current
+//            // looper loop instead of enqueueing the update in the next loop causing a one frame delay.
+//            ReactChoreographer
+//                .getInstance()
+//                .postFrameCallback(
+//                    ReactChoreographer.CallbackType.NATIVE_ANIMATED_MODULE,
+//                    layoutCallback,
+//                )
         }
     }
 

android/src/main/java/com/swmansion/rnscreens/stack/views/ScreensCoordinatorLayout.kt

@@ -23,6 +23,9 @@ internal class ScreensCoordinatorLayout(
         PointerEventsBoxNoneImpl(),
     )
 
+    internal var blockFrameworkTransitionFinalization = false
+    internal var needsTransitionFinalization = false
+
     override fun onApplyWindowInsets(insets: WindowInsets?): WindowInsets = super.onApplyWindowInsets(insets)
 
     private val animationListener: Animation.AnimationListener =
@@ -32,7 +35,12 @@ internal class ScreensCoordinatorLayout(
             }
 
             override fun onAnimationEnd(animation: Animation) {
+                if (blockFrameworkTransitionFinalization) {
+                    blockFrameworkTransitionFinalization = false
+                    needsTransitionFinalization = true
+                }
                 fragment.onViewAnimationEnd()
+                needsTransitionFinalization = false
             }
 
             override fun onAnimationRepeat(animation: Animation) {}
@@ -50,6 +58,16 @@ internal class ScreensCoordinatorLayout(
         // We also add fakeAnimation to the set of animations, which sends the progress of animation
         val fakeAnimation = ScreensAnimation(fragment).apply { duration = animation.duration }
 
+        if (fragment.isRemoving) {
+            // This is a hack.
+            // We'll finalize the transition via our listener.
+            // We do it to prevent the framework from ending the transition prematurely,
+            // due to interaction between `FragmentAnim.EndViewTransitionAnimation` and
+            // `SafeAreaView` drawing blocking logic. For detailed description see:
+            // TODO LINK THE PR HERE
+            blockFrameworkTransitionFinalization = true
+        }
+
         if (animation is AnimationSet && !fragment.isRemoving) {
             animation
                 .apply {