fix(android): nested frames were sometimes not recreated (#9725)

BREAKING CHANGE:

AndroidFragmentCallbacks now requires onResume as well

Migration steps:
specify onResume on custom fragment implementations

packages/core/ui/frame/fragment.android.ts

@@ -19,6 +19,10 @@ const FragmentClass = (<any>org.nativescript.widgets.FragmentBase).extend('com.t
 		this._callbacks.onPause(this, superProto.onPause);
 	},
 
+	onResume(): void {
+		this._callbacks.onResume(this, superProto.onResume);
+	},
+
 	onCreate(savedInstanceState: android.os.Bundle) {
 		if (!this._callbacks) {
 			setFragmentCallbacks(this);

packages/core/ui/frame/fragment.transitions.android.ts

@@ -51,6 +51,7 @@ export interface ExpandedEntry extends BackstackEntry {
 	frameId: number;
 
 	isNestedDefaultTransition: boolean;
+	isAnimationRunning: boolean;
 }
 
 export function _setAndroidFragmentTransitions(animated: boolean, navigationTransition: NavigationTransition, currentEntry: ExpandedEntry, newEntry: ExpandedEntry, frameId: number, fragmentTransaction: androidx.fragment.app.FragmentTransaction, isNestedDefaultTransition?: boolean): void {
@@ -60,6 +61,7 @@ export function _setAndroidFragmentTransitions(animated: boolean, navigationTran
 	if (entries && entries.size > 0) {
 		throw new Error('Calling navigation before previous navigation finish.');
 	}
+	newEntry.isAnimationRunning = false;
 
 	allowTransitionOverlap(currentFragment);
 	allowTransitionOverlap(newFragment);
@@ -227,6 +229,7 @@ function getAnimationListener(): android.animation.Animator.AnimatorListener {
 				if (Trace.isEnabled()) {
 					Trace.write(`START ${animator.transitionType} for ${entry.fragmentTag}`, Trace.categories.Transition);
 				}
+				entry.isAnimationRunning = true;
 			}
 
 			onAnimationRepeat(animator: ExpandedAnimator): void {
@@ -239,6 +242,7 @@ function getAnimationListener(): android.animation.Animator.AnimatorListener {
 				if (Trace.isEnabled()) {
 					Trace.write(`END ${animator.transitionType} for ${animator.entry.fragmentTag}`, Trace.categories.Transition);
 				}
+				animator.entry.isAnimationRunning = false;
 				transitionOrAnimationCompleted(animator.entry, animator.backEntry);
 			}
 
@@ -246,6 +250,7 @@ function getAnimationListener(): android.animation.Animator.AnimatorListener {
 				if (Trace.isEnabled()) {
 					Trace.write(`CANCEL ${animator.transitionType} for ${animator.entry.fragmentTag}`, Trace.categories.Transition);
 				}
+				animator.entry.isAnimationRunning = false;
 			}
 		}
 

packages/core/ui/frame/index.android.ts

@@ -237,6 +237,21 @@ export class Frame extends FrameBase {
 			this.backgroundColor = this._originalBackground;
 			this._originalBackground = null;
 		}
+		setTimeout(() => {
+			// there's a bug with nested frames where sometimes the nested fragment is not recreated at all
+			// so we manually check on loaded event if the fragment is not recreated and recreate it
+			const currentEntry = this._currentEntry || this._executingContext?.entry;
+			if (currentEntry) {
+				if (!currentEntry.fragment) {
+					const manager = this._getFragmentManager();
+					const transaction = manager.beginTransaction();
+					currentEntry.fragment = this.createFragment(currentEntry, currentEntry.fragmentTag);
+					_updateTransitions(currentEntry);
+					transaction.replace(this.containerViewId, currentEntry.fragment, currentEntry.fragmentTag);
+					transaction.commitAllowingStateLoss();
+				}
+			}
+		}, 0);
 
 		super.onLoaded();
 	}
@@ -1002,6 +1017,19 @@ class FragmentCallbacksImplementation implements AndroidFragmentCallbacks {
 		}
 	}
 
+	@profile
+	public onResume(fragment: org.nativescript.widgets.FragmentBase, superFunc: Function): void {
+		const frame = this.entry.resolvedPage.frame;
+		// on some cases during the first navigation on nested frames the animation doesn't trigger
+		// we depend on the animation (even None animation) to set the entry as the current entry
+		// animation should start between start and resume, so if we have an executing navigation here it probably means the animation was skipped
+		// so we manually set the entry
+		if (frame._executingContext && !(<any>this.entry).isAnimationRunning) {
+			frame.setCurrent(this.entry, frame._executingContext.navigationType);
+		}
+		superFunc.call(fragment);
+	}
+
 	@profile
 	public onStop(fragment: androidx.fragment.app.Fragment, superFunc: Function): void {
 		superFunc.call(fragment);

packages/core/ui/frame/index.d.ts

@@ -476,6 +476,7 @@ export interface AndroidFragmentCallbacks {
 	onDestroyView(fragment: any, superFunc: Function): void;
 	onDestroy(fragment: any, superFunc: Function): void;
 	onPause(fragment: any, superFunc: Function): void;
+	onResume(fragment: any, superFunc: Function): void;
 	onStop(fragment: any, superFunc: Function): void;
 	toStringOverride(fragment: any, superFunc: Function): string;
 }