From 582f5fa6eb7dc00333bffd4c4db254fda20b059f Mon Sep 17 00:00:00 2001
From: Martin Guillon <martin.guillon@akylas.fr>
Date: Fri, 7 Aug 2020 11:33:26 +0200
Subject: [PATCH] dont use replace transaction anymore.
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That way we dont “unload” and “load” fragments.
This fixes black screens and slow transitions with opengl or cameras

# Conflicts:
#	packages/core/ui/frame/fragment.transitions.android.ts
#	packages/core/ui/frame/frame-common.ts
#	packages/core/ui/frame/index.android.ts
---
 .../ui/frame/fragment.transitions.android.ts  |  3 +-
 packages/core/ui/frame/frame-common.ts        |  4 ---
 packages/core/ui/frame/index.android.ts       | 30 +++++++++++++++++--
 3 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/packages/core/ui/frame/fragment.transitions.android.ts b/packages/core/ui/frame/fragment.transitions.android.ts
index 83fe2dd1a..cea73620d 100644
--- a/packages/core/ui/frame/fragment.transitions.android.ts
+++ b/packages/core/ui/frame/fragment.transitions.android.ts
@@ -143,13 +143,12 @@ export function _setAndroidFragmentTransitions(animated: boolean, navigationTran
 		if (currentFragmentNeedsDifferentAnimation) {
 			setupCurrentFragmentFadeTransition(navigationTransition, currentEntry);
 		}
-	} else if (name === 'explode') {
+	} else if (name === 'explode') { 
 		setupNewFragmentExplodeTransition(navigationTransition, newEntry);
 		if (currentFragmentNeedsDifferentAnimation) {
 			setupCurrentFragmentExplodeTransition(navigationTransition, currentEntry);
 		}
 	} else if (name.indexOf('flip') === 0) {
-		navigationTransition = { duration: 3000, curve: null };
 		const direction = name.substr('flip'.length) || 'right'; //Extract the direction from the string
 		const flipTransition = new FlipTransition(direction, navigationTransition.duration, navigationTransition.curve);
 
diff --git a/packages/core/ui/frame/frame-common.ts b/packages/core/ui/frame/frame-common.ts
index e89038db2..f8b98e87e 100644
--- a/packages/core/ui/frame/frame-common.ts
+++ b/packages/core/ui/frame/frame-common.ts
@@ -296,10 +296,6 @@ export class FrameBase extends CustomLayoutView {
 	private raiseCurrentPageNavigatedEvents(isBack: boolean) {
 		const page = this.currentPage;
 		if (page) {
-			if (page.isLoaded) {
-				// Forward navigation does not remove page from frame so we raise unloaded manually.
-				page.callUnloaded();
-			}
 			page.onNavigatedFrom(isBack);
 		}
 	}
diff --git a/packages/core/ui/frame/index.android.ts b/packages/core/ui/frame/index.android.ts
index 91cd68408..40d1af199 100644
--- a/packages/core/ui/frame/index.android.ts
+++ b/packages/core/ui/frame/index.android.ts
@@ -324,6 +324,8 @@ export class Frame extends FrameBase {
 
 			// If we had real navigation process queue.
 			this._processNavigationQueue(entry.resolvedPage);
+
+
 		} else {
 			// Otherwise currentPage was recreated so this wasn't real navigation.
 			// Continue with next item in the queue.
@@ -436,7 +438,7 @@ export class Frame extends FrameBase {
 			//transaction.setTransition(androidx.fragment.app.FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
 		}
 
-		transaction.replace(this.containerViewId, newFragment, newFragmentTag);
+		transaction.add(this.containerViewId, newFragment, newFragmentTag);
 		transaction.commitAllowingStateLoss();
 	}
 
@@ -458,8 +460,30 @@ export class Frame extends FrameBase {
 
 		_reverseTransitions(backstackEntry, this._currentEntry);
 
-		transaction.replace(this.containerViewId, backstackEntry.fragment, backstackEntry.fragmentTag);
-
+		const currentIndex =this.backStack.length;
+		const gotBackToIndex = this.backStack.indexOf(backstackEntry);
+		
+		for (let index = gotBackToIndex + 1; index < currentIndex; index++) {
+			transaction.remove(this.backStack[index].fragment);
+		}
+		if (this._currentEntry !== backstackEntry) {
+			// if we are going back we need to store where we are backing to
+			// so that we can set the current entry
+			if ((this._currentEntry as any).exitTransitionListener) {
+				(this._currentEntry as any).exitTransitionListener.backEntry = backstackEntry;
+			}
+			if ((this._currentEntry as any).returnTransitionListener) {
+				(this._currentEntry as any).returnTransitionListener.backEntry = backstackEntry;
+			}
+			if ((this._currentEntry as any).enterTransitionListener) {
+				(this._currentEntry as any).enterTransitionListener.backEntry = backstackEntry;
+			}
+			if ((this._currentEntry as any).reenterTransitionListener) {
+				(this._currentEntry as any).reenterTransitionListener.backEntry = backstackEntry;
+			}
+			transaction.remove((this._currentEntry).fragment);
+			
+		}
 		transaction.commitAllowingStateLoss();
 	}