[flutter_adaptive_scaffold] Fix some memory leaks [prod-leak-fix]

[ValentinVignal]

Fixes some memory leaks

See the documentation: https://github.com/dart-lang/leak_tracker/blob/main/doc%2Fleak_tracking%2FDETECT.md

Pre-launch Checklist

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• I read the Tree Hygiene page, which explains my responsibilities.
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• I signed the CLA.
• The title of the PR starts with the name of the package surrounded by square brackets, e.g. [shared_preferences]
• I linked to at least one issue that this PR fixes in the description above.
• I updated pubspec.yaml with an appropriate new version according to the pub versioning philosophy, or this PR is exempt from version changes.
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• I updated/added relevant documentation (doc comments with ///).
• I added new tests to check the change I am making, or this PR is test-exempt.
• All existing and new tests are passing.

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[flutter-dashboard]

It looks like this pull request may not have tests. Please make sure to add tests before merging. If you need an exemption, contact "@test-exemption-reviewer" in the #hackers channel in Discord (don't just cc them here, they won't see it!).

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[ValentinVignal]

cc @polina-c

[ValentinVignal]

More leaks must be fixed so we cannot yet activate leak testing on the package. I'd have 2 questions around that

1. This PR doesn't contain any test, the test would be to activate leak testing. Is this PR exempted from tests or is it better to activate leak testing the tests that got fix with experimentalLeakTesting: LeakTesting.settings.withTrackedAll(), ?
2. Here are some leaks that we cannot easily fix:
   

   packages/packages/flutter_adaptive_scaffold/lib/src/adaptive_scaffold.dart

   Lines 526 to 543 in 45c1997

   	/// Fade in animation.
   	static Widget fadeIn(Widget child, Animation<double> animation) {
   	return FadeTransition(
   	opacity: CurvedAnimation(parent: animation, curve: Curves.easeInCubic),
   	child: child,
   	);
   	}
   	/// Fade out animation.
   	static Widget fadeOut(Widget child, Animation<double> animation) {
   	return FadeTransition(
   	opacity: CurvedAnimation(
   	parent: ReverseAnimation(animation),
   	curve: Curves.easeInCubic,
   	),
   	child: child,
   	);
   	}

   
   Those static method create CurvedAnimations that never get disposed. They are then used in a build method:
   

   packages/packages/flutter_adaptive_scaffold/lib/src/adaptive_scaffold.dart

   Lines 700 to 707 in 45c1997

   	body: SlotLayout(
   	config: <Breakpoint, SlotLayoutConfig?>{
   	Breakpoints.standard: SlotLayout.from(
   	key: const Key('body'),
   	inAnimation: AdaptiveScaffold.fadeIn,
   	outAnimation: AdaptiveScaffold.fadeOut,
   	builder: widget.body,
   	),

How do you suggest with can fix them?

[ValentinVignal]

Any feedback on this @gspencergoog ?

[gspencergoog]

Thanks for the fixes!

[dkwingsmt]

LGTM

[Piinks]

LGTM thank you! It looks like there are some merge conflicts, can you take a look? After resolving those we can land this. 🎊

[ValentinVignal]

Sure I'll fix them

Do you have any suggestion on how to "fix" the static method (ex: fadeIn and fadeOut). They create CurvedAnimations that are not disposed.

Are we willing to do breaking changes? If not, what would be the best approach?

[ValentinVignal]

Oh never mind, I just saw the readme saying it is dis-continuated. Is it still worth spending effort on it?

[Piinks]

We can still land this change, I really appreciate your work on this. :)
To follow up on potential new forks/maintainers of this package see flutter/flutter#162965

[hanskokx]

We can still land this change, I really appreciate your work on this. :) To follow up on potential new forks/maintainers of this package see flutter/flutter#162965

I pulled these changes into my fork! Are there any other changes I might be missing that should also be pulled in?

[ValentinVignal]

@hanskokx there is no more changes to pull (from this PR at least).

However, the design of the package creates memory leaks and should be changed in my opinion.

Those memory leaks can be detected with leak_tracker https://github.com/dart-lang/leak_tracker/blob/main/doc%2Fleak_tracking%2FDETECT.md

Some detected memory leaks are from the CurvedAnimation that are never disposed:

packages/packages/flutter_adaptive_scaffold/lib/src/adaptive_scaffold.dart

Lines 526 to 543 in 45c1997

	/// Fade in animation.
	static Widget fadeIn(Widget child, Animation<double> animation) {
	return FadeTransition(
	opacity: CurvedAnimation(parent: animation, curve: Curves.easeInCubic),
	child: child,
	);
	}
	/// Fade out animation.
	static Widget fadeOut(Widget child, Animation<double> animation) {
	return FadeTransition(
	opacity: CurvedAnimation(
	parent: ReverseAnimation(animation),
	curve: Curves.easeInCubic,
	),
	child: child,
	);
	}

Those static methods create CurvedAnimations that never get disposed. They are then used in a build method:

packages/packages/flutter_adaptive_scaffold/lib/src/adaptive_scaffold.dart

Lines 700 to 707 in 45c1997

	body: SlotLayout(
	config: <Breakpoint, SlotLayoutConfig?>{
	Breakpoints.standard: SlotLayout.from(
	key: const Key('body'),
	inAnimation: AdaptiveScaffold.fadeIn,
	outAnimation: AdaptiveScaffold.fadeOut,
	builder: widget.body,
	),