Frequent, consistent Garbage Collection in Android Studio Profiler (Memory) is not good.
CoordinatorLayout leaked does not necessarily mean that you should look into the XML code of CoordinatorLayout. Refer to the The Sandbox: LeakCanary - YouTube to see how to read such leak trace.
At times, when using the Android Studio profiler (memory), you may want to disable or comment out LeakCanary dependency from your build gradle file. (Not necessarily).
Different Types of Memory Leak and Reference
The list is not exhaustive.
Note, not all code is tested. But helpful references.
(Draft)
Setup
Getting Started - LeakCanary
Tutorial
Practical demonstration of identifying Memory Leaks in Mozilla Firefox (Fenix on GitHub)
Shows how to read the "leak trace", how to identify memory leaks.
The Sandbox: LeakCanary - YouTube
General info and what's new in LeakCanary 2
Ask the Expert #2: LeakCanary 2.x is out, track your memory leaks - YouTube
Tools
The Android Profiler | Android Developers - Only Memory section of Profiler is relevant.
LeakCanary
Code
Reproducible Sample of Memory Leak
Run the app in Android Studio.
maxkohne/Android-Memory-Leaks: This is an example of how memory leaks happen with fragments in Android. It also has a solution to the problem.
Notes
Frequent, consistent Garbage Collection in Android Studio Profiler (Memory) is not good.
CoordinatorLayout leaked does not necessarily mean that you should look into the XML code of CoordinatorLayout. Refer to the The Sandbox: LeakCanary - YouTube to see how to read such leak trace.
At times, when using the Android Studio profiler (memory), you may want to disable or comment out LeakCanary dependency from your build gradle file. (Not necessarily).
Different Types of Memory Leak and Reference
The list is not exhaustive.
Note, not all code is tested. But helpful references.
RecyclerView adapter null
fenix/AddonsManagementFragment.kt at 7070bb5607f5ac9fd0825ab21e7abba675f98bdc · mozilla-mobile/fenix
How to Fix Memory Leak in RecyclerView (LeakCanary) - YouTube
AlertDialog Memory Leak
florisboard/TypingFragment.kt at 9a146ba2f0040e8cf1652cd21dd358268cda3759 · florisboard/florisboard
android - Leak Canary detects memory leaks for TabLayout with ViewPager2 - Stack Overflow
Using backing field pattern (when necessary)
The Sandbox: LeakCanary - YouTube
Need to close actionMode if contextual actionMode is showing.
food-recipes/FavoriteRecipesFragment.kt at 3a66c9b796d99cd5926f7743f2699c470d5acbb4 · ZattWine/food-recipes
setOnRefreshListener null
SkateShare/FeedFragment.kt at ab2d4499b841b6c8cb6ea2f3d261570e8f05b336 · avhagedorn/SkateShare
searchView.setOnQueryTextListener(null)
GreedyNewsApp/NewsFragment.kt at e3b290a07d53d83a5b5a8dd5fb60e9a6fcf8bd04 · ShobhitCoder/GreedyNewsApp
drawerHelper.removeDrawerListener(listener)
Tv/MeFragment.kt at 3c22f2baad651c3df53b3615fd6fc28263621a42 · bytebyte6/Tv
Dismiss Dialog (set to null) and Input Method Manager
NfcDemo/MainActivity.kt at 2cce6dc82fddc18c1c00aa04cdee25b300ecb77a · ewgcat/NfcDemo
viewpager2
ViewPager2 internally uses RecyclerView I think, so use the same technique to prevent memory leaks as you would use for RecyclerView adapter.
ViewPager2 holds on to FragmentStateAdapter after detach [151212195] - Visible to Public - Issue Tracker
NavigationComponents-Tutorials/ViewPagerContainerFragment.kt at c2fcaf175fbd99183d424d1281a47275e1101f85 · SmartToolFactory/NavigationComponents-Tutorials
Do it before super.onDestroyView (!?)
Not sure if before or after nulling the view is preferred. People do either ways.
architecture-components-samples/InflateFragment.kt at main · android/architecture-components-samples
Avoid references to the Fragment's Views after onDestroyView() by ianhanniballake · Pull Request #785 · android/architecture-components-samples