If you re wondering why I ask this in a kotlin related chann

Question

If you re wondering why I ask this in a kotlin related channel it is because I see multiple examples where people use `lazy` or `lateinit` which will retain the instances The same goes for views unless you use synthetics which in itself is a bit hacky imo

ghedeon · Answer

Why would you go an extra mile to mess with adapter instance instead of letting the GC to do its work It s a field probably lateinit in the fragment like many others It will go once the fragment is destroyed Do you face any particular issues with that

Fredrik Larsen · Answer

Because the fragment is not destroyed Only the view When you navigate and put the fragment in the backstack it s retained Meaning GC will not collect the adapter

ghedeon · Answer

yes that s how it should be

ghedeon · Answer

also adapter doesn t keep views only items

Fredrik Larsen · Answer

So you re saying the recyclerview adapter will not retain the viewholders

Fredrik Larsen · Answer

In that case you re right there is no need to manually release recreate the adapter

ghedeon · Answer

adapter is kind of a viewmodel for the view recycler Normally you don t clean the model when the view is destroyed

ghedeon · Answer

Holders are kept in the RecyclerView not in the adapter

Fredrik Larsen · Answer

That s true Thank you for clearing that up

Fredrik Larsen · Answer

On a similar note though If I did not use synthetics but rather ``` lateinit var recyclerView RecyclerView ``` then I would be retaining that view even after `onDestroyView `

Fredrik Larsen · Answer

which in the case with recyclerViews full of images would retain a lot of memory

Fredrik Larsen · Answer

I didn t phrase that as a question but I do wonder how other deal with that use case

Fredrik Larsen · Answer

Apart from the obvious making it nullable and setting it to null in `onDestroyView `

ghedeon · Answer

yes you d need to set it to null manually Or call `unbind ` from ButterKnife Or just use synthetics it s so simple I can t see myself going back smirk

Sam · Answer

< Fredrik Larsen> I had similar issues I don t use members to keep a reference to views anymore

Sam · Answer

Also when in doubt just enable leak canary fragments that will give you a hint when there is a leak

Sam · Answer

Optional if you use support library fragments debugImplementation com squareup leakcanary leakcanary support fragment 1 6 3

Fredrik Larsen · Answer

I did some more digging and ViewHolders are retained by the LayoutManager så destroying the recyclerview doesn t release them You need to destroy the LayoutManager as well

Fredrik Larsen · Answer

In other words if you add a lot of fragments to the backstack navigation and you deal with many images then this essentially a memory leak ``` private lateinit var layoutManager RecyclerView LayoutManager ```

ghedeon · Answer

I don t think any of discussed cases qualify as proper leaks once the fragment is gone it will go as well But yes if you keep it in a field then it won t be released onDestroyView Thus if you don t nullify your references you retain views longer than you d want

Fredrik Larsen · Answer

It s nice to be aware of it as memory builds up But I agree not a leak per say