Prevent re-rendering of account sidebar when switching account

[Simon-Laux]

Closes #3776

Alternative to #3787 (which showed caching issues when switching accounts)

The only thing that is a bit annoying in terms of flickering now are the gallery tabs (when the experimental feature location streaming is enabled), though that is only minor, we could solve that by splitting the setting store up in one that caches account setting and another one that caches config.json/DesktopSettings, the latter stores the experimental option for location streaming and does not need to be reloaded everytime the account id changes.

[adzialocha]

This might cause the chat state to be temporarily invalid, right? I can see how switching the account id will not reset the chat id to undefined, leaving the chat state with an chat not matching the account. Probably most components do not see that invalid state because they are too slow, but it might be a bug cause for the future. Ideally we would call unselectChat whenever we unselect an account (similar to how I did it in my other PR #3787)

[Simon-Laux]

I used a ref instead of refactoring and moving the component up.

[WofWca]

Ehh, looks a little fragile. We reset all state of ChatProvider with unselectChat, but <ContextMenuProvider>, <DialogContextProvider> etc also have their state that could become invalid, don't they?

[WofWca]

Maybe just keeping the scroll position is good enough for now? With getSnapshotBeforeUpdate

Though if you're sure it's all good, I won't insist. I'm just voicing my thoughts.

[farooqkz]

What does this mean here? Looks weird to me :)

[WofWca]

The function is set from inside ChatContext. Read it as chatContext.unselectChat()

[adzialocha]

An alternative to doing it like that is to introduce the unselectChat as a prop to the classic class-style React component:

https://github.com/deltachat/deltachat-desktop/blob/adz/i3776-fix-rerendering/src/renderer/ScreenController.tsx#L330-L337

[Simon-Laux]

<ContextMenuProvider>, <DialogContextProvider> etc also have their state that could become invalid, don't they?

I guess yes in theory: a dialog like settings could still be open when you switch account from a notification that was for another account.

Maybe just keeping the scroll position is good enough for now? With getSnapshotBeforeUpdate

no, because:

1. the sidebar is a functional component not a class component
2. the react "key" hack forces complete re-rendering, so this won't help as the component does not exist anymore
3. it would still flicker which is annoying.

[Simon-Laux]

The only way to switch accounts without clicking in the interface (which means no context menu / dialog can be open at the same time), is to click on a notification that is for another account (I just added a commit to close all dialogs in that case).

(At least to according to my current knowledge.)