Previously when the user interacted with a status the operation (reblog,
favourite, etc) travels through multiple layers of code, carrying with
it the position of the item in the list that the user operated on.
At some point the status is retrieved from the list using its position
so that the correct status ID can be used in the network operation.
If this happens while the list is also refreshing there's a possible
race condition, and the original status' position may have changed in
the list. Looking up the status by position to determine which status to
perform the action on may cause the action to happen on the wrong
status.
Fix this by passing the status' viewdata to any actions instead of its
position. This includes all the information necessary to make the API
call, so there is no chance of a race.
This is quite an involved change because there are three types of
viewdata:
- `StatusViewData`, used for regular timelines
- `NotificationViewData`, used for notifications, may wrap a status that
can be operated on
- `ConversationViewData`, used for conversations, does wrap a status
The previous code treated them all differently, which is probably why it
operated by position instead of type.
The high level fix is to:
1. Create an interface, `IStatusViewData`, that contains the data
exposed by any viewdata that contains a status.
2. Implement the interface in `StatusViewData`, `NotificationViewData`,
and `ConversationViewData`.
3. Change the code that operates on viewdata (`SFragment`,
`StatusActionListener`, etc) to be generic over anything that implements
`IStatusViewData`.
4. Change the code that handles actions to pass the viewdata instead of
the position.
Fixes#370
fc81e8bad7