Compress activity stack for duplicate/similar activities #1852
Description
The Flutter app has the same problem as the legacy app when it comes to handling new activities, e.g. from notifications: duplicate activities (and what are effectively duplicates for being similar enough) are retained, so going back in the stack can result in going through lots of similar-looking screens for as many times as you added to the stack. This is not good UX, especially if the user just wants to get back to the main app view or to a previous topic they were in.
For example: Let's say you go from a topic to talking to a user in DMs, and this flow happens:
- You switch apps and do something else.
- Tap a notification from the user sending you a message.
- Repeat steps 1-2 a few times.
- You now want to go back to the topic you were at previously. But pressing the back arrow or using Android navigation to go back, appears to do nothing, and shows the user's DMs again. This happens for as many times as you repeated 1-2.
I propose that the last activity on the stack be removed when adding a new activity, when it is in the same scope (i.e. same topic or DM) and is identical to or within the same few messages as the last activity. A scope without a narrow should consider the last sent message [when the view was active?] when comparing message position. Scroll position [or the nearest message to the top of the scrolled view] could also be used, since you can scroll away from the narrow, and that position is saved in the stack.
I also propose the existing hamburger menu button (bottom right of main page) be added to the top bar in message views, either behind the back button or to the opposite side—if you get deep in the activity stack, you have to go back a lot to get back to the main page to pick somewhere else to navigate to. This is a regression from the old app where the menu button was available in most views.