Extract and re-use details screen starting code. #589

[lemonboston]

No description provided.

[dmfs]

The interface looks quite generic. Why not just call it after something that can launch any activity? I mean, how would the same interface for the task editor?

[lemonboston]

You're right, this can be more generic. How about something like this?:

interface Showable<C extends Context>
{
    void show(C context);
}

It could represent a 'meaningful' UI of the app that can be shown. By 'meaningful' I mean that it represents a use-case, like 'details of the task', or like a 'permission request dialog'. Something that makes sense on its own and may be fired/shown independently of the place(s) where it is used.

The followings could be covered by this for example:

• opening a new screen by starting an Activity (C as Context)
• showing a DialogFragment (C as Activity to call getFragmentManager())
• showing a Toast (C as Context)
• showing a SnackBar (using findViewById(..content) (C as Activity)
• showing a Notification (using activity.getSystemService(NotificationManager).notify(n)) (C as Context)

Fragment transactions would not be included. (Except for DialogFragment)

Of course we wouldn't need to actually start to use it everywhere, I mentioned them just for the concept.
Let me know if you think that interface makes sense, I would update the code in this PR in that case.

[lemonboston]

I've updated this with using that Showable interface, and squashed and rebased.

I also noticed however that there are 5 more places in the codebase where Intents are created with Intent.ACTION_VIEW, so those should probably be reviewed as well. But that leads to questions on how we should generally handle these Intents and extras.
So now I am not sure that the changes in this pull request makes sense to merge, it introduces something new in that matter which may be inconsistent with usage elsewhere.

More specifically, we could create Single<Intent>s but I am not sure if that's good. Also, the Box solution (with Keys and Argument) could also effect how it is good to approach this.

It probably makes sense to put this on hold, and discuss it before proceeding.