TTY Interface

Provides simple TTY-based user interface capabilities including partial re-renders of multi-line displays. Uses Termion for basic TTY terminal interactions, though consumers of TTY Interface need not depend on Termion directly themselves; TTY Interface will accept and output to any Write writer.

Overview

Fundamentally, this crate introduces a data structure and API for describing and interacting with a terminal-based user interface. This allows for partial/differential updates and an abstraction away from having to arrange ANSI escape sequences for cursor movement, line clearing, etc.

To accomplish this, a terminal interface is broken into lines with each line containing a number of segments. This allows for differential updates defined to the level of a segment within a line, with the specificity/scope of that segment being left to the user. Larger segments mean more of the screen must be cleared/re-written to make an update, smaller segments may require more complexity for the user to manage.

Updates to the interface are performed in batches. A batch contains a list of staged changes (referred to as "steps") which can then be applied to the terminal at the user's discretion. The steps described by a batch are applied in the order they're staged, and it is up to the user how many changes are included in a batch, while bearing in mind there are some operations performed automatically for every batch (e.g. cursor restoration and writer flushing).