Module libnoentiendo::keyboard

Various representations of keyboard scancodes are required in different parts of the codebase. Each platform typically has its own definition of a scancode (e.g. JavaScript’s event.code or Winit’s VirtualKeyCode), and each emulated system has a different set of keys (e.g. the Commodore key on the VIC-20 or the standalone " key on the PET).

Utilities for handling keyboard input are defined in the keyboard module. This module defines a keyboard::KeyPosition enum to represent the physical keys which appear on a modern host keyboard and a keyboard::KeySymbol enum to represent the symbols which can be typed with a modern host keyboard. It also defines a keyboard::KeyState<T> struct to represent the set of currently-pressed keys in some representation T.

Mapping between different keyboard representations is handled using keyboard::KeyAdapter<F, T> implementations. These exist for four different scenarios:

• Mapping from platform-specific scancodes to the common keyboard::KeyPosition representation
• Mapping from keyboard::KeyPosition to system-specific scancodes, using a one-to-one “physical” mapping strategy
• Mapping from keyboard::KeyPosition to keyboard::KeySymbol, respecting the currently-pressed modifier keys
• Mapping from keyboard::KeySymbol to system-specific scancodes, to preserve the symbols that the user pressed even if it requires rewriting the currently-pressed modifier keys

Modules

• commodore
  Keys and adapters for the Commodore 64, VIC-20, and other Commodore machines.

Structs

• KeyState
  A set of keys that are currently pressed. Parameter T is the type of the key symbols.
• SymbolAdapter
  An adapter that maps physical key positions to symbols.

Enums

• KeyMappingStrategy
  Represents different approaches to mapping key states, to allow the user to indicate their preference.
• KeyPosition
  A representation for a position on a modern keyboard. Source: https://en.wikipedia.org/wiki/Keyboard_layout#/media/File:Qwerty.svg
• KeySymbol
  A representation for a symbol on a modern keyboard.
• VirtualKey

Traits

• KeyAdapter
  Represents a mapping from a key state of one type to a key state of another type. Mappings can be symbolic (preserve symbols across the mapping, and rewrite modifier keys as needed) or physical (maintain a one-to-one mapping from physical keys to physical keys).