Remapping Hardware Macro Keys In Kanata: A Feature Request

Have you ever encountered a keyboard with hardcoded macro keys that you just can't remap? It's a frustrating problem, especially when those keys are essential to your workflow. In this article, we'll explore a feature request for Kanata, a powerful keyboard remapping tool, that aims to solve this issue by allowing users to consume hardware macro keys and convert them into regular, usable keys. This is a game-changer for anyone stuck with keyboards that have unreprogrammable macro functions.

The Problem: Unusable Hardware Macro Keys

Many keyboards, particularly those designed for media consumption or specific applications, come with pre-programmed macro keys. While these keys can be useful in some situations, they often become a hindrance when they can't be customized to fit your needs. Imagine having a set of keys that trigger specific actions, but you can't change them, and they interfere with your preferred shortcuts or workflows. This is the exact problem that prompted the feature request we're discussing today.

Take the Logitech K400+ keyboard, for instance. It's a popular choice for living room media PC setups due to its integrated trackpad and wireless connectivity. However, four of its physical keys are effectively unusable because they generate hardcoded macros:

• F3: LAlt+Tab
• F6: LGui+D
• F7: LGui+Up
• F8: LGui+P

These keys, while potentially useful for some, can be a major annoyance if you have different plans for them. For users like jtroo, who initiated this feature request, these keys are so disruptive that they've resorted to putting tape over them as a constant reminder not to press them. This highlights a significant usability issue that a software-based remapping solution could address effectively. The core of the problem is the inflexibility of these hardware macros. They are baked into the keyboard's firmware, making them inaccessible to standard remapping tools. This is where a more sophisticated solution, like the one proposed for Kanata, becomes essential.

Proposed Solution: Detecting and Transforming Macro Sequences

The proposed solution involves a clever approach: detecting the event sequences generated by these macro keys and transforming them into something resembling a normal key press. This would allow users to remap these previously unusable keys to functions that better suit their needs. The idea is to identify specific sequences of key presses and releases that constitute a macro and then convert them into a single, remappable event.

Here's a conceptual configuration example in Lisp, the language Kanata uses for its configuration:

(defvar
  ;; how long (in ms) a srcmacro can take to be emitted from the input device
  srcmacro-timeout 10
)
(defsrcmacros
  ;; a "+" suffix is a key-pressed event, "-" suffix is a key-release event
  kf3 (lalt+ tab+ tab- lalt-)
  kf6 (lmet+ d+ d- lmet-)
  kf7 (lmet+ up+ up- lmet-)
  kf8 (lmet+ p+ p- lmet-)
)

In this configuration, defsrcmacros defines custom macros based on specific key sequences. For example, kf3 is defined as the sequence