# Layouts: Using a Keymap with Multiple Keyboards The `layouts/` folder contains different physical key layouts that can apply to different keyboards. ``` layouts/ + default/ | + 60_ansi/ | | + readme.md | | + layout.json | | + a_good_keymap/ | | | + keymap.c | | | + readme.md | | | + config.h | | | + rules.mk | | + <keymap folder>/ | | + ... | + <layout folder>/ + community/ | + <layout folder>/ | + ... ``` The `layouts/default/` and `layouts/community/` are two examples of layout "repositories" - currently `default` will contain all of the information concerning the layout, and one default keymap named `default_<layout>`, for users to use as a reference. `community` contains all of the community keymaps, with the eventual goal of being split-off into a separate repo for users to clone into `layouts/`. QMK searches through all folders in `layouts/`, so it's possible to have multiple repositories here. Each layout folder is named (`[a-z0-9_]`) after the physical aspects of the layout, in the most generic way possible, and contains a `readme.md` with the layout to be defined by the keyboard: ```md # 60_ansi LAYOUT_60_ansi ``` New names should try to stick to the standards set by existing layouts, and can be discussed in the PR/Issue. ## Supporting a Layout For a keyboard to support a layout, the variable must be defined in it's `<keyboard>.h`, and match the number of arguments/keys (and preferably the physical layout): #define LAYOUT_60_ansi KEYMAP_ANSI The name of the layout must match this regex: `[a-z0-9_]+` The folder name must be added to the keyboard's `rules.mk`: LAYOUTS = 60_ansi `LAYOUTS` can be set in any keyboard folder level's `rules.mk`: LAYOUTS = 60_iso but the `LAYOUT_<layout>` variable must be defined in `<folder>.h` as well. ## Tips for Making Layouts Keyboard-Agnostic ### Includes Instead of using `#include "planck.h"`, you can use this line to include whatever `<keyboard>.h` (`<folder>.h` should not be included here) file that is being compiled: #include QMK_KEYBOARD_H If you want to keep some keyboard-specific code, you can use these variables to escape it with an `#ifdef` statement: * `KEYBOARD_<folder1>_<folder2>` For example: ```c #ifdef KEYBOARD_planck #ifdef KEYBOARD_planck_rev4 planck_rev4_function(); #endif #endif ``` Note that the names are lowercase and match the folder/file names for the keyboard/revision exactly. ### Keymaps In order to support both split and non-split keyboards with the same layout, you need to use the keyboard agnostic `LAYOUT_<layout name>` macro in your keymap. For instance, in order for a Let's Split and Planck to share the same layout file, you need to use `LAYOUT_ortho_4x12` instead of `LAYOUT_planck_grid` or just `{}` for a C array.