# Swap-Hands Action | QMK Firmware
Documentation for QMK Firmware

Skip to content

# Swap-Hands Action ​

The swap-hands action allows support for one-handed typing without requiring a separate layer. Set `SWAP_HANDS_ENABLE = yes` in your keymap's `rules.mk` (creating it if needed), and define a `hand_swap_config` entry in your keymap. Now whenever the `ACTION_SWAP_HANDS` command key is pressed the keyboard is mirrored. For instance, to type "Hello, World" on QWERTY you would type `^Ge^s^s^w^c W^wr^sd`

## Configuration ​

The configuration table is a simple 2-dimensional array to map from column/row to new column/row. Example `hand_swap_config` for Planck:

c

    const keypos_t PROGMEM hand_swap_config[MATRIX_ROWS][MATRIX_COLS] = {
      {{11, 0}, {10, 0}, {9, 0}, {8, 0}, {7, 0}, {6, 0}, {5, 0}, {4, 0}, {3, 0}, {2, 0}, {1, 0}, {0, 0}},
      {{11, 1}, {10, 1}, {9, 1}, {8, 1}, {7, 1}, {6, 1}, {5, 1}, {4, 1}, {3, 1}, {2, 1}, {1, 1}, {0, 1}},
      {{11, 2}, {10, 2}, {9, 2}, {8, 2}, {7, 2}, {6, 2}, {5, 2}, {4, 2}, {3, 2}, {2, 2}, {1, 2}, {0, 2}},
      {{11, 3}, {10, 3}, {9, 3}, {8, 3}, {7, 3}, {6, 3}, {5, 3}, {4, 3}, {3, 3}, {2, 3}, {1, 3}, {0, 3}},
    };

Note that the array indices are reversed same as the matrix and the values are of type `keypos_t` which is `{col, row}` and all values are zero-based. In the example above, `hand_swap_config[2][4]` (third row, fifth column) would return `{7, 2}` (third row, eighth column). Yes, this is confusing.

## Swap Keycodes ​

Key | Aliases | Description
--- | --- | ---
`SH_T(kc)` |  | Momentary swap when held, `kc` when tapped
`QK_SWAP_HANDS_ON` | `SH_ON` | Turn on hand swap
`QK_SWAP_HANDS_OFF` | `SH_OFF` | Turn off hand swap
`QK_SWAP_HANDS_MOMENTARY_ON` | `SH_MON` | Turn on hand swap while held
`QK_SWAP_HANDS_MOMENTARY_OFF` | `SH_MOFF` | Turn off hand swap while held
`QK_SWAP_HANDS_TOGGLE` | `SH_TOGG` | Toggle hand swap
`QK_SWAP_HANDS_TAP_TOGGLE` | `SH_TT` | Momentary swap when held, toggle when tapped
`QK_SWAP_HANDS_ONE_SHOT` | `SH_OS` | Turn on hand swap while held or until next key press

`SH_TT` swap-hands tap-toggle key is similar to layer tap-toggle. Tapping repeatedly (5 taps by default) will toggle swap-hands on or off, like `SH_TOGG`. Tap-toggle count can be changed by defining a value for `TAPPING_TOGGLE`.

## Encoder Mapping ​

When using an encoder mapping, it's also able to handle swapping encoders between sides, too.

Encoder indexes are defined as left-to-right, and the extent of the array needs to match the number of encoders on the keyboard.

As an example, if a split keyboard has a single encoder per side, you can swap the order by using the following code in your keymap:

c

    #if defined(SWAP_HANDS_ENABLE) && defined(ENCODER_MAP_ENABLE)
    const uint8_t PROGMEM encoder_hand_swap_config[NUM_ENCODERS] = { 1, 0 };
    #endif

### Functions ​

User callback functions to manipulate Swap-Hands:

Function | Description
--- | ---
`swap_hands_on()` | Turns Swap-Hands on.
`swap_hands_off()` | Turns Swap-Hands off.
`swap_hands_toggle()` | Toggles Swap-Hands.
`is_swap_hands_on()` | Returns true if Swap-Hands is currently on.