# Switching and Toggling Layers
-These functions allow you to activate layers in various ways. Note that layers are not generally independent layouts -- multiple layers can be activated at once, and it's typical for layers to use `KC_TRNS` to allow keypresses to pass through to lower layers. For a detailed explanation of layers, see [Keymap Overview](keymap.md#keymap-and-layers)
+These functions allow you to activate layers in various ways. Note that layers are not generally independent layouts -- multiple layers can be activated at once, and it's typical for layers to use `KC_TRNS` to allow keypresses to pass through to lower layers. For a detailed explanation of layers, see [Keymap Overview](keymap.md#keymap-and-layers) When using momentary layer switching with MO(), LM(), TT(), or LT(), make sure to leave the key on the above layers transparent or it may not work as intended.
* `DF(layer)` - switches the default layer. The default layer is the always-active base layer that other layers stack on top of. See below for more about the default layer. This might be used to switch from QWERTY to Dvorak layout. (Note that this is a temporary switch that only persists until the keyboard loses power. To modify the default layer in a persistent way requires deeper customization, such as calling the `set_single_persistent_default_layer` function inside of [process_record_user](custom_quantum_functions.md#programming-the-behavior-of-any-keycode).)
* `MO(layer)` - momentarily activates *layer*. As soon as you let go of the key, the layer is deactivated.
-* `LM(layer, mod)` - Momentarily activates *layer* (like `MO`), but with modifier(s) *mod* active. Only supports layers 0-15 and the left modifiers.
+* `LM(layer, mod)` - Momentarily activates *layer* (like `MO`), but with modifier(s) *mod* active. Only supports layers 0-15 and the left modifiers: `MOD_LCTL`, `MOD_LSFT`, `MOD_LALT`, `MOD_LGUI` (note the use of `MOD_` constants instead of `KC_`). These modifiers can be combined using bitwise OR, e.g. `LM(_RAISE, MOD_LCTL | MOD_LALT)`.
* `LT(layer, kc)` - momentarily activates *layer* when held, and sends *kc* when tapped. Only supports layers 0-15.
* `OSL(layer)` - momentarily activates *layer* until the next key is pressed. See [One Shot Keys](#one-shot-keys) for details and additional functionality.
* `TG(layer)` - toggles *layer*, activating it if it's inactive and vice versa
For convenience, QMK includes some Mod-Tap shortcuts to make common combinations more compact in your keymap:
-|Key |Aliases |Description |
-|------------|---------------------------------------|-------------------------------------------------------|
-|`LCTL_T(kc)`|`CTL_T(kc)` |Left Control when held, `kc` when tapped |
-|`RCTL_T(kc)`| |Right Control when held, `kc` when tapped |
-|`LSFT_T(kc)`|`SFT_T(kc)` |Left Shift when held, `kc` when tapped |
-|`RSFT_T(kc)`| |Right Shift when held, `kc` when tapped |
-|`LALT_T(kc)`|`ALT_T(kc)` |Left Alt when held, `kc` when tapped |
-|`RALT_T(kc)`|`ALGR_T(kc)` |Right Alt when held, `kc` when tapped |
-|`LGUI_T(kc)`|`LCMD_T(kc)`, `RWIN_T(kc)`, `GUI_T(kc)`|Left GUI when held, `kc` when tapped |
-|`RGUI_T(kc)`|`RCMD_T(kc)`, `RWIN_T(kc)` |Right GUI when held, `kc` when tapped |
-|`C_S_T(kc)` | |Left Control and Shift when held, `kc` when tapped |
-|`MEH_T(kc)` | |Left Control, Shift and Alt when held, `kc` when tapped|
-|`LCAG_T(kc)`| |Left Control, Alt and GUI when held, `kc` when tapped |
-|`RCAG_T(kc)`| |Right Control, Alt and GUI when held, `kc` when tapped |
-|`ALL_T(kc)` | |Left Control, Shift, Alt and GUI when held, `kc` when tapped - more info [here](http://brettterpstra.com/2012/12/08/a-useful-caps-lock-key/)|
-|`SGUI_T(kc)`|`SCMD_T(kc)`, `SWIN_T(kc)` |Left Shift and GUI when held, `kc` when tapped |
-|`LCA_T(kc)` | |Left Control and Alt when held, `kc` when tapped |
+|Key |Aliases |Description |
+|------------|-----------------------------------------------------------------|-------------------------------------------------------|
+|`LCTL_T(kc)`|`CTL_T(kc)` |Left Control when held, `kc` when tapped |
+|`RCTL_T(kc)`| |Right Control when held, `kc` when tapped |
+|`LSFT_T(kc)`|`SFT_T(kc)` |Left Shift when held, `kc` when tapped |
+|`RSFT_T(kc)`| |Right Shift when held, `kc` when tapped |
+|`LALT_T(kc)`|`ALT_T(kc)` |Left Alt when held, `kc` when tapped |
+|`RALT_T(kc)`|`ALGR_T(kc)` |Right Alt when held, `kc` when tapped |
+|`LGUI_T(kc)`|`LCMD_T(kc)`, `LWIN_T(kc)`, `GUI_T(kc)`, `CMD_T(kc)`, `WIN_T(kc)`|Left GUI when held, `kc` when tapped |
+|`RGUI_T(kc)`|`RCMD_T(kc)`, `RWIN_T(kc)` |Right GUI when held, `kc` when tapped |
+|`C_S_T(kc)` | |Left Control and Shift when held, `kc` when tapped |
+|`MEH_T(kc)` | |Left Control, Shift and Alt when held, `kc` when tapped|
+|`LCAG_T(kc)`| |Left Control, Alt and GUI when held, `kc` when tapped |
+|`RCAG_T(kc)`| |Right Control, Alt and GUI when held, `kc` when tapped |
+|`HYPR_T(kc)`|`ALL_T(kc)` |Left Control, Shift, Alt and GUI when held, `kc` when tapped - more info [here](http://brettterpstra.com/2012/12/08/a-useful-caps-lock-key/)|
+|`SGUI_T(kc)`|`SCMD_T(kc)`, `SWIN_T(kc)` |Left Shift and GUI when held, `kc` when tapped |
+|`LCA_T(kc)` | |Left Control and Alt when held, `kc` when tapped |
## Caveats
projects / qmk_firmware.git / blobdiff