milestone

22 Nov 2020

Last night / this morning I read a lot about how QMK works with layers. Then I worked up keymaps for both the Butterstick and the Georgi!
The first milestone is complete: I can successfully alt-tab any number of times!

Next milestones:

• make the nav layer key (and fn layer key) momentary-layers (like OSL, but that didn’t seem to work immediately).

  OSL(layer) - momentarily activates layer until the next key is pressed. See One Shot Keys for details and additional functionality.

  // One-shot layer - 256 layer max
  #define OSL(layer) (QK_ONE_SHOT_LAYER | ((layer)&0xFF))
  

  Defined in quantum/quantum_keycodes.h and used in the action_for_keycode function of quantum/keymap_common.c.

  #ifndef NO_ACTION_ONESHOT
      case QK_ONE_SHOT_LAYER ... QK_ONE_SHOT_LAYER_MAX:;
          // OSL(action_layer) - One-shot action_layer
          action_layer = keycode & 0xFF;
          action.code  = ACTION_LAYER_ONESHOT(action_layer);
          break;
      case QK_ONE_SHOT_MOD ... QK_ONE_SHOT_MOD_MAX:;
          // OSM(mod) - One-shot mod
          mod         = mod_config(keycode & 0xFF);
          action.code = ACTION_MODS_ONESHOT(mod);
          break;
  #endif
  

  which leads to

  #define ACTION_LAYER_ONESHOT(layer) ACTION_LAYER_TAP((layer), OP_ONESHOT)
  ...
  #define ACTION_LAYER_TAP(layer, key) ACTION(ACT_LAYER_TAP, (layer) << 8 | (key))
  ...
  num action_kind_id { ACT_LAYER_TAP = 0b1010 /* Layer 0-15 */ }
  #define ACTION(kind, param) ((kind) << 12 | (param))
  

  Of course all this code is just a bunch of bit shifting!
  Let’s try OSL() one more time, just in case…
  Yeah, it’s probably because I had #define NO_ACTION_ONESHOT in my config.h, huh?
  Nope, OSL still isn’t working on the georgi. Switching to Butterstick to see if it’s a steno mode thing.
  Yes, OSL works on the butterstick. Also, implementing oneshot_layer_changed_user in keymap.c makes it print to the QMK toolbox (I wasn’t seeing those prints from Georgi).
  Switching back to Georgi for one more shot, then I’ll compromise with TG and hope I don’t get in a bad layer state.

  I got it! I had to delete the #define NO_ACTION_ONESHOT, and go into rules.mk (beware there’s one for the keyboard and one for the keymap!) and set NO_TAPPING = no! Now I can use OSL to shift layers.

• maybe write a custom function like TH(kc1, kc2), where if you tap it sends kc1, and if you hold it sends kc2. For inspiration:

  LT(layer, kc) - momentarily activates layer when held, and sends kc when tapped. Only supports layers 0-15.

  // L-ayer, T-ap - 256 keycode max, 16 layer max
  #define LT(layer, kc) (QK_LAYER_TAP | (((layer)&0xF) << 8) | ((kc)&0xFF))
  ...
  // M-od, T-ap - 256 keycode max
  #define MT(mod, kc) (QK_MOD_TAP | (((mod)&0x1F) << 8) | ((kc)&0xFF))
  

  Since stubbing this out and then playing with my layers quite a bit above, I realized I had an extra blank key next to the media keys, so I no longer need to double up TH(KC_VOLD, KC_MUTE), but maybe it’d be a fun experiment sometime anyway. Another day. Today my nav and media layers work great and I should take some time to practice them (and to practice steno lol).