feat: Add hidden property to ComboSpec

Fixes #104

KEYMAP_SPEC.md

@@ -178,8 +178,9 @@ This is an optional field that contains a list of `ComboSpec`s, each of which is
 | `height (h)`        | `float`                                           | `null`        | the height of the combo box (in pixels), defaults to `draw_config.combo_h` if null                                                                                                |
 | `rotation (r)`      | `float`                                           | `0.0`         | the rotation of the combo box in degrees -- only applies to the box itself and not any dendrons                                                                                   |
 | `draw_separate`     | `null \| bool`                                    | `null`        | whether to draw the combo separate from layers, using a dedicated diagram. defaults to `draw_config.separate_combo_diagrams` if null                                              |
+| `hidden`            | `bool`                                            | `false`       | do not draw this combo at all -- useful when you have the combo in the parse output but you want to ignore it through your config                                                 |
 
-All fields except `key_positions`, `key` and `type` are ignored when combo is drawn in a separate diagram using `draw_separate` or `draw_config.separate_combo_diagrams`.
+All fields except `key_positions`, `key`, `type` and `hidden` are ignored when combo is drawn in a separate diagram using `draw_separate` or `draw_config.separate_combo_diagrams`.
 
 [^5]: Key indices start from `0` on the first key position and increase by columns and then rows, corresponding to their ordering in the `layers` field. This matches the `key-positions` property in ZMK combo definitions.
 [^6]: Just like for keys in a layer under the `layers` field, `key` field can be specified with a string value as a shortcut, or a mapping (where the `type` field will be ignored).

keymap_drawer/draw/combo.py

@@ -170,9 +170,7 @@ def print_combos_for_layer(self, combos: Sequence[ComboSpec]) -> tuple[float | N
         Print SVG for all given combos, relative to that point.
         Return min and max y-coordinates of combo boxes, for bounding box calculations.
         """
-        combo_pts = []
-        for combo_ind, combo_spec in enumerate(combos):
-            combo_pts.append(self.print_combo(combo_spec, combo_ind))
+        combo_pts = [self.print_combo(combo, ind) for ind, combo in enumerate(combos) if not combo.hidden]
         return min((p.y for p, _ in combo_pts), default=None), max((p.y for _, p in combo_pts), default=None)
 
     def create_combo_diagrams(
@@ -194,6 +192,9 @@ def create_combo_diagrams(
 
         layers = {}
         for ind, combo in enumerate(combos):
+            if combo.hidden:
+                continue
+
             empty_layer = [LayoutKey() for _ in range(len(self.layout))]
             if ghost_keys:
                 for key_position in ghost_keys:

keymap_drawer/keymap.py

@@ -79,6 +79,7 @@ class ComboSpec(BaseModel, populate_by_name=True, extra="forbid"):
     height: float | None = Field(alias="h", default=None)
     rotation: float = Field(alias="r", default=0.0)
     draw_separate: bool | None = None
+    hidden: bool = False
 
     @classmethod
     def normalize_fields(cls, spec_dict: dict) -> dict: