Instead of returning a bool, to signal whether further processing should be
done, return a Key. Reason being, if we want to replace a key with another, for
subsequent handlers, it is a lot easier if we can modify what gets passed along,
than it is to inject a key, and try to avoid loops and infinite recursion.
Nevertheless, injecting keys is still possible.
This is not immediately useful for the core firmware, but makes it trivially
easy to upgrade keys from their normal behaviour to something special: for
example, a one-shot handler can auto-promote modifiers to one-shot, simply by
scheduling a promoter handler before the real one.
Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
`keymapEntry.rawKey` contains the target layer, but offset by
`MOMENTARY_OFFSET`. That value must be subtracted from the value before
comparing it to anything, or switching to another layer.
Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
Instead of having a primary and a temporary layer, store the state of at
most 32 layers in a bitfield. These can be individually turned on and
off, and key lookup starts from the top, and goes downwards until the
default layer to find a non-transparent key.
This allows one to reuse a partially transparent layer: set the default,
and the transparent parts will be reused. The numpad layer was updated
accordingly.
Having an interface to the layer switching things also makes it easier
to build other behaviour on top of these.
As part of the rework, layer handling was moved to a separate file, and into its
own, full-blown handler. Furthermore, we now use a single bit for all keymap
events.
Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
Gergely Nagy