process_key_override.h
8573 bytes
1/*
2 * Copyright 2021 Jonas Gessner
3 *
4 * This program is free software: you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation, either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program. If not, see <http://www.gnu.org/licenses/>.
16 */
17
18#pragma once
19
20#include <stdbool.h>
21#include <stdint.h>
22#include "action.h"
23#include "action_layer.h"
24
25/**
26 * Key overrides allow you to send a different key-modifier combination or perform a custom action when a certain modifier-key combination is pressed.
27 *
28 * For example, you may configure a key override to send the delete key when shift + backspace are pressed together, or that your volume keys become screen brightness keys when holding ctrl. The possibilities are quite vast and the documentation contains a few examples for inspiration.
29 *
30 * See the documentation and examples here: https://docs.qmk.fm/#/feature_key_overrides
31 */
32
33/** Bitfield with various options controlling the behavior of a key override. */
34typedef enum {
35 /** Allow activating when the trigger key is pressed down. */
36 ko_option_activation_trigger_down = (1 << 0),
37 /** Allow activating when a necessary modifier is pressed down. */
38 ko_option_activation_required_mod_down = (1 << 1),
39 /** Allow activating when a negative modifier is released. */
40 ko_option_activation_negative_mod_up = (1 << 2),
41
42 ko_options_all_activations = ko_option_activation_negative_mod_up | ko_option_activation_required_mod_down | ko_option_activation_trigger_down,
43
44 /** If set, any of the modifiers in trigger_mods will be enough to activate the override (logical OR of modifiers). If not set, all the modifiers in trigger_mods have to be pressed (logical AND of modifiers). */
45 ko_option_one_mod = (1 << 3),
46
47 /** If set, the trigger key will never be registered again after the override is deactivated. */
48 ko_option_no_reregister_trigger = (1 << 4),
49
50 /** If set, the override will not deactivate when another key is pressed down. Use only if you really know you need this. */
51 ko_option_no_unregister_on_other_key_down = (1 << 5),
52
53 /** The default options used by the ko_make_xxx functions. */
54 ko_options_default = ko_options_all_activations,
55} ko_option_t;
56
57/** Defines a single key override */
58typedef struct key_override_t {
59 // The non-modifier keycode that triggers the override. This keycode, and the necessary modifiers (trigger_mods) must be pressed to activate this override. Set this to the keycode of the key that should activate the override. Set to KC_NO to require only the necessary modifiers to be pressed and no non-modifier.
60 uint16_t trigger;
61
62 // Which mods need to be down for activation. If both sides of a modifier are set (e.g. left ctrl and right ctrl) then only one is required to be pressed (e.g. left ctrl suffices). Use the MOD_MASK_XXX and MOD_BIT() macros for this.
63 uint8_t trigger_mods;
64
65 // This is a BITMASK (!), defining which layers this override applies to. To use this override on layer i set the ith bit (1 << i).
66 layer_state_t layers;
67
68 // Which modifiers cannot be down. It must hold that (active_mods & negative_mod_mask) == 0, otherwise the key override will not be activated. An active override will be deactivated once this is no longer true.
69 uint8_t negative_mod_mask;
70
71 // Modifiers to 'suppress' while the override is active. To suppress a modifier means that even though the modifier key is held down, the host OS sees the modifier as not pressed. Can be used to suppress the trigger modifiers, as a trivial example.
72 uint8_t suppressed_mods;
73
74 // The complex keycode to send as replacement when this override is triggered. This can be a simple keycode, a key-modifier combination (e.g. C(KC_A)), or KC_NO (to register no replacement keycode). Use in combination with suppressed_mods to get the correct modifiers to be sent.
75 uint16_t replacement;
76
77 // Options controlling the behavior of the override, such as what actions are allowed to activate the override.
78 ko_option_t options;
79
80 // If not NULL, this function will be called right before the replacement key is registered, along with the provided context and a flag indicating whether the override was activated or deactivated. This function allows you to run some custom actions for specific key overrides. If you return `false`, the replacement key is not registered/unregistered as it would normally. Return `true` to register and unregister the override normally.
81 bool (*custom_action)(bool activated, void *context);
82
83 // A context that will be passed to the custom action function.
84 void *context;
85
86 // If this points to false this override will not be used. Set to NULL to always have this override enabled.
87 bool *enabled;
88} key_override_t;
89
90/** Turns key overrides on */
91void key_override_on(void);
92
93/** Turns key overrides off */
94void key_override_off(void);
95
96/** Toggles key overrides on */
97void key_override_toggle(void);
98
99/** Returns whether key overrides are enabled */
100bool key_override_is_enabled(void);
101
102/** Handling of key overrides and its implemented keycodes */
103bool process_key_override(const uint16_t keycode, const keyrecord_t *const record);
104
105/** Perform any deferred keys */
106void key_override_task(void);
107
108/**
109 * Preferrably use these macros to create key overrides. They fix many of the options to a standard setting that should satisfy most basic use-cases. Only directly create a key_override_t struct when you really need to.
110 */
111
112// clang-format off
113
114/**
115 * Convenience initializer to create a basic key override. Activates the override on all layers.
116 */
117#define ko_make_basic(trigger_mods, trigger_key, replacement_key) \
118 ko_make_with_layers(trigger_mods, trigger_key, replacement_key, ~0)
119
120/**
121 * Convenience initializer to create a basic key override. Provide a bitmap (of type layer_state_t) with the bits set for each layer on which the override should activate.
122 */
123#define ko_make_with_layers(trigger_mods, trigger_key, replacement_key, layers) \
124 ko_make_with_layers_and_negmods(trigger_mods, trigger_key, replacement_key, layers, 0)
125
126/**
127 * Convenience initializer to create a basic key override. Provide a bitmap with the bits set for each layer on which the override should activate. Also provide a negative modifier mask, that is used to define which modifiers may not be pressed.
128 */
129#define ko_make_with_layers_and_negmods(trigger_mods, trigger_key, replacement_key, layers, negative_mask) \
130 ko_make_with_layers_negmods_and_options(trigger_mods, trigger_key, replacement_key, layers, negative_mask, ko_options_default)
131
132 /**
133 * Convenience initializer to create a basic key override. Provide a bitmap with the bits set for each layer on which the override should activate. Also provide a negative modifier mask, that is used to define which modifiers may not be pressed. Provide options for additional control of the behavior of the override.
134 */
135#define ko_make_with_layers_negmods_and_options(trigger_mods_, trigger_key, replacement_key, layer_mask, negative_mask, options_) \
136 ((const key_override_t){ \
137 .trigger_mods = (trigger_mods_), \
138 .layers = (layer_mask), \
139 .suppressed_mods = (trigger_mods_), \
140 .options = (options_), \
141 .negative_mod_mask = (negative_mask), \
142 .custom_action = NULL, \
143 .context = NULL, \
144 .trigger = (trigger_key), \
145 .replacement = (replacement_key), \
146 .enabled = NULL \
147 })
148
149// clang-format on