diff --git a/keyboards/melody96/keymaps/zunger/keymap.c b/keyboards/melody96/keymaps/zunger/keymap.c
index d396de6839..d0d2698b7a 100644
--- a/keyboards/melody96/keymaps/zunger/keymap.c
+++ b/keyboards/melody96/keymaps/zunger/keymap.c
@@ -14,6 +14,83 @@
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include QMK_KEYBOARD_H
+#include <assert.h>
+
+// This keymap is designed to make it easy to type in a wide variety of languages, as well as
+// generate mathematical symbols (à la Space Cadet).
+//
+// LAYER MAGIC (aka, typing in many alphabets)
+// This keyboard has three "base" layers: QWERTY, GREEK, and CADET. The GREEK and CADET layers
+// are actually full of Unicode points, and so which point they generate depends on things like
+// whether the shift key is down. To handle this, each of those layers is actually *two* layers, one
+// with and one without shift. In our main loop, we manage modifier state detection, as well as
+// layer switch detection, and pick the right layer on the fly.
+// Layers are selected with a combination of three keys. The "Greek" and "Cadet" keys act like
+// modifiers: When held down, they transiently select the indicated base layer. The "Layer Lock" key
+// locks the value of the base layer at whatever is currently held; so e.g., if you hold Greek +
+// Layer Lock, you'll stay in Greek mode until you hit Layer Lock again without any of the mods
+// held.
+// TODO: This system of layer selection is nice for math, but it's not very nice for actually
+// typing in multiple languages. It seems like a better plan will be to reserve one key for each
+// base layer -- maybe fn + F(n) -- which can either be held as a modifier or tapped to switch
+// layers. That will open up adding some more languages, like Yiddish, but to do this effectively
+// we'll need to find a good UI with which to show the currently selected layer. Need to check what
+// the melody96 has in the way of outputs (LEDs, sound, etc).
+//
+// ACCENT MAGIC (aka, typing conveniently in Romance languages)
+// We want to support easy typing of diacritical marks. We can't rely on the host OS for this,
+// because (e.g.) on MacOS, to make any of the other stuff work, we need to be using the Unicode
+// input method at the OS level, which breaks all the normal accent stuff on that end. So we do it
+// ourselves. Accents can actually be invoked in two different ways: one fast and very compatible,
+// one very versatile but with occasional compatibility problems.
+//
+// THE MAIN WAY: You can hit one of the "accent request" key patterns immediately *before* typing
+// a letter to be accented. It will emit the corresponding accented Unicode. For example, you can
+// hit fn-e to request an acute accent, followed by i, and it will output í, U+00ED LATIN SMALL
+// LETTER I WITH ACUTE. These "combined characters" are in Unicode normal form C (NFKC), which is
+// important because many European websites and apps, in particular, tend to behave very badly
+// (misunderstanding and/or crashing) when presented with characters in other forms! The catch is
+// that this only works for the various combinations of letters and accents found in the Latin-1
+// supplement block of Unicode -- basically, things you need for Western European languages.
+//
+// (NB: If you make an accent request followed by a letter which can't take the corresponding
+// accent, it will output the uncombined form of the accent followed by whatever you typed; so
+// e.g., if you hit fn-e followed by f, it will output ´f, U+00B4 ACUTE ACCENT followed by an
+// ordinary f. This is very similar to the default behavior of MacOS.)
+//
+// THE FLEXIBLE WAY: If you hit the accent request with a shift -- e.g., fn-shift-e -- it will
+// instead immediately output the corresponding *combining* Unicode accent mark, which will modify
+// the *previous* character you typed. For example, if you type i followed by fn-shift-e, it will
+// generate í. But don't be fooled by visual similarity: unlike the previous example, this one is
+// an ordinary i followed by U+0301 COMBINING ACUTE ACCENT. It's actually *two symbols*, and this
+// is Unicode normal form D (NFKD). Unlike NFKC, there are NFKD representations of far more
+// combinations of letters and accents, and it's easy to add more of these if you need. (The NFKC
+// representation of such combinations is identical to their NFKD representation)
+//
+// Programs that try to compare Unicode strings *should* first normalize them by converting them
+// all into one normal form or another, and there are functions in every programming language to
+// do this -- e.g., JavaScript's string.normalize() -- but lots of programmers fail to understand
+// this, and so write code that massively freaks out when it encounters the wrong form.
+//
+// The current accent request codes are modeled on the ones in MacOS.
+//
+// fn+` Grave accent (`)
+// fn+e Acute accent (´)
+// fn+i Circumflex (^)
+// fn+u Diaresis / umlaut / trema (¨)
+// fn+c Cedilla (¸)
+// fn+n Tilde (˜)
+//
+// Together, these functions make for a nice "polyglot" keyboard: one that can easily type in a wide
+// variety of languages, which is very useful for people who, well, need to type in a bunch of
+// languages.
+//
+// The major TODOs are:
+// - Update the layer selection logic (and add visible layer cues);
+// - Factor the code below so that the data layers are more clearly separated from the code logic,
+// so that other users of this keymap can easily add whichever alphabets they need without
+// having to deeply understand the implementation.
+
enum custom_keycodes {
// We provide special layer management keys:
@@ -32,6 +109,16 @@ enum custom_keycodes {
KC_GREEK = SAFE_RANGE,
KC_CADET,
KC_LAYER_LOCK,
+
+ // These are the keycodes generated by the various "accent request" keystrokes.
+ KC_ACCENT_START,
+ KC_CGRV = KC_ACCENT_START, // Grave accent
+ KC_CAGU, // Acute accent
+ KC_CDIA, // Diaresis / umlaut / trema
+ KC_CCIR, // Circumflex
+ KC_CCED, // Cedilla
+ KC_CTIL, // Tilde
+ KC_ACCENT_END,
};
enum layers_keymap {
@@ -49,21 +136,6 @@ enum layers_keymap {
#define MO_FN MO(_FUNCTION)
#define KC_LLCK KC_LAYER_LOCK
-// TODO: To generalize this, we want some #defines that let us specify how each key on the base
-// layer should map to the four special layers, and then use that plus the base layer definition to
-// autogenerate the keymaps for the other layers.
-// TODO: It would also be nice to be able to put the actual code points in here, rather than
-// numbers.
-
-// Accent marks
-#define CMB_GRV H(0300)
-#define CMB_AGU H(0301)
-#define CMB_DIA H(0308)
-#define CMB_CIR H(0302)
-#define CMB_MAC H(0304)
-#define CMB_CED H(0327)
-#define CMB_TIL H(0303)
-
const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
// NB: Using GESC for escape in the QWERTY layer as a temporary hack because I messed up the
@@ -164,14 +236,119 @@ const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
// Function layer is mostly for keyboard meta-control operations, but also contains the combining
// accent marks. These are deliberately placed to match where the analogous controls go on Mac OS.
[_FUNCTION] = LAYOUT_hotswap(
- CMB_GRV, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, KC_MUTE, KC_VOLD, KC_VOLU, _______, _______, RESET,
- CMB_GRV, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______,
- _______, _______, _______, CMB_AGU, _______, _______, _______, CMB_DIA, CMB_CIR, CMB_MAC, _______, _______, _______, _______, _______, _______, _______,
+ KC_CGRV, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, KC_MUTE, KC_VOLD, KC_VOLU, _______, _______, RESET,
+ KC_CGRV, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______,
+ _______, _______, _______, KC_CAGU, _______, _______, _______, KC_CDIA, KC_CCIR, _______, _______, _______, _______, _______, _______, _______, _______,
_______, _______, _______, UC_M_OS, UC_M_LN, UC_M_WI, UC_M_BS, UC_M_WC, _______, _______, _______, _______, _______, _______, _______, _______, _______,
- _______, _______, _______, CMB_CED, _______, _______, CMB_TIL, _______, _______, _______, _______, _______, _______, _______, _______, _______,
+ _______, _______, _______, KC_CCED, _______, _______, KC_CTIL, _______, _______, _______, _______, _______, _______, _______, _______, _______,
_______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______),
};
+////////////////////////////////////////////////////////////////////////////////////////////////////
+// Accent implementation
+//
+// In the body of process_record_user, we store an "accent_request", which is the accent keycode if
+// one was just selected, or zero otherwise. When the *next* key is hit, we look up whether the
+// accent request plus that next keycode (plus the state of the shift key) together amount to an
+// interesting combined (NFKC) character, and if so, emit it; otherwise, we emit the accent as a
+// separate character and then process the next key normally. The resulting UI behavior is similar
+// to that of the combining accent keys in MacOS.
+//
+// We store two arrays, depending on whether shift is or isn't held. Each is two-dimensional, with
+// its outer key by the next keycode struck, and the inner key by the accent requested. The outer
+// array has KC_Z + 1 as its upper bound, so that we can save memory by only coding alphabetic keys.
+// The contents are either Unicode code points, or zero to indicate that we don't have a point for
+// this combination.
+
+#define KC_NUM_ACCENTS (KC_ACCENT_END - KC_ACCENT_START)
+#define KC_NUM_SLOTS (KC_Z + 1)
+
+const uint16_t PROGMEM unshifted_accents[KC_NUM_SLOTS][KC_NUM_ACCENTS] = {
+ // KC_CGRV, KC_CAGU, KC_CDIA, KC_CCIR, KC_CCED, KC_CTIL
+ [KC_A] = { 0x00e0, 0x00e1, 0x00e4, 0x00e2, 0, 0x00e3 },
+ [KC_E] = { 0x00e8, 0x00e9, 0x00eb, 0x00ea, 0, 0 },
+ [KC_I] = { 0x00ec, 0x00ed, 0x00ef, 0x00ee, 0, 0 },
+ [KC_O] = { 0x00f2, 0x00f3, 0x00f6, 0x00f4, 0, 0x00f5 },
+ [KC_U] = { 0x00f9, 0x00fa, 0x00fc, 0x00fb, 0, 0 },
+ [KC_Y] = { 0, 0, 0x00ff, 0, 0, 0 },
+ [KC_N] = { 0, 0, 0, 0, 0, 0x00f1 },
+ [KC_C] = { 0, 0, 0, 0, 0x00e7, 0 },
+};
+
+const uint16_t PROGMEM shifted_accents[KC_NUM_SLOTS][KC_NUM_ACCENTS] = {
+ // KC_CGRV, KC_CAGU, KC_CDIA, KC_CCIR, KC_CCED, KC_CTIL
+ [KC_A] = { 0x00c0, 0x00c1, 0x00c4, 0x00c2, 0, 0x00c3 },
+ [KC_E] = { 0x00c8, 0x00c9, 0x00cb, 0x00ca, 0, 0 },
+ [KC_I] = { 0x00cc, 0x00cd, 0x00cf, 0x00ce, 0, 0 },
+ [KC_O] = { 0x00d2, 0x00d3, 0x00d6, 0x00d4, 0, 0x00d5 },
+ [KC_U] = { 0x00d9, 0x00da, 0x00dc, 0x00db, 0, 0 },
+ [KC_Y] = { 0, 0, 0x00df, 0, 0, 0 },
+ [KC_N] = { 0, 0, 0, 0, 0, 0x00d1 },
+ [KC_C] = { 0, 0, 0, 0, 0x00c7, 0 },
+};
+
+// The uncombined and combined forms of the accents, for when we want to emit them as single
+// characters.
+const uint16_t PROGMEM uncombined_accents[KC_NUM_ACCENTS] = {
+ [KC_CGRV - KC_ACCENT_START] = 0x0060,
+ [KC_CAGU - KC_ACCENT_START] = 0x00b4,
+ [KC_CDIA - KC_ACCENT_START] = 0x00a8,
+ [KC_CCIR - KC_ACCENT_START] = 0x005e,
+ [KC_CCED - KC_ACCENT_START] = 0x00b8,
+ [KC_CTIL - KC_ACCENT_START] = 0x02dc,
+};
+
+const uint16_t PROGMEM combined_accents[KC_NUM_ACCENTS] = {
+ [KC_CGRV - KC_ACCENT_START] = 0x0300,
+ [KC_CAGU - KC_ACCENT_START] = 0x0301,
+ [KC_CDIA - KC_ACCENT_START] = 0x0308,
+ [KC_CCIR - KC_ACCENT_START] = 0x0302,
+ [KC_CCED - KC_ACCENT_START] = 0x0327,
+ [KC_CTIL - KC_ACCENT_START] = 0x0303,
+};
+
+// This function manages keypresses that happen after an accent has been selected by an earlier
+// keypress.
+// Args:
+// accent_key: The accent key which was earlier selected. This must be in the range
+// [KC_ACCENT_START, KC_ACCENT_END).
+// keycode: The keycode which was just pressed.
+// is_shifted: The current shift state (as set by a combination of shift and caps lock)
+// force_no_accent: If true, we're in a situation where we want to force there to be no
+// accent combination -- if e.g. we're in a non-QWERTY layer, or if other modifier keys
+// are held.
+//
+// Returns true if the keycode has been completely handled by this function (and so should not be
+// processed further by process_record_user) or false otherwise.
+bool process_key_after_accent(
+ uint16_t accent_key,
+ uint16_t keycode,
+ bool is_shifted,
+ bool force_no_accent
+) {
+ assert(accent_key >= KC_ACCENT_START);
+ assert(accent_key < KC_ACCENT_END);
+ const int accent_index = accent_key - KC_ACCENT_START;
+
+ // If the keycode is outside A..Z, or force_no_accent is set, we know we shouldn't even bother
+ // with a table lookup.
+ if (keycode <= KC_Z && !force_no_accent) {
+ // Pick the correct array. Because this is progmem, we're going to need to do the
+ // two-dimensional array indexing by hand, and so we just cast it to a single-dimensional array.
+ const uint16_t *points = (const uint16_t*)(is_shifted ? shifted_accents : unshifted_accents);
+ const uint16_t code_point = pgm_read_word_near(points + KC_NUM_ACCENTS * keycode + accent_index);
+ if (code_point) {
+ register_unicode(code_point);
+ return true;
+ }
+ }
+
+ // If we get here, there was no accent match. Emit the accent as its own character, and then let
+ // the caller figure out what to do next.
+ register_unicode(pgm_read_word_near(uncombined_accents + accent_index));
+ return false;
+}
+
// Layer bitfields.
#define GREEK_LAYER (1UL << _GREEK)
#define SHIFTGREEK_LAYER (1UL << _SHIFTGREEK)
@@ -185,6 +362,8 @@ bool process_record_user(uint16_t keycode, keyrecord_t *record) {
// get_mods or the like, because this function is called *before* that's updated!
static bool shift_held = false;
static bool alt_held = false;
+ static bool ctrl_held = false;
+ static bool super_held = false;
static bool greek_held = false;
static bool cadet_held = false;
@@ -192,18 +371,36 @@ bool process_record_user(uint16_t keycode, keyrecord_t *record) {
static bool shift_lock = false;
static int layer_lock = _QWERTY;
- // Process any modifier key presses.
+ // The accent request, or zero if there isn't one.
+ static uint16_t accent_request = 0;
+
+ // If this is set to true, don't trigger any handling of pending accent requests. That's what we
+ // want to do if e.g. the user just hit the shift key or something.
+ bool ignore_accent_change = !record->event.pressed;
+
+ // Step 1: Process any modifier key state changes, so we can maintain that state.
if (keycode == KC_LSHIFT || keycode == KC_RSHIFT) {
shift_held = record->event.pressed;
+ ignore_accent_change = true;
} else if (keycode == KC_LALT || keycode == KC_RALT) {
alt_held = record->event.pressed;
+ ignore_accent_change = true;
+ } else if (keycode == KC_LCTRL || keycode == KC_RCTRL) {
+ ctrl_held = record->event.pressed;
+ ignore_accent_change = true;
+ } else if (keycode == KC_LGUI || keycode == KC_RGUI) {
+ super_held = record->event.pressed;
+ ignore_accent_change = true;
} else if (keycode == KC_GREEK) {
greek_held = record->event.pressed;
+ ignore_accent_change = true;
} else if (keycode == KC_CADET) {
cadet_held = record->event.pressed;
+ ignore_accent_change = true;
}
- // Now let's transform these into the "cadet request" and "greek request."
+ // Step 2: Figure out which layer we're supposed to be in, by transforming all the prior stuff
+ // into layer requests.
const bool greek_request = (greek_held && !alt_held);
const bool cadet_request = (cadet_held || (greek_held && alt_held));
@@ -260,8 +457,33 @@ bool process_record_user(uint16_t keycode, keyrecord_t *record) {
layer_state_set(new_layer_state);
}
- // TODO: We can update LED states based on shift_lock (caps), layer_lock (layer lock), and
- // base_layer (base layer).
+ // Step 3: Handle accents. If there's a pending accent request, process it. If what the user just
+ // hit creates a new accent request, update the pending state for the next keypress.
+ if (!ignore_accent_change && accent_request && record->event.pressed) {
+ // Only do the accent stuff if we're in the QWERTY layer and we aren't modifying something.
+ const bool force_no_accent = (
+ actual_layer != _QWERTY ||
+ ctrl_held ||
+ super_held ||
+ alt_held
+ );
+ const uint16_t old_accent = accent_request;
+ accent_request = 0;
+ if (process_key_after_accent(old_accent, keycode, shifted, force_no_accent)) {
+ return false;
+ }
+ }
+
+ // And if a new accent request just arrived, update accent_request.
+ if (keycode >= KC_ACCENT_START && keycode < KC_ACCENT_END && record->event.pressed) {
+ if (shifted) {
+ // Shift + accent request generates the combining accent key, and leaves accent_request alone.
+ register_unicode(pgm_read_word_near(combined_accents + keycode - KC_ACCENT_START));
+ return false;
+ } else {
+ accent_request = keycode;
+ }
+ }
return true;
}