[Keymap] emp keymap for keebio/iris (#16858)

* added new layout for keebio/iris

* Update keyboards/keebio/iris/keymaps/emp/config.h

* Update keyboards/keebio/iris/keymaps/emp/keymap.c

Replace #defines with enum

* Update keyboards/keebio/iris/keymaps/emp/keymap.c

Made requested changes about formatting and the license.

* Update config.h

Cleaned up formatting

* Update keyboards/keebio/iris/keymaps/emp/keymap.c

Small changes to improve readability:
* changed whitespace in license
* added more whitespace around if/else blocks
* fixed bracket style in places

1 files changed, 277 insertions, 0 deletions

diff --git a/keyboards/keebio/iris/keymaps/emp/keymap.c b/keyboards/keebio/iris/keymaps/emp/keymap.c
new file mode 100644
index 0000000000..d89477ed96
--- /dev/null
+++ b/keyboards/keebio/iris/keymaps/emp/keymap.c
@@ -0,0 +1,277 @@
+/* Copyright 2022 elliotpatros
+ * 
+ * This program is free software: you can redistribute it and/or modify 
+ * it under the terms of the GNU General Public License as published by 
+ * the Free Software Foundation, either version 2 of the License, or 
+ * (at your option) any later version. 
+ * 
+ * This program is distributed in the hope that it will be useful, 
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of 
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
+ * GNU General Public License for more details. 
+ * 
+ * You should have received a copy of the GNU General Public License 
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>. 
+ */ 
+
+#include QMK_KEYBOARD_H
+
+// Layer definitions
+enum custom_layers {
+    _COLEMAK,
+    _FUNCTION,
+};
+
+// Custom keycodes, implemented later, in function: process_record_user()
+enum custom_keycodes {
+    CTL_ESC = SAFE_RANGE,   // mod tap: left control / esc
+    SFT_ENT,                // mod tap: left shift / enter
+    LST_PRN,                // mod tap: left shift / left parenthesis
+    RST_PRN,                // mod tap: right shift / right parenthesis
+};
+
+// Shorthand keycode definitions
+#define OSM_CAG OSM(MOD_LCTL | MOD_LALT | MOD_LGUI)
+#define LT_BSFN LT(_FUNCTION, KC_BSLS)
+
+// The layout
+const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
+    
+    // Default layer
+    [_COLEMAK] = LAYOUT (
+
+// ┌────────┬────────┬────────┬────────┬────────┬────────┐                  ┌────────┬────────┬────────┬────────┬────────┬────────┐
+    KC_GRV,  KC_1,    KC_2,    KC_3,    KC_4,    KC_5,                       KC_6,    KC_7,    KC_8,    KC_9,    KC_0,    KC_MINS,
+// ├────────┼────────┼────────┼────────┼────────┼────────┤                  ├────────┼────────┼────────┼────────┼────────┼────────┤
+    KC_TAB,  KC_Q,    KC_W,    KC_F,    KC_P,    KC_G,                       KC_J,    KC_L,    KC_U,    KC_Y,    KC_SCLN, KC_EQL,
+// ├────────┼────────┼────────┼────────┼────────┼────────┤                  ├────────┼────────┼────────┼────────┼────────┼────────┤
+    CTL_ESC, KC_A,    KC_R,    KC_S,    KC_T,    KC_D,                       KC_H,    KC_N,    KC_E,    KC_I,    KC_O,    KC_QUOT,
+// ├────────┼────────┼────────┼────────┼────────┼────────┼────────┐┌────────┼────────┼────────┼────────┼────────┼────────┼────────┤
+    LST_PRN, KC_Z,    KC_X,    KC_C,    KC_V,    KC_B,    KC_SPC,   KC_ENT,  KC_K,    KC_M,    KC_COMM, KC_DOT,  KC_SLSH, RST_PRN,
+// └────────┴────────┴────────┴────────┼────────┼────────┼────────┘└────────┼────────┴────────┴────────┴────────┴────────┴────────┘
+                                        KC_LALT, KC_LGUI, SFT_ENT,  KC_SPC,  LT_BSFN, KC_BSPC
+//                                     └────────┴────────┴────────┘└────────┴────────┴────────┘
+    ),
+
+    // Function (and I guess also media & navigation) layer
+    [_FUNCTION] = LAYOUT (
+
+// ┌────────┬────────┬────────┬────────┬────────┬────────┐                  ┌────────┬────────┬────────┬────────┬────────┬────────┐
+    _______, KC_F1,   KC_F2,   KC_F3,   KC_F4,   KC_F5,                      KC_F6,   KC_F7,   KC_F8,   KC_F9,   KC_F10,  _______,
+// ├────────┼────────┼────────┼────────┼────────┼────────┤                  ├────────┼────────┼────────┼────────┼────────┼────────┤
+    _______, KC_GRV,  KC_LPRN, KC_RPRN, KC_F11,  KC_F12,                     KC_INS,  KC_HOME, KC_UP,   KC_PGUP, _______, _______,
+// ├────────┼────────┼────────┼────────┼────────┼────────┤                  ├────────┼────────┼────────┼────────┼────────┼────────┤
+    _______, KC_LCBR, KC_LBRC, KC_RBRC, KC_RCBR, OSM_CAG,                    KC_VOLU, KC_LEFT, KC_DOWN, KC_RGHT, KC_BSPC, _______,
+// ├────────┼────────┼────────┼────────┼────────┼────────┼────────┐┌────────┼────────┼────────┼────────┼────────┼────────┼────────┤
+    _______, _______, _______, _______, _______, KC_MUTE, _______,  _______, KC_VOLD, KC_DEL,  KC_END,  KC_PGDN, _______, _______,
+// └────────┴────────┴────────┴────────┼────────┼────────┼────────┘└────────┼────────┴────────┴────────┴────────┴────────┴────────┘
+                                        _______, _______, _______,  _______, _______, _______
+//                                     └────────┴────────┴────────┘└────────┴────────┴────────┘
+    )
+
+};
+
+static inline bool dualfunckey_was_tapped(const uint16_t time_when_pressed) {
+    return timer_elapsed(time_when_pressed) < TAPPING_TERM;
+}
+
+bool process_record_user(uint16_t keycode, keyrecord_t* record) {
+    
+    // Static variables
+    static uint16_t timer_control_escape = 0;
+    static uint16_t timer_shift_enter = 0;
+    static uint16_t timer_shift_lparen = 0;
+    static uint16_t timer_shift_rparen = 0;
+
+    static bool dualfunckey_pending = false;
+
+    static bool shift_enter_is_pressed = false;
+    static bool shift_lparen_is_pressed = false;
+
+    // Was this function called to handle a keydown? If not, it was called by a 
+    // key up.
+    const bool pressed = record->event.pressed;
+
+    // Any keydown (at all) spends a pending dual function key check. Why? If,
+    // for example, you use shift to type a capital letter, and shift keys down
+    // and up faster than the tapping term, did you mean to call shift's tapping
+    // key? No. You just meant to call shift.
+    if (pressed) {
+        dualfunckey_pending = false;
+    }
+
+    // Only keycodes >= SAFE_RANGE are handled in this function
+    if (keycode < SAFE_RANGE) {
+        // This keypress was not handled
+        return true;
+    }
+
+    // Handle custom keypresses here
+    switch (keycode) {
+
+    // -------------------------------------------------------------------------
+    // Dual function key (hold: left shift; tap: enter)
+    // -------------------------------------------------------------------------
+    case SFT_ENT:
+            
+        // There are multiple keys that are mapped to left shift. Keep track of
+        // which are pressed
+        shift_enter_is_pressed = pressed;
+
+        // Handle keypress routine
+        if (pressed) {
+            
+            // The [left shift/enter] key was pressed
+            register_code(KC_LSFT);
+
+            // Save keydown time for checking hold/tap on keyup
+            timer_shift_enter = timer_read();
+
+            // Pressing a dual function key requires a hold/tap check on key up
+            dualfunckey_pending = true;
+            
+        } else {
+            
+            // The [left shift/enter] key was unpressed
+            // Note: unregister shift before pressing ENT so that ENT registers
+            // correctly
+
+            // If no other left shift keys are currently pressed, unregister it
+            if (! shift_lparen_is_pressed) {
+                unregister_code(KC_LSFT);
+            }
+
+            // If a pending dual function key hasn't been used yet, use it here
+            if (dualfunckey_pending && dualfunckey_was_tapped(timer_shift_enter)) {
+                tap_code(KC_ENT);
+                dualfunckey_pending = false;
+            }
+        }
+
+        // This keypress was handled
+        return false;
+
+    // -------------------------------------------------------------------------
+    // Dual function key (hold: left control; tap: escape)
+    // -------------------------------------------------------------------------
+    case CTL_ESC:
+
+        // Handle keypress routine
+        if (pressed) {
+            
+            // Control/escape key was pressed
+            register_code(KC_LCTL);
+
+            // Save keydown time for checking hold/tap on keyup
+            timer_control_escape = timer_read();
+
+            // Pressing a dual function key requires a hold/tap check on key up
+            dualfunckey_pending = true;
+            
+        } else {
+            
+            // Control/escape key was unpressed
+            unregister_code(KC_LCTL);
+
+            // If a pending dual function key hasn't been used yet, use it here
+            if (dualfunckey_pending && dualfunckey_was_tapped(timer_control_escape)) {
+                tap_code(KC_ESC);
+                dualfunckey_pending = false;
+            }
+        }
+
+        // This keypress was handled
+        return false;
+
+    // -------------------------------------------------------------------------
+    // Dual function key (hold: left shift; tap: left parenthesis)
+    // -------------------------------------------------------------------------
+    case LST_PRN:
+
+        // There are multiple keys that are mapped to left shift. Keep track of
+        // which are pressed
+        shift_lparen_is_pressed = pressed;
+
+        // Handle keypress routine
+        if (pressed) {
+            
+            // The [left shift/left parenthesis] key was pressed
+            register_code(KC_LSFT);
+
+            // Save keydown time for checking hold/tap on keyup
+            timer_shift_lparen = timer_read();
+
+            // Pressing a dual function key requires a hold/tap check on key up
+            dualfunckey_pending = true;
+            
+        } else {
+            
+            // The [left shift/left parenthesis] key was unpressed
+            // Note: unregister shift after tapping 9 so that left parenthesis
+            // registers correctly
+
+            // If a pending dual function key hasn't been used yet, use it here
+            if (dualfunckey_pending && dualfunckey_was_tapped(timer_shift_lparen)) {
+                tap_code(KC_9);
+                dualfunckey_pending = false;
+            }
+
+            // If no other left shift keys are currently pressed, unregister it
+            if (! shift_enter_is_pressed) {
+                unregister_code(KC_LSFT);
+            }
+        }
+
+        // This keypress was handled
+        return false;
+
+    // -------------------------------------------------------------------------
+    // Dual function key (hold: right shift; tap: right parenthesis)
+    // -------------------------------------------------------------------------
+    case RST_PRN:
+
+        // Handle keypress routine
+        if (pressed) {
+            
+            // The [right shift/right parenthesis] key was pressed
+            register_code(KC_RSFT);
+
+            // Save keydown time for checking hold/tap on keyup
+            timer_shift_rparen = timer_read();
+
+            // Pressing a dual function key requires a hold/tap check on key up
+            dualfunckey_pending = true;
+            
+        } else {
+            
+            // The [right shift/right parenthesis] key was unpressed
+            // Note: unregister shift after tapping 0 so that right parenthesis
+            // registers correctly
+
+            // If a pending dual function key hasn't been used yet, use it here
+            if (dualfunckey_pending && dualfunckey_was_tapped(timer_shift_rparen)) {
+                
+                // Space cadet shift: If the [left shift/left parenthesis] key
+                // is currently pressed, then tap the sequence ()
+                if (shift_lparen_is_pressed) {
+                    tap_code(KC_9);
+                }
+
+                tap_code(KC_0);
+                dualfunckey_pending = false;
+            }
+
+            unregister_code(KC_RSFT);
+        }
+
+        // This keypress was handled
+        return false;
+
+    // -------------------------------------------------------------------------
+    // Some other key was pressed (this shouldn't happen)
+    // -------------------------------------------------------------------------
+    default:
+        // This keypress was not handled
+        return true;        
+    }
+}