Keymap: DZ60 layout based on stephengrier's with PgUp/PgDn/Home/End, Insert, etc. (#4110)

* DZ60 layout based on stephengrier's with customisations.

* CapsLock is used as Fn key.
* Del is available as Fn+Backspace & Shift+Backspace (using a macro)
* PgUp / PgDn / Home / End = Fn+Arrows (as on macOS, Microsoft Surface)
* Tilde = Shift+Esc
* Backtick = Fn+Esc
* Underglow toggle and mode selection are available as Fn+Q and Fn+W
* Reset (bootloader mode) = Fn+B

* Standardised layout formatting and Ctrl+Del & Shift+Del support.

Using 7 underscores for KC_TRNS in layouts and aligning the keycodes
according to LAYOUT_directional.

Del is now only Fn+Del, Ctrl+Backspace translates to Ctrl+Del,
Shift+Backspace translates to Shift+Del.

* Documented new Backspace/Del related macros.

Del is now just Fn+Backspace, pressing Ctrl+Backspace sends Ctrl+Del,
pressing Shift+Backspace sends Shift+Del

keyboards/dz60/keymaps/boris_burger/README.md

@@ -0,0 +1,52 @@
+### boris_burger's DZ60 layout
+
+This layout is for a DZ60 with a 2U left shift, 1U right shift and an arrow cluster in
+the bottom right.
+
+It is based off stephengrier's layout adding support for Home/End/PgUp/PgDn using Fn+arrows
+as used on macOS and Microsoft Surface. It has Insert instead of Fn near the arrow cluster
+and other smaller tweaks:
+- CapsLock is the only Fn key (CapsLock by itself is not available)
+- Del is available as Fn+Backspace
+- Ctrl+Del is available as Ctrl+Backspace (e.g. deleting word to the right of the cursor)
+- Shift+Del is available as Shift+Backspace (e.g. permanently deleting file or e-mail)
+- PgUp = Fn+Up
+- PgDn = Fn+Down
+- Home = Fn+Left
+- End = Fn+Right
+- Tilde = Shift+Esc 
+- Backtick = Fn+Esc
+- Underglow toggle and mode selection are available as Fn+Q and Fn+W
+- Reset (bootloader mode) = Fn+B
+
+### 0 Qwerty
+```
+,-----------------------------------------------------------------------------------------.
+| Esc |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  8  |  9  |  0  |  -  |  =  |   Bkspc   |
+|-----------------------------------------------------------------------------------------+
+| Tab    |  Q  |  W  |  E  |  R  |  T  |  Y  |  U  |  I  |  O  |  P  |  [  |  ]  |    \   |
+|-----------------------------------------------------------------------------------------+
+|   Fn    |  A  |  S  |  D  |  F  |  G  |  H  |  J  |  K  |  L  |  ;  |  '  |    Enter    |
+|-----------------------------------------------------------------------------------------+
+| Shift     |  Z  |  X  |  C  |  V  |  B  |  N  |  M  |  ,  |  .  |  /  | RSh |  U  | Ins |
+|-----------------------------------------------------------------------------------------+
+| Ctrl |  Win  |  Alt  |              Space                | Alt | Menu |  L  |  D  |  R  |
+`-----------------------------------------------------------------------------------------'
+```
+
+### 1 Fn Layer
+```
+FN Layer
+,-----------------------------------------------------------------------------------------.
+|  `  |  F1 |  F2 |  F3 |  F4 |  F5 |  F6 |  F7 |  F8 |  F9 | F10 | F11 | F12 |    DEL    |
+|-----------------------------------------------------------------------------------------+
+|        |RBB T|RGB M| Hue+| Hue-| Sat+| Sat-| Val+| Val-|     |     |      |     |       |
+|-----------------------------------------------------------------------------------------+
+|         | BL T| BL M| BL+ | BL- |     |     |     |     |     |     |     |             |
+|-----------------------------------------------------------------------------------------+
+|           |     |     |     |     |RESET|     |     |     |     |     |     | PgUp|     |
+|-----------------------------------------------------------------------------------------+
+|      |       |       |                                   |     |      | Home| PgDn| End |
+`-----------------------------------------------------------------------------------------'
+```
+

keyboards/dz60/keymaps/boris_burger/config.h

@@ -0,0 +1 @@
+#define GRAVE_ESC_GUI_OVERRIDE    # Always send Escape if GUI is pressed

keyboards/dz60/keymaps/boris_burger/keymap.c

@@ -0,0 +1,87 @@
+#include QMK_KEYBOARD_H
+
+/* Holds state of modifiers when Backspace was pressed.
+ * Used to ensure that the correct keycode is unregistered when Backspace is released.
+ */
+static uint8_t bspc_mods = 0;
+
+const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
+
+    /* Qwerty
+    * ,-----------------------------------------------------------------------------------------.
+    * | Esc |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  8  |  9  |  0  |  -  |  =  |   Bkspc   |
+    * |-----------------------------------------------------------------------------------------+
+    * | Tab    |  Q  |  W  |  E  |  R  |  T  |  Y  |  U  |  I  |  O  |  P  |  [  |  ]  |    \   |
+    * |-----------------------------------------------------------------------------------------+
+    * |   Fn    |  A  |  S  |  D  |  F  |  G  |  H  |  J  |  K  |  L  |  ;  |  '  |    Enter    |
+    * |-----------------------------------------------------------------------------------------+
+    * | Shift     |  Z  |  X  |  C  |  V  |  B  |  N  |  M  |  ,  |  .  |  /  | RSh |  U  | Ins |
+    * |-----------------------------------------------------------------------------------------+
+    * | Ctrl |  Win  |  Alt  |              Space                | Alt | Menu |  L  |  D  |  R  |
+    * `-----------------------------------------------------------------------------------------'
+    */
+    LAYOUT_directional(
+        KC_GESC, KC_1   , KC_2   , KC_3   , KC_4   , KC_5   , KC_6   , KC_7   , KC_8   , KC_9   , KC_0   , KC_MINS, KC_EQL , _______, KC_BSPC,
+        KC_TAB ,          KC_Q   , KC_W   , KC_E   , KC_R   , KC_T   , KC_Y   , KC_U   , KC_I   , KC_O   , KC_P   , KC_LBRC, KC_RBRC, KC_BSLS,
+        MO(1)  ,          KC_A   , KC_S   , KC_D   , KC_F   , KC_G   , KC_H   , KC_J   , KC_K   , KC_L   , KC_SCLN, KC_QUOT, KC_ENT ,
+        KC_LSFT,          KC_Z   , KC_X   , KC_C   , KC_V   , KC_B   , KC_N   , KC_M   , KC_COMM, KC_DOT , KC_SLSH, KC_RSFT, KC_UP  , KC_INS ,
+        KC_LCTL, KC_LGUI,          KC_LALT, KC_SPC ,          KC_SPC ,          KC_SPC ,          KC_RALT, KC_RGUI, KC_LEFT, KC_DOWN, KC_RIGHT
+    ),
+
+    /* FN Layer
+    * ,-----------------------------------------------------------------------------------------.
+    * |  `  |  F1 |  F2 |  F3 |  F4 |  F5 |  F6 |  F7 |  F8 |  F9 | F10 | F11 | F12 |    DEL    |
+    * |-----------------------------------------------------------------------------------------+
+    * |        |RBB T|RGB M| Hue+| Hue-| Sat+| Sat-| Val+| Val-|     |     |      |     |       |
+    * |-----------------------------------------------------------------------------------------+
+    * |         | BL T| BL M| BL+ | BL- |     |     |     |     |     |     |     |             |
+    * |-----------------------------------------------------------------------------------------+
+    * |           |     |     |     |     |RESET|     |     |     |     |     |     | PgUp|     |
+    * |-----------------------------------------------------------------------------------------+
+    * |      |       |       |                                   |     |      | Home| PgDn| End |
+    * `-----------------------------------------------------------------------------------------'
+    */
+    LAYOUT_directional(
+        KC_GRV , KC_F1  , KC_F2  , KC_F3  , KC_F4  , KC_F5  , KC_F6  , KC_F7  , KC_F8  , KC_F9  , KC_F10 , KC_F11 , KC_F12 , _______, KC_DEL ,
+        _______,          RGB_TOG, RGB_MOD, RGB_HUI, RGB_HUD, RGB_SAI, RGB_SAD, RGB_VAI, RGB_VAD, _______, _______, _______, _______, _______,
+        _______,          BL_TOGG, BL_STEP, BL_INC , BL_DEC , _______, _______, _______, _______, _______, _______, _______, _______,
+        _______,          _______, _______, _______, _______, RESET  , _______, _______, _______, _______, _______, _______, KC_PGUP, _______,
+        _______, _______,          _______, _______,          _______,          _______,          _______, _______, KC_HOME, KC_PGDN, KC_END
+        ),
+};
+
+
+bool process_record_user(uint16_t keycode, keyrecord_t *record) {
+    switch(keycode) {
+        case KC_BSPC: {
+            if (record->event.pressed) {
+                const uint8_t current_mods = get_mods();
+                const uint8_t shift = current_mods & (MOD_BIT(KC_LSHIFT)|MOD_BIT(KC_RSHIFT));
+                const uint8_t ctrl = current_mods & (MOD_BIT(KC_LCTL)|MOD_BIT(KC_RCTL));
+                bspc_mods = current_mods;
+                if(shift || ctrl) {
+                    add_key(KC_DEL);
+                    add_mods(current_mods);
+                    send_keyboard_report();
+                } else {
+                    return true;
+                }
+            }
+            else {
+                if(bspc_mods & (MOD_BIT(KC_LSHIFT)|MOD_BIT(KC_RSHIFT)|MOD_BIT(KC_LCTL)|MOD_BIT(KC_RCTL))) {
+                    // if Shift or Ctrl was pressed with Backspace, than that was intepreted as Del, so we need
+                    // to unregister the Del key 
+                    del_key(KC_DEL);
+                } else {
+                    // Either Backspace was pressed without mods, or with a modifier other than Shift or Ctrl
+                    // so it is simply taken as Backspace
+                    del_key(KC_BSPC);
+                }
+                send_keyboard_report();
+            }
+            return false;
+        }
+        default:
+            return true;
+    }
+}