From 81aae23fe7d86c7cf2b79e4589e092f946965141 Mon Sep 17 00:00:00 2001
From: Richard Acayan <mailingradian@gmail.com>
Date: Wed, 25 Sep 2024 19:53:13 -0400
Subject: [PATCH] wayland: keyboard: assign static key codes for some keys

Some applications like Waydroid and Klavaro (with the Enter key) ignore
the keyboard layout and expect a key code from the Linux input UAPI.
Assign static key codes for keys on the QWERTY layout so some keys can
still work with these applications.
---
 src/wayland/keyboard.rs | 107 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 107 insertions(+)

diff --git a/src/wayland/keyboard.rs b/src/wayland/keyboard.rs
index a81eadc..f6c7e2e 100644
--- a/src/wayland/keyboard.rs
+++ b/src/wayland/keyboard.rs
@@ -24,6 +24,85 @@ use wayland_client::protocol::wl_seat::WlSeat;
 use wayland_client::protocol::wl_keyboard::KeymapFormat;
 use xkeysym::Keysym;
 
+const STATIC_KEYCODES: [(Keysym, u8); 76] = [
+    (Keysym::space, 65),
+    (Keysym::apostrophe, 48),
+    (Keysym::comma, 59),
+    (Keysym::minus, 20),
+    (Keysym::period, 60),
+    (Keysym::slash, 61),
+    (Keysym::_0, 19),
+    (Keysym::_1, 10),
+    (Keysym::_2, 11),
+    (Keysym::_3, 12),
+    (Keysym::_4, 13),
+    (Keysym::_5, 14),
+    (Keysym::_6, 15),
+    (Keysym::_7, 16),
+    (Keysym::_8, 17),
+    (Keysym::_9, 18),
+    (Keysym::semicolon, 47),
+    (Keysym::equal, 21),
+    (Keysym::bracketleft, 34),
+    (Keysym::backslash, 51),
+    (Keysym::bracketright, 35),
+    (Keysym::grave, 49),
+    (Keysym::a, 38),
+    (Keysym::b, 56),
+    (Keysym::c, 54),
+    (Keysym::d, 40),
+    (Keysym::e, 26),
+    (Keysym::f, 41),
+    (Keysym::g, 42),
+    (Keysym::h, 43),
+    (Keysym::i, 31),
+    (Keysym::j, 44),
+    (Keysym::k, 45),
+    (Keysym::l, 46),
+    (Keysym::m, 58),
+    (Keysym::n, 57),
+    (Keysym::o, 32),
+    (Keysym::p, 33),
+    (Keysym::q, 24),
+    (Keysym::r, 27),
+    (Keysym::s, 39),
+    (Keysym::t, 28),
+    (Keysym::u, 30),
+    (Keysym::v, 55),
+    (Keysym::w, 25),
+    (Keysym::x, 53),
+    (Keysym::y, 29),
+    (Keysym::z, 52),
+    (Keysym::BackSpace, 22),
+    (Keysym::Tab, 23),
+    (Keysym::Return, 36),
+    (Keysym::Escape, 9),
+    (Keysym::Home, 110),
+    (Keysym::Left, 113),
+    (Keysym::Up, 111),
+    (Keysym::Right, 114),
+    (Keysym::Down, 116),
+    (Keysym::Prior, 112),
+    (Keysym::Next, 117),
+    (Keysym::End, 115),
+    (Keysym::Insert, 118),
+    (Keysym::F1, 67),
+    (Keysym::F2, 68),
+    (Keysym::F3, 69),
+    (Keysym::F4, 70),
+    (Keysym::F5, 71),
+    (Keysym::F6, 72),
+    (Keysym::F7, 73),
+    (Keysym::F8, 74),
+    (Keysym::F9, 75),
+    (Keysym::F10, 76),
+    (Keysym::F11, 95),
+    (Keysym::F12, 96),
+    (Keysym::Shift_L, 50),
+    (Keysym::Control_L, 37),
+    (Keysym::Delete, 119),
+];
+
 pub struct VirtualKeyboard {
     vk: Option<ZwpVirtualKeyboardV1>,
     keymap: File,
@@ -196,6 +275,7 @@ impl Keyboard for VirtualKeyboard {
     fn change_layout(&mut self, layout: &Layout)
     {
         let mut keycode = 8;
+        let mut used_codes = [false; 248];
 
         self.keymap_id = match self.keymap_id {
             0 => 1,
@@ -214,6 +294,23 @@ impl Keyboard for VirtualKeyboard {
         self.keymap.write_all(b"  xkb_symbols \"ufkbd\" {\n").unwrap();
 
         self.keycodes.clear();
+        for row in layout.rows() {
+            for key in row {
+                for part in &key.parts {
+                    if !part.key_available() {
+                        continue;
+                    }
+
+                    if let Ok(idx) = STATIC_KEYCODES.binary_search_by_key(&part.sym(), |(s, _)| *s) {
+                        let (sym, code) = STATIC_KEYCODES[idx];
+                        self.keycodes.insert(sym, code - 8);
+                        self.write_key(part, code);
+                        used_codes[code as usize - 8] = true;
+                    }
+                }
+            }
+        }
+
         for row in layout.rows() {
             for key in row {
                 for part in &key.parts {
@@ -225,6 +322,10 @@ impl Keyboard for VirtualKeyboard {
                         continue;
                     }
 
+                    while used_codes[keycode as usize - 8] {
+                        keycode += 1;
+                    }
+
                     self.keycodes.insert(part.sym(), keycode - 8);
                     self.write_key(part, keycode);
                     keycode += 1;
@@ -242,6 +343,12 @@ impl Keyboard for VirtualKeyboard {
             writeln!(self.keymap, "    <I{:03}> = {};", i, i).unwrap();
         }
 
+        for i in keycode..255 {
+            if used_codes[i as usize - 8] {
+                writeln!(self.keymap, "    <I{:03}> = {};", i, i).unwrap();
+            }
+        }
+
         self.keymap.write_all(b"    indicator 1 = \"Caps Lock\";\n").unwrap();
         self.keymap.write_all(b"  };\n").unwrap();
         self.keymap.write_all(b"\n").unwrap();