fix: correct keyboard scancode mapping from KeyTranslator.java

The mapping was built assuming keynr followed physical keyboard order
with Escape=0. In reality, KeyTranslator.java maps Java VK_* codes to
keynr values with a different layout:

- keynr 0 = Backquote (not Escape)
- keynr 59 = Escape
- keynr 27 = Enter (not 40)
- keynr 40 = Backslash (not 42)

This caused the number row and QWERTY row to be off by 1 (Escape
was inserted at position 0, pushing everything). The home row
(CapsLock=28, A=29...L=37) happened to align by coincidence, which
is why 'g'(33) worked but 'r'(should be 18, was 19=T) didn't.

Also fixes: F1-F12 off by 1, PrintScreen/ScrollLock/Pause off by 1,
numpad operator keys swapped with numpad 7/8/9.

Corrected both Rust (input.rs) and TypeScript (input.ts) mappings
to match the authoritative KeyTranslator.java VK→keynr table.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

crates/ericrfb-frontend/src/input.ts

@@ -1,47 +1,59 @@
 // JavaScript KeyboardEvent.code → e-RIC scancode (KbdLayout_104pc)
+// Derived from KeyTranslator.java line 14 (Java VK_* → keynr table).
 // Must match crates/ericrfb/src/input.rs js_code_to_scancode()
 
 const KEY_MAP: Record<string, number> = {
-  Escape: 0,
+  // Number row (keynr 0-13)
-  F1: 59, F2: 60, F3: 61, F4: 62, F5: 63, F6: 64,
+  Backquote: 0,
-  F7: 65, F8: 66, F9: 67, F10: 68, F11: 69, F12: 70,
+  Digit1: 1, Digit2: 2, Digit3: 3, Digit4: 4, Digit5: 5,
+  Digit6: 6, Digit7: 7, Digit8: 8, Digit9: 9, Digit0: 10,
+  Minus: 11, Equal: 12, Backspace: 13,
 
-  Backquote: 1,
+  // QWERTY row (keynr 14-27)
-  Digit1: 2, Digit2: 3, Digit3: 4, Digit4: 5, Digit5: 6,
+  Tab: 14,
-  Digit6: 7, Digit7: 8, Digit8: 9, Digit9: 10, Digit0: 11,
+  KeyQ: 15, KeyW: 16, KeyE: 17, KeyR: 18, KeyT: 19,
-  Minus: 12, Equal: 13, Backspace: 14,
+  KeyY: 20, KeyU: 21, KeyI: 22, KeyO: 23, KeyP: 24,
-
+  BracketLeft: 25, BracketRight: 26, Enter: 27,
-  Tab: 15,
-  KeyQ: 16, KeyW: 17, KeyE: 18, KeyR: 19, KeyT: 20,
-  KeyY: 21, KeyU: 22, KeyI: 23, KeyO: 24, KeyP: 25,
-  BracketLeft: 26, BracketRight: 27,
 
+  // Home row (keynr 28-40)
   CapsLock: 28,
   KeyA: 29, KeyS: 30, KeyD: 31, KeyF: 32, KeyG: 33,
   KeyH: 34, KeyJ: 35, KeyK: 36, KeyL: 37,
-  Semicolon: 38, Quote: 39, Enter: 40,
+  Semicolon: 38, Quote: 39, Backslash: 40,
 
-  ShiftLeft: 41, Backslash: 42,
+  // Bottom row (keynr 41-53)
+  ShiftLeft: 41,
   KeyZ: 43, KeyX: 44, KeyC: 45, KeyV: 46, KeyB: 47,
   KeyN: 48, KeyM: 49, Comma: 50, Period: 51, Slash: 52,
   ShiftRight: 53,
 
-  ControlLeft: 54, MetaLeft: 105, AltLeft: 55,
+  // Modifiers (keynr 54-58)
-  Space: 56,
+  ControlLeft: 54, AltLeft: 55, Space: 56,
-  AltRight: 57, MetaRight: 106, ControlRight: 58,
+  AltRight: 57, ControlRight: 58,
 
-  PrintScreen: 71, ScrollLock: 72, Pause: 73,
+  // Escape + Function keys (keynr 59-71)
+  Escape: 59,
+  F1: 60, F2: 61, F3: 62, F4: 63, F5: 64, F6: 65,
+  F7: 66, F8: 67, F9: 68, F10: 69, F11: 70, F12: 71,
+
+  // Navigation cluster (keynr 72-84)
+  PrintScreen: 72, ScrollLock: 73, Pause: 74,
   Insert: 75, Home: 76, PageUp: 77,
   Delete: 78, End: 79, PageDown: 80,
-
   ArrowUp: 81, ArrowLeft: 82, ArrowDown: 83, ArrowRight: 84,
 
-  NumLock: 85, NumpadDivide: 86, NumpadMultiply: 87, NumpadSubtract: 88,
+  // Numpad (keynr 85-101)
-  NumpadAdd: 89, NumpadEnter: 98,
+  NumLock: 85,
-  Numpad7: 90, Numpad8: 94, Numpad9: 99,
+  Numpad7: 86, Numpad8: 87, Numpad9: 88,
+  NumpadAdd: 89, NumpadDivide: 90,
   Numpad4: 91, Numpad5: 92, Numpad6: 93,
+  NumpadMultiply: 94,
   Numpad1: 95, Numpad2: 96, Numpad3: 97,
+  NumpadEnter: 98, NumpadSubtract: 99,
   Numpad0: 100, NumpadDecimal: 101,
+
+  // Windows/Meta keys (keynr 105-106)
+  MetaLeft: 105, MetaRight: 106,
 }
 
 export function codeToScancode(code: string): number | undefined {

crates/ericrfb/src/input.rs

@@ -49,54 +49,41 @@ pub const HOTKEY_CTRL_ALT_DEL: &str = "36 f0 37 f0 4e";
 /// Map a JavaScript `KeyboardEvent.code` string to an e-RIC scancode.
 /// Returns `None` for unmapped keys.
 pub fn js_code_to_scancode(code: &str) -> Option<u8> {
+    // Mapping derived from KeyTranslator.java line 14 (Java VK_* → keynr table).
     Some(match code {
-        // Function row
+        // Number row (keynr 0-13)
-        "Escape" => 0,
+        "Backquote" => 0,
-        "F1" => 59,
+        "Digit1" => 1,
-        "F2" => 60,
+        "Digit2" => 2,
-        "F3" => 61,
+        "Digit3" => 3,
-        "F4" => 62,
+        "Digit4" => 4,
-        "F5" => 63,
+        "Digit5" => 5,
-        "F6" => 64,
+        "Digit6" => 6,
-        "F7" => 65,
+        "Digit7" => 7,
-        "F8" => 66,
+        "Digit8" => 8,
-        "F9" => 67,
+        "Digit9" => 9,
-        "F10" => 68,
+        "Digit0" => 10,
-        "F11" => 69,
+        "Minus" => 11,
-        "F12" => 70,
+        "Equal" => 12,
+        "Backspace" => 13,
 
-        // Number row
+        // QWERTY row (keynr 14-27)
-        "Backquote" => 1,
+        "Tab" => 14,
-        "Digit1" => 2,
+        "KeyQ" => 15,
-        "Digit2" => 3,
+        "KeyW" => 16,
-        "Digit3" => 4,
+        "KeyE" => 17,
-        "Digit4" => 5,
+        "KeyR" => 18,
-        "Digit5" => 6,
+        "KeyT" => 19,
-        "Digit6" => 7,
+        "KeyY" => 20,
-        "Digit7" => 8,
+        "KeyU" => 21,
-        "Digit8" => 9,
+        "KeyI" => 22,
-        "Digit9" => 10,
+        "KeyO" => 23,
-        "Digit0" => 11,
+        "KeyP" => 24,
-        "Minus" => 12,
+        "BracketLeft" => 25,
-        "Equal" => 13,
+        "BracketRight" => 26,
-        "Backspace" => 14,
+        "Enter" => 27,
 
-        // QWERTY row
+        // Home row (keynr 28-40)
-        "Tab" => 15,
-        "KeyQ" => 16,
-        "KeyW" => 17,
-        "KeyE" => 18,
-        "KeyR" => 19,
-        "KeyT" => 20,
-        "KeyY" => 21,
-        "KeyU" => 22,
-        "KeyI" => 23,
-        "KeyO" => 24,
-        "KeyP" => 25,
-        "BracketLeft" => 26,
-        "BracketRight" => 27,
-
-        // Home row
         "CapsLock" => 28,
         "KeyA" => 29,
         "KeyS" => 30,
@@ -109,11 +96,10 @@ pub fn js_code_to_scancode(code: &str) -> Option<u8> {
         "KeyL" => 37,
         "Semicolon" => 38,
         "Quote" => 39,
-        "Enter" => 40,
+        "Backslash" => 40,
 
-        // Bottom row
+        // Bottom row (keynr 41-53)
         "ShiftLeft" => 41,
-        "Backslash" => 42,
         "KeyZ" => 43,
         "KeyX" => 44,
         "KeyC" => 45,
@@ -126,51 +112,66 @@ pub fn js_code_to_scancode(code: &str) -> Option<u8> {
         "Slash" => 52,
         "ShiftRight" => 53,
 
-        // Modifier / bottom row
+        // Modifiers (keynr 54-58)
         "ControlLeft" => 54,
-        "MetaLeft" => 105,
         "AltLeft" => 55,
         "Space" => 56,
         "AltRight" => 57,
-        "MetaRight" => 106,
         "ControlRight" => 58,
 
-        // Navigation cluster
+        // Escape + Function keys (keynr 59-71)
-        "PrintScreen" => 71,
+        "Escape" => 59,
-        "ScrollLock" => 72,
+        "F1" => 60,
-        "Pause" => 73,
+        "F2" => 61,
+        "F3" => 62,
+        "F4" => 63,
+        "F5" => 64,
+        "F6" => 65,
+        "F7" => 66,
+        "F8" => 67,
+        "F9" => 68,
+        "F10" => 69,
+        "F11" => 70,
+        "F12" => 71,
+
+        // Navigation cluster (keynr 72-84)
+        "PrintScreen" => 72,
+        "ScrollLock" => 73,
+        "Pause" => 74,
         "Insert" => 75,
         "Home" => 76,
         "PageUp" => 77,
         "Delete" => 78,
         "End" => 79,
         "PageDown" => 80,
-
-        // Arrow keys
         "ArrowUp" => 81,
         "ArrowLeft" => 82,
         "ArrowDown" => 83,
         "ArrowRight" => 84,
 
-        // Numpad
+        // Numpad (keynr 85-101)
         "NumLock" => 85,
-        "NumpadDivide" => 86,
+        "Numpad7" => 86,
-        "NumpadMultiply" => 87,
+        "Numpad8" => 87,
-        "NumpadSubtract" => 88,
+        "Numpad9" => 88,
         "NumpadAdd" => 89,
-        "NumpadEnter" => 98,
+        "NumpadDivide" => 90,
-        "Numpad7" => 90,
-        "Numpad8" => 94,
-        "Numpad9" => 99,
         "Numpad4" => 91,
         "Numpad5" => 92,
         "Numpad6" => 93,
+        "NumpadMultiply" => 94,
         "Numpad1" => 95,
         "Numpad2" => 96,
         "Numpad3" => 97,
+        "NumpadEnter" => 98,
+        "NumpadSubtract" => 99,
         "Numpad0" => 100,
         "NumpadDecimal" => 101,
 
+        // Windows/Meta keys (keynr 105-106)
+        "MetaLeft" => 105,
+        "MetaRight" => 106,
+
         _ => return None,
     })
 }
@@ -214,10 +215,20 @@ mod tests {
 
     #[test]
     fn test_js_code_mapping() {
+        // From KeyTranslator.java: VK_A(65)→29, VK_ESCAPE(27)→59, etc.
         assert_eq!(js_code_to_scancode("KeyA"), Some(29));
-        assert_eq!(js_code_to_scancode("Escape"), Some(0));
+        assert_eq!(js_code_to_scancode("KeyR"), Some(18));
+        assert_eq!(js_code_to_scancode("KeyG"), Some(33));
+        assert_eq!(js_code_to_scancode("Escape"), Some(59));
+        assert_eq!(js_code_to_scancode("Backspace"), Some(13));
+        assert_eq!(js_code_to_scancode("Enter"), Some(27));
+        assert_eq!(js_code_to_scancode("Backslash"), Some(40));
+        assert_eq!(js_code_to_scancode("Backquote"), Some(0));
+        assert_eq!(js_code_to_scancode("F1"), Some(60));
         assert_eq!(js_code_to_scancode("ControlLeft"), Some(54));
         assert_eq!(js_code_to_scancode("Delete"), Some(78));
+        assert_eq!(js_code_to_scancode("Numpad7"), Some(86));
+        assert_eq!(js_code_to_scancode("NumpadMultiply"), Some(94));
         assert_eq!(js_code_to_scancode("Unknown"), None);
     }
 }