fix(macos): build key map with UCKeyTranslate to honor keyboard type

src/lib/platform/CMakeLists.txt

@@ -84,6 +84,8 @@ elseif(APPLE)
     OSXCocoaApp.m
     OSXEventQueueBuffer.cpp
     OSXEventQueueBuffer.h
+    OSXKeyLayoutResource.cpp
+    OSXKeyLayoutResource.h
     OSXKeyState.cpp
     OSXKeyState.h
     OSXMediaKeySupport.h
@@ -99,8 +101,6 @@ elseif(APPLE)
     OSXScreenSaverControl.h
     OSXScreenSaverUtil.h
     OSXScreenSaverUtil.m
-    OSXUchrKeyResource.cpp
-    OSXUchrKeyResource.h
   )
 elseif(UNIX)
   set(PLATFORM_SOURCES

src/lib/platform/OSXKeyLayoutResource.cpp

@@ -0,0 +1,93 @@
+/*
+ * Deskflow -- mouse and keyboard sharing utility
+ * SPDX-FileCopyrightText: (C) 2026 Deskflow Developers
+ * SPDX-License-Identifier: GPL-2.0-only WITH LicenseRef-OpenSSL-Exception
+ */
+
+#include "platform/OSXKeyLayoutResource.h"
+
+// there are 128 virtual key codes and 32 modifier combinations (the
+// right-handed modifier bits are ignored, matching the uchr parser).
+static const uint32_t s_numButtons = 128;
+static const uint32_t s_numModifierCombinations = 32;
+
+OSXKeyLayoutResource::OSXKeyLayoutResource(const void *resource, uint32_t keyboardType)
+    : m_layout(static_cast<const UCKeyboardLayout *>(resource)),
+      m_keyboardType(keyboardType)
+{
+}
+
+bool OSXKeyLayoutResource::isValid() const
+{
+  return m_layout != nullptr;
+}
+
+uint32_t OSXKeyLayoutResource::getNumModifierCombinations() const
+{
+  return s_numModifierCombinations;
+}
+
+uint32_t OSXKeyLayoutResource::getNumTables() const
+{
+  // one table per modifier combination
+  return s_numModifierCombinations;
+}
+
+uint32_t OSXKeyLayoutResource::getNumButtons() const
+{
+  return s_numButtons;
+}
+
+uint32_t OSXKeyLayoutResource::getTableForModifier(uint32_t mask) const
+{
+  // the modifier combination is the table
+  return (mask < s_numModifierCombinations) ? mask : 0;
+}
+
+KeyID OSXKeyLayoutResource::getKey(uint32_t table, uint32_t button) const
+{
+  if (m_layout == nullptr || button >= s_numButtons) {
+    return kKeyNone;
+  }
+
+  // UCKeyTranslate's modifier key state uses the same low five bits as our
+  // table index (cmd, shift, caps, option, control).
+  const UInt32 modifierState = table;
+
+  UInt32 deadKeyState = 0;
+  UniChar chars[4] = {0};
+  UniCharCount count = 0;
+  OSStatus status = UCKeyTranslate(
+      m_layout, static_cast<UInt16>(button), kUCKeyActionDown, modifierState, m_keyboardType, 0, &deadKeyState,
+      sizeof(chars) / sizeof(chars[0]), &count, chars
+  );
+  if (status != noErr) {
+    return kKeyNone;
+  }
+
+  if (count == 0) {
+    // no output.  a non-zero dead-key state means this is a dead key: resolve
+    // it to its spacing character by following it with a space, then convert
+    // to the dead KeyID.
+    if (deadKeyState == 0) {
+      return kKeyNone;
+    }
+    UniChar spaceChars[4] = {0};
+    UniCharCount spaceCount = 0;
+    status = UCKeyTranslate(
+        m_layout, kVK_Space, kUCKeyActionDown, 0, m_keyboardType, 0, &deadKeyState,
+        sizeof(spaceChars) / sizeof(spaceChars[0]), &spaceCount, spaceChars
+    );
+    if (status != noErr || spaceCount != 1) {
+      return kKeyNone;
+    }
+    return deskflow::KeyMap::getDeadKey(unicharToKeyID(spaceChars[0]));
+  }
+
+  // no support for multi-character output (matches the uchr parser).
+  if (count != 1) {
+    return kKeyNone;
+  }
+
+  return unicharToKeyID(chars[0]);
+}

src/lib/platform/OSXKeyLayoutResource.h

@@ -0,0 +1,34 @@
+/*
+ * Deskflow -- mouse and keyboard sharing utility
+ * SPDX-FileCopyrightText: (C) 2026 Deskflow Developers
+ * SPDX-License-Identifier: GPL-2.0-only WITH LicenseRef-OpenSSL-Exception
+ */
+
+#pragma once
+
+#include "platform/IOSXKeyResource.h"
+
+#include <Carbon/Carbon.h>
+
+//! Key resource for a keyboard layout, backed by UCKeyTranslate
+/*!
+Builds the key map for a keyboard layout using UCKeyTranslate.  Each modifier
+combination is treated as its own table.
+*/
+class OSXKeyLayoutResource : public IOSXKeyResource
+{
+public:
+  OSXKeyLayoutResource(const void *resource, uint32_t keyboardType);
+
+  // IOSXKeyResource overrides
+  bool isValid() const override;
+  uint32_t getNumModifierCombinations() const override;
+  uint32_t getNumTables() const override;
+  uint32_t getNumButtons() const override;
+  uint32_t getTableForModifier(uint32_t mask) const override;
+  KeyID getKey(uint32_t table, uint32_t button) const override;
+
+private:
+  const UCKeyboardLayout *m_layout;
+  uint32_t m_keyboardType;
+};

src/lib/platform/OSXKeyState.cpp

@@ -8,8 +8,8 @@
 #include "platform/OSXKeyState.h"
 #include "arch/Arch.h"
 #include "base/Log.h"
+#include "platform/OSXKeyLayoutResource.h"
 #include "platform/OSXMediaKeySupport.h"
-#include "platform/OSXUchrKeyResource.h"
 
 #include <Carbon/Carbon.h>
 #include <IOKit/hidsystem/IOHIDLib.h>
@@ -527,8 +527,7 @@ void OSXKeyState::getKeyMap(deskflow::KeyMap &keyMap)
     const void *resource;
     bool layoutValid = false;
 
-    // add regular keys
+    // add regular keys from the layout's key data
-    // try uchr resource first
     TISInputSourceRef keyboardLayout = (TISInputSourceRef)CFArrayGetValueAtIndex(m_groups.get(), g);
     CFDataRef resourceRef = nullptr;
     {
@@ -541,10 +540,10 @@ void OSXKeyState::getKeyMap(deskflow::KeyMap &keyMap)
       resource = CFDataGetBytePtr(resourceRef);
 
     if (layoutValid) {
-      OSXUchrKeyResource uchr(resource, keyboardType);
+      OSXKeyLayoutResource keyResource(resource, keyboardType);
-      if (uchr.isValid()) {
+      if (keyResource.isValid()) {
-        LOG_VERBOSE("using uchr resource for group %d", g);
+        LOG_VERBOSE("using key layout for group %d", g);
-        getKeyMap(keyMap, g, uchr);
+        getKeyMap(keyMap, g, keyResource);
         continue;
       }
     }

src/lib/platform/OSXUchrKeyResource.cpp

@@ -1,257 +0,0 @@
-/*
- * Deskflow -- mouse and keyboard sharing utility
- * SPDX-FileCopyrightText: (C) 2016 Synergy App Ltd
- * SPDX-License-Identifier: GPL-2.0-only WITH LicenseRef-OpenSSL-Exception
- */
-
-#include "platform/OSXUchrKeyResource.h"
-
-#include <Carbon/Carbon.h>
-
-//
-// OSXUchrKeyResource
-//
-
-OSXUchrKeyResource::OSXUchrKeyResource(const void *resource, uint32_t keyboardType)
-    : m_m(nullptr),
-      m_cti(nullptr),
-      m_sdi(nullptr),
-      m_sri(nullptr),
-      m_st(nullptr)
-{
-  m_resource = static_cast<const UCKeyboardLayout *>(resource);
-  if (m_resource == nullptr) {
-    return;
-  }
-
-  // find the keyboard info for the current keyboard type
-  const UCKeyboardTypeHeader *th = nullptr;
-  const UCKeyboardLayout *r = m_resource;
-  for (ItemCount i = 0; i < r->keyboardTypeCount; ++i) {
-    if (keyboardType >= r->keyboardTypeList[i].keyboardTypeFirst &&
-        keyboardType <= r->keyboardTypeList[i].keyboardTypeLast) {
-      th = r->keyboardTypeList + i;
-      break;
-    }
-    if (r->keyboardTypeList[i].keyboardTypeFirst == 0) {
-      // found the default.  use it unless we find a match.
-      th = r->keyboardTypeList + i;
-    }
-  }
-  if (th == nullptr) {
-    // cannot find a suitable keyboard type
-    return;
-  }
-
-  // get tables for keyboard type
-  const uint8_t *const base = reinterpret_cast<const uint8_t *>(m_resource);
-  m_m = reinterpret_cast<const UCKeyModifiersToTableNum *>(base + th->keyModifiersToTableNumOffset);
-  m_cti = reinterpret_cast<const UCKeyToCharTableIndex *>(base + th->keyToCharTableIndexOffset);
-  m_sdi = reinterpret_cast<const UCKeySequenceDataIndex *>(base + th->keySequenceDataIndexOffset);
-  if (th->keyStateRecordsIndexOffset != 0) {
-    m_sri = reinterpret_cast<const UCKeyStateRecordsIndex *>(base + th->keyStateRecordsIndexOffset);
-  }
-  if (th->keyStateTerminatorsOffset != 0) {
-    m_st = reinterpret_cast<const UCKeyStateTerminators *>(base + th->keyStateTerminatorsOffset);
-  }
-
-  // find the space key, but only if it can combine with dead keys.
-  // a dead key followed by a space yields the non-dead version of
-  // the dead key.
-  m_spaceOutput = 0xffffu;
-  uint32_t table = getTableForModifier(0);
-  for (uint32_t button = 0, n = getNumButtons(); button < n; ++button) {
-    KeyID id = getKey(table, button);
-    if (id == 0x20) {
-      UCKeyOutput c = reinterpret_cast<const UCKeyOutput *>(base + m_cti->keyToCharTableOffsets[table])[button];
-      if ((c & kUCKeyOutputTestForIndexMask) == kUCKeyOutputStateIndexMask) {
-        m_spaceOutput = (c & kUCKeyOutputGetIndexMask);
-        break;
-      }
-    }
-  }
-}
-
-bool OSXUchrKeyResource::isValid() const
-{
-  return (m_m != nullptr);
-}
-
-uint32_t OSXUchrKeyResource::getNumModifierCombinations() const
-{
-  // only 32 (not 256) because the righthanded modifier bits are ignored
-  return 32;
-}
-
-uint32_t OSXUchrKeyResource::getNumTables() const
-{
-  return m_cti->keyToCharTableCount;
-}
-
-uint32_t OSXUchrKeyResource::getNumButtons() const
-{
-  return m_cti->keyToCharTableSize;
-}
-
-uint32_t OSXUchrKeyResource::getTableForModifier(uint32_t mask) const
-{
-  if (mask >= m_m->modifiersCount) {
-    return m_m->defaultTableNum;
-  } else {
-    return m_m->tableNum[mask];
-  }
-}
-
-KeyID OSXUchrKeyResource::getKey(uint32_t table, uint32_t button) const
-{
-  assert(table < getNumTables());
-  assert(button < getNumButtons());
-
-  const uint8_t *const base = reinterpret_cast<const uint8_t *>(m_resource);
-  const UCKeyOutput *cPtr = reinterpret_cast<const UCKeyOutput *>(base + m_cti->keyToCharTableOffsets[table]);
-
-  const UCKeyOutput c = cPtr[button];
-
-  KeySequence keys;
-  switch (c & kUCKeyOutputTestForIndexMask) {
-  case kUCKeyOutputStateIndexMask:
-    if (!getDeadKey(keys, c & kUCKeyOutputGetIndexMask)) {
-      return kKeyNone;
-    }
-    break;
-
-  case kUCKeyOutputSequenceIndexMask:
-  default:
-    if (!addSequence(keys, c)) {
-      return kKeyNone;
-    }
-    break;
-  }
-
-  // XXX -- no support for multiple characters
-  if (keys.size() != 1) {
-    return kKeyNone;
-  }
-
-  return keys.front();
-}
-
-bool OSXUchrKeyResource::getDeadKey(KeySequence &keys, uint16_t index) const
-{
-  if (m_sri == nullptr || index >= m_sri->keyStateRecordCount) {
-    // XXX -- should we be using some other fallback?
-    return false;
-  }
-
-  uint16_t state = 0;
-  if (!getKeyRecord(keys, index, state)) {
-    return false;
-  }
-  if (state == 0) {
-    // not a dead key
-    return true;
-  }
-
-  // no dead keys if we couldn't find the space key
-  if (m_spaceOutput == 0xffffu) {
-    return false;
-  }
-
-  // the dead key should not have put anything in the key list
-  if (!keys.empty()) {
-    return false;
-  }
-
-  // get the character generated by pressing the space key after the
-  // dead key.  if we're still in a compose state afterwards then we're
-  // confused so we bail.
-  if (!getKeyRecord(keys, m_spaceOutput, state) || state != 0) {
-    return false;
-  }
-
-  // convert keys to their dead counterparts
-  for (KeySequence::iterator i = keys.begin(); i != keys.end(); ++i) {
-    *i = deskflow::KeyMap::getDeadKey(*i);
-  }
-
-  return true;
-}
-
-bool OSXUchrKeyResource::getKeyRecord(KeySequence &keys, uint16_t index, uint16_t &state) const
-{
-  const uint8_t *const base = reinterpret_cast<const uint8_t *>(m_resource);
-  const UCKeyStateRecord *sr = reinterpret_cast<const UCKeyStateRecord *>(base + m_sri->keyStateRecordOffsets[index]);
-  const UCKeyStateEntryTerminal *kset = reinterpret_cast<const UCKeyStateEntryTerminal *>(sr->stateEntryData);
-
-  uint16_t nextState = 0;
-  bool found = false;
-  if (state == 0) {
-    found = true;
-    nextState = sr->stateZeroNextState;
-    if (!addSequence(keys, sr->stateZeroCharData)) {
-      return false;
-    }
-  } else {
-    // we have a next entry
-    switch (sr->stateEntryFormat) {
-    case kUCKeyStateEntryTerminalFormat:
-      for (uint16_t j = 0; j < sr->stateEntryCount; ++j) {
-        if (kset[j].curState == state) {
-          if (!addSequence(keys, kset[j].charData)) {
-            return false;
-          }
-          nextState = 0;
-          found = true;
-          break;
-        }
-      }
-      break;
-
-    case kUCKeyStateEntryRangeFormat:
-      // XXX -- not supported yet
-      break;
-
-    default:
-      // XXX -- unknown format
-      return false;
-    }
-  }
-  if (!found) {
-    // use a terminator
-    if (m_st != nullptr && state < m_st->keyStateTerminatorCount) {
-      if (!addSequence(keys, m_st->keyStateTerminators[state - 1])) {
-        return false;
-      }
-    }
-    nextState = sr->stateZeroNextState;
-    if (!addSequence(keys, sr->stateZeroCharData)) {
-      return false;
-    }
-  }
-
-  // next
-  state = nextState;
-
-  return true;
-}
-
-bool OSXUchrKeyResource::addSequence(KeySequence &keys, UCKeyCharSeq c) const
-{
-  if ((c & kUCKeyOutputTestForIndexMask) == kUCKeyOutputSequenceIndexMask) {
-    uint16_t index = (c & kUCKeyOutputGetIndexMask);
-    if (index < m_sdi->charSequenceCount &&
-        m_sdi->charSequenceOffsets[index] != m_sdi->charSequenceOffsets[index + 1]) {
-      // XXX -- sequences not supported yet
-      return false;
-    }
-  }
-
-  if (c != 0xfffe && c != 0xffff) {
-    KeyID id = unicharToKeyID(c);
-    if (id != kKeyNone) {
-      keys.push_back(id);
-    }
-  }
-
-  return true;
-}

src/lib/platform/OSXUchrKeyResource.h

@@ -1,43 +0,0 @@
-/*
- * Deskflow -- mouse and keyboard sharing utility
- * SPDX-FileCopyrightText: (C) 2016 Synergy App Ltd
- * SPDX-License-Identifier: GPL-2.0-only WITH LicenseRef-OpenSSL-Exception
- */
-
-#pragma once
-
-#include "platform/IOSXKeyResource.h"
-
-#include <Carbon/Carbon.h>
-
-using KeyLayout = TISInputSourceRef;
-
-class OSXUchrKeyResource : public IOSXKeyResource
-{
-public:
-  OSXUchrKeyResource(const void *, uint32_t keyboardType);
-
-  // KeyResource overrides
-  bool isValid() const override;
-  uint32_t getNumModifierCombinations() const override;
-  uint32_t getNumTables() const override;
-  uint32_t getNumButtons() const override;
-  uint32_t getTableForModifier(uint32_t mask) const override;
-  KeyID getKey(uint32_t table, uint32_t button) const override;
-
-private:
-  using KeySequence = std::vector<KeyID>;
-
-  bool getDeadKey(KeySequence &keys, uint16_t index) const;
-  bool getKeyRecord(KeySequence &keys, uint16_t index, uint16_t &state) const;
-  bool addSequence(KeySequence &keys, UCKeyCharSeq c) const;
-
-private:
-  const UCKeyboardLayout *m_resource;
-  const UCKeyModifiersToTableNum *m_m;
-  const UCKeyToCharTableIndex *m_cti;
-  const UCKeySequenceDataIndex *m_sdi;
-  const UCKeyStateRecordsIndex *m_sri;
-  const UCKeyStateTerminators *m_st;
-  uint16_t m_spaceOutput;
-};