feat(ime): generalize IME key-mapping to any installed input source (multilingual)

apps/cmd-ime-swift/Sources/CmdIMESwift/InputSourceCatalog.swift

@@ -0,0 +1,97 @@
+//
+//  InputSourceCatalog.swift
+//  ⌘IME
+//
+//  Enumerates and selects installed keyboard input sources for the
+//  multilingual key-mapping action (Settings > Shortcuts). This is a
+//  distinct mechanism from the Eisu/Kana key-post in
+//  `KeyboardShortcut.postEvent()`: that one drives the Japanese IME's
+//  internal mode by synthesizing keystrokes, because bare
+//  `TISSelectInputSource` only moves the menu-bar indicator for it. Every
+//  other language's mapping (ABC <-> Pinyin, ABC <-> 2-Set Korean, ...) is a
+//  switch between *separate* input sources, where `TISSelectInputSource`
+//  works directly — confirmed live by InputSourceSwitchSpikeTests.
+//
+
+import Carbon.HIToolbox
+import Foundation
+
+enum InputSourceCatalog {
+    struct Entry: Identifiable, Equatable {
+        let id: String
+        let localizedName: String
+    }
+
+    /// Installed (enabled or not) selectable keyboard input sources —
+    /// standalone layouts (e.g. ABC) and IME modes (e.g. Google Japanese's
+    /// `.base`, SCIM's `.ITABC`). Filtering by category + select-capable
+    /// naturally excludes both the parent input-method entries (not
+    /// select-capable themselves, only their modes are) and palette sources
+    /// (Character Viewer, emoji, etc. sit in a different category — a known
+    /// contamination risk when enumerating "enabled sources" naively).
+    static func selectableKeyboardSources() -> [Entry] {
+        let conditions = [
+            kTISPropertyInputSourceCategory as String: kTISCategoryKeyboardInputSource as Any,
+            kTISPropertyInputSourceIsSelectCapable as String: true
+        ] as CFDictionary
+        guard let list = TISCreateInputSourceList(conditions, true)?.takeRetainedValue() else { return [] }
+        let sources = (list as NSArray) as? [TISInputSource] ?? []
+        return sources.compactMap { source -> Entry? in
+            guard let id = stringProperty(source, kTISPropertyInputSourceID) else { return nil }
+            let name = stringProperty(source, kTISPropertyLocalizedName) ?? id
+            return Entry(id: id, localizedName: name)
+        }
+        .sorted { $0.localizedName < $1.localizedName }
+    }
+
+    /// Enables `id`'s parent input method (if it has one) and `id` itself
+    /// when needed, then selects it. A mode's parent is not enabled
+    /// automatically by enabling the mode — see InputSourceSwitchSpikeTests,
+    /// which found this the hard way for SCIM.ITABC / Korean.2SetKorean.
+    /// Returns false if `id` isn't installed or the select call fails.
+    @discardableResult
+    static func select(id: String) -> Bool {
+        guard let source = find(id: id) else { return false }
+
+        if let parentID = parentCandidateID(for: id),
+           let parent = find(id: parentID), !isEnabled(parent) {
+            TISEnableInputSource(parent)
+        }
+        if !isEnabled(source) {
+            TISEnableInputSource(source)
+        }
+        return TISSelectInputSource(source) == noErr
+    }
+
+    /// A mode id's parent input method id is conventionally its id with the
+    /// last dot-separated component dropped (`com.apple.inputmethod.SCIM.ITABC`
+    /// -> `com.apple.inputmethod.SCIM`, `com.google.inputmethod.Japanese.base`
+    /// -> `com.google.inputmethod.Japanese`). `kTISPropertyInputModeID` isn't
+    /// reliable for this: it can equal the mode's own id (SCIM.ITABC) instead
+    /// of the parent's. Standalone layouts (`com.apple.keylayout.ABC`) yield a
+    /// candidate that resolves to no installed source, which is correct — they
+    /// have no parent to enable.
+    static func parentCandidateID(for id: String) -> String? {
+        guard let lastDot = id.lastIndex(of: ".") else { return nil }
+        return String(id[..<lastDot])
+    }
+
+    // MARK: - TIS helpers
+
+    private static func find(id: String) -> TISInputSource? {
+        let conditions = [kTISPropertyInputSourceID as String: id] as CFDictionary
+        guard let list = TISCreateInputSourceList(conditions, true)?.takeRetainedValue() else { return nil }
+        let sources = (list as NSArray) as? [TISInputSource] ?? []
+        return sources.first
+    }
+
+    private static func isEnabled(_ source: TISInputSource) -> Bool {
+        guard let ptr = TISGetInputSourceProperty(source, kTISPropertyInputSourceIsEnabled) else { return false }
+        return CFBooleanGetValue(Unmanaged<CFBoolean>.fromOpaque(ptr).takeUnretainedValue())
+    }
+
+    private static func stringProperty(_ source: TISInputSource, _ key: CFString) -> String? {
+        guard let ptr = TISGetInputSourceProperty(source, key) else { return nil }
+        return Unmanaged<CFString>.fromOpaque(ptr).takeUnretainedValue() as String
+    }
+}

apps/cmd-ime-swift/Sources/CmdIMESwift/KeyEvent.swift

@@ -34,6 +34,12 @@ class KeyEvent: NSObject {
     // system-wide event.
     var postModifierTap: (KeyboardShortcut) -> Void = { $0.postEvent() }
 
+    // Test seam: modifierKeyUp selects a TIS input source through this when
+    // the mapping carries `outputInputSourceID` instead of a key-post output.
+    // Overridden in unit tests to capture the selection instead of mutating
+    // real system input-source state.
+    var selectInputSourceAction: (String) -> Void = { InputSourceCatalog.select(id: $0) }
+
     var isExclusionApp = false
     let bundleId = Bundle.main.infoDictionary?["CFBundleIdentifier"] as? String ?? "com.kazuki.cmdime"
 
@@ -370,13 +376,15 @@ class KeyEvent: NSObject {
     func modifierKeyUp(_ event: CGEvent) -> Unmanaged<CGEvent>? {
         let code = CGKeyCode(event.getIntegerValueField(.keyboardEventKeycode))
 
-        if pendingModifierTaps.remove(code) != nil,
-           let mapping = findMapping(for: event),
-           mapping.output.keyCode != 999 {
-            // Post the bare output shortcut. Residual held modifiers (e.g. a
-            // still-held Shift) must not leak into the synthesized tap, or
-            // the IME sees Shift+英数 instead of 英数 and ignores it.
-            postModifierTap(KeyboardShortcut(keyCode: mapping.output.keyCode, flags: mapping.output.flags))
+        if pendingModifierTaps.remove(code) != nil, let mapping = findMapping(for: event) {
+            if let sourceID = mapping.outputInputSourceID {
+                selectInputSourceAction(sourceID)
+            } else if mapping.output.keyCode != 999 {
+                // Post the bare output shortcut. Residual held modifiers (e.g. a
+                // still-held Shift) must not leak into the synthesized tap, or
+                // the IME sees Shift+英数 instead of 英数 and ignores it.
+                postModifierTap(KeyboardShortcut(keyCode: mapping.output.keyCode, flags: mapping.output.flags))
+            }
         }
 
         return Unmanaged.passRetained(event)

apps/cmd-ime-swift/Sources/CmdIMESwift/KeyMapping.swift

@@ -15,11 +15,17 @@ class KeyMapping: NSObject, Identifiable {
     var input: KeyboardShortcut
     var output: KeyboardShortcut
     var enable: Bool
+    // Non-nil selects this TIS input source id via InputSourceCatalog.select(id:)
+    // instead of posting `output` as a key (see KeyEvent.modifierKeyUp). Mutually
+    // exclusive with a key-post output — set by updateKeyMappingOutputSource(at:)
+    // and cleared whenever a key-based output is chosen again.
+    var outputInputSourceID: String?
 
-    init(input: KeyboardShortcut, output: KeyboardShortcut, enable: Bool = true) {
+    init(input: KeyboardShortcut, output: KeyboardShortcut, enable: Bool = true, outputInputSourceID: String? = nil) {
         self.input = input
         self.output = output
         self.enable = enable
+        self.outputInputSourceID = outputInputSourceID
 
         super.init()
     }
@@ -28,6 +34,7 @@ class KeyMapping: NSObject, Identifiable {
         input = KeyboardShortcut()
         output = KeyboardShortcut()
         self.enable = true
+        self.outputInputSourceID = nil
         super.init()
     }
 
@@ -41,6 +48,8 @@ class KeyMapping: NSObject, Identifiable {
             self.input = inputKey
             self.output = outputKey
             self.enable = enable
+            // Absent in dictionaries persisted before this field existed.
+            self.outputInputSourceID = dictionary["outputInputSourceID"] as? String
 
             super.init()
         } else {
@@ -49,10 +58,12 @@ class KeyMapping: NSObject, Identifiable {
     }
 
     func toDictionary() -> [AnyHashable: Any] {
-        return [
+        var dictionary: [AnyHashable: Any] = [
             "input": input.toDictionary(),
             "output": output.toDictionary(),
             "enable": enable
         ]
+        dictionary["outputInputSourceID"] = outputInputSourceID
+        return dictionary
     }
 }

apps/cmd-ime-swift/Sources/CmdIMESwift/Resources/Localizable.xcstrings

@@ -2871,6 +2871,47 @@
         }
       }
     },
+    "shortcuts.actionSwitchToInputSource": {
+      "extractionState": "manual",
+      "localizations": {
+        "en": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Switch to Input Source"
+          }
+        },
+        "ja": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "入力ソースに切り替え"
+          }
+        },
+        "zh-Hans": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "切换到输入法"
+          }
+        },
+        "zh-Hant": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "切換到輸入方式"
+          }
+        },
+        "ko": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "입력 소스로 전환"
+          }
+        },
+        "vi": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Chuyển sang nguồn nhập"
+          }
+        }
+      }
+    },
     "shortcuts.actionDisableKey": {
       "extractionState": "manual",
       "localizations": {

apps/cmd-ime-swift/Sources/CmdIMESwift/Resources/en.lproj/Localizable.strings

@@ -118,6 +118,8 @@
 	<string>Choose what happens when this key is pressed</string>
 	<key>shortcuts.actionSwitchToAlphanumeric</key>
 	<string>Switch to Alphanumeric</string>
+	<key>shortcuts.actionSwitchToInputSource</key>
+	<string>Switch to Input Source</string>
 	<key>shortcuts.actionSwitchToKana</key>
 	<string>Switch to Kana</string>
 	<key>shortcuts.addButton</key>

apps/cmd-ime-swift/Sources/CmdIMESwift/Resources/ja.lproj/Localizable.strings

@@ -118,6 +118,8 @@
 	<string>このキーを押したときの動作を選択します</string>
 	<key>shortcuts.actionSwitchToAlphanumeric</key>
 	<string>英数に切り替え</string>
+	<key>shortcuts.actionSwitchToInputSource</key>
+	<string>入力ソースに切り替え</string>
 	<key>shortcuts.actionSwitchToKana</key>
 	<string>かなに切り替え</string>
 	<key>shortcuts.addButton</key>

apps/cmd-ime-swift/Sources/CmdIMESwift/Resources/ko.lproj/Localizable.strings

@@ -118,6 +118,8 @@
 	<string>이 키를 눌렀을 때 실행할 작업을 선택하세요</string>
 	<key>shortcuts.actionSwitchToAlphanumeric</key>
 	<string>영숫자로 전환</string>
+	<key>shortcuts.actionSwitchToInputSource</key>
+	<string>입력 소스로 전환</string>
 	<key>shortcuts.actionSwitchToKana</key>
 	<string>가나로 전환</string>
 	<key>shortcuts.addButton</key>

apps/cmd-ime-swift/Sources/CmdIMESwift/Resources/vi.lproj/Localizable.strings

@@ -118,6 +118,8 @@
 	<string>Chọn điều xảy ra khi phím này được nhấn</string>
 	<key>shortcuts.actionSwitchToAlphanumeric</key>
 	<string>Chuyển sang chữ và số</string>
+	<key>shortcuts.actionSwitchToInputSource</key>
+	<string>Chuyển sang nguồn nhập</string>
 	<key>shortcuts.actionSwitchToKana</key>
 	<string>Chuyển sang Kana</string>
 	<key>shortcuts.addButton</key>

apps/cmd-ime-swift/Sources/CmdIMESwift/Resources/zh-Hans.lproj/Localizable.strings

@@ -118,6 +118,8 @@
 	<string>选择按下此键时执行的操作</string>
 	<key>shortcuts.actionSwitchToAlphanumeric</key>
 	<string>切换到英数</string>
+	<key>shortcuts.actionSwitchToInputSource</key>
+	<string>切换到输入法</string>
 	<key>shortcuts.actionSwitchToKana</key>
 	<string>切换到假名</string>
 	<key>shortcuts.addButton</key>

apps/cmd-ime-swift/Sources/CmdIMESwift/Resources/zh-Hant.lproj/Localizable.strings

@@ -118,6 +118,8 @@
 	<string>選擇按下此按鍵時執行的操作</string>
 	<key>shortcuts.actionSwitchToAlphanumeric</key>
 	<string>切換到英數</string>
+	<key>shortcuts.actionSwitchToInputSource</key>
+	<string>切換到輸入方式</string>
 	<key>shortcuts.actionSwitchToKana</key>
 	<string>切換到假名</string>
 	<key>shortcuts.addButton</key>

apps/cmd-ime-swift/Sources/CmdIMESwift/Settings/AppSettings.swift

@@ -138,7 +138,12 @@ final class AppSettings: ObservableObject {
     func updateKeyMapping(at index: Int, input: KeyboardShortcut? = nil, output: KeyboardShortcut? = nil) {
         guard keyMappings.indices.contains(index) else { return }
         if let input = input { keyMappings[index].input = input }
-        if let output = output { keyMappings[index].output = output }
+        if let output = output {
+            keyMappings[index].output = output
+            // A key-post output supersedes any input-source output previously
+            // chosen on this row — the two mechanisms are mutually exclusive.
+            keyMappings[index].outputInputSourceID = nil
+        }
         // A freshly-added row stays disabled until both sides have been
         // explicitly chosen through the preset menus (see addKeyMapping()).
         if !keyMappings[index].input.isUnset && !keyMappings[index].output.isUnset {
@@ -147,6 +152,17 @@ final class AppSettings: ObservableObject {
         keyMappings = keyMappings  // trigger didSet
     }
 
+    /// Sets this row's action to "select this input source" (TIS mechanism)
+    /// instead of posting a key. See KeyMapping.outputInputSourceID.
+    func updateKeyMappingOutputSource(at index: Int, sourceID: String) {
+        guard keyMappings.indices.contains(index) else { return }
+        keyMappings[index].outputInputSourceID = sourceID
+        if !keyMappings[index].input.isUnset {
+            keyMappings[index].enable = true
+        }
+        keyMappings = keyMappings  // trigger didSet
+    }
+
     func addExclusion(_ app: AppData) {
         guard !exclusionApps.contains(where: { $0.id == app.id }) else { return }
         exclusionApps.append(app)