1.8.7 // Rescue. Merge Gitee PR!73 from dev/bleed

2022-08-02 13:49:01 +00:00 · 2022-08-02 13:49:01 +00:00 · d5f0ed4b6f
parent a306097358 0c316aa30f
commit d5f0ed4b6f
43 changed files with 781 additions and 411 deletions
--- a/README-CHT.md
+++ b/README-CHT.md
@ -97,7 +97,7 @@
 - 天權星語彙處理引擎：Shiki Suen (MIT-NTL License)。
 - 威注音詞庫由 Shiki Suen 維護，以 3-Clause BSD License 授權釋出。其中的詞頻數據[由 NAER 授權用於非商業用途](https://twitter.com/ShikiSuen/status/1479329302713831424)。

-使用者可自由使用、散播本軟體，惟散播時必須完整保留版權聲明及軟體授權、且一旦經過修改便不可以再繼續使用威注音的產品名稱。
+使用者可自由使用、散播本軟體，惟散播時必須完整保留版權聲明及軟體授權、且「一旦經過修改便不可以再繼續使用威注音的產品名稱」。換言之，這條相對上游 MIT 而言新增的規定就是：你 Fork 可以，但 Fork 成單獨發行的產品名稱時就必須修改產品名稱。這條新增規定對 OpenVanilla 與威注音雙方都有益，免得各自的旗號被盜版下載販子等挪用做意外用途。

 ## 資料來源

--- a/README.md
+++ b/README.md
@ -97,7 +97,7 @@
 - 天权星语汇处理引擎：Shiki Suen (MIT-NTL License)。
 - 威注音词库由 Shiki Suen 维护，以 3-Clause BSD License 授权释出。其中的词频数据[由 NAER 授权用于非商业用途](https://twitter.com/ShikiSuen/status/1479329302713831424)。

-使用者可自由使用、散播本软件，惟散播时必须完整保留版权声明及软件授权、且一旦经过修改便不可以再继续使用威注音的产品名称。
+使用者可自由使用、散播本软件，惟散播时必须完整保留版权声明及软件授权、且「一旦经过修改便不可以再继续使用威注音的产品名称」。换言之，这条相对上游 MIT 而言新增的规定就是：你 Fork 可以，但 Fork 成单独发行的产品名称时就必须修改产品名称。这条新增规定对 OpenVanilla 与威注音双方都有益，免得各自的旗号被盗版下载贩子等挪用做意外用途。

 ## 资料来源

--- a/Source/Data
+++ b/Source/Data
@ -1 +1 @@
-Subproject commit 30a5bc773a21d67c3f117eef5346d3b35433bbaa
+Subproject commit 144db528de84caff0fa20802b144421bcc58419f
--- a/Source/Modules/AppDelegate.swift
+++ b/Source/Modules/AppDelegate.swift
@ -29,7 +29,7 @@ import InputMethodKit

@objc(AppDelegate)
 class AppDelegate: NSObject, NSApplicationDelegate, ctlNonModalAlertWindowDelegate,
-  FSEventStreamHelperDelegate
+  FSEventStreamHelperDelegate, NSUserNotificationCenterDelegate
 {
  func helper(_: FSEventStreamHelper, didReceive _: [FSEventStreamHelper.Event]) {
    // 拖 100ms 再重載，畢竟有些有特殊需求的使用者可能會想使用巨型自訂語彙檔案。
@ -63,7 +63,25 @@ class AppDelegate: NSObject, NSApplicationDelegate, ctlNonModalAlertWindowDelega
    fsStreamHelper.delegate = nil
  }

+  func userNotificationCenter(_: NSUserNotificationCenter, shouldPresent _: NSUserNotification) -> Bool {
+    return true
+  }
+
  func applicationDidFinishLaunching(_: Notification) {
+    NSUserNotificationCenter.default.delegate = self
+    // 一旦發現與使用者半衰模組的觀察行為有關的崩潰標記被開啟，就清空既有的半衰記憶資料檔案。
+    if mgrPrefs.failureFlagForUOMObservation {
+      mgrLangModel.clearUserOverrideModelData(.imeModeCHS)
+      mgrLangModel.clearUserOverrideModelData(.imeModeCHT)
+      mgrPrefs.failureFlagForUOMObservation = false
+      let userNotification = NSUserNotification()
+      userNotification.title = NSLocalizedString("vChewing", comment: "")
+      userNotification.informativeText =
+        "\(NSLocalizedString("vChewing crashed while handling previously loaded UOM observation data. These data files are cleaned now to ensure the usability.", comment: ""))"
+      userNotification.soundName = NSUserNotificationDefaultSoundName
+      NSUserNotificationCenter.default.deliver(userNotification)
+    }
+
    DispatchQueue.main.asyncAfter(deadline: DispatchTime.now()) {
      IME.initLangModels(userOnly: false)
    }
--- a/Source/Modules/ControllerModules/InputState.swift
+++ b/Source/Modules/ControllerModules/InputState.swift
@ -29,7 +29,7 @@ import Cocoa
 // 註：所有 InputState 型別均不適合使用 Struct，因為 Struct 無法相互繼承派生。

 // 用以讓每個狀態自描述的 enum。
-enum StateType {
+public enum StateType {
  case ofDeactivated
  case ofAssociatedPhrases
  case ofEmpty
@ -38,12 +38,12 @@ enum StateType {
  case ofNotEmpty
  case ofInputting
  case ofMarking
-  case ofChooseCandidate
+  case ofChoosingCandidate
  case ofSymbolTable
 }

 // 所有 InputState 均遵守該協定：
-protocol InputStateProtocol {
+public protocol InputStateProtocol {
  var type: StateType { get }
 }

@ -79,7 +79,7 @@ protocol InputStateProtocol {
 ///   詞音組合放入語彙濾除清單。
 /// - .ChoosingCandidate: 叫出選字窗、允許使用者選字。
 /// - .SymbolTable: 波浪鍵符號選單專用的狀態，有自身的特殊處理。
-enum InputState {
+public enum InputState {
  /// .Deactivated: 使用者沒在使用輸入法。
  class Deactivated: InputStateProtocol {
    public var type: StateType { .ofDeactivated }
@ -175,6 +175,8 @@ enum InputState {
    public var type: StateType { .ofNotEmpty }
    private(set) var composingBuffer: String
    private(set) var cursorIndex: Int = 0 { didSet { cursorIndex = max(cursorIndex, 0) } }
+    private(set) var reading: String = ""
+    private(set) var nodeValuesArray = [String]()
    public var composingBufferConverted: String {
      let converted = IME.kanjiConversionIfRequired(composingBuffer)
      if converted.utf16.count != composingBuffer.utf16.count
@ -185,21 +187,39 @@ enum InputState {
      return converted
    }

-    init(composingBuffer: String, cursorIndex: Int) {
+    init(composingBuffer: String, cursorIndex: Int, reading: String = "", nodeValuesArray: [String] = []) {
      self.composingBuffer = composingBuffer
+      self.reading = reading
+      self.nodeValuesArray = nodeValuesArray
      defer { self.cursorIndex = cursorIndex }
    }

    var attributedString: NSMutableAttributedString {
      /// 考慮到因為滑鼠點擊等其它行為導致的組字區內容遞交情況，
      /// 這裡對組字區內容也加上康熙字轉換或者 JIS 漢字轉換處理。
-      let attributedString = NSMutableAttributedString(
-        string: composingBufferConverted,
-        attributes: [
-          .underlineStyle: NSUnderlineStyle.single.rawValue,
-          .markedClauseSegment: 0,
-        ]
-      )
+      guard reading.isEmpty else {
+        let attributedString = NSMutableAttributedString(
+          string: composingBufferConverted,
+          attributes: [
+            /// 不能用 .thick，否則會看不到游標。
+            .underlineStyle: NSUnderlineStyle.single.rawValue,
+            .markedClauseSegment: 0,
+          ]
+        )
+        return attributedString
+      }
+      let attributedString = NSMutableAttributedString(string: composingBufferConverted)
+      var newBegin = 0
+      for (i, neta) in nodeValuesArray.enumerated() {
+        attributedString.setAttributes(
+          [
+            /// 不能用 .thick，否則會看不到游標。
+            .underlineStyle: NSUnderlineStyle.single.rawValue,
+            .markedClauseSegment: i,
+          ], range: NSRange(location: newBegin, length: neta.utf16.count)
+        )
+        newBegin += neta.utf16.count
+      }
      return attributedString
    }

@ -216,8 +236,9 @@ enum InputState {
    var textToCommit: String = ""
    var tooltip: String = ""

-    override init(composingBuffer: String, cursorIndex: Int) {
-      super.init(composingBuffer: composingBuffer, cursorIndex: cursorIndex)
+    override init(composingBuffer: String, cursorIndex: Int, reading: String = "", nodeValuesArray: [String] = []) {
+      super.init(
+        composingBuffer: composingBuffer, cursorIndex: cursorIndex, reading: reading, nodeValuesArray: nodeValuesArray)
    }

    override var description: String {
@ -264,9 +285,9 @@ enum InputState {
    private var deleteTargetExists = false
    var tooltip: String {
      if composingBuffer.count != readings.count {
-        ctlInputMethod.tooltipController.setColor(state: .redAlert)
+        ctlInputMethod.tooltipController.setColor(state: .denialOverflow)
        return NSLocalizedString(
-          "⚠︎ Unhandlable: Chars and Readings in buffer doesn't match.", comment: ""
+          "⚠︎ Beware: Chars and Readings in buffer doesn't match.", comment: ""
        )
      }
      if mgrPrefs.phraseReplacementEnabled {
@ -376,14 +397,9 @@ enum InputState {
    }

    var validToWrite: Bool {
-      /// The input method allows users to input a string whose length differs
-      /// from the amount of Bopomofo readings. In this case, the range
-      /// in the composing buffer and the readings could not match, so
-      /// we disable the function to write user phrases in this case.
-      /// 這裡的 deleteTargetExists 是防止使用者排除「詞庫內尚未存在的詞」，
-      /// 免得使用者誤操作之後靠北「我怎麼敲不了這個詞？」之類的。
-      ((composingBuffer.count != readings.count)
-        || (ctlInputMethod.areWeDeleting && !deleteTargetExists))
+      /// 與小麥注音不同，威注音會自動解消「游標插斷字符」的異常狀態，所以允許在字音長度不相符的情況下加詞。
+      /// 這裡的 deleteTargetExists 是防止使用者排除「詞庫內尚未存在的詞」。
+      (ctlInputMethod.areWeDeleting && !deleteTargetExists)
        ? false
        : allowedMarkRange.contains(literalMarkedRange.count)
    }
@ -418,7 +434,7 @@ enum InputState {

  /// .ChoosingCandidate: 叫出選字窗、允許使用者選字。
  class ChoosingCandidate: NotEmpty {
-    override public var type: StateType { .ofChooseCandidate }
+    override public var type: StateType { .ofChoosingCandidate }
    private(set) var candidates: [(String, String)]
    private(set) var isTypingVertical: Bool

--- a/Source/Modules/ControllerModules/KeyHandler_Core.swift
+++ b/Source/Modules/ControllerModules/KeyHandler_Core.swift
@ -34,10 +34,10 @@ import Cocoa

 /// KeyHandler 委任協定
 protocol KeyHandlerDelegate {
-  func ctlCandidate() -> ctlCandidate
+  func ctlCandidate() -> ctlCandidateProtocol
  func keyHandler(
    _: KeyHandler, didSelectCandidateAt index: Int,
-    ctlCandidate controller: ctlCandidate
+    ctlCandidate controller: ctlCandidateProtocol
  )
  func keyHandler(_ keyHandler: KeyHandler, didRequestWriteUserPhraseWith state: InputStateProtocol)
    -> Bool
@ -46,9 +46,11 @@ protocol KeyHandlerDelegate {
 // MARK: - 核心 (Kernel).

 /// KeyHandler 按鍵調度模組。
-class KeyHandler {
+public class KeyHandler {
  /// 半衰模組的衰減指數
  let kEpsilon: Double = 0.000001
+  /// 檢測是否出現游標切斷組字圈內字符的情況
+  var isCursorCuttingChar = false

  /// 規定最大動態爬軌範圍。組字器內超出該範圍的節錨都會被自動標記為「已經手動選字過」，減少爬軌運算負擔。
  let kMaxComposingBufferNeedsToWalkSize = Int(max(12, ceil(Double(mgrPrefs.composingBufferSize) / 2)))
@ -182,14 +184,20 @@ class KeyHandler {
          addToUserOverrideModel = false
        }
      }
-      if addToUserOverrideModel {
+      if addToUserOverrideModel, mgrPrefs.fetchSuggestionsFromUserOverrideModel {
        IME.prtDebugIntel("UOM: Start Observation.")
+        // 這個過程可能會因為使用者半衰記憶模組內部資料錯亂、而導致輸入法在選字時崩潰。
+        // 於是在這裡引入災後狀況察覺專用變數，且先開啟該開關。順利執行完觀察後會關閉。
+        // 一旦輸入法崩潰，會在重啟時發現這個開關是開著的，屆時 AppDelegate 會做出應對。
+        mgrPrefs.failureFlagForUOMObservation = true
        // 令半衰記憶模組觀測給定的三元圖。
        // 這個過程會讓半衰引擎根據當前上下文生成三元圖索引鍵。
        currentUOM.observe(
          walkedAnchors: walkedAnchors, cursorIndex: adjustedCursor, candidate: theCandidate.value,
          timestamp: NSDate().timeIntervalSince1970, saveCallback: { mgrLangModel.saveUserOverrideModelData() }
        )
+        // 如果沒有出現崩框的話，那就將這個開關復位。
+        mgrPrefs.failureFlagForUOMObservation = false
      }
    }

--- a/Source/Modules/ControllerModules/KeyHandler_HandleCandidate.swift
+++ b/Source/Modules/ControllerModules/KeyHandler_HandleCandidate.swift
@ -46,7 +46,7 @@ extension KeyHandler {
  ) -> Bool {
    let inputText = input.inputText
    let charCode: UniChar = input.charCode
-    guard let ctlCandidateCurrent = delegate?.ctlCandidate() else {
+    guard var ctlCandidateCurrent = delegate?.ctlCandidate() else {
      IME.prtDebugIntel("06661F6E")
      errorCallback()
      return true
@ -69,6 +69,7 @@ extension KeyHandler {
        // 所以這裡需要對 compositor.isEmpty 做判定。
        clear()
        stateCallback(InputState.EmptyIgnoringPreviousState())
+        stateCallback(InputState.Empty())
      } else {
        stateCallback(buildInputtingState)
      }
@ -84,6 +85,7 @@ extension KeyHandler {
      if state is InputState.AssociatedPhrases, !mgrPrefs.alsoConfirmAssociatedCandidatesByEnter {
        clear()
        stateCallback(InputState.EmptyIgnoringPreviousState())
+        stateCallback(InputState.Empty())
        return true
      }
      delegate?.keyHandler(
@ -293,14 +295,12 @@ extension KeyHandler {
    let match: String =
      (state is InputState.AssociatedPhrases) ? input.inputTextIgnoringModifiers ?? "" : inputText

-    var j = 0
-    while j < ctlCandidateCurrent.keyLabels.count {
+    for j in 0..<ctlCandidateCurrent.keyLabels.count {
      let label: CandidateKeyLabel = ctlCandidateCurrent.keyLabels[j]
      if match.compare(label.key, options: .caseInsensitive, range: nil, locale: .current) == .orderedSame {
        index = j
        break
      }
-      j += 1
    }

    if index != NSNotFound {
@ -352,10 +352,10 @@ extension KeyHandler {
            ctlCandidate: ctlCandidateCurrent
          )
          clear()
-          let empty = InputState.EmptyIgnoringPreviousState()
-          stateCallback(empty)
+          stateCallback(InputState.EmptyIgnoringPreviousState())
+          stateCallback(InputState.Empty())
          return handle(
-            input: input, state: empty, stateCallback: stateCallback, errorCallback: errorCallback
+            input: input, state: InputState.Empty(), stateCallback: stateCallback, errorCallback: errorCallback
          )
        }
        return true
--- a/Source/Modules/ControllerModules/KeyHandler_HandleComposition.swift
+++ b/Source/Modules/ControllerModules/KeyHandler_HandleComposition.swift
@ -30,17 +30,14 @@ extension KeyHandler {
  /// 用來處理 KeyHandler.HandleInput() 當中的與組字有關的行為。
  /// - Parameters:
  ///   - input: 輸入訊號。
-  ///   - state: 給定狀態（通常為當前狀態）。
  ///   - stateCallback: 狀態回呼，交給對應的型別內的專有函式來處理。
  ///   - errorCallback: 錯誤回呼。
  /// - Returns: 告知 IMK「該按鍵是否已經被輸入法攔截處理」。
  func handleComposition(
    input: InputSignal,
-    state: InputStateProtocol,
    stateCallback: @escaping (InputStateProtocol) -> Void,
    errorCallback: @escaping () -> Void
  ) -> Bool? {
-
    // MARK: 注音按鍵輸入處理 (Handle BPMF Keys)

    var keyConsumedByReading = false
@ -63,7 +60,7 @@ extension KeyHandler {
      }
    }

-    var composeReading = composer.hasToneMarker()  // 這裡不需要做排他性判斷。
+    var composeReading = composer.hasToneMarker() && composer.inputValidityCheck(key: input.charCode)  // 這裡不需要做排他性判斷。

    // 如果當前的按鍵是 Enter 或 Space 的話，這時就可以取出 _composer 內的注音來做檢查了。
    // 來看看詞庫內到底有沒有對應的讀音索引。這裡用了類似「|=」的判斷處理方式。
@ -81,9 +78,21 @@ extension KeyHandler {
      if !currentLM.hasUnigramsFor(key: readingKey) {
        IME.prtDebugIntel("B49C0979：語彙庫內無「\(readingKey)」的匹配記錄。")
        errorCallback()
+
+        if mgrPrefs.keepReadingUponCompositionError {
+          composer.intonation.clear()  // 砍掉聲調。
+          stateCallback(buildInputtingState)
+          return true
+        }
+
        composer.clear()
        // 根據「組字器是否為空」來判定回呼哪一種狀態。
-        stateCallback((compositor.isEmpty) ? InputState.EmptyIgnoringPreviousState() : buildInputtingState)
+        switch compositor.isEmpty {
+          case false: stateCallback(buildInputtingState)
+          case true:
+            stateCallback(InputState.EmptyIgnoringPreviousState())
+            stateCallback(InputState.Empty())
+        }
        return true  // 向 IMK 報告說這個按鍵訊號已經被輸入法攔截處理了。
      }

@ -141,9 +150,7 @@ extension KeyHandler {
      return true
    }

-    /// 如果此時這個選項是 true 的話，可知當前注拼槽輸入了聲調、且上一次按鍵不是聲調按鍵。
-    /// 比方說大千傳統佈局敲「6j」會出現「ˊㄨ」但並不會被認為是「ㄨˊ」，因為先輸入的調號
-    /// 並非用來確認這個注音的調號。除非是：「ㄨˊ」「ˊㄨˊ」「ˊㄨˇ」「ˊㄨ 」等。
+    /// 是說此時注拼槽並非為空、卻還沒組音。這種情況下只可能是「注拼槽內只有聲調」。
    if keyConsumedByReading {
      // 以回呼組字狀態的方式來執行 updateClientComposingBuffer()。
      stateCallback(buildInputtingState)
--- a/Source/Modules/ControllerModules/KeyHandler_HandleInput.swift
+++ b/Source/Modules/ControllerModules/KeyHandler_HandleInput.swift
@ -159,8 +159,8 @@ extension KeyHandler {
    // MARK: 注音按鍵輸入處理 (Handle BPMF Keys)

    if let compositionHandled = handleComposition(
-      input: input, state: state, stateCallback: stateCallback, errorCallback: errorCallback)
-    {
+      input: input, stateCallback: stateCallback, errorCallback: errorCallback
+    ) {
      return compositionHandled
    }

--- a/Source/Modules/ControllerModules/KeyHandler_States.swift
+++ b/Source/Modules/ControllerModules/KeyHandler_States.swift
@ -38,7 +38,7 @@ extension KeyHandler {
    /// 「更新內文組字區 (Update the composing buffer)」是指要求客體軟體將組字緩衝區的內容
    /// 換成由此處重新生成的組字字串（NSAttributeString，否則會不顯示）。
    var tooltipParameterRef: [String] = ["", ""]
-    var composingBuffer = ""
+    let nodeValuesArray: [String] = walkedAnchors.map(\.node.currentPair.value)
    var composedStringCursorIndex = 0
    var readingCursorIndex = 0
    /// IMK 協定的內文組字區的游標長度與游標位置無法正確統計 UTF8 高萬字（比如 emoji）的長度，
@ -47,7 +47,6 @@ extension KeyHandler {
    for theAnchor in walkedAnchors {
      let theNode = theAnchor.node
      let strNodeValue = theNode.currentPair.value
-      composingBuffer += strNodeValue
      let arrSplit: [String] = Array(strNodeValue).map { String($0) }
      let codepointCount = arrSplit.count
      /// 藉下述步驟重新將「可見游標位置」對齊至「組字器內的游標所在的讀音位置」。
@ -57,57 +56,45 @@ extension KeyHandler {
      if readingCursorIndex + spanningLength <= compositor.cursor {
        composedStringCursorIndex += strNodeValue.utf16.count
        readingCursorIndex += spanningLength
-      } else {
-        if codepointCount == spanningLength {
-          var i = 0
-          while i < codepointCount, readingCursorIndex < compositor.cursor {
-            composedStringCursorIndex += arrSplit[i].utf16.count
-            readingCursorIndex += 1
-            i += 1
-          }
-        } else {
-          if readingCursorIndex < compositor.cursor {
-            composedStringCursorIndex += strNodeValue.utf16.count
-            readingCursorIndex += spanningLength
-            readingCursorIndex = min(readingCursorIndex, compositor.cursor)
-            /// 接下來再處理這麼一種情況：
-            /// 某些錨點內的當前候選字詞長度與讀音長度不相等。
-            /// 但此時游標還是按照每個讀音單位來移動的，
-            /// 所以需要上下文工具提示來顯示游標的相對位置。
-            /// 這裡先計算一下要用在工具提示當中的顯示參數的內容。
-            switch compositor.cursor {
-              case compositor.readings.count...:
-                // 這裡的 compositor.cursor 數值不可能大於 readings.count，因為會被 Megrez 自動糾正。
-                tooltipParameterRef[0] = compositor.readings[compositor.cursor - 1]
-              case 0:
-                tooltipParameterRef[1] = compositor.readings[compositor.cursor]
-              default:
-                tooltipParameterRef[0] = compositor.readings[compositor.cursor - 1]
-                tooltipParameterRef[1] = compositor.readings[compositor.cursor]
-            }
-            /// 注音轉拼音
-            for (i, _) in tooltipParameterRef.enumerated() {
-              if tooltipParameterRef[i].isEmpty { continue }
-              if tooltipParameterRef[i].contains("_") { continue }
-              if mgrPrefs.showHanyuPinyinInCompositionBuffer {  // 恢復陰平標記->注音轉拼音->轉教科書式標調
-                tooltipParameterRef[i] = Tekkon.restoreToneOneInZhuyinKey(target: tooltipParameterRef[i])
-                tooltipParameterRef[i] = Tekkon.cnvPhonaToHanyuPinyin(target: tooltipParameterRef[i])
-                tooltipParameterRef[i] = Tekkon.cnvHanyuPinyinToTextbookStyle(target: tooltipParameterRef[i])
-              } else {
-                tooltipParameterRef[i] = Tekkon.cnvZhuyinChainToTextbookReading(target: tooltipParameterRef[i])
-              }
-            }
-          }
+        continue
+      }
+      if codepointCount == spanningLength {
+        for i in 0..<codepointCount {
+          guard readingCursorIndex < compositor.cursor else { continue }
+          composedStringCursorIndex += arrSplit[i].utf16.count
+          readingCursorIndex += 1
        }
+        continue
+      }
+      guard readingCursorIndex < compositor.cursor else { continue }
+      composedStringCursorIndex += strNodeValue.utf16.count
+      readingCursorIndex += spanningLength
+      readingCursorIndex = min(readingCursorIndex, compositor.cursor)
+      /// 接下來再處理這麼一種情況：
+      /// 某些錨點內的當前候選字詞長度與讀音長度不相等。
+      /// 但此時游標還是按照每個讀音單位來移動的，
+      /// 所以需要上下文工具提示來顯示游標的相對位置。
+      /// 這裡先計算一下要用在工具提示當中的顯示參數的內容。
+      switch compositor.cursor {
+        case compositor.readings.count...:
+          // 這裡的 compositor.cursor 數值不可能大於 readings.count，因為會被 Megrez 自動糾正。
+          tooltipParameterRef[0] = compositor.readings[compositor.cursor - 1]
+        case 0:
+          tooltipParameterRef[1] = compositor.readings[compositor.cursor]
+        default:
+          tooltipParameterRef[0] = compositor.readings[compositor.cursor - 1]
+          tooltipParameterRef[1] = compositor.readings[compositor.cursor]
      }
    }

+    isCursorCuttingChar = !tooltipParameterRef[0].isEmpty || !tooltipParameterRef[1].isEmpty
+
    /// 再接下來，藉由已經計算成功的「可見游標位置」，咱們計算一下在這個游標之前與之後的
    /// 組字區內容，以便之後在這之間插入正在輸入的漢字讀音（藉由鐵恨 composer 注拼槽取得）。
    var arrHead = [String.UTF16View.Element]()
    var arrTail = [String.UTF16View.Element]()

-    for (i, n) in composingBuffer.utf16.enumerated() {
+    for (i, n) in nodeValuesArray.joined().utf16.enumerated() {
      if i < composedStringCursorIndex {
        arrHead.append(n)
      } else {
@ -126,42 +113,16 @@ extension KeyHandler {
    // 防止組字區內出現不可列印的字元。
    var cleanedComposition = ""
    for theChar in composedText {
-      if let charCode = theChar.utf16.first {
-        if !(theChar.isASCII && !(charCode.isPrintable)) {
-          cleanedComposition += String(theChar)
-        }
+      guard let charCode = theChar.utf16.first else { continue }
+      if !(theChar.isASCII && !(charCode.isPrintable)) {
+        cleanedComposition += String(theChar)
      }
    }

    /// 這裡生成準備要拿來回呼的「正在輸入」狀態，但還不能立即使用，因為工具提示仍未完成。
-    let stateResult = InputState.Inputting(composingBuffer: cleanedComposition, cursorIndex: cursorIndex)
-
-    /// 根據上文的參數結果來決定生成怎樣的工具提示。
-    switch (tooltipParameterRef[0].isEmpty, tooltipParameterRef[1].isEmpty) {
-      case (true, true): stateResult.tooltip.removeAll()
-      case (true, false):
-        stateResult.tooltip = String(
-          format: NSLocalizedString("Cursor is to the rear of \"%@\".", comment: ""),
-          tooltipParameterRef[1]
-        )
-      case (false, true):
-        stateResult.tooltip = String(
-          format: NSLocalizedString("Cursor is in front of \"%@\".", comment: ""),
-          tooltipParameterRef[0]
-        )
-      case (false, false):
-        stateResult.tooltip = String(
-          format: NSLocalizedString("Cursor is between \"%@\" and \"%@\".", comment: ""),
-          tooltipParameterRef[0], tooltipParameterRef[1]
-        )
-    }
-
-    /// 給工具提示設定提示配色。
-    if !stateResult.tooltip.isEmpty {
-      ctlInputMethod.tooltipController.setColor(state: .denialOverflow)
-    }
-
-    return stateResult
+    return InputState.Inputting(
+      composingBuffer: cleanedComposition, cursorIndex: cursorIndex, reading: reading, nodeValuesArray: nodeValuesArray
+    )
  }

  // MARK: - 用以生成候選詞陣列及狀態
@ -459,8 +420,12 @@ extension KeyHandler {
      composer.doBackSpace()
    }

-    stateCallback(
-      composer.isEmpty && compositor.isEmpty ? InputState.EmptyIgnoringPreviousState() : buildInputtingState)
+    switch composer.isEmpty && compositor.isEmpty {
+      case false: stateCallback(buildInputtingState)
+      case true:
+        stateCallback(InputState.EmptyIgnoringPreviousState())
+        stateCallback(InputState.Empty())
+    }
    return true
  }

@ -497,7 +462,12 @@ extension KeyHandler {
    walk()
    let inputting = buildInputtingState
    // 這裡不用「count > 0」，因為該整數變數只要「!isEmpty」那就必定滿足這個條件。
-    stateCallback(inputting.composingBuffer.isEmpty ? InputState.EmptyIgnoringPreviousState() : inputting)
+    switch inputting.composingBuffer.isEmpty {
+      case false: stateCallback(inputting)
+      case true:
+        stateCallback(InputState.EmptyIgnoringPreviousState())
+        stateCallback(InputState.Empty())
+    }
    return true
  }

@ -609,11 +579,17 @@ extension KeyHandler {
      /// 此乃 macOS 內建注音輸入法預設之行為，但不太受 Windows 使用者群體之待見。
      clear()
      stateCallback(InputState.EmptyIgnoringPreviousState())
+      stateCallback(InputState.Empty())
    } else {
      if composer.isEmpty { return true }
      /// 如果注拼槽不是空的話，則清空之。
      composer.clear()
-      stateCallback(compositor.isEmpty ? InputState.EmptyIgnoringPreviousState() : buildInputtingState)
+      switch compositor.isEmpty {
+        case false: stateCallback(buildInputtingState)
+        case true:
+          stateCallback(InputState.EmptyIgnoringPreviousState())
+          stateCallback(InputState.Empty())
+      }
    }
    return true
  }
@ -661,6 +637,7 @@ extension KeyHandler {
        stateCallback(state)
      }
    } else if input.isOptionHold {
+      isCursorCuttingChar = false
      if input.isControlHold {
        return handleEnd(state: state, stateCallback: stateCallback, errorCallback: errorCallback)
      }
@ -675,7 +652,12 @@ extension KeyHandler {
    } else {
      if compositor.cursor < compositor.length {
        compositor.cursor += 1
-        stateCallback(buildInputtingState)
+        var inputtingState = buildInputtingState
+        if isCursorCuttingChar == true {
+          compositor.jumpCursorBySpan(to: .front)
+          inputtingState = buildInputtingState
+        }
+        stateCallback(inputtingState)
      } else {
        IME.prtDebugIntel("A96AAD58")
        errorCallback()
@ -729,6 +711,7 @@ extension KeyHandler {
        stateCallback(state)
      }
    } else if input.isOptionHold {
+      isCursorCuttingChar = false
      if input.isControlHold {
        return handleHome(state: state, stateCallback: stateCallback, errorCallback: errorCallback)
      }
@ -743,7 +726,12 @@ extension KeyHandler {
    } else {
      if compositor.cursor > 0 {
        compositor.cursor -= 1
-        stateCallback(buildInputtingState)
+        var inputtingState = buildInputtingState
+        if isCursorCuttingChar == true {
+          compositor.jumpCursorBySpan(to: .rear)
+          inputtingState = buildInputtingState
+        }
+        stateCallback(inputtingState)
      } else {
        IME.prtDebugIntel("7045E6F3")
        errorCallback()
--- a/Source/Modules/ControllerModules/ctlInputMethod_Core.swift
+++ b/Source/Modules/ControllerModules/ctlInputMethod_Core.swift
@ -41,7 +41,7 @@ class ctlInputMethod: IMKInputController {
  static var areWeDeleting = false

  /// 目前在用的的選字窗副本。
-  static var ctlCandidateCurrent = ctlCandidateUniversal.init(.horizontal)
+  static var ctlCandidateCurrent: ctlCandidateProtocol = ctlCandidateUniversal.init(.horizontal)

  /// 工具提示視窗的副本。
  static let tooltipController = TooltipController()
@ -85,6 +85,7 @@ class ctlInputMethod: IMKInputController {
    keyHandler.delegate = self
    // 下述兩行很有必要，否則輸入法會在手動重啟之後無法立刻生效。
    activateServer(inputClient)
+    keyHandler.ensureParser()
    resetKeyHandler()
  }

@ -99,7 +100,7 @@ class ctlInputMethod: IMKInputController {
    // 因為偶爾會收到與 activateServer 有關的以「強制拆 nil」為理由的報錯，
    // 所以這裡添加這句、來試圖應對這種情況。
    if keyHandler.delegate == nil { keyHandler.delegate = self }
-
+    setValue(IME.currentInputMode.rawValue, forTag: 114514, client: client())
    keyHandler.clear()
    keyHandler.ensureParser()

@ -236,4 +237,30 @@ class ctlInputMethod: IMKInputController {
    _ = sender  // 防止格式整理工具毀掉與此對應的參數。
    resetKeyHandler()
  }
+
+  /// 生成 IMK 選字窗專用的候選字串陣列。
+  /// - Parameter sender: 呼叫了該函式的客體（無須使用）。
+  /// - Returns: IMK 選字窗專用的候選字串陣列。
+  override func candidates(_ sender: Any!) -> [Any]! {
+    _ = sender  // 防止格式整理工具毀掉與此對應的參數。
+    if let state = state as? InputState.AssociatedPhrases {
+      return state.candidates.map { theCandidate -> String in
+        let theConverted = IME.kanjiConversionIfRequired(theCandidate.1)
+        return (theCandidate.1 == theConverted) ? theCandidate.1 : "\(theConverted)(\(theCandidate.1))"
+      }
+    }
+    if let state = state as? InputState.ChoosingCandidate {
+      return state.candidates.map { theCandidate -> String in
+        let theConverted = IME.kanjiConversionIfRequired(theCandidate.1)
+        return (theCandidate.1 == theConverted) ? theCandidate.1 : "\(theConverted)(\(theCandidate.1))"
+      }
+    }
+    if let state = state as? InputState.SymbolTable {
+      return state.candidates.map { theCandidate -> String in
+        let theConverted = IME.kanjiConversionIfRequired(theCandidate.1)
+        return (theCandidate.1 == theConverted) ? theCandidate.1 : "\(theConverted)(\(theCandidate.1))"
+      }
+    }
+    return .init()
+  }
 }
--- a/Source/Modules/ControllerModules/ctlInputMethod_Delegates.swift
+++ b/Source/Modules/ControllerModules/ctlInputMethod_Delegates.swift
@ -24,16 +24,16 @@ IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

-import Foundation
+import Cocoa

 // MARK: - KeyHandler Delegate

 extension ctlInputMethod: KeyHandlerDelegate {
-  func ctlCandidate() -> ctlCandidate { ctlInputMethod.ctlCandidateCurrent }
+  func ctlCandidate() -> ctlCandidateProtocol { ctlInputMethod.ctlCandidateCurrent }

  func keyHandler(
    _: KeyHandler, didSelectCandidateAt index: Int,
-    ctlCandidate controller: ctlCandidate
+    ctlCandidate controller: ctlCandidateProtocol
  ) {
    ctlCandidate(controller, didSelectCandidateAtIndex: index)
  }
@ -70,7 +70,54 @@ extension ctlInputMethod: KeyHandlerDelegate {
 // MARK: - Candidate Controller Delegate

 extension ctlInputMethod: ctlCandidateDelegate {
-  func candidateCountForController(_ controller: ctlCandidate) -> Int {
+  func handleDelegateEvent(_ event: NSEvent!) -> Bool {
+    /// 這裡仍舊需要判斷 flags。之前使輸入法狀態卡住無法敲漢字的問題已在 KeyHandler 內修復。
+    /// 這裡不判斷 flags 的話，用方向鍵前後定位光標之後，再次試圖觸發組字區時、反而會在首次按鍵時失敗。
+    /// 同時注意：必須在 event.type == .flagsChanged 結尾插入 return false，
+    /// 否則，每次處理這種判斷時都會觸發 NSInternalInconsistencyException。
+    if event.type == .flagsChanged {
+      return false
+    }
+
+    // 準備修飾鍵，用來判定是否需要利用就地新增語彙時的 Enter 鍵來砍詞。
+    ctlInputMethod.areWeDeleting = event.modifierFlags.contains([.shift, .command])
+
+    var textFrame = NSRect.zero
+
+    let attributes: [AnyHashable: Any]? = client().attributes(
+      forCharacterIndex: 0, lineHeightRectangle: &textFrame
+    )
+
+    let isTypingVertical =
+      (attributes?["IMKTextOrientation"] as? NSNumber)?.intValue == 0 || false
+
+    if client().bundleIdentifier()
+      == "org.atelierInmu.vChewing.vChewingPhraseEditor"
+    {
+      IME.areWeUsingOurOwnPhraseEditor = true
+    } else {
+      IME.areWeUsingOurOwnPhraseEditor = false
+    }
+
+    let input = InputSignal(event: event, isVerticalTyping: isTypingVertical)
+
+    // 無法列印的訊號輸入，一概不作處理。
+    // 這個過程不能放在 KeyHandler 內，否則不會起作用。
+    if !input.charCode.isPrintable {
+      return false
+    }
+
+    /// 將按鍵行為與當前輸入法狀態結合起來、交給按鍵調度模組來處理。
+    /// 再根據返回的 result bool 數值來告知 IMK「這個按鍵事件是被處理了還是被放行了」。
+    let result = keyHandler.handleCandidate(state: state, input: input) { newState in
+      self.handle(state: newState)
+    } errorCallback: {
+      clsSFX.beep()
+    }
+    return result
+  }
+
+  func candidateCountForController(_ controller: ctlCandidateProtocol) -> Int {
    _ = controller  // 防止格式整理工具毀掉與此對應的參數。
    if let state = state as? InputState.ChoosingCandidate {
      return state.candidates.count
@ -80,7 +127,20 @@ extension ctlInputMethod: ctlCandidateDelegate {
    return 0
  }

-  func ctlCandidate(_ controller: ctlCandidate, candidateAtIndex index: Int)
+  /// 直接給出全部的候選字詞的字音配對陣列
+  /// - Parameter controller: 對應的控制器。因為有唯一解，所以填錯了也不會有影響。
+  /// - Returns: 候選字詞陣列（字音配對）。
+  func candidatesForController(_ controller: ctlCandidateProtocol) -> [(String, String)] {
+    _ = controller  // 防止格式整理工具毀掉與此對應的參數。
+    if let state = state as? InputState.ChoosingCandidate {
+      return state.candidates
+    } else if let state = state as? InputState.AssociatedPhrases {
+      return state.candidates
+    }
+    return .init()
+  }
+
+  func ctlCandidate(_ controller: ctlCandidateProtocol, candidateAtIndex index: Int)
    -> (String, String)
  {
    _ = controller  // 防止格式整理工具毀掉與此對應的參數。
@ -92,7 +152,7 @@ extension ctlInputMethod: ctlCandidateDelegate {
    return ("", "")
  }

-  func ctlCandidate(_ controller: ctlCandidate, didSelectCandidateAtIndex index: Int) {
+  func ctlCandidate(_ controller: ctlCandidateProtocol, didSelectCandidateAtIndex index: Int) {
    _ = controller  // 防止格式整理工具毀掉與此對應的參數。

    if let state = state as? InputState.SymbolTable,
--- a/Source/Modules/ControllerModules/ctlInputMethod_HandleDisplay.swift
+++ b/Source/Modules/ControllerModules/ctlInputMethod_HandleDisplay.swift
@ -81,11 +81,11 @@ extension ctlInputMethod {
    /// 該問題徹底解決的價值並不大，直接等到 macOS 10.x 全線淘汰之後用 SwiftUI 重寫選字窗吧。

    if isCandidateWindowVertical {  // 縱排輸入時強制使用縱排選字窗
-      ctlInputMethod.ctlCandidateCurrent = .init(.vertical)
+      ctlInputMethod.ctlCandidateCurrent = ctlCandidateUniversal.init(.vertical)
    } else if mgrPrefs.useHorizontalCandidateList {
-      ctlInputMethod.ctlCandidateCurrent = .init(.horizontal)
+      ctlInputMethod.ctlCandidateCurrent = ctlCandidateUniversal.init(.horizontal)
    } else {
-      ctlInputMethod.ctlCandidateCurrent = .init(.vertical)
+      ctlInputMethod.ctlCandidateCurrent = ctlCandidateUniversal.init(.vertical)
    }

    // set the attributes for the candidate panel (which uses NSAttributedString)
@ -100,12 +100,22 @@ extension ctlInputMethod {
    }

    func candidateFont(name: String?, size: CGFloat) -> NSFont {
-      let currentMUIFont =
-        (keyHandler.inputMode == InputMode.imeModeCHS)
-        ? "Sarasa Term Slab SC" : "Sarasa Term Slab TC"
-      var finalReturnFont =
-        NSFont(name: currentMUIFont, size: size) ?? NSFont.systemFont(ofSize: size)
-      // 對更紗黑體的依賴到 macOS 11 Big Sur 為止。macOS 12 Monterey 開始則依賴系統內建的函式使用蘋方來處理。
+      var finalReturnFont: NSFont =
+        {
+          switch IME.currentInputMode {
+            case InputMode.imeModeCHS:
+              return CTFontCreateUIFontForLanguage(.system, size, "zh-Hans" as CFString)
+            case InputMode.imeModeCHT:
+              return (mgrPrefs.shiftJISShinjitaiOutputEnabled || mgrPrefs.chineseConversionEnabled)
+                ? CTFontCreateUIFontForLanguage(.system, size, "ja" as CFString)
+                : CTFontCreateUIFontForLanguage(.system, size, "zh-Hant" as CFString)
+            default:
+              return CTFontCreateUIFontForLanguage(.system, size, nil)
+          }
+        }()
+        ?? NSFont.systemFont(ofSize: size)
+      // 上述方法對 macOS 10.11-10.15 有效，但對 macOS 12 Monterey 無效（懷疑是 Bug）。
+      // macOS 12 Monterey 開始就用系統內建的函式來處理，相關流程直接寫在 ctlCandidateUniversal 內。
      if #available(macOS 12.0, *) { finalReturnFont = NSFont.systemFont(ofSize: size) }
      if let name = name {
        return NSFont(name: name, size: size) ?? finalReturnFont
--- a/Source/Modules/IMEModules/mgrPrefs.swift
+++ b/Source/Modules/IMEModules/mgrPrefs.swift
@ -26,56 +26,58 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

 import Cocoa

-struct UserDef {
-  static let kIsDebugModeEnabled = "_DebugMode"
-  static let kMostRecentInputMode = "MostRecentInputMode"
-  static let kUserDataFolderSpecified = "UserDataFolderSpecified"
-  static let kCheckUpdateAutomatically = "CheckUpdateAutomatically"
-  static let kMandarinParser = "MandarinParser"
-  static let kBasicKeyboardLayout = "BasicKeyboardLayout"
-  static let kShowPageButtonsInCandidateWindow = "ShowPageButtonsInCandidateWindow"
-  static let kCandidateListTextSize = "CandidateListTextSize"
-  static let kAppleLanguages = "AppleLanguages"
-  static let kShouldAutoReloadUserDataFiles = "ShouldAutoReloadUserDataFiles"
-  static let kuseRearCursorMode = "useRearCursorMode"
-  static let kUseHorizontalCandidateList = "UseHorizontalCandidateList"
-  static let kComposingBufferSize = "ComposingBufferSize"
-  static let kChooseCandidateUsingSpace = "ChooseCandidateUsingSpace"
-  static let kCNS11643Enabled = "CNS11643Enabled"
-  static let kSymbolInputEnabled = "SymbolInputEnabled"
-  static let kChineseConversionEnabled = "ChineseConversionEnabled"
-  static let kShiftJISShinjitaiOutputEnabled = "ShiftJISShinjitaiOutputEnabled"
-  static let kCurrencyNumeralsEnabled = "CurrencyNumeralsEnabled"
-  static let kHalfWidthPunctuationEnabled = "HalfWidthPunctuationEnable"
-  static let kMoveCursorAfterSelectingCandidate = "MoveCursorAfterSelectingCandidate"
-  static let kEscToCleanInputBuffer = "EscToCleanInputBuffer"
-  static let kSpecifyShiftTabKeyBehavior = "SpecifyShiftTabKeyBehavior"
-  static let kSpecifyShiftSpaceKeyBehavior = "SpecifyShiftSpaceKeyBehavior"
-  static let kAllowBoostingSingleKanjiAsUserPhrase = "AllowBoostingSingleKanjiAsUserPhrase"
-  static let kUseSCPCTypingMode = "UseSCPCTypingMode"
-  static let kMaxCandidateLength = "MaxCandidateLength"
-  static let kShouldNotFartInLieuOfBeep = "ShouldNotFartInLieuOfBeep"
-  static let kShowHanyuPinyinInCompositionBuffer = "ShowHanyuPinyinInCompositionBuffer"
-  static let kInlineDumpPinyinInLieuOfZhuyin = "InlineDumpPinyinInLieuOfZhuyin"
-  static let kFetchSuggestionsFromUserOverrideModel = "FetchSuggestionsFromUserOverrideModel"
-  static let kUseFixecCandidateOrderOnSelection = "UseFixecCandidateOrderOnSelection"
-  static let kAutoCorrectReadingCombination = "AutoCorrectReadingCombination"
-  static let kAlsoConfirmAssociatedCandidatesByEnter = "AlsoConfirmAssociatedCandidatesByEnter"
+public enum UserDef: String, CaseIterable {
+  case kIsDebugModeEnabled = "_DebugMode"
+  case kFailureFlagForUOMObservation = "_FailureFlag_UOMObservation"
+  case kMostRecentInputMode = "MostRecentInputMode"
+  case kUserDataFolderSpecified = "UserDataFolderSpecified"
+  case kCheckUpdateAutomatically = "CheckUpdateAutomatically"
+  case kMandarinParser = "MandarinParser"
+  case kBasicKeyboardLayout = "BasicKeyboardLayout"
+  case kShowPageButtonsInCandidateWindow = "ShowPageButtonsInCandidateWindow"
+  case kCandidateListTextSize = "CandidateListTextSize"
+  case kAppleLanguages = "AppleLanguages"
+  case kShouldAutoReloadUserDataFiles = "ShouldAutoReloadUserDataFiles"
+  case kUseRearCursorMode = "useRearCursorMode"
+  case kUseHorizontalCandidateList = "UseHorizontalCandidateList"
+  case kComposingBufferSize = "ComposingBufferSize"
+  case kChooseCandidateUsingSpace = "ChooseCandidateUsingSpace"
+  case kCNS11643Enabled = "CNS11643Enabled"
+  case kSymbolInputEnabled = "SymbolInputEnabled"
+  case kChineseConversionEnabled = "ChineseConversionEnabled"
+  case kShiftJISShinjitaiOutputEnabled = "ShiftJISShinjitaiOutputEnabled"
+  case kCurrencyNumeralsEnabled = "CurrencyNumeralsEnabled"
+  case kHalfWidthPunctuationEnabled = "HalfWidthPunctuationEnable"
+  case kMoveCursorAfterSelectingCandidate = "MoveCursorAfterSelectingCandidate"
+  case kEscToCleanInputBuffer = "EscToCleanInputBuffer"
+  case kSpecifyShiftTabKeyBehavior = "SpecifyShiftTabKeyBehavior"
+  case kSpecifyShiftSpaceKeyBehavior = "SpecifyShiftSpaceKeyBehavior"
+  case kAllowBoostingSingleKanjiAsUserPhrase = "AllowBoostingSingleKanjiAsUserPhrase"
+  case kUseSCPCTypingMode = "UseSCPCTypingMode"
+  case kMaxCandidateLength = "MaxCandidateLength"
+  case kShouldNotFartInLieuOfBeep = "ShouldNotFartInLieuOfBeep"
+  case kShowHanyuPinyinInCompositionBuffer = "ShowHanyuPinyinInCompositionBuffer"
+  case kInlineDumpPinyinInLieuOfZhuyin = "InlineDumpPinyinInLieuOfZhuyin"
+  case kFetchSuggestionsFromUserOverrideModel = "FetchSuggestionsFromUserOverrideModel"
+  case kUseFixecCandidateOrderOnSelection = "UseFixecCandidateOrderOnSelection"
+  case kAutoCorrectReadingCombination = "AutoCorrectReadingCombination"
+  case kAlsoConfirmAssociatedCandidatesByEnter = "AlsoConfirmAssociatedCandidatesByEnter"
+  case kKeepReadingUponCompositionError = "KeepReadingUponCompositionError"

-  static let kCandidateTextFontName = "CandidateTextFontName"
-  static let kCandidateKeyLabelFontName = "CandidateKeyLabelFontName"
-  static let kCandidateKeys = "CandidateKeys"
+  case kCandidateTextFontName = "CandidateTextFontName"
+  case kCandidateKeyLabelFontName = "CandidateKeyLabelFontName"
+  case kCandidateKeys = "CandidateKeys"

-  static let kAssociatedPhrasesEnabled = "AssociatedPhrasesEnabled"
-  static let kPhraseReplacementEnabled = "PhraseReplacementEnabled"
+  case kAssociatedPhrasesEnabled = "AssociatedPhrasesEnabled"
+  case kPhraseReplacementEnabled = "PhraseReplacementEnabled"

-  static let kUsingHotKeySCPC = "UsingHotKeySCPC"
-  static let kUsingHotKeyAssociates = "UsingHotKeyAssociates"
-  static let kUsingHotKeyCNS = "UsingHotKeyCNS"
-  static let kUsingHotKeyKangXi = "UsingHotKeyKangXi"
-  static let kUsingHotKeyJIS = "UsingHotKeyJIS"
-  static let kUsingHotKeyHalfWidthASCII = "UsingHotKeyHalfWidthASCII"
-  static let kUsingHotKeyCurrencyNumerals = "UsingHotKeyCurrencyNumerals"
+  case kUsingHotKeySCPC = "UsingHotKeySCPC"
+  case kUsingHotKeyAssociates = "UsingHotKeyAssociates"
+  case kUsingHotKeyCNS = "UsingHotKeyCNS"
+  case kUsingHotKeyKangXi = "UsingHotKeyKangXi"
+  case kUsingHotKeyJIS = "UsingHotKeyJIS"
+  case kUsingHotKeyHalfWidthASCII = "UsingHotKeyHalfWidthASCII"
+  case kUsingHotKeyCurrencyNumerals = "UsingHotKeyCurrencyNumerals"
 }

 private let kDefaultCandidateListTextSize: CGFloat = 18
@ -237,92 +239,117 @@ enum MandarinParser: Int {

 public enum mgrPrefs {
  public static func setMissingDefaults() {
-    UserDefaults.standard.setDefault(mgrPrefs.isDebugModeEnabled, forKey: UserDef.kIsDebugModeEnabled)
-    UserDefaults.standard.setDefault(mgrPrefs.mostRecentInputMode, forKey: UserDef.kMostRecentInputMode)
-    UserDefaults.standard.setDefault(mgrPrefs.checkUpdateAutomatically, forKey: UserDef.kCheckUpdateAutomatically)
+    UserDefaults.standard.setDefault(mgrPrefs.isDebugModeEnabled, forKey: UserDef.kIsDebugModeEnabled.rawValue)
    UserDefaults.standard.setDefault(
-      mgrPrefs.showPageButtonsInCandidateWindow, forKey: UserDef.kShowPageButtonsInCandidateWindow
+      mgrPrefs.failureFlagForUOMObservation, forKey: UserDef.kFailureFlagForUOMObservation.rawValue
    )
-    UserDefaults.standard.setDefault(mgrPrefs.symbolInputEnabled, forKey: UserDef.kSymbolInputEnabled)
-    UserDefaults.standard.setDefault(mgrPrefs.candidateListTextSize, forKey: UserDef.kCandidateListTextSize)
-    UserDefaults.standard.setDefault(mgrPrefs.chooseCandidateUsingSpace, forKey: UserDef.kChooseCandidateUsingSpace)
+    UserDefaults.standard.setDefault(mgrPrefs.mostRecentInputMode, forKey: UserDef.kMostRecentInputMode.rawValue)
    UserDefaults.standard.setDefault(
-      mgrPrefs.shouldAutoReloadUserDataFiles, forKey: UserDef.kShouldAutoReloadUserDataFiles
+      mgrPrefs.checkUpdateAutomatically, forKey: UserDef.kCheckUpdateAutomatically.rawValue
    )
    UserDefaults.standard.setDefault(
-      mgrPrefs.specifyShiftTabKeyBehavior, forKey: UserDef.kSpecifyShiftTabKeyBehavior
+      mgrPrefs.showPageButtonsInCandidateWindow, forKey: UserDef.kShowPageButtonsInCandidateWindow.rawValue
+    )
+    UserDefaults.standard.setDefault(mgrPrefs.symbolInputEnabled, forKey: UserDef.kSymbolInputEnabled.rawValue)
+    UserDefaults.standard.setDefault(mgrPrefs.candidateListTextSize, forKey: UserDef.kCandidateListTextSize.rawValue)
+    UserDefaults.standard.setDefault(
+      mgrPrefs.chooseCandidateUsingSpace, forKey: UserDef.kChooseCandidateUsingSpace.rawValue
    )
    UserDefaults.standard.setDefault(
-      mgrPrefs.specifyShiftSpaceKeyBehavior, forKey: UserDef.kSpecifyShiftSpaceKeyBehavior
-    )
-    UserDefaults.standard.setDefault(mgrPrefs.useSCPCTypingMode, forKey: UserDef.kUseSCPCTypingMode)
-    UserDefaults.standard.setDefault(mgrPrefs.associatedPhrasesEnabled, forKey: UserDef.kAssociatedPhrasesEnabled)
-    UserDefaults.standard.setDefault(
-      mgrPrefs.useRearCursorMode, forKey: UserDef.kuseRearCursorMode
+      mgrPrefs.shouldAutoReloadUserDataFiles, forKey: UserDef.kShouldAutoReloadUserDataFiles.rawValue
    )
    UserDefaults.standard.setDefault(
-      mgrPrefs.moveCursorAfterSelectingCandidate, forKey: UserDef.kMoveCursorAfterSelectingCandidate
+      mgrPrefs.specifyShiftTabKeyBehavior, forKey: UserDef.kSpecifyShiftTabKeyBehavior.rawValue
    )
    UserDefaults.standard.setDefault(
-      mgrPrefs.useHorizontalCandidateList, forKey: UserDef.kUseHorizontalCandidateList
+      mgrPrefs.specifyShiftSpaceKeyBehavior, forKey: UserDef.kSpecifyShiftSpaceKeyBehavior.rawValue
    )
-    UserDefaults.standard.setDefault(mgrPrefs.cns11643Enabled, forKey: UserDef.kCNS11643Enabled)
-    UserDefaults.standard.setDefault(mgrPrefs.chineseConversionEnabled, forKey: UserDef.kChineseConversionEnabled)
+    UserDefaults.standard.setDefault(mgrPrefs.useSCPCTypingMode, forKey: UserDef.kUseSCPCTypingMode.rawValue)
    UserDefaults.standard.setDefault(
-      mgrPrefs.shiftJISShinjitaiOutputEnabled, forKey: UserDef.kShiftJISShinjitaiOutputEnabled
-    )
-    UserDefaults.standard.setDefault(mgrPrefs.phraseReplacementEnabled, forKey: UserDef.kPhraseReplacementEnabled)
-    UserDefaults.standard.setDefault(mgrPrefs.shouldNotFartInLieuOfBeep, forKey: UserDef.kShouldNotFartInLieuOfBeep)
-    UserDefaults.standard.setDefault(
-      mgrPrefs.showHanyuPinyinInCompositionBuffer, forKey: UserDef.kShowHanyuPinyinInCompositionBuffer
+      mgrPrefs.associatedPhrasesEnabled, forKey: UserDef.kAssociatedPhrasesEnabled.rawValue
    )
    UserDefaults.standard.setDefault(
-      mgrPrefs.inlineDumpPinyinInLieuOfZhuyin, forKey: UserDef.kInlineDumpPinyinInLieuOfZhuyin
+      mgrPrefs.useRearCursorMode, forKey: UserDef.kUseRearCursorMode.rawValue
    )
    UserDefaults.standard.setDefault(
-      mgrPrefs.allowBoostingSingleKanjiAsUserPhrase, forKey: UserDef.kAllowBoostingSingleKanjiAsUserPhrase
+      mgrPrefs.moveCursorAfterSelectingCandidate, forKey: UserDef.kMoveCursorAfterSelectingCandidate.rawValue
    )
    UserDefaults.standard.setDefault(
-      mgrPrefs.fetchSuggestionsFromUserOverrideModel, forKey: UserDef.kFetchSuggestionsFromUserOverrideModel
+      mgrPrefs.useHorizontalCandidateList, forKey: UserDef.kUseHorizontalCandidateList.rawValue
+    )
+    UserDefaults.standard.setDefault(mgrPrefs.cns11643Enabled, forKey: UserDef.kCNS11643Enabled.rawValue)
+    UserDefaults.standard.setDefault(
+      mgrPrefs.chineseConversionEnabled, forKey: UserDef.kChineseConversionEnabled.rawValue
    )
    UserDefaults.standard.setDefault(
-      mgrPrefs.useFixecCandidateOrderOnSelection, forKey: UserDef.kUseFixecCandidateOrderOnSelection
+      mgrPrefs.shiftJISShinjitaiOutputEnabled, forKey: UserDef.kShiftJISShinjitaiOutputEnabled.rawValue
    )
    UserDefaults.standard.setDefault(
-      mgrPrefs.autoCorrectReadingCombination, forKey: UserDef.kAutoCorrectReadingCombination
+      mgrPrefs.phraseReplacementEnabled, forKey: UserDef.kPhraseReplacementEnabled.rawValue
    )
    UserDefaults.standard.setDefault(
-      mgrPrefs.alsoConfirmAssociatedCandidatesByEnter, forKey: UserDef.kAlsoConfirmAssociatedCandidatesByEnter
+      mgrPrefs.shouldNotFartInLieuOfBeep, forKey: UserDef.kShouldNotFartInLieuOfBeep.rawValue
    )
    UserDefaults.standard.setDefault(
-      mgrPrefs.currencyNumeralsEnabled, forKey: UserDef.kCurrencyNumeralsEnabled
+      mgrPrefs.showHanyuPinyinInCompositionBuffer, forKey: UserDef.kShowHanyuPinyinInCompositionBuffer.rawValue
+    )
+    UserDefaults.standard.setDefault(
+      mgrPrefs.inlineDumpPinyinInLieuOfZhuyin, forKey: UserDef.kInlineDumpPinyinInLieuOfZhuyin.rawValue
+    )
+    UserDefaults.standard.setDefault(
+      mgrPrefs.allowBoostingSingleKanjiAsUserPhrase, forKey: UserDef.kAllowBoostingSingleKanjiAsUserPhrase.rawValue
+    )
+    UserDefaults.standard.setDefault(
+      mgrPrefs.fetchSuggestionsFromUserOverrideModel, forKey: UserDef.kFetchSuggestionsFromUserOverrideModel.rawValue
+    )
+    UserDefaults.standard.setDefault(
+      mgrPrefs.useFixecCandidateOrderOnSelection, forKey: UserDef.kUseFixecCandidateOrderOnSelection.rawValue
+    )
+    UserDefaults.standard.setDefault(
+      mgrPrefs.autoCorrectReadingCombination, forKey: UserDef.kAutoCorrectReadingCombination.rawValue
+    )
+    UserDefaults.standard.setDefault(
+      mgrPrefs.alsoConfirmAssociatedCandidatesByEnter, forKey: UserDef.kAlsoConfirmAssociatedCandidatesByEnter.rawValue
+    )
+    UserDefaults.standard.setDefault(
+      mgrPrefs.currencyNumeralsEnabled, forKey: UserDef.kCurrencyNumeralsEnabled.rawValue
+    )
+    UserDefaults.standard.setDefault(
+      mgrPrefs.keepReadingUponCompositionError, forKey: UserDef.kKeepReadingUponCompositionError.rawValue
    )

-    UserDefaults.standard.setDefault(mgrPrefs.usingHotKeySCPC, forKey: UserDef.kUsingHotKeySCPC)
-    UserDefaults.standard.setDefault(mgrPrefs.usingHotKeyAssociates, forKey: UserDef.kUsingHotKeyAssociates)
-    UserDefaults.standard.setDefault(mgrPrefs.usingHotKeyCNS, forKey: UserDef.kUsingHotKeyCNS)
-    UserDefaults.standard.setDefault(mgrPrefs.usingHotKeyKangXi, forKey: UserDef.kUsingHotKeyKangXi)
-    UserDefaults.standard.setDefault(mgrPrefs.usingHotKeyJIS, forKey: UserDef.kUsingHotKeyJIS)
-    UserDefaults.standard.setDefault(mgrPrefs.usingHotKeyHalfWidthASCII, forKey: UserDef.kUsingHotKeyHalfWidthASCII)
-    UserDefaults.standard.setDefault(mgrPrefs.usingHotKeyCurrencyNumerals, forKey: UserDef.kUsingHotKeyCurrencyNumerals)
+    UserDefaults.standard.setDefault(mgrPrefs.usingHotKeySCPC, forKey: UserDef.kUsingHotKeySCPC.rawValue)
+    UserDefaults.standard.setDefault(mgrPrefs.usingHotKeyAssociates, forKey: UserDef.kUsingHotKeyAssociates.rawValue)
+    UserDefaults.standard.setDefault(mgrPrefs.usingHotKeyCNS, forKey: UserDef.kUsingHotKeyCNS.rawValue)
+    UserDefaults.standard.setDefault(mgrPrefs.usingHotKeyKangXi, forKey: UserDef.kUsingHotKeyKangXi.rawValue)
+    UserDefaults.standard.setDefault(mgrPrefs.usingHotKeyJIS, forKey: UserDef.kUsingHotKeyJIS.rawValue)
+    UserDefaults.standard.setDefault(
+      mgrPrefs.usingHotKeyHalfWidthASCII, forKey: UserDef.kUsingHotKeyHalfWidthASCII.rawValue
+    )
+    UserDefaults.standard.setDefault(
+      mgrPrefs.usingHotKeyCurrencyNumerals, forKey: UserDef.kUsingHotKeyCurrencyNumerals.rawValue
+    )

    UserDefaults.standard.synchronize()
  }

-  @UserDefault(key: UserDef.kIsDebugModeEnabled, defaultValue: false)
+  @UserDefault(key: UserDef.kIsDebugModeEnabled.rawValue, defaultValue: false)
  static var isDebugModeEnabled: Bool

-  @UserDefault(key: UserDef.kMostRecentInputMode, defaultValue: "")
+  @UserDefault(key: UserDef.kFailureFlagForUOMObservation.rawValue, defaultValue: false)
+  static var failureFlagForUOMObservation: Bool
+
+  @UserDefault(key: UserDef.kMostRecentInputMode.rawValue, defaultValue: "")
  static var mostRecentInputMode: String

-  @UserDefault(key: UserDef.kCheckUpdateAutomatically, defaultValue: false)
+  @UserDefault(key: UserDef.kCheckUpdateAutomatically.rawValue, defaultValue: false)
  static var checkUpdateAutomatically: Bool

-  @UserDefault(key: UserDef.kUserDataFolderSpecified, defaultValue: "")
+  @UserDefault(key: UserDef.kUserDataFolderSpecified.rawValue, defaultValue: "")
  static var userDataFolderSpecified: String

  static func ifSpecifiedUserDataPathExistsInPlist() -> Bool {
-    UserDefaults.standard.object(forKey: UserDef.kUserDataFolderSpecified) != nil
+    UserDefaults.standard.object(forKey: UserDef.kUserDataFolderSpecified.rawValue) != nil
  }

  static func resetSpecifiedUserDataFolder() {
@ -330,10 +357,10 @@ public enum mgrPrefs {
    IME.initLangModels(userOnly: true)
  }

-  @UserDefault(key: UserDef.kAppleLanguages, defaultValue: [])
+  @UserDefault(key: UserDef.kAppleLanguages.rawValue, defaultValue: [])
  static var appleLanguages: [String]

-  @UserDefault(key: UserDef.kMandarinParser, defaultValue: 0)
+  @UserDefault(key: UserDef.kMandarinParser.rawValue, defaultValue: 0)
  static var mandarinParser: Int

  static var mandarinParserName: String {
@ -341,103 +368,106 @@ public enum mgrPrefs {
  }

  @UserDefault(
-    key: UserDef.kBasicKeyboardLayout, defaultValue: "com.apple.keylayout.ZhuyinBopomofo"
+    key: UserDef.kBasicKeyboardLayout.rawValue, defaultValue: "com.apple.keylayout.ZhuyinBopomofo"
  )
  static var basicKeyboardLayout: String

-  @UserDefault(key: UserDef.kShowPageButtonsInCandidateWindow, defaultValue: true)
+  @UserDefault(key: UserDef.kShowPageButtonsInCandidateWindow.rawValue, defaultValue: true)
  static var showPageButtonsInCandidateWindow: Bool

-  @CandidateListTextSize(key: UserDef.kCandidateListTextSize)
+  @CandidateListTextSize(key: UserDef.kCandidateListTextSize.rawValue)
  static var candidateListTextSize: CGFloat

  static var minKeyLabelSize: CGFloat { kDefaultMinKeyLabelSize }

-  @UserDefault(key: UserDef.kShouldAutoReloadUserDataFiles, defaultValue: true)
+  @UserDefault(key: UserDef.kShouldAutoReloadUserDataFiles.rawValue, defaultValue: true)
  static var shouldAutoReloadUserDataFiles: Bool

-  @UserDefault(key: UserDef.kuseRearCursorMode, defaultValue: false)
+  @UserDefault(key: UserDef.kUseRearCursorMode.rawValue, defaultValue: false)
  static var useRearCursorMode: Bool

-  @UserDefault(key: UserDef.kMoveCursorAfterSelectingCandidate, defaultValue: true)
+  @UserDefault(key: UserDef.kMoveCursorAfterSelectingCandidate.rawValue, defaultValue: true)
  static var moveCursorAfterSelectingCandidate: Bool

-  @UserDefault(key: UserDef.kUseHorizontalCandidateList, defaultValue: true)
+  @UserDefault(key: UserDef.kUseHorizontalCandidateList.rawValue, defaultValue: true)
  static var useHorizontalCandidateList: Bool

-  @ComposingBufferSize(key: UserDef.kComposingBufferSize)
+  @ComposingBufferSize(key: UserDef.kComposingBufferSize.rawValue)
  static var composingBufferSize: Int

-  @UserDefault(key: UserDef.kChooseCandidateUsingSpace, defaultValue: true)
+  @UserDefault(key: UserDef.kChooseCandidateUsingSpace.rawValue, defaultValue: true)
  static var chooseCandidateUsingSpace: Bool

-  @UserDefault(key: UserDef.kAllowBoostingSingleKanjiAsUserPhrase, defaultValue: false)
+  @UserDefault(key: UserDef.kAllowBoostingSingleKanjiAsUserPhrase.rawValue, defaultValue: false)
  static var allowBoostingSingleKanjiAsUserPhrase: Bool

-  @UserDefault(key: UserDef.kFetchSuggestionsFromUserOverrideModel, defaultValue: true)
+  @UserDefault(key: UserDef.kFetchSuggestionsFromUserOverrideModel.rawValue, defaultValue: true)
  static var fetchSuggestionsFromUserOverrideModel: Bool

-  @UserDefault(key: UserDef.kUseFixecCandidateOrderOnSelection, defaultValue: false)
+  @UserDefault(key: UserDef.kUseFixecCandidateOrderOnSelection.rawValue, defaultValue: false)
  static var useFixecCandidateOrderOnSelection: Bool

-  @UserDefault(key: UserDef.kAutoCorrectReadingCombination, defaultValue: true)
+  @UserDefault(key: UserDef.kAutoCorrectReadingCombination.rawValue, defaultValue: true)
  static var autoCorrectReadingCombination: Bool

-  @UserDefault(key: UserDef.kAlsoConfirmAssociatedCandidatesByEnter, defaultValue: true)
+  @UserDefault(key: UserDef.kAlsoConfirmAssociatedCandidatesByEnter.rawValue, defaultValue: true)
  static var alsoConfirmAssociatedCandidatesByEnter: Bool

+  @UserDefault(key: UserDef.kAlsoConfirmAssociatedCandidatesByEnter.rawValue, defaultValue: false)
+  static var keepReadingUponCompositionError: Bool
+
  static var minCandidateLength: Int {
    mgrPrefs.allowBoostingSingleKanjiAsUserPhrase ? 1 : 2
  }

-  @UserDefault(key: UserDef.kUseSCPCTypingMode, defaultValue: false)
+  @UserDefault(key: UserDef.kUseSCPCTypingMode.rawValue, defaultValue: false)
  static var useSCPCTypingMode: Bool

  static func toggleSCPCTypingModeEnabled() -> Bool {
    useSCPCTypingMode = !useSCPCTypingMode
-    UserDefaults.standard.set(useSCPCTypingMode, forKey: UserDef.kUseSCPCTypingMode)
+    UserDefaults.standard.set(useSCPCTypingMode, forKey: UserDef.kUseSCPCTypingMode.rawValue)
    return useSCPCTypingMode
  }

-  @UserDefault(key: UserDef.kMaxCandidateLength, defaultValue: 10)
+  @UserDefault(key: UserDef.kMaxCandidateLength.rawValue, defaultValue: 10)
  static var maxCandidateLength: Int

-  @UserDefault(key: UserDef.kShouldNotFartInLieuOfBeep, defaultValue: true)
+  @UserDefault(key: UserDef.kShouldNotFartInLieuOfBeep.rawValue, defaultValue: true)
  static var shouldNotFartInLieuOfBeep: Bool

-  @UserDefault(key: UserDef.kShowHanyuPinyinInCompositionBuffer, defaultValue: false)
+  @UserDefault(key: UserDef.kShowHanyuPinyinInCompositionBuffer.rawValue, defaultValue: false)
  static var showHanyuPinyinInCompositionBuffer: Bool

-  @UserDefault(key: UserDef.kInlineDumpPinyinInLieuOfZhuyin, defaultValue: false)
+  @UserDefault(key: UserDef.kInlineDumpPinyinInLieuOfZhuyin.rawValue, defaultValue: false)
  static var inlineDumpPinyinInLieuOfZhuyin: Bool

  static func toggleShouldNotFartInLieuOfBeep() -> Bool {
    shouldNotFartInLieuOfBeep = !shouldNotFartInLieuOfBeep
-    UserDefaults.standard.set(shouldNotFartInLieuOfBeep, forKey: UserDef.kShouldNotFartInLieuOfBeep)
+    UserDefaults.standard.set(shouldNotFartInLieuOfBeep, forKey: UserDef.kShouldNotFartInLieuOfBeep.rawValue)
    return shouldNotFartInLieuOfBeep
  }

-  @UserDefault(key: UserDef.kCNS11643Enabled, defaultValue: false)
+  @UserDefault(key: UserDef.kCNS11643Enabled.rawValue, defaultValue: false)
  static var cns11643Enabled: Bool

  static func toggleCNS11643Enabled() -> Bool {
    cns11643Enabled = !cns11643Enabled
    mgrLangModel.setCNSEnabled(cns11643Enabled)  // 很重要
-    UserDefaults.standard.set(cns11643Enabled, forKey: UserDef.kCNS11643Enabled)
+    UserDefaults.standard.set(cns11643Enabled, forKey: UserDef.kCNS11643Enabled.rawValue)
    return cns11643Enabled
  }

-  @UserDefault(key: UserDef.kSymbolInputEnabled, defaultValue: true)
+  @UserDefault(key: UserDef.kSymbolInputEnabled.rawValue, defaultValue: true)
  static var symbolInputEnabled: Bool

  static func toggleSymbolInputEnabled() -> Bool {
    symbolInputEnabled = !symbolInputEnabled
    mgrLangModel.setSymbolEnabled(symbolInputEnabled)  // 很重要
-    UserDefaults.standard.set(symbolInputEnabled, forKey: UserDef.kSymbolInputEnabled)
+    UserDefaults.standard.set(symbolInputEnabled, forKey: UserDef.kSymbolInputEnabled.rawValue)
    return symbolInputEnabled
  }

-  @UserDefault(key: UserDef.kChineseConversionEnabled, defaultValue: false)
+  @UserDefault(key: UserDef.kChineseConversionEnabled.rawValue, defaultValue: false)
  static var chineseConversionEnabled: Bool

  @discardableResult static func toggleChineseConversionEnabled() -> Bool {
@ -446,14 +476,14 @@ public enum mgrPrefs {
    if chineseConversionEnabled, shiftJISShinjitaiOutputEnabled {
      toggleShiftJISShinjitaiOutputEnabled()
      UserDefaults.standard.set(
-        shiftJISShinjitaiOutputEnabled, forKey: UserDef.kShiftJISShinjitaiOutputEnabled
+        shiftJISShinjitaiOutputEnabled, forKey: UserDef.kShiftJISShinjitaiOutputEnabled.rawValue
      )
    }
-    UserDefaults.standard.set(chineseConversionEnabled, forKey: UserDef.kChineseConversionEnabled)
+    UserDefaults.standard.set(chineseConversionEnabled, forKey: UserDef.kChineseConversionEnabled.rawValue)
    return chineseConversionEnabled
  }

-  @UserDefault(key: UserDef.kShiftJISShinjitaiOutputEnabled, defaultValue: false)
+  @UserDefault(key: UserDef.kShiftJISShinjitaiOutputEnabled.rawValue, defaultValue: false)
  static var shiftJISShinjitaiOutputEnabled: Bool

  @discardableResult static func toggleShiftJISShinjitaiOutputEnabled() -> Bool {
@ -463,12 +493,12 @@ public enum mgrPrefs {
      toggleChineseConversionEnabled()
    }
    UserDefaults.standard.set(
-      shiftJISShinjitaiOutputEnabled, forKey: UserDef.kShiftJISShinjitaiOutputEnabled
+      shiftJISShinjitaiOutputEnabled, forKey: UserDef.kShiftJISShinjitaiOutputEnabled.rawValue
    )
    return shiftJISShinjitaiOutputEnabled
  }

-  @UserDefault(key: UserDef.kCurrencyNumeralsEnabled, defaultValue: false)
+  @UserDefault(key: UserDef.kCurrencyNumeralsEnabled.rawValue, defaultValue: false)
  static var currencyNumeralsEnabled: Bool

  static func toggleCurrencyNumeralsEnabled() -> Bool {
@ -476,7 +506,7 @@ public enum mgrPrefs {
    return currencyNumeralsEnabled
  }

-  @UserDefault(key: UserDef.kHalfWidthPunctuationEnabled, defaultValue: false)
+  @UserDefault(key: UserDef.kHalfWidthPunctuationEnabled.rawValue, defaultValue: false)
  static var halfWidthPunctuationEnabled: Bool

  static func toggleHalfWidthPunctuationEnabled() -> Bool {
@ -484,24 +514,24 @@ public enum mgrPrefs {
    return halfWidthPunctuationEnabled
  }

-  @UserDefault(key: UserDef.kEscToCleanInputBuffer, defaultValue: true)
+  @UserDefault(key: UserDef.kEscToCleanInputBuffer.rawValue, defaultValue: true)
  static var escToCleanInputBuffer: Bool

-  @UserDefault(key: UserDef.kSpecifyShiftTabKeyBehavior, defaultValue: false)
+  @UserDefault(key: UserDef.kSpecifyShiftTabKeyBehavior.rawValue, defaultValue: false)
  static var specifyShiftTabKeyBehavior: Bool

-  @UserDefault(key: UserDef.kSpecifyShiftSpaceKeyBehavior, defaultValue: false)
+  @UserDefault(key: UserDef.kSpecifyShiftSpaceKeyBehavior.rawValue, defaultValue: false)
  static var specifyShiftSpaceKeyBehavior: Bool

  // MARK: - Optional settings

-  @UserDefault(key: UserDef.kCandidateTextFontName, defaultValue: nil)
+  @UserDefault(key: UserDef.kCandidateTextFontName.rawValue, defaultValue: nil)
  static var candidateTextFontName: String?

-  @UserDefault(key: UserDef.kCandidateKeyLabelFontName, defaultValue: nil)
+  @UserDefault(key: UserDef.kCandidateKeyLabelFontName.rawValue, defaultValue: nil)
  static var candidateKeyLabelFontName: String?

-  @UserDefault(key: UserDef.kCandidateKeys, defaultValue: kDefaultKeys)
+  @UserDefault(key: UserDef.kCandidateKeys.rawValue, defaultValue: kDefaultKeys)
  static var candidateKeys: String

  static var defaultCandidateKeys: String {
@ -566,46 +596,46 @@ public enum mgrPrefs {
    }
  }

-  @UserDefault(key: UserDef.kPhraseReplacementEnabled, defaultValue: false)
+  @UserDefault(key: UserDef.kPhraseReplacementEnabled.rawValue, defaultValue: false)
  static var phraseReplacementEnabled: Bool

  static func togglePhraseReplacementEnabled() -> Bool {
    phraseReplacementEnabled = !phraseReplacementEnabled
    mgrLangModel.setPhraseReplacementEnabled(phraseReplacementEnabled)
-    UserDefaults.standard.set(phraseReplacementEnabled, forKey: UserDef.kPhraseReplacementEnabled)
+    UserDefaults.standard.set(phraseReplacementEnabled, forKey: UserDef.kPhraseReplacementEnabled.rawValue)
    return phraseReplacementEnabled
  }

-  @UserDefault(key: UserDef.kAssociatedPhrasesEnabled, defaultValue: false)
+  @UserDefault(key: UserDef.kAssociatedPhrasesEnabled.rawValue, defaultValue: false)
  static var associatedPhrasesEnabled: Bool

  static func toggleAssociatedPhrasesEnabled() -> Bool {
    associatedPhrasesEnabled = !associatedPhrasesEnabled
-    UserDefaults.standard.set(associatedPhrasesEnabled, forKey: UserDef.kAssociatedPhrasesEnabled)
+    UserDefaults.standard.set(associatedPhrasesEnabled, forKey: UserDef.kAssociatedPhrasesEnabled.rawValue)
    return associatedPhrasesEnabled
  }

  // MARK: - Keyboard HotKey Enable / Disable

-  @UserDefault(key: UserDef.kUsingHotKeySCPC, defaultValue: true)
+  @UserDefault(key: UserDef.kUsingHotKeySCPC.rawValue, defaultValue: true)
  static var usingHotKeySCPC: Bool

-  @UserDefault(key: UserDef.kUsingHotKeyAssociates, defaultValue: true)
+  @UserDefault(key: UserDef.kUsingHotKeyAssociates.rawValue, defaultValue: true)
  static var usingHotKeyAssociates: Bool

-  @UserDefault(key: UserDef.kUsingHotKeyCNS, defaultValue: true)
+  @UserDefault(key: UserDef.kUsingHotKeyCNS.rawValue, defaultValue: true)
  static var usingHotKeyCNS: Bool

-  @UserDefault(key: UserDef.kUsingHotKeyKangXi, defaultValue: true)
+  @UserDefault(key: UserDef.kUsingHotKeyKangXi.rawValue, defaultValue: true)
  static var usingHotKeyKangXi: Bool

-  @UserDefault(key: UserDef.kUsingHotKeyJIS, defaultValue: true)
+  @UserDefault(key: UserDef.kUsingHotKeyJIS.rawValue, defaultValue: true)
  static var usingHotKeyJIS: Bool

-  @UserDefault(key: UserDef.kUsingHotKeyHalfWidthASCII, defaultValue: true)
+  @UserDefault(key: UserDef.kUsingHotKeyHalfWidthASCII.rawValue, defaultValue: true)
  static var usingHotKeyHalfWidthASCII: Bool

-  @UserDefault(key: UserDef.kUsingHotKeyCurrencyNumerals, defaultValue: true)
+  @UserDefault(key: UserDef.kUsingHotKeyCurrencyNumerals.rawValue, defaultValue: true)
  static var usingHotKeyCurrencyNumerals: Bool
 }

@ -614,45 +644,23 @@ public enum mgrPrefs {
 var snapshot: [String: Any]?

 extension mgrPrefs {
-  static var allKeys: [String] {
-    [
-      UserDef.kIsDebugModeEnabled, UserDef.kMostRecentInputMode, UserDef.kUserDataFolderSpecified,
-      UserDef.kCheckUpdateAutomatically, UserDef.kMandarinParser, UserDef.kBasicKeyboardLayout,
-      UserDef.kShowPageButtonsInCandidateWindow, UserDef.kCandidateListTextSize, UserDef.kAppleLanguages,
-      UserDef.kShouldAutoReloadUserDataFiles, UserDef.kuseRearCursorMode, UserDef.kUseHorizontalCandidateList,
-      UserDef.kComposingBufferSize, UserDef.kChooseCandidateUsingSpace, UserDef.kCNS11643Enabled,
-      UserDef.kSymbolInputEnabled, UserDef.kChineseConversionEnabled, UserDef.kShiftJISShinjitaiOutputEnabled,
-      UserDef.kHalfWidthPunctuationEnabled, UserDef.kMoveCursorAfterSelectingCandidate, UserDef.kEscToCleanInputBuffer,
-      UserDef.kSpecifyShiftTabKeyBehavior, UserDef.kSpecifyShiftSpaceKeyBehavior,
-      UserDef.kAllowBoostingSingleKanjiAsUserPhrase, UserDef.kUseSCPCTypingMode, UserDef.kMaxCandidateLength,
-      UserDef.kShouldNotFartInLieuOfBeep, UserDef.kShowHanyuPinyinInCompositionBuffer,
-      UserDef.kInlineDumpPinyinInLieuOfZhuyin, UserDef.kFetchSuggestionsFromUserOverrideModel,
-      UserDef.kCandidateTextFontName, UserDef.kCandidateKeyLabelFontName, UserDef.kCandidateKeys,
-      UserDef.kAssociatedPhrasesEnabled, UserDef.kPhraseReplacementEnabled, UserDef.kUsingHotKeySCPC,
-      UserDef.kUsingHotKeyAssociates, UserDef.kUsingHotKeyCNS, UserDef.kUsingHotKeyKangXi, UserDef.kUsingHotKeyJIS,
-      UserDef.kUsingHotKeyHalfWidthASCII, UserDef.kUseFixecCandidateOrderOnSelection,
-      UserDef.kAutoCorrectReadingCombination, UserDef.kAlsoConfirmAssociatedCandidatesByEnter,
-      UserDef.kCurrencyNumeralsEnabled, UserDef.kUsingHotKeyCurrencyNumerals,
-    ]
-  }
-
  func reset() {
-    mgrPrefs.allKeys.forEach {
-      UserDefaults.standard.removeObject(forKey: $0)
+    UserDef.allCases.forEach {
+      UserDefaults.standard.removeObject(forKey: $0.rawValue)
    }
  }

  func makeSnapshot() -> [String: Any] {
    var dict = [String: Any]()
-    mgrPrefs.allKeys.forEach {
-      dict[$0] = UserDefaults.standard.object(forKey: $0)
+    UserDef.allCases.forEach {
+      dict[$0.rawValue] = UserDefaults.standard.object(forKey: $0.rawValue)
    }
    return dict
  }

  func restore(from snapshot: [String: Any]) {
-    mgrPrefs.allKeys.forEach {
-      UserDefaults.standard.set(snapshot[$0], forKey: $0)
+    UserDef.allCases.forEach {
+      UserDefaults.standard.set(snapshot[$0.rawValue], forKey: $0.rawValue)
    }
  }
 }
--- a/Source/Modules/LangModelRelated/SubLMs/lmAssociates.swift
+++ b/Source/Modules/LangModelRelated/SubLMs/lmAssociates.swift
@ -62,7 +62,7 @@ extension vChewing {
      do {
        strData = try String(contentsOfFile: path, encoding: .utf8).replacingOccurrences(of: "\t", with: " ")
        strData = strData.replacingOccurrences(of: "\r", with: "\n")
-        strData.ranges(splitBy: "\n").filter({ !$0.isEmpty }).forEach {
+        strData.ranges(splitBy: "\n").filter { !$0.isEmpty }.forEach {
          let neta = strData[$0].split(separator: " ")
          if neta.count >= 2 {
            let theKey = String(neta[0])
--- a/Source/Modules/LangModelRelated/SubLMs/lmCoreEX.swift
+++ b/Source/Modules/LangModelRelated/SubLMs/lmCoreEX.swift
@ -87,7 +87,7 @@ extension vChewing {
      do {
        strData = try String(contentsOfFile: path, encoding: .utf8).replacingOccurrences(of: "\t", with: " ")
        strData = strData.replacingOccurrences(of: "\r", with: "\n")
-        strData.ranges(splitBy: "\n").filter({ !$0.isEmpty }).forEach {
+        strData.ranges(splitBy: "\n").filter { !$0.isEmpty }.forEach {
          let neta = strData[$0].split(separator: " ")
          if neta.count >= 2, String(neta[0]).first != "#" {
            if !neta[0].isEmpty, !neta[1].isEmpty {
--- a/Source/Modules/LangModelRelated/SubLMs/lmReplacements.swift
+++ b/Source/Modules/LangModelRelated/SubLMs/lmReplacements.swift
@ -53,7 +53,7 @@ extension vChewing {
      do {
        strData = try String(contentsOfFile: path, encoding: .utf8).replacingOccurrences(of: "\t", with: " ")
        strData = strData.replacingOccurrences(of: "\r", with: "\n")
-        strData.ranges(splitBy: "\n").filter({ !$0.isEmpty }).forEach {
+        strData.ranges(splitBy: "\n").filter { !$0.isEmpty }.forEach {
          let neta = strData[$0].split(separator: " ")
          if neta.count >= 2 {
            let theKey = String(neta[0])
--- a/Source/Modules/LangModelRelated/SubLMs/lmUserOverride.swift
+++ b/Source/Modules/LangModelRelated/SubLMs/lmUserOverride.swift
@ -326,9 +326,8 @@ extension vChewing.LMUserOverride {
  public func saveData(toURL fileURL: URL) {
    let encoder = JSONEncoder()
    do {
-      if let jsonData = try? encoder.encode(mutLRUMap) {
-        try jsonData.write(to: fileURL, options: .atomic)
-      }
+      guard let jsonData = try? encoder.encode(mutLRUMap) else { return }
+      try jsonData.write(to: fileURL, options: .atomic)
    } catch {
      IME.prtDebugIntel("UOM Error: Unable to save data, abort saving. Details: \(error)")
      return
--- a/Source/Modules/main.swift
+++ b/Source/Modules/main.swift
@ -67,4 +67,6 @@ else {
  exit(-1)
 }

+public let theServer = server
+
 NSApp.run()
--- a/Source/Resources/Base.lproj/Localizable.strings
+++ b/Source/Resources/Base.lproj/Localizable.strings
@ -1,3 +1,5 @@
+"vChewing" = "vChewing";
+"vChewing crashed while handling previously loaded UOM observation data. These data files are cleaned now to ensure the usability." = "vChewing crashed while handling previously loaded UOM observation data. These data files are cleaned now to ensure the usability.";
 "About vChewing…" = "About vChewing…";
 "vChewing Preferences…" = "vChewing Preferences…";
 "Uninstallation" = "Uninstallation";
@ -37,7 +39,7 @@
 "Please specify at least 4 candidate keys." = "Please specify at least 4 candidate keys.";
 "Maximum 15 candidate keys allowed." = "Maximum 15 candidate keys allowed.";
 "⚠︎ Phrase replacement mode enabled, interfering user phrase entry." = "⚠︎ Phrase replacement mode enabled, interfering user phrase entry.";
-"⚠︎ Unhandlable: Chars and Readings in buffer doesn't match." = "⚠︎ Unhandlable: Chars and Readings in buffer doesn't match.";
+"⚠︎ Beware: Chars and Readings in buffer doesn't match." = "⚠︎ Beware: Chars and Readings in buffer doesn't match.";
 "Per-Char Select Mode" = "Per-Char Select Mode";
 "CNS11643 Mode" = "CNS11643 Mode";
 "JIS Shinjitai Output" = "JIS Shinjitai Output";
@ -85,6 +87,7 @@

 // SwiftUI Preferences
 "(Shift+)Space:" = "(Shift+)Space:";
+"Allow backspace-editing miscomposed readings" = "Allow backspace-editing miscomposed readings";
 "Allow boosting / excluding a candidate of single kanji" = "Allow boosting / excluding a candidate of single kanji";
 "Allow using Enter key to confirm associated candidate selection" = "Allow using Enter key to confirm associated candidate selection";
 "Always use fixed listing order in candidate window" = "Always use fixed listing order in candidate window";
--- a/Source/Resources/en.lproj/Localizable.strings
+++ b/Source/Resources/en.lproj/Localizable.strings
@ -1,3 +1,5 @@
+"vChewing" = "vChewing";
+"vChewing crashed while handling previously loaded UOM observation data. These data files are cleaned now to ensure the usability." = "vChewing crashed while handling previously loaded UOM observation data. These data files are cleaned now to ensure the usability.";
 "About vChewing…" = "About vChewing…";
 "vChewing Preferences…" = "vChewing Preferences…";
 "Uninstallation" = "Uninstallation";
@ -37,7 +39,7 @@
 "Please specify at least 4 candidate keys." = "Please specify at least 4 candidate keys.";
 "Maximum 15 candidate keys allowed." = "Maximum 15 candidate keys allowed.";
 "⚠︎ Phrase replacement mode enabled, interfering user phrase entry." = "⚠︎ Phrase replacement mode enabled, interfering user phrase entry.";
-"⚠︎ Unhandlable: Chars and Readings in buffer doesn't match." = "⚠︎ Unhandlable: Chars and Readings in buffer doesn't match.";
+"⚠︎ Beware: Chars and Readings in buffer doesn't match." = "⚠︎ Beware: Chars and Readings in buffer doesn't match.";
 "Per-Char Select Mode" = "Per-Char Select Mode";
 "CNS11643 Mode" = "CNS11643 Mode";
 "JIS Shinjitai Output" = "JIS Shinjitai Output";
@ -85,6 +87,7 @@

 // SwiftUI Preferences
 "(Shift+)Space:" = "(Shift+)Space:";
+"Allow backspace-editing miscomposed readings" = "Allow backspace-editing miscomposed readings";
 "Allow boosting / excluding a candidate of single kanji" = "Allow boosting / excluding a candidate of single kanji";
 "Allow using Enter key to confirm associated candidate selection" = "Allow using Enter key to confirm associated candidate selection";
 "Always use fixed listing order in candidate window" = "Always use fixed listing order in candidate window";
--- a/Source/Resources/ja.lproj/Localizable.strings
+++ b/Source/Resources/ja.lproj/Localizable.strings
@ -1,3 +1,5 @@
+"vChewing" = "威注音入力アプリ";
+"vChewing crashed while handling previously loaded UOM observation data. These data files are cleaned now to ensure the usability." = "臨時記憶モジュールの観測行為による威注音入力アプリの意外中止は発生した。威注音入力アプリの無事利用のために、既存臨時記憶データは全てお消しした。";
 "About vChewing…" = "威注音について…";
 "vChewing Preferences…" = "入力機能設定…";
 "Uninstallation" = "入力アプリの卸除（おろしのぞき）";
@ -37,7 +39,7 @@
 "Please specify at least 4 candidate keys." = "言選り用キー陣列に少なくとも４つのキーをご登録ください。";
 "Maximum 15 candidate keys allowed." = "言選り用キー陣列には最多１５つキー登録できます。";
 "⚠︎ Phrase replacement mode enabled, interfering user phrase entry." = "⚠︎ 言葉置換機能稼働中、新添付言葉にも影響。";
-"⚠︎ Unhandlable: Chars and Readings in buffer doesn't match." = "⚠︎ 緩衝列の字数は読みの数と不同等のため、対処不可。";
+"⚠︎ Beware: Chars and Readings in buffer doesn't match." = "⚠︎ 注意：緩衝列の字数は読みの数と不同等。";
 "Per-Char Select Mode" = "全候補入力モード";
 "CNS11643 Mode" = "全字庫モード";
 "JIS Shinjitai Output" = "JIS 新字体モード";
@ -85,6 +87,7 @@

 // SwiftUI Preferences
 "(Shift+)Space:" = "(Shift+)Space:";
+"Allow backspace-editing miscomposed readings" = "効かぬ音読みを BackSpace で再編集";
 "Allow boosting / excluding a candidate of single kanji" = "即排除/即最優先にできる候補の文字数の最低限は１字とする";
 "Allow using Enter key to confirm associated candidate selection" = "Enter キーを連想語彙候補の確認のために使う";
 "Always use fixed listing order in candidate window" = "候補文字を固定順番で陳列する";
--- a/Source/Resources/zh-Hans.lproj/Localizable.strings
+++ b/Source/Resources/zh-Hans.lproj/Localizable.strings
@ -1,3 +1,5 @@
+"vChewing" = "威注音输入法";
+"vChewing crashed while handling previously loaded UOM observation data. These data files are cleaned now to ensure the usability." = "威注音输入法的使用者半衰记忆模组在观测时崩溃，相关半衰记忆资料档案内容已全部清空。";
 "About vChewing…" = "关于威注音…";
 "vChewing Preferences…" = "威注音偏好设定…";
 "Uninstallation" = "卸除输入法";
@ -37,7 +39,7 @@
 "Please specify at least 4 candidate keys." = "请至少指定四个选字键。";
 "Maximum 15 candidate keys allowed." = "选字键最多只能指定十五个。";
 "⚠︎ Phrase replacement mode enabled, interfering user phrase entry." = "⚠︎ 语汇置换功能已启用，会波及语汇自订。";
-"⚠︎ Unhandlable: Chars and Readings in buffer doesn't match." = "⚠︎ 无法处理组字区字数与读音数不对应的情形。";
+"⚠︎ Beware: Chars and Readings in buffer doesn't match." = "⚠︎ 注意：组字区字数与读音数不对应。";
 "Per-Char Select Mode" = "仿真逐字选字输入";
 "CNS11643 Mode" = "全字库模式";
 "JIS Shinjitai Output" = "JIS 新字体模式";
@ -85,6 +87,7 @@

 // SwiftUI Preferences
 "(Shift+)Space:" = "(Shift+)空格键:";
+"Allow backspace-editing miscomposed readings" = "允许对无效的读音使用 BackSpace 编辑";
 "Allow boosting / excluding a candidate of single kanji" = "将可以就地升权/排除的候选字词的最短词长设为单个汉字";
 "Allow using Enter key to confirm associated candidate selection" = "允许使用 Enter 确认当前选中的联想词";
 "Always use fixed listing order in candidate window" = "以固定顺序来陈列选字窗内的候选字";
--- a/Source/Resources/zh-Hant.lproj/Localizable.strings
+++ b/Source/Resources/zh-Hant.lproj/Localizable.strings
@ -1,3 +1,5 @@
+"vChewing" = "威注音輸入法";
+"vChewing crashed while handling previously loaded UOM observation data. These data files are cleaned now to ensure the usability." = "威注音輸入法的使用者半衰記憶模組在觀測時崩潰，相關半衰記憶資料檔案內容已全部清空。";
 "About vChewing…" = "關於威注音…";
 "vChewing Preferences…" = "威注音偏好設定…";
 "Uninstallation" = "卸除輸入法";
@ -37,7 +39,7 @@
 "Please specify at least 4 candidate keys." = "請至少指定四個選字鍵。";
 "Maximum 15 candidate keys allowed." = "選字鍵最多只能指定十五個。";
 "⚠︎ Phrase replacement mode enabled, interfering user phrase entry." = "⚠︎ 語彙置換功能已啟用，會波及語彙自訂。";
-"⚠︎ Unhandlable: Chars and Readings in buffer doesn't match." = "⚠︎ 無法處理組字區字數與讀音數不對應的情形。";
+"⚠︎ Beware: Chars and Readings in buffer doesn't match." = "⚠︎ 注意：組字區字數與讀音數不對應。";
 "Per-Char Select Mode" = "模擬逐字選字輸入";
 "CNS11643 Mode" = "全字庫模式";
 "JIS Shinjitai Output" = "JIS 新字體模式";
@ -85,6 +87,7 @@

 // SwiftUI Preferences
 "(Shift+)Space:" = "(Shift+)空格鍵:";
+"Allow backspace-editing miscomposed readings" = "允許對無效的讀音使用 BackSpace 編輯";
 "Allow boosting / excluding a candidate of single kanji" = "將可以就地升權/排除的候選字詞的最短詞長設為單個漢字";
 "Allow using Enter key to confirm associated candidate selection" = "允許使用 Enter 確認當前選中的聯想詞";
 "Always use fixed listing order in candidate window" = "以固定順序來陳列選字窗內的候選字";
--- a/Source/UI/CandidateUI/ctlCandidate.swift
+++ b/Source/UI/CandidateUI/ctlCandidate.swift
@ -26,6 +26,11 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

 import Cocoa

+public enum CandidateLayout {
+  case horizontal
+  case vertical
+}
+
 public class CandidateKeyLabel: NSObject {
  public private(set) var key: String
  public private(set) var displayedText: String
@ -38,21 +43,39 @@ public class CandidateKeyLabel: NSObject {
 }

 public protocol ctlCandidateDelegate: AnyObject {
-  func candidateCountForController(_ controller: ctlCandidate) -> Int
-  func ctlCandidate(_ controller: ctlCandidate, candidateAtIndex index: Int)
+  func handleDelegateEvent(_ event: NSEvent!) -> Bool
+  func candidateCountForController(_ controller: ctlCandidateProtocol) -> Int
+  func candidatesForController(_ controller: ctlCandidateProtocol) -> [(String, String)]
+  func ctlCandidate(_ controller: ctlCandidateProtocol, candidateAtIndex index: Int)
    -> (String, String)
  func ctlCandidate(
-    _ controller: ctlCandidate, didSelectCandidateAtIndex index: Int
+    _ controller: ctlCandidateProtocol, didSelectCandidateAtIndex index: Int
  )
 }

-public class ctlCandidate: NSWindowController {
-  public enum Layout {
-    case horizontal
-    case vertical
-  }
+public protocol ctlCandidateProtocol {
+  var currentLayout: CandidateLayout { get set }
+  var delegate: ctlCandidateDelegate? { get set }
+  var selectedCandidateIndex: Int { get set }
+  var visible: Bool { get set }
+  var windowTopLeftPoint: NSPoint { get set }
+  var keyLabels: [CandidateKeyLabel] { get set }
+  var keyLabelFont: NSFont { get set }
+  var candidateFont: NSFont { get set }
+  var tooltip: String { get set }

-  public var currentLayout: Layout = .horizontal
+  init(_ layout: CandidateLayout)
+  func reloadData()
+  func showNextPage() -> Bool
+  func showPreviousPage() -> Bool
+  func highlightNextCandidate() -> Bool
+  func highlightPreviousCandidate() -> Bool
+  func candidateIndexAtKeyLabelIndex(_: Int) -> Int
+  func set(windowTopLeftPoint: NSPoint, bottomOutOfScreenAdjustmentHeight height: CGFloat)
+}
+
+public class ctlCandidate: NSWindowController, ctlCandidateProtocol {
+  public var currentLayout: CandidateLayout = .horizontal
  public weak var delegate: ctlCandidateDelegate? {
    didSet {
      reloadData()
@ -85,6 +108,16 @@ public class ctlCandidate: NSWindowController {
    }
  }

+  public required init(_: CandidateLayout = .horizontal) {
+    super.init(window: .init())
+    visible = false
+  }
+
+  @available(*, unavailable)
+  required init?(coder _: NSCoder) {
+    fatalError("init(coder:) has not been implemented")
+  }
+
  public var keyLabels: [CandidateKeyLabel] = ["1", "2", "3", "4", "5", "6", "7", "8", "9"]
    .map {
      CandidateKeyLabel(key: $0, displayedText: $0)
--- a/Source/UI/CandidateUI/ctlCandidateIMK.swift
+++ b/Source/UI/CandidateUI/ctlCandidateIMK.swift
@ -0,0 +1,141 @@
+// Copyright (c) 2021 and onwards The vChewing Project (MIT-NTL License).
+/*
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+1. The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+2. No trademark license is granted to use the trade names, trademarks, service
+marks, or product names of Contributor, except as required to fulfill notice
+requirements above.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+*/
+
+import Foundation
+import InputMethodKit
+
+public class ctlCandidateIMK: IMKCandidates, ctlCandidateProtocol {
+  public var currentLayout: CandidateLayout = .horizontal
+
+  public weak var delegate: ctlCandidateDelegate? {
+    didSet {
+      reloadData()
+    }
+  }
+
+  public var selectedCandidateIndex: Int = .max
+
+  public var visible: Bool = false {
+    didSet {
+      if visible {
+        show()
+      } else {
+        hide()
+      }
+    }
+  }
+
+  public var windowTopLeftPoint: NSPoint = .init(x: 0, y: 0) {
+    didSet {
+      DispatchQueue.main.asyncAfter(deadline: DispatchTime.now()) {
+        self.set(windowTopLeftPoint: self.windowTopLeftPoint, bottomOutOfScreenAdjustmentHeight: 0)
+      }
+    }
+  }
+
+  public var keyLabels: [CandidateKeyLabel] = ["1", "2", "3", "4", "5", "6", "7", "8", "9"]
+    .map {
+      CandidateKeyLabel(key: $0, displayedText: $0)
+    }
+
+  public var keyLabelFont: NSFont = NSFont.monospacedDigitSystemFont(
+    ofSize: 14, weight: .medium
+  )
+  public var candidateFont: NSFont = NSFont.systemFont(ofSize: 18)
+  public var tooltip: String = ""
+
+  var keyCount = 0
+  var displayedCandidates = [String]()
+
+  public func specifyLayout(_ layout: CandidateLayout = .horizontal) {
+    currentLayout = layout
+    switch currentLayout {
+      case .horizontal:
+        setPanelType(kIMKScrollingGridCandidatePanel)
+      case .vertical:
+        setPanelType(kIMKSingleColumnScrollingCandidatePanel)
+    }
+    setAttributes([IMKCandidatesSendServerKeyEventFirst: false])
+  }
+
+  public required init(_ layout: CandidateLayout = .horizontal) {
+    super.init(server: theServer, panelType: kIMKScrollingGridCandidatePanel)
+    specifyLayout(layout)
+    visible = false
+  }
+
+  @available(*, unavailable)
+  required init?(coder _: NSCoder) {
+    fatalError("init(coder:) has not been implemented")
+  }
+
+  public func reloadData() {
+    guard let delegate = delegate else { return }
+    let candidates = delegate.candidatesForController(self).map { theCandidate -> String in
+      let theConverted = IME.kanjiConversionIfRequired(theCandidate.1)
+      return (theCandidate.1 == theConverted) ? theCandidate.1 : "\(theConverted)(\(theCandidate.1))"
+    }
+    setCandidateData(candidates)
+    keyCount = selectionKeys().count
+    selectedCandidateIndex = 0
+    update()
+  }
+
+  public func showNextPage() -> Bool {
+    if selectedCandidateIndex == candidates(self).count - 1 { return false }
+    selectedCandidateIndex = min(selectedCandidateIndex + keyCount, candidates(self).count - 1)
+    return selectCandidate(withIdentifier: selectedCandidateIndex)
+  }
+
+  public func showPreviousPage() -> Bool {
+    if selectedCandidateIndex == 0 { return true }
+    selectedCandidateIndex = max(selectedCandidateIndex - keyCount, 0)
+    return selectCandidate(withIdentifier: selectedCandidateIndex)
+  }
+
+  public func highlightNextCandidate() -> Bool {
+    if selectedCandidateIndex == candidates(self).count - 1 { return false }
+    selectedCandidateIndex = min(selectedCandidateIndex + 1, candidates(self).count - 1)
+    return selectCandidate(withIdentifier: selectedCandidateIndex)
+  }
+
+  public func highlightPreviousCandidate() -> Bool {
+    if selectedCandidateIndex == 0 { return true }
+    selectedCandidateIndex = max(selectedCandidateIndex - 1, 0)
+    return selectCandidate(withIdentifier: selectedCandidateIndex)
+  }
+
+  public func candidateIndexAtKeyLabelIndex(_: Int) -> Int {
+    selectedCandidateIndex
+  }
+
+  public func set(windowTopLeftPoint: NSPoint, bottomOutOfScreenAdjustmentHeight _: CGFloat = 0) {
+    setCandidateFrameTopLeft(windowTopLeftPoint)
+  }
+
+  override public func handle(_ event: NSEvent!, client _: Any!) -> Bool {
+    guard let delegate = delegate else { return false }
+    return delegate.handleDelegateEvent(event)
+  }
+}
--- a/Source/UI/CandidateUI/ctlCandidateUniversal.swift
+++ b/Source/UI/CandidateUI/ctlCandidateUniversal.swift
@ -370,7 +370,7 @@ public class ctlCandidateUniversal: ctlCandidate {
  private var nextPageButton: NSButton
  private var pageCounterLabel: NSTextField
  private var currentPageIndex: Int = 0
-  override public var currentLayout: Layout {
+  override public var currentLayout: CandidateLayout {
    get { candidateView.isVerticalLayout ? .vertical : .horizontal }
    set {
      switch newValue {
@ -380,7 +380,7 @@ public class ctlCandidateUniversal: ctlCandidate {
    }
  }

-  public init(_ layout: Layout = .horizontal) {
+  public required init(_ layout: CandidateLayout = .horizontal) {
    var contentRect = NSRect(x: 128.0, y: 128.0, width: 0.0, height: 0.0)
    let styleMask: NSWindow.StyleMask = [.nonactivatingPanel]
    let panel = NSPanel(
@ -448,7 +448,8 @@ public class ctlCandidateUniversal: ctlCandidate {

    // MARK: Post-Init()

-    super.init(window: panel)
+    super.init(layout)
+    window = panel
    currentLayout = layout

    candidateView.target = self
--- a/Source/UI/PrefUI/suiPrefPaneDictionary.swift
+++ b/Source/UI/PrefUI/suiPrefPaneDictionary.swift
@ -28,19 +28,19 @@ import SwiftUI
 struct suiPrefPaneDictionary: View {
  private var fdrDefault = mgrLangModel.dataFolderPath(isDefaultFolder: true)
  @State private var tbxUserDataPathSpecified: String =
-    UserDefaults.standard.string(forKey: UserDef.kUserDataFolderSpecified)
+    UserDefaults.standard.string(forKey: UserDef.kUserDataFolderSpecified.rawValue)
    ?? mgrLangModel.dataFolderPath(isDefaultFolder: true)
  @State private var selAutoReloadUserData: Bool = UserDefaults.standard.bool(
-    forKey: UserDef.kShouldAutoReloadUserDataFiles)
-  @State private var selEnableCNS11643: Bool = UserDefaults.standard.bool(forKey: UserDef.kCNS11643Enabled)
+    forKey: UserDef.kShouldAutoReloadUserDataFiles.rawValue)
+  @State private var selEnableCNS11643: Bool = UserDefaults.standard.bool(forKey: UserDef.kCNS11643Enabled.rawValue)
  @State private var selEnableSymbolInputSupport: Bool = UserDefaults.standard.bool(
-    forKey: UserDef.kSymbolInputEnabled)
+    forKey: UserDef.kSymbolInputEnabled.rawValue)
  @State private var selAllowBoostingSingleKanjiAsUserPhrase: Bool = UserDefaults.standard.bool(
-    forKey: UserDef.kAllowBoostingSingleKanjiAsUserPhrase)
+    forKey: UserDef.kAllowBoostingSingleKanjiAsUserPhrase.rawValue)
  @State private var selFetchSuggestionsFromUserOverrideModel: Bool = UserDefaults.standard.bool(
-    forKey: UserDef.kFetchSuggestionsFromUserOverrideModel)
+    forKey: UserDef.kFetchSuggestionsFromUserOverrideModel.rawValue)
  @State private var selUseFixecCandidateOrderOnSelection: Bool = UserDefaults.standard.bool(
-    forKey: UserDef.kUseFixecCandidateOrderOnSelection)
+    forKey: UserDef.kUseFixecCandidateOrderOnSelection.rawValue)
  private let contentWidth: Double = {
    switch mgrPrefs.appleLanguages[0] {
      case "ja":
--- a/Source/UI/PrefUI/suiPrefPaneExperience.swift
+++ b/Source/UI/PrefUI/suiPrefPaneExperience.swift
@ -29,27 +29,30 @@ import SwiftUI
 struct suiPrefPaneExperience: View {
  @State private var selSelectionKeysList = mgrPrefs.suggestedCandidateKeys
  @State private var selSelectionKeys =
-    (UserDefaults.standard.string(forKey: UserDef.kCandidateKeys) ?? mgrPrefs.defaultCandidateKeys) as String
+    (UserDefaults.standard.string(forKey: UserDef.kCandidateKeys.rawValue) ?? mgrPrefs.defaultCandidateKeys) as String
  @State private var selCursorPosition =
    UserDefaults.standard.bool(
-      forKey: UserDef.kuseRearCursorMode) ? 1 : 0
+      forKey: UserDef.kUseRearCursorMode.rawValue) ? 1 : 0
  @State private var selPushCursorAfterSelection = UserDefaults.standard.bool(
-    forKey: UserDef.kMoveCursorAfterSelectingCandidate)
+    forKey: UserDef.kMoveCursorAfterSelectingCandidate.rawValue)
  @State private var selKeyBehaviorShiftTab =
-    UserDefaults.standard.bool(forKey: UserDef.kSpecifyShiftTabKeyBehavior) ? 1 : 0
+    UserDefaults.standard.bool(forKey: UserDef.kSpecifyShiftTabKeyBehavior.rawValue) ? 1 : 0
  @State private var selKeyBehaviorShiftSpace =
    UserDefaults.standard.bool(
-      forKey: UserDef.kSpecifyShiftSpaceKeyBehavior) ? 1 : 0
+      forKey: UserDef.kSpecifyShiftSpaceKeyBehavior.rawValue) ? 1 : 0
  @State private var selKeyBehaviorSpaceForCallingCandidate = UserDefaults.standard.bool(
-    forKey: UserDef.kChooseCandidateUsingSpace)
+    forKey: UserDef.kChooseCandidateUsingSpace.rawValue)
  @State private var selKeyBehaviorESCForClearingTheBuffer = UserDefaults.standard.bool(
-    forKey: UserDef.kEscToCleanInputBuffer)
-  @State private var selEnableSCPCTypingMode = UserDefaults.standard.bool(forKey: UserDef.kUseSCPCTypingMode)
-  @State private var selComposingBufferSize = UserDefaults.standard.integer(forKey: UserDef.kComposingBufferSize)
+    forKey: UserDef.kEscToCleanInputBuffer.rawValue)
+  @State private var selEnableSCPCTypingMode = UserDefaults.standard.bool(forKey: UserDef.kUseSCPCTypingMode.rawValue)
+  @State private var selComposingBufferSize = UserDefaults.standard.integer(
+    forKey: UserDef.kComposingBufferSize.rawValue)
  @State private var selAutoCorrectReadingCombination = UserDefaults.standard.bool(
-    forKey: UserDef.kAutoCorrectReadingCombination)
+    forKey: UserDef.kAutoCorrectReadingCombination.rawValue)
  @State private var selAlsoConfirmAssociatedCandidatesByEnter = UserDefaults.standard.bool(
-    forKey: UserDef.kAlsoConfirmAssociatedCandidatesByEnter)
+    forKey: UserDef.kAlsoConfirmAssociatedCandidatesByEnter.rawValue)
+  @State private var selKeepReadingUponCompositionError = UserDefaults.standard.bool(
+    forKey: UserDef.kKeepReadingUponCompositionError.rawValue)
  private let contentWidth: Double = {
    switch mgrPrefs.appleLanguages[0] {
      case "ja":
@ -188,6 +191,12 @@ struct suiPrefPaneExperience: View {
        ).onChange(of: selAlsoConfirmAssociatedCandidatesByEnter) { value in
          mgrPrefs.alsoConfirmAssociatedCandidatesByEnter = value
        }
+        Toggle(
+          LocalizedStringKey("Allow backspace-editing miscomposed readings"),
+          isOn: $selKeepReadingUponCompositionError
+        ).onChange(of: selKeepReadingUponCompositionError) { value in
+          mgrPrefs.keepReadingUponCompositionError = value
+        }
      }
    }
  }
--- a/Source/UI/PrefUI/suiPrefPaneGeneral.swift
+++ b/Source/UI/PrefUI/suiPrefPaneGeneral.swift
@ -27,29 +27,32 @@ import SwiftUI

@available(macOS 11.0, *)
 struct suiPrefPaneGeneral: View {
-  @State private var selCandidateUIFontSize = UserDefaults.standard.integer(forKey: UserDef.kCandidateListTextSize)
+  @State private var selCandidateUIFontSize = UserDefaults.standard.integer(
+    forKey: UserDef.kCandidateListTextSize.rawValue)
  @State private var selUILanguage: [String] =
    IME.arrSupportedLocales.contains(
-      ((UserDefaults.standard.object(forKey: UserDef.kAppleLanguages) == nil)
-        ? ["auto"] : UserDefaults.standard.array(forKey: UserDef.kAppleLanguages) as? [String] ?? ["auto"])[0])
-    ? ((UserDefaults.standard.object(forKey: UserDef.kAppleLanguages) == nil)
-      ? ["auto"] : UserDefaults.standard.array(forKey: UserDef.kAppleLanguages) as? [String] ?? ["auto"])
+      ((UserDefaults.standard.object(forKey: UserDef.kAppleLanguages.rawValue) == nil)
+        ? ["auto"] : UserDefaults.standard.array(forKey: UserDef.kAppleLanguages.rawValue) as? [String] ?? ["auto"])[0])
+    ? ((UserDefaults.standard.object(forKey: UserDef.kAppleLanguages.rawValue) == nil)
+      ? ["auto"] : UserDefaults.standard.array(forKey: UserDef.kAppleLanguages.rawValue) as? [String] ?? ["auto"])
    : ["auto"]
  @State private var selEnableHorizontalCandidateLayout = UserDefaults.standard.bool(
-    forKey: UserDef.kUseHorizontalCandidateList)
+    forKey: UserDef.kUseHorizontalCandidateList.rawValue)
  @State private var selShowPageButtonsInCandidateUI = UserDefaults.standard.bool(
-    forKey: UserDef.kShowPageButtonsInCandidateWindow)
+    forKey: UserDef.kShowPageButtonsInCandidateWindow.rawValue)
  @State private var selEnableKanjiConvToKangXi = UserDefaults.standard.bool(
-    forKey: UserDef.kChineseConversionEnabled)
+    forKey: UserDef.kChineseConversionEnabled.rawValue)
  @State private var selEnableKanjiConvToJIS = UserDefaults.standard.bool(
-    forKey: UserDef.kShiftJISShinjitaiOutputEnabled)
+    forKey: UserDef.kShiftJISShinjitaiOutputEnabled.rawValue)
  @State private var selShowHanyuPinyinInCompositionBuffer = UserDefaults.standard.bool(
-    forKey: UserDef.kShowHanyuPinyinInCompositionBuffer)
+    forKey: UserDef.kShowHanyuPinyinInCompositionBuffer.rawValue)
  @State private var selInlineDumpPinyinInLieuOfZhuyin = UserDefaults.standard.bool(
-    forKey: UserDef.kInlineDumpPinyinInLieuOfZhuyin)
-  @State private var selEnableFartSuppressor = UserDefaults.standard.bool(forKey: UserDef.kShouldNotFartInLieuOfBeep)
-  @State private var selEnableAutoUpdateCheck = UserDefaults.standard.bool(forKey: UserDef.kCheckUpdateAutomatically)
-  @State private var selEnableDebugMode = UserDefaults.standard.bool(forKey: UserDef.kIsDebugModeEnabled)
+    forKey: UserDef.kInlineDumpPinyinInLieuOfZhuyin.rawValue)
+  @State private var selEnableFartSuppressor = UserDefaults.standard.bool(
+    forKey: UserDef.kShouldNotFartInLieuOfBeep.rawValue)
+  @State private var selEnableAutoUpdateCheck = UserDefaults.standard.bool(
+    forKey: UserDef.kCheckUpdateAutomatically.rawValue)
+  @State private var selEnableDebugMode = UserDefaults.standard.bool(forKey: UserDef.kIsDebugModeEnabled.rawValue)
  private let contentWidth: Double = {
    switch mgrPrefs.appleLanguages[0] {
      case "ja":
@ -94,14 +97,14 @@ struct suiPrefPaneGeneral: View {
          IME.prtDebugIntel(value[0])
          if selUILanguage == mgrPrefs.appleLanguages
            || (selUILanguage[0] == "auto"
-              && UserDefaults.standard.object(forKey: UserDef.kAppleLanguages) == nil)
+              && UserDefaults.standard.object(forKey: UserDef.kAppleLanguages.rawValue) == nil)
          {
            return
          }
          if selUILanguage[0] != "auto" {
            mgrPrefs.appleLanguages = value
          } else {
-            UserDefaults.standard.removeObject(forKey: UserDef.kAppleLanguages)
+            UserDefaults.standard.removeObject(forKey: UserDef.kAppleLanguages.rawValue)
          }
          NSLog("vChewing App self-terminated due to UI language change.")
          NSApplication.shared.terminate(nil)
--- a/Source/UI/PrefUI/suiPrefPaneKeyboard.swift
+++ b/Source/UI/PrefUI/suiPrefPaneKeyboard.swift
@ -26,19 +26,20 @@ import SwiftUI

@available(macOS 11.0, *)
 struct suiPrefPaneKeyboard: View {
-  @State private var selMandarinParser = UserDefaults.standard.integer(forKey: UserDef.kMandarinParser)
+  @State private var selMandarinParser = UserDefaults.standard.integer(forKey: UserDef.kMandarinParser.rawValue)
  @State private var selBasicKeyboardLayout: String =
-    UserDefaults.standard.string(forKey: UserDef.kBasicKeyboardLayout) ?? mgrPrefs.basicKeyboardLayout
+    UserDefaults.standard.string(forKey: UserDef.kBasicKeyboardLayout.rawValue) ?? mgrPrefs.basicKeyboardLayout

-  @State private var selUsingHotKeySCPC = UserDefaults.standard.bool(forKey: UserDef.kUsingHotKeySCPC)
-  @State private var selUsingHotKeyAssociates = UserDefaults.standard.bool(forKey: UserDef.kUsingHotKeyAssociates)
-  @State private var selUsingHotKeyCNS = UserDefaults.standard.bool(forKey: UserDef.kUsingHotKeyCNS)
-  @State private var selUsingHotKeyKangXi = UserDefaults.standard.bool(forKey: UserDef.kUsingHotKeyKangXi)
-  @State private var selUsingHotKeyJIS = UserDefaults.standard.bool(forKey: UserDef.kUsingHotKeyJIS)
+  @State private var selUsingHotKeySCPC = UserDefaults.standard.bool(forKey: UserDef.kUsingHotKeySCPC.rawValue)
+  @State private var selUsingHotKeyAssociates = UserDefaults.standard.bool(
+    forKey: UserDef.kUsingHotKeyAssociates.rawValue)
+  @State private var selUsingHotKeyCNS = UserDefaults.standard.bool(forKey: UserDef.kUsingHotKeyCNS.rawValue)
+  @State private var selUsingHotKeyKangXi = UserDefaults.standard.bool(forKey: UserDef.kUsingHotKeyKangXi.rawValue)
+  @State private var selUsingHotKeyJIS = UserDefaults.standard.bool(forKey: UserDef.kUsingHotKeyJIS.rawValue)
  @State private var selUsingHotKeyHalfWidthASCII = UserDefaults.standard.bool(
-    forKey: UserDef.kUsingHotKeyHalfWidthASCII)
+    forKey: UserDef.kUsingHotKeyHalfWidthASCII.rawValue)
  @State private var selUsingHotKeyCurrencyNumerals = UserDefaults.standard.bool(
-    forKey: UserDef.kUsingHotKeyCurrencyNumerals)
+    forKey: UserDef.kUsingHotKeyCurrencyNumerals.rawValue)

  private let contentWidth: Double = {
    switch mgrPrefs.appleLanguages[0] {
--- a/Source/WindowControllers/ctlAboutWindow.swift
+++ b/Source/WindowControllers/ctlAboutWindow.swift
@ -57,13 +57,13 @@ class ctlAboutWindow: NSWindowController {
    )
  }

-  @IBAction func btnBugReport(_ sender: NSButton) {
+  @IBAction func btnBugReport(_: NSButton) {
    if let url = URL(string: "https://vchewing.github.io/BUGREPORT.html") {
      NSWorkspace.shared.open(url)
    }
  }

-  @IBAction func btnWebsite(_ sender: NSButton) {
+  @IBAction func btnWebsite(_: NSButton) {
    if let url = URL(string: "https://vchewing.github.io/") {
      NSWorkspace.shared.open(url)
    }
--- a/Source/WindowControllers/ctlPrefWindow.swift
+++ b/Source/WindowControllers/ctlPrefWindow.swift
@ -388,7 +388,8 @@ extension ctlPrefWindow: NSToolbarDelegate {
        item.label = title
        if #available(macOS 11.0, *) {
          item.image = NSImage(
-            systemSymbolName: "wrench.and.screwdriver.fill", accessibilityDescription: "General Preferences")
+            systemSymbolName: "wrench.and.screwdriver.fill", accessibilityDescription: "General Preferences"
+          )
        } else {
          item.image = NSImage(named: NSImage.homeTemplateName)
        }
@ -399,7 +400,8 @@ extension ctlPrefWindow: NSToolbarDelegate {
        item.label = title
        if #available(macOS 11.0, *) {
          item.image = NSImage(
-            systemSymbolName: "person.fill.questionmark", accessibilityDescription: "Experiences Preferences")
+            systemSymbolName: "person.fill.questionmark", accessibilityDescription: "Experiences Preferences"
+          )
        } else {
          item.image = NSImage(named: NSImage.flowViewTemplateName)
        }
@ -410,7 +412,8 @@ extension ctlPrefWindow: NSToolbarDelegate {
        item.label = title
        if #available(macOS 11.0, *) {
          item.image = NSImage(
-            systemSymbolName: "character.book.closed.fill", accessibilityDescription: "Dictionary Preferences")
+            systemSymbolName: "character.book.closed.fill", accessibilityDescription: "Dictionary Preferences"
+          )
        } else {
          item.image = NSImage(named: NSImage.bookmarksTemplateName)
        }
--- a/Source/WindowNIBs/Base.lproj/frmPrefWindow.xib
+++ b/Source/WindowNIBs/Base.lproj/frmPrefWindow.xib
@ -591,12 +591,23 @@
                        <binding destination="32" name="value" keyPath="values.AlsoConfirmAssociatedCandidatesByEnter" id="P1C-j9-N88"/>
                    </connections>
                </button>
+                <button verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="HaB-rc-AcW">
+                    <rect key="frame" x="19" y="40.5" width="388" height="16"/>
+                    <buttonCell key="cell" type="check" title="Allow backspace-editing miscomposed readings" bezelStyle="regularSquare" imagePosition="left" controlSize="small" inset="2" id="chkKeepReadingUponCompositionError">
+                        <behavior key="behavior" changeContents="YES" doesNotDimImage="YES" lightByContents="YES"/>
+                        <font key="font" metaFont="cellTitle"/>
+                    </buttonCell>
+                    <connections>
+                        <binding destination="32" name="value" keyPath="values.KeepReadingUponCompositionError" id="ddF-qg-jes"/>
+                    </connections>
+                </button>
            </subviews>
            <constraints>
                <constraint firstItem="n7q-ew-DYu" firstAttribute="leading" secondItem="XWo-36-xGi" secondAttribute="leading" constant="33" id="2gT-9Z-6F4"/>
                <constraint firstItem="109" firstAttribute="top" secondItem="YkJ-lr-EP6" secondAttribute="bottom" constant="9" id="3tl-Zc-C5n"/>
                <constraint firstItem="13" firstAttribute="top" secondItem="d5f-bq-dRQ" secondAttribute="bottom" constant="8" symbolic="YES" id="4pp-NX-pCc"/>
                <constraint firstItem="YkJ-lr-EP6" firstAttribute="top" secondItem="J0f-Aw-dxC" secondAttribute="bottom" constant="7" id="5fd-qi-hJ6"/>
+                <constraint firstItem="HaB-rc-AcW" firstAttribute="leading" secondItem="6MM-WC-Mpd" secondAttribute="leading" id="7Fs-9l-g66"/>
                <constraint firstItem="d5f-bq-dRQ" firstAttribute="leading" secondItem="XWo-36-xGi" secondAttribute="leading" constant="20" id="9wo-7x-RKb"/>
                <constraint firstItem="TMn-LX-3Ub" firstAttribute="top" secondItem="7z2-DD-c58" secondAttribute="bottom" constant="9" id="AXY-LV-HMX"/>
                <constraint firstItem="7z2-DD-c58" firstAttribute="leading" secondItem="XWo-36-xGi" secondAttribute="leading" constant="34" id="BUo-Us-u2B"/>
@ -618,6 +629,7 @@
                <constraint firstItem="IpX-f7-rTL" firstAttribute="top" secondItem="XWo-36-xGi" secondAttribute="top" constant="20" id="YaG-ab-LJH"/>
                <constraint firstItem="uHU-aL-du7" firstAttribute="top" secondItem="IpX-f7-rTL" secondAttribute="bottom" constant="8" symbolic="YES" id="aet-Zq-v6x"/>
                <constraint firstAttribute="trailing" relation="greaterThanOrEqual" secondItem="TMn-LX-3Ub" secondAttribute="trailing" constant="20" symbolic="YES" id="atz-4L-U9s"/>
+                <constraint firstItem="HaB-rc-AcW" firstAttribute="top" secondItem="6MM-WC-Mpd" secondAttribute="bottom" constant="6" symbolic="YES" id="cBa-57-gWH"/>
                <constraint firstItem="ETa-09-qWI" firstAttribute="top" secondItem="IpX-f7-rTL" secondAttribute="bottom" constant="11" id="cx2-US-uOU"/>
                <constraint firstItem="6MM-WC-Mpd" firstAttribute="top" secondItem="j8R-Hj-3dj" secondAttribute="bottom" constant="6" id="dmy-Au-peI"/>
                <constraint firstItem="YkJ-lr-EP6" firstAttribute="leading" secondItem="XWo-36-xGi" secondAttribute="leading" constant="33" id="e3v-m2-co7"/>
@ -630,6 +642,7 @@
                <constraint firstItem="6MM-WC-Mpd" firstAttribute="leading" secondItem="j8R-Hj-3dj" secondAttribute="leading" id="mbl-sV-kc8"/>
                <constraint firstItem="mzw-F2-aAQ" firstAttribute="leading" secondItem="XWo-36-xGi" secondAttribute="leading" constant="20" id="pHT-DE-qdx"/>
                <constraint firstItem="ETa-09-qWI" firstAttribute="leading" secondItem="XWo-36-xGi" secondAttribute="leading" constant="33" id="qFL-i6-eUT"/>
+                <constraint firstItem="HaB-rc-AcW" firstAttribute="trailing" secondItem="6MM-WC-Mpd" secondAttribute="trailing" id="rA7-0f-akd"/>
                <constraint firstItem="JG6-RM-ZdJ" firstAttribute="top" secondItem="uHU-aL-du7" secondAttribute="bottom" constant="8" id="shS-7h-z7u"/>
                <constraint firstItem="TMn-LX-3Ub" firstAttribute="leading" secondItem="XWo-36-xGi" secondAttribute="leading" constant="20" id="tFX-Eg-X70"/>
                <constraint firstItem="J0f-Aw-dxC" firstAttribute="leading" secondItem="XWo-36-xGi" secondAttribute="leading" constant="20" id="v75-cS-TsO"/>
--- a/Source/WindowNIBs/en.lproj/frmPrefWindow.strings
+++ b/Source/WindowNIBs/en.lproj/frmPrefWindow.strings
@ -43,6 +43,7 @@
 "chkAlsoConfirmAssociatedCandidatesByEnter.title" = "Allow using Enter key to confirm associated candidate selection";
 "chkAutoCorrectReadingCombination.title" = "Automatically correct reading combinations when typing";
 "chkFetchSuggestionsFromUserOverrideModel.title" = "Applying typing suggestions from half-life user override model";
+"chkKeepReadingUponCompositionError.title" = "Allow backspace-editing miscomposed readings";
 "chkUseFixecCandidateOrderOnSelection.title" = "Always use fixed listing order in candidate window";
 "DbW-eq-ZdB.title" = "Starlight";
 "dIN-TZ-67g.title" = "Space to +cycle candidates, Shift+Space to +cycle pages";
--- a/Source/WindowNIBs/ja.lproj/frmPrefWindow.strings
+++ b/Source/WindowNIBs/ja.lproj/frmPrefWindow.strings
@ -43,6 +43,7 @@
 "chkAlsoConfirmAssociatedCandidatesByEnter.title" = "Enter キーを連想語彙候補の確認のために使う";
 "chkAutoCorrectReadingCombination.title" = "入力中で打ち間違った発音組み合わせを自動的に訂正する";
 "chkFetchSuggestionsFromUserOverrideModel.title" = "入力中で臨時記憶モジュールからお薦めの候補を自動的に選ぶ";
+"chkKeepReadingUponCompositionError.title" = "効かぬ音読みを BackSpace で再編集";
 "chkUseFixecCandidateOrderOnSelection.title" = "候補文字を固定順番で陳列する";
 "DbW-eq-ZdB.title" = "星光";
 "dIN-TZ-67g.title" = "Shift+Space で次のページ、Space で次の候補文字を";
--- a/Source/WindowNIBs/zh-Hans.lproj/frmPrefWindow.strings
+++ b/Source/WindowNIBs/zh-Hans.lproj/frmPrefWindow.strings
@ -43,6 +43,7 @@
 "chkAlsoConfirmAssociatedCandidatesByEnter.title" = "允许使用 Enter 确认当前选中的联想词";
 "chkAutoCorrectReadingCombination.title" = "敲字时自动纠正读音组合";
 "chkFetchSuggestionsFromUserOverrideModel.title" = "在敲字时自动套用来自半衰记忆模组的建议";
+"chkKeepReadingUponCompositionError.title" = "允许对无效的读音使用 BackSpace 编辑";
 "chkUseFixecCandidateOrderOnSelection.title" = "以固定顺序来陈列选字窗内的候选字";
 "DbW-eq-ZdB.title" = "星光";
 "dIN-TZ-67g.title" = "Shift+Space 换下一页，Space 换选下一个候选字。";
--- a/Source/WindowNIBs/zh-Hant.lproj/frmPrefWindow.strings
+++ b/Source/WindowNIBs/zh-Hant.lproj/frmPrefWindow.strings
@ -43,6 +43,7 @@
 "chkAlsoConfirmAssociatedCandidatesByEnter.title" = "允許使用 Enter 確認當前選中的聯想詞";
 "chkAutoCorrectReadingCombination.title" = "敲字時自動糾正讀音組合";
 "chkFetchSuggestionsFromUserOverrideModel.title" = "在敲字時自動套用來自半衰記憶模組的建議";
+"chkKeepReadingUponCompositionError.title" = "允許對無效的讀音使用 BackSpace 編輯";
 "chkUseFixecCandidateOrderOnSelection.title" = "以固定順序來陳列選字窗內的候選字";
 "DbW-eq-ZdB.title" = "星光";
 "dIN-TZ-67g.title" = "Shift+Space 換下一頁，Space 換選下一個候選字";
--- a/Update-Info.plist
+++ b/Update-Info.plist
@ -3,9 +3,9 @@
 <plist version="1.0">
 <dict>
 	<key>CFBundleShortVersionString</key>
-	<string>1.8.6</string>
+	<string>1.8.7</string>
 	<key>CFBundleVersion</key>
-	<string>1986</string>
+	<string>1987</string>
 	<key>UpdateInfoEndpoint</key>
 	<string>https://gitee.com/vchewing/vChewing-macOS/raw/main/Update-Info.plist</string>
 	<key>UpdateInfoSite</key>
--- a/UserPhraseEditor/ctlAboutWindow.swift
+++ b/UserPhraseEditor/ctlAboutWindow.swift
@ -57,7 +57,7 @@ import Cocoa
    )
  }

-  @IBAction func btnWebsite(_ sender: NSButton) {
+  @IBAction func btnWebsite(_: NSButton) {
    if let url = URL(string: "https://vchewing.github.io/") {
      NSWorkspace.shared.open(url)
    }
--- a/vChewing.pkgproj
+++ b/vChewing.pkgproj
@ -726,7 +726,7 @@
 				<key>USE_HFS+_COMPRESSION</key>
 				<false/>
 				<key>VERSION</key>
-				<string>1.8.6</string>
+				<string>1.8.7</string>
 			</dict>
 			<key>TYPE</key>
 			<integer>0</integer>
--- a/vChewing.xcodeproj/project.pbxproj
+++ b/vChewing.xcodeproj/project.pbxproj
@ -116,6 +116,7 @@
 		5BF9DA2A28840E6200DBD48E /* template-replacements.txt in Resources */ = {isa = PBXBuildFile; fileRef = 5BF9DA2528840E6200DBD48E /* template-replacements.txt */; };
 		5BF9DA2B28840E6200DBD48E /* template-userphrases.txt in Resources */ = {isa = PBXBuildFile; fileRef = 5BF9DA2628840E6200DBD48E /* template-userphrases.txt */; };
 		5BF9DA2D288427E000DBD48E /* template-associatedPhrases-cht.txt in Resources */ = {isa = PBXBuildFile; fileRef = 5BF9DA2C2884247800DBD48E /* template-associatedPhrases-cht.txt */; };
+		5BFDF011289635C100417BBC /* ctlCandidateIMK.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5BFDF010289635C100417BBC /* ctlCandidateIMK.swift */; };
 		6A187E2616004C5900466B2E /* MainMenu.xib in Resources */ = {isa = PBXBuildFile; fileRef = 6A187E2816004C5900466B2E /* MainMenu.xib */; };
 		6A225A1F23679F2600F685C6 /* NotarizedArchives in Resources */ = {isa = PBXBuildFile; fileRef = 6A225A1E23679F2600F685C6 /* NotarizedArchives */; };
 		6A2E40F6253A69DA00D1AE1D /* Images.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 6A2E40F5253A69DA00D1AE1D /* Images.xcassets */; };
@ -320,6 +321,7 @@
 		5BF9DA2528840E6200DBD48E /* template-replacements.txt */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text; lineEnding = 0; path = "template-replacements.txt"; sourceTree = "<group>"; usesTabs = 0; };
 		5BF9DA2628840E6200DBD48E /* template-userphrases.txt */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text; lineEnding = 0; path = "template-userphrases.txt"; sourceTree = "<group>"; usesTabs = 0; };
 		5BF9DA2C2884247800DBD48E /* template-associatedPhrases-cht.txt */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text; lineEnding = 0; name = "template-associatedPhrases-cht.txt"; path = "../Data/components/cht/template-associatedPhrases-cht.txt"; sourceTree = "<group>"; };
+		5BFDF010289635C100417BBC /* ctlCandidateIMK.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ctlCandidateIMK.swift; sourceTree = "<group>"; };
 		5BFDF48C27B51867009523B6 /* zh-Hant */ = {isa = PBXFileReference; lastKnownFileType = text.plist.strings; name = "zh-Hant"; path = "zh-Hant.lproj/Main.strings"; sourceTree = "<group>"; };
 		6A0D4EA215FC0D2D00ABF4B3 /* vChewing.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = vChewing.app; sourceTree = BUILT_PRODUCTS_DIR; };
 		6A0D4EF515FC0DA600ABF4B3 /* IME-Info.plist */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.plist.xml; path = "IME-Info.plist"; sourceTree = "<group>"; };
@ -570,6 +572,7 @@
 			children = (
 				5B62A34027AE7CD900A19448 /* ctlCandidate.swift */,
 				5B242402284B0D6500520FE4 /* ctlCandidateUniversal.swift */,
+				5BFDF010289635C100417BBC /* ctlCandidateIMK.swift */,
 			);
 			path = CandidateUI;
 			sourceTree = "<group>";
@ -1203,6 +1206,7 @@
 				5BA9FD4727FEF3C9002DE248 /* PreferencesStyleController.swift in Sources */,
 				5B949BDB2816DDBC00D87B5D /* LMConsolidator.swift in Sources */,
 				5B38F59F281E2E49007D5F5D /* 3_NodeAnchor.swift in Sources */,
+				5BFDF011289635C100417BBC /* ctlCandidateIMK.swift in Sources */,
 				5B62A34727AE7CD900A19448 /* ctlCandidate.swift in Sources */,
 				5BA9FD3F27FEF3C8002DE248 /* Pane.swift in Sources */,
 				5BB802DA27FABA8300CF1C19 /* ctlInputMethod_Menu.swift in Sources */,
@ -1393,7 +1397,7 @@
 				CLANG_WARN_OBJC_ROOT_CLASS = YES_ERROR;
 				CLANG_WARN_UNGUARDED_AVAILABILITY = YES_AGGRESSIVE;
 				CODE_SIGN_STYLE = Automatic;
-				CURRENT_PROJECT_VERSION = 1986;
+				CURRENT_PROJECT_VERSION = 1987;
 				GCC_C_LANGUAGE_STANDARD = gnu11;
 				GCC_DYNAMIC_NO_PIC = NO;
 				GCC_PREPROCESSOR_DEFINITIONS = (
@ -1403,7 +1407,7 @@
 				GCC_WARN_ABOUT_RETURN_TYPE = YES_ERROR;
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GENERATE_INFOPLIST_FILE = YES;
-				MARKETING_VERSION = 1.8.6;
+				MARKETING_VERSION = 1.8.7;
 				MTL_ENABLE_DEBUG_INFO = INCLUDE_SOURCE;
 				MTL_FAST_MATH = YES;
 				PRODUCT_BUNDLE_IDENTIFIER = org.atelierInmu.vChewingTests;
@ -1432,13 +1436,13 @@
 				CLANG_WARN_OBJC_ROOT_CLASS = YES_ERROR;
 				CLANG_WARN_UNGUARDED_AVAILABILITY = YES_AGGRESSIVE;
 				CODE_SIGN_STYLE = Automatic;
-				CURRENT_PROJECT_VERSION = 1986;
+				CURRENT_PROJECT_VERSION = 1987;
 				ENABLE_NS_ASSERTIONS = NO;
 				GCC_C_LANGUAGE_STANDARD = gnu11;
 				GCC_WARN_ABOUT_RETURN_TYPE = YES_ERROR;
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GENERATE_INFOPLIST_FILE = YES;
-				MARKETING_VERSION = 1.8.6;
+				MARKETING_VERSION = 1.8.7;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				MTL_FAST_MATH = YES;
 				PRODUCT_BUNDLE_IDENTIFIER = org.atelierInmu.vChewingTests;
@ -1469,7 +1473,7 @@
 				CODE_SIGN_IDENTITY = "-";
 				CODE_SIGN_STYLE = Automatic;
 				COMBINE_HIDPI_IMAGES = YES;
-				CURRENT_PROJECT_VERSION = 1986;
+				CURRENT_PROJECT_VERSION = 1987;
 				DEAD_CODE_STRIPPING = YES;
 				GCC_C_LANGUAGE_STANDARD = gnu11;
 				GCC_DYNAMIC_NO_PIC = NO;
@ -1490,7 +1494,7 @@
 					"$(inherited)",
 					"@executable_path/../Frameworks",
 				);
-				MARKETING_VERSION = 1.8.6;
+				MARKETING_VERSION = 1.8.7;
 				MTL_ENABLE_DEBUG_INFO = INCLUDE_SOURCE;
 				MTL_FAST_MATH = YES;
 				PRODUCT_BUNDLE_IDENTIFIER = org.atelierInmu.vChewing.vChewingPhraseEditor;
@ -1519,7 +1523,7 @@
 				CODE_SIGN_IDENTITY = "-";
 				CODE_SIGN_STYLE = Automatic;
 				COMBINE_HIDPI_IMAGES = YES;
-				CURRENT_PROJECT_VERSION = 1986;
+				CURRENT_PROJECT_VERSION = 1987;
 				DEAD_CODE_STRIPPING = YES;
 				ENABLE_NS_ASSERTIONS = NO;
 				GCC_C_LANGUAGE_STANDARD = gnu11;
@ -1536,7 +1540,7 @@
 					"$(inherited)",
 					"@executable_path/../Frameworks",
 				);
-				MARKETING_VERSION = 1.8.6;
+				MARKETING_VERSION = 1.8.7;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				MTL_FAST_MATH = YES;
 				PRODUCT_BUNDLE_IDENTIFIER = org.atelierInmu.vChewing.vChewingPhraseEditor;
@ -1650,7 +1654,7 @@
 				CODE_SIGN_IDENTITY = "-";
 				CODE_SIGN_STYLE = Automatic;
 				COMBINE_HIDPI_IMAGES = YES;
-				CURRENT_PROJECT_VERSION = 1986;
+				CURRENT_PROJECT_VERSION = 1987;
 				DEAD_CODE_STRIPPING = YES;
 				DEVELOPMENT_ASSET_PATHS = "";
 				DEVELOPMENT_TEAM = "";
@ -1678,7 +1682,7 @@
 					"$(inherited)",
 					"@executable_path/../Frameworks",
 				);
-				MARKETING_VERSION = 1.8.6;
+				MARKETING_VERSION = 1.8.7;
 				ONLY_ACTIVE_ARCH = YES;
 				PRODUCT_BUNDLE_IDENTIFIER = org.atelierInmu.inputmethod.vChewing;
 				PRODUCT_NAME = "$(TARGET_NAME)";
@ -1705,7 +1709,7 @@
 				CODE_SIGN_IDENTITY = "-";
 				CODE_SIGN_STYLE = Automatic;
 				COMBINE_HIDPI_IMAGES = YES;
-				CURRENT_PROJECT_VERSION = 1986;
+				CURRENT_PROJECT_VERSION = 1987;
 				DEAD_CODE_STRIPPING = YES;
 				DEVELOPMENT_ASSET_PATHS = "";
 				DEVELOPMENT_TEAM = "";
@ -1727,7 +1731,7 @@
 					"$(inherited)",
 					"@executable_path/../Frameworks",
 				);
-				MARKETING_VERSION = 1.8.6;
+				MARKETING_VERSION = 1.8.7;
 				PRODUCT_BUNDLE_IDENTIFIER = org.atelierInmu.inputmethod.vChewing;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				PROVISIONING_PROFILE_SPECIFIER = "";
@ -1749,7 +1753,7 @@
 				CODE_SIGN_IDENTITY = "-";
 				CODE_SIGN_STYLE = Automatic;
 				COMBINE_HIDPI_IMAGES = YES;
-				CURRENT_PROJECT_VERSION = 1986;
+				CURRENT_PROJECT_VERSION = 1987;
 				DEAD_CODE_STRIPPING = YES;
 				DEVELOPMENT_TEAM = "";
 				GCC_C_LANGUAGE_STANDARD = gnu99;
@ -1769,7 +1773,7 @@
 					"$(inherited)",
 					"@executable_path/../Frameworks",
 				);
-				MARKETING_VERSION = 1.8.6;
+				MARKETING_VERSION = 1.8.7;
 				ONLY_ACTIVE_ARCH = YES;
 				PRODUCT_BUNDLE_IDENTIFIER = "org.atelierInmu.vChewing.${PRODUCT_NAME:rfc1034identifier}";
 				PRODUCT_NAME = "$(TARGET_NAME)";
@ -1791,7 +1795,7 @@
 				CODE_SIGN_IDENTITY = "-";
 				CODE_SIGN_STYLE = Automatic;
 				COMBINE_HIDPI_IMAGES = YES;
-				CURRENT_PROJECT_VERSION = 1986;
+				CURRENT_PROJECT_VERSION = 1987;
 				DEAD_CODE_STRIPPING = YES;
 				DEVELOPMENT_TEAM = "";
 				GCC_C_LANGUAGE_STANDARD = gnu99;
@ -1805,7 +1809,7 @@
 					"$(inherited)",
 					"@executable_path/../Frameworks",
 				);
-				MARKETING_VERSION = 1.8.6;
+				MARKETING_VERSION = 1.8.7;
 				PRODUCT_BUNDLE_IDENTIFIER = "org.atelierInmu.vChewing.${PRODUCT_NAME:rfc1034identifier}";
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				PROVISIONING_PROFILE_SPECIFIER = "";
--- a/vChewingTests/KeyHandlerTestsSCPCCHT.swift
+++ b/vChewingTests/KeyHandlerTestsSCPCCHT.swift
@ -357,7 +357,7 @@ extension String {

 extension vChewing.LMAssociates {
  public mutating func forceOpenStringInstead(_ strData: String) {
-    strData.ranges(splitBy: "\n").filter({ !$0.isEmpty }).forEach {
+    strData.ranges(splitBy: "\n").filter { !$0.isEmpty }.forEach {
      let neta = strData[$0].split(separator: " ")
      if neta.count >= 2 {
        let theKey = String(neta[0])