From 234c2656b7d18cebe55756f772d38a674d798df9 Mon Sep 17 00:00:00 2001
From: ShikiSuen <shikisuen@outlook.com>
Date: Sat, 24 Jun 2023 16:59:12 +0800
Subject: [PATCH] SessionCtl // Patch fixIndexForIMKCandidates(), etc.

---
 Source/Modules/InputHandler_Core.swift        |  4 +--
 .../SessionCtl_IMKCandidatesData.swift        | 28 +++++++++++--------
 2 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/Source/Modules/InputHandler_Core.swift b/Source/Modules/InputHandler_Core.swift
index a9c02322..7deb70d7 100644
--- a/Source/Modules/InputHandler_Core.swift
+++ b/Source/Modules/InputHandler_Core.swift
@@ -71,8 +71,8 @@ public protocol InputHandlerDelegate {
   func candidateSelectionConfirmedByInputHandler(at index: Int)
   func setInlineDisplayWithCursor()
   func updatePopupDisplayWithCursor()
-  func performUserPhraseOperation(addToFilter: Bool)
-    -> Bool
+  func performUserPhraseOperation(addToFilter: Bool) -> Bool
+  func deductCandidateIndex(from candidateString: String) -> Int
 }
 
 // MARK: - 核心 (Kernel).
diff --git a/Source/Modules/SessionCtl_IMKCandidatesData.swift b/Source/Modules/SessionCtl_IMKCandidatesData.swift
index 19577ff5..281c6d73 100644
--- a/Source/Modules/SessionCtl_IMKCandidatesData.swift
+++ b/Source/Modules/SessionCtl_IMKCandidatesData.swift
@@ -74,13 +74,11 @@ public extension SessionCtl {
   /// IMK 選字窗限定函式，只要選字窗內的高亮內容選擇出現變化了、就會呼叫這個函式。
   /// - Parameter currentSelection: 已經高亮選中的候選字詞內容。
   override func candidateSelectionChanged(_ currentSelection: NSAttributedString!) {
+    guard state.isCandidateContainer else { return }
     guard let candidateString = currentSelection?.string, !candidateString.isEmpty else { return }
     // Handle candidatePairHighlightChanged().
-    var indexDeducted = 0
-    fixIndexForIMKCandidates(&indexDeducted, source: candidateString)
-    if state.type == .ofCandidates {
-      candidatePairHighlightChanged(at: indexDeducted)
-    }
+    let indexDeducted = deductCandidateIndex(from: candidateString)
+    candidatePairHighlightChanged(at: indexDeducted)
     let realCandidateString = state.candidates[indexDeducted].value
     // Handle IMK Annotation... We just use this to tell Apple that this never works in IMKCandidates.
     DispatchQueue.main.async { [self] in
@@ -97,6 +95,7 @@ public extension SessionCtl {
   /// - Remark: 不要被 IMK 的 API 命名方式困惑到。這其實是 Confirm Selection 確認選字。
   /// - Parameter candidateString: 已經確認的候選字詞內容。
   override func candidateSelected(_ candidateString: NSAttributedString!) {
+    guard state.isCandidateContainer else { return }
     let candidateString: String = candidateString?.string ?? ""
     if state.type == .ofAssociates {
       // 聯想詞的 Shift+選字鍵的處理已經在其它位置實作完成。
@@ -106,13 +105,18 @@ public extension SessionCtl {
       }
     }
 
+    let indexDeducted = deductCandidateIndex(from: candidateString)
+    candidatePairSelectionConfirmed(at: indexDeducted)
+  }
+
+  func deductCandidateIndex(from candidateString: String) -> Int {
     var indexDeducted = 0
 
     // 分類符號選單不會出現同符異音項、不需要康熙 / JIS 轉換，所以使用簡化過的處理方式。
     func fixSymbolIndexForIMKCandidates() {
       for (i, neta) in state.candidates.enumerated() {
         if candidateString == neta.value {
-          indexDeducted = i
+          indexDeducted = min(i, state.candidates.count - 1)
           break
         }
       }
@@ -126,7 +130,7 @@ public extension SessionCtl {
     case .ofSymbolTable:
       fixSymbolIndexForIMKCandidates()
     case .ofCandidates:
-      guard !state.candidates.isEmpty else { return }
+      guard !state.candidates.isEmpty else { break }
       if state.candidates[0].keyArray.description.contains("_punctuation") {
         fixSymbolIndexForIMKCandidates() // 標點符號選單處理。
       } else {
@@ -134,11 +138,11 @@ public extension SessionCtl {
       }
     default: break
     }
-    candidatePairSelectionConfirmed(at: indexDeducted)
+    return indexDeducted
   }
 
   /// 解析 IMKCandidates 給出的資料參數，據此推算正確的被確認的候選字詞配對的編號。
-  /// - Remark: 該函式當中的不可列印字元`\u{1A`是用來方便在 IMEState 當中用來分割資料的。
+  /// - Remark: 該函式當中的不可列印字元`\u{1A}`是用來方便在 IMEState 當中用來分割資料的。
   /// - Parameters:
   ///   - prefix: 前綴（僅限於聯想詞模式）。
   ///   - indexToFix: 要糾正的編號變數。
@@ -146,8 +150,10 @@ public extension SessionCtl {
   private func fixIndexForIMKCandidates(
     _ indexDeducted: inout Int, prefix: String = "", source candidateString: String
   ) {
+    guard state.isCandidateContainer else { return }
     guard let separator = inputHandler?.keySeparator else { return }
     let candidates = state.candidates
+    let maxIndex = candidates.count - 1
     for (i, neta) in candidates.enumerated() {
       let theConverted = ChineseConverter.kanjiConversionIfRequired(neta.value)
       let netaShown = (neta.value == theConverted)
@@ -169,11 +175,11 @@ public extension SessionCtl {
             : neta.keyArray.joined(separator: separator))
       let netaShownWithPronunciation = "\(netaShown)\u{17}(\(reading))"
       if candidateString == prefix + netaShownWithPronunciation {
-        indexDeducted = i
+        indexDeducted = min(i, maxIndex)
         break
       }
       if candidateString == prefix + netaShown {
-        indexDeducted = i
+        indexDeducted = min(i, maxIndex)
         break
       }
     }