From 0e8b027674aced32867e562d9fc848988b053321 Mon Sep 17 00:00:00 2001
From: ShikiSuen <shikisuen@outlook.com>
Date: Wed, 27 Jul 2022 14:55:42 +0800
Subject: [PATCH] SymbolNode // Add and call previous node references.

---
 Source/Modules/ControllerModules/InputState.swift            | 5 ++++-
 .../ControllerModules/KeyHandler_HandleCandidate.swift       | 5 ++++-
 .../Modules/ControllerModules/ctlInputMethod_Delegates.swift | 2 +-
 Source/Modules/LangModelRelated/LMSymbolNode.swift           | 1 +
 4 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/Source/Modules/ControllerModules/InputState.swift b/Source/Modules/ControllerModules/InputState.swift
index 5230386c..baf085b8 100644
--- a/Source/Modules/ControllerModules/InputState.swift
+++ b/Source/Modules/ControllerModules/InputState.swift
@@ -440,8 +440,11 @@ enum InputState {
     override public var type: StateType { .ofSymbolTable }
     var node: SymbolNode
 
-    init(node: SymbolNode, isTypingVertical: Bool) {
+    init(node: SymbolNode, previous: SymbolNode? = nil, isTypingVertical: Bool) {
       self.node = node
+      if let previous = previous {
+        self.node.previous = previous
+      }
       let candidates = node.children?.map(\.title) ?? [String]()
       super.init(
         composingBuffer: "", cursorIndex: 0, candidates: candidates.map { ("", $0) },
diff --git a/Source/Modules/ControllerModules/KeyHandler_HandleCandidate.swift b/Source/Modules/ControllerModules/KeyHandler_HandleCandidate.swift
index 2f8eba7b..83501782 100644
--- a/Source/Modules/ControllerModules/KeyHandler_HandleCandidate.swift
+++ b/Source/Modules/ControllerModules/KeyHandler_HandleCandidate.swift
@@ -59,7 +59,7 @@ extension KeyHandler {
       || ((input.isCursorBackward || input.isCursorForward) && input.isShiftHold)
 
     if cancelCandidateKey {
-      if (state is InputState.AssociatedPhrases)
+      if state is InputState.AssociatedPhrases
         || mgrPrefs.useSCPCTypingMode
         || compositor.isEmpty
       {
@@ -72,6 +72,9 @@ extension KeyHandler {
       } else {
         stateCallback(buildInputtingState)
       }
+      if let state = state as? InputState.SymbolTable, let nodePrevious = state.node.previous {
+        stateCallback(InputState.SymbolTable(node: nodePrevious, isTypingVertical: state.isTypingVertical))
+      }
       return true
     }
 
diff --git a/Source/Modules/ControllerModules/ctlInputMethod_Delegates.swift b/Source/Modules/ControllerModules/ctlInputMethod_Delegates.swift
index 817176ce..c6f19fb3 100644
--- a/Source/Modules/ControllerModules/ctlInputMethod_Delegates.swift
+++ b/Source/Modules/ControllerModules/ctlInputMethod_Delegates.swift
@@ -101,7 +101,7 @@ extension ctlInputMethod: ctlCandidateDelegate {
       if let children = node.children, !children.isEmpty {
         handle(state: InputState.Empty())  // 防止縱橫排選字窗同時出現
         handle(
-          state: InputState.SymbolTable(node: node, isTypingVertical: state.isTypingVertical)
+          state: InputState.SymbolTable(node: node, previous: state.node, isTypingVertical: state.isTypingVertical)
         )
       } else {
         handle(state: InputState.Committing(textToCommit: node.title))
diff --git a/Source/Modules/LangModelRelated/LMSymbolNode.swift b/Source/Modules/LangModelRelated/LMSymbolNode.swift
index e7270e83..dc2ae11c 100644
--- a/Source/Modules/LangModelRelated/LMSymbolNode.swift
+++ b/Source/Modules/LangModelRelated/LMSymbolNode.swift
@@ -29,6 +29,7 @@ import Foundation
 class SymbolNode {
   var title: String
   var children: [SymbolNode]?
+  var previous: SymbolNode?
 
   init(_ title: String, _ children: [SymbolNode]? = nil) {
     self.title = title