From ab62321f7a852cf9f246648d2783cacbe90aa2c1 Mon Sep 17 00:00:00 2001
From: ShikiSuen <shikisuen@outlook.com>
Date: Thu, 16 Jun 2022 14:46:02 +0800
Subject: [PATCH] KeyHandler // Switch candidates by Shift(+CMD)+Space.

---
 .../ControllerModules/KeyHandler_HandleInput.swift    | 11 ++++++++---
 .../Modules/ControllerModules/KeyHandler_States.swift | 10 +++++-----
 2 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/Source/Modules/ControllerModules/KeyHandler_HandleInput.swift b/Source/Modules/ControllerModules/KeyHandler_HandleInput.swift
index e9137323..416f0ca6 100644
--- a/Source/Modules/ControllerModules/KeyHandler_HandleInput.swift
+++ b/Source/Modules/ControllerModules/KeyHandler_HandleInput.swift
@@ -247,7 +247,7 @@ extension KeyHandler {
     {
       if input.isSpace {
         // If the Space key is NOT set to be a selection key
-        if input.isShiftHold || !mgrPrefs.chooseCandidateUsingSpace {
+        if !mgrPrefs.chooseCandidateUsingSpace {
           if compositorCursorIndex >= compositorLength {
             let composingBuffer = currentState.composingBuffer
             if !composingBuffer.isEmpty {
@@ -264,6 +264,11 @@ extension KeyHandler {
             stateCallback(inputting)
           }
           return true
+        } else if input.isShiftHold {  // 臉書等網站會攔截 Tab 鍵，所以用 Shift+CMD+Space 對候選字詞做正向/反向輪替。
+          return handleInlineCandidateRotation(
+            state: state, reverseModifier: input.isCommandHold, stateCallback: stateCallback,
+            errorCallback: errorCallback
+          )
         }
       }
       stateCallback(buildCandidate(state: currentState, isTypingVertical: input.isTypingVertical))
@@ -279,8 +284,8 @@ extension KeyHandler {
     // MARK: Tab
 
     if input.isTab {
-      return handleTab(
-        state: state, isShiftHold: input.isShiftHold, stateCallback: stateCallback, errorCallback: errorCallback
+      return handleInlineCandidateRotation(
+        state: state, reverseModifier: input.isShiftHold, stateCallback: stateCallback, errorCallback: errorCallback
       )
     }
 
diff --git a/Source/Modules/ControllerModules/KeyHandler_States.swift b/Source/Modules/ControllerModules/KeyHandler_States.swift
index 039772e2..715a6c31 100644
--- a/Source/Modules/ControllerModules/KeyHandler_States.swift
+++ b/Source/Modules/ControllerModules/KeyHandler_States.swift
@@ -642,11 +642,11 @@ extension KeyHandler {
     return true
   }
 
-  // MARK: - 處理 Tab 按鍵行為
+  // MARK: - 處理上下文候選字詞輪替（Tab 按鍵，或者 Shift+Space）
 
-  func handleTab(
+  func handleInlineCandidateRotation(
     state: InputState,
-    isShiftHold: Bool,
+    reverseModifier: Bool,
     stateCallback: @escaping (InputState) -> Void,
     errorCallback: @escaping () -> Void
   ) -> Bool {
@@ -709,7 +709,7 @@ extension KeyHandler {
       if candidates[0] == currentValue {
         // If the first candidate is the value of the
         // current node, we use next one.
-        if isShiftHold {
+        if reverseModifier {
           currentIndex = candidates.count - 1
         } else {
           currentIndex = 1
@@ -718,7 +718,7 @@ extension KeyHandler {
     } else {
       for candidate in candidates {
         if candidate == currentValue {
-          if isShiftHold {
+          if reverseModifier {
             if currentIndex == 0 {
               currentIndex = candidates.count - 1
             } else {