diff --git a/Packages/vChewing_Shared/Sources/Shared/Protocols/CtlCandidateProtocol.swift b/Packages/vChewing_Shared/Sources/Shared/Protocols/CtlCandidateProtocol.swift
index 5e673391..ba45bd4d 100644
--- a/Packages/vChewing_Shared/Sources/Shared/Protocols/CtlCandidateProtocol.swift
+++ b/Packages/vChewing_Shared/Sources/Shared/Protocols/CtlCandidateProtocol.swift
@@ -15,6 +15,7 @@ public protocol CtlCandidateDelegate {
   @discardableResult func reverseLookup(for value: String) -> [String]
   var selectionKeys: String { get }
   var isVerticalTyping: Bool { get }
+  var isCandidateState: Bool { get }
   var showReverseLookupResult: Bool { get }
 }
 
diff --git a/Source/Modules/SessionCtl_Delegates.swift b/Source/Modules/SessionCtl_Delegates.swift
index a538c0c8..00ab6081 100644
--- a/Source/Modules/SessionCtl_Delegates.swift
+++ b/Source/Modules/SessionCtl_Delegates.swift
@@ -56,6 +56,8 @@ extension SessionCtl: InputHandlerDelegate {
 // MARK: - Candidate Controller Delegate
 
 extension SessionCtl: CtlCandidateDelegate {
+  public var isCandidateState: Bool { state.isCandidateContainer }
+
   public var showReverseLookupResult: Bool {
     !isVerticalTyping && PrefMgr.shared.showReverseLookupInCandidateUI
   }