From ffe90560cd719a095ccd73dafa09ee370ced51c9 Mon Sep 17 00:00:00 2001
From: fanlusky <1730976608@qq.com>
Date: Sat, 22 Aug 2026 19:40:33 +0800
Subject: [PATCH] Fix the issue where the language bar and FTB are out of sync
 for the Chinese-Japanese status.

---
 src/IME/MetasequoiaIME.cpp      |  4 ++++
 src/LanguageBar/LanguageBar.cpp | 14 +++++++++++++-
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/src/IME/MetasequoiaIME.cpp b/src/IME/MetasequoiaIME.cpp
index c92121a1..f442d36d 100644
--- a/src/IME/MetasequoiaIME.cpp
+++ b/src/IME/MetasequoiaIME.cpp
@@ -2399,6 +2399,10 @@ LRESULT CALLBACK CMetasequoiaIME_WindowProc(HWND hWnd, UINT message, WPARAM wPar
         break;
     }
     case WM_ThreadFocus: {
+        // Some Chromium/Electron window switches surface only as thread-focus
+        // changes. Refresh this thread's cached TSF language-bar item even when
+        // there was no document-focus transition.
+        pIME->_RefreshLanguageBarThemeIcons();
         SendCurrentImeStatusSnapshot(pIME);
         break;
     }
diff --git a/src/LanguageBar/LanguageBar.cpp b/src/LanguageBar/LanguageBar.cpp
index 559ae070..3709b04f 100644
--- a/src/LanguageBar/LanguageBar.cpp
+++ b/src/LanguageBar/LanguageBar.cpp
@@ -109,7 +109,19 @@ void CMetasequoiaIME::_UpdateLanguageBarOnSetFocus(_In_ ITfDocumentMgr *pDocMgrF
     CCompositionProcessorEngine *pCompositionProcessorEngine = nullptr;
     pCompositionProcessorEngine = _pCompositionProcessorEngine;
 
-    pCompositionProcessorEngine->SetLanguageBarStatus(TF_LBI_STATUS_DISABLED, needDisableButtons);
+    pCompositionProcessorEngine->SetLanguageBarStatus(TF_LBI_STATUS_DISABLED, needDisableButtons);
+
+    // SetStatus intentionally keeps the item enabled when focus is absent so
+    // Firefox does not replace our mode glyph with its disabled/close glyph.
+    // Consequently, returning to a document may not change the status bits and
+    // therefore may not generate an ITfLangBarItemSink update.  Always refresh
+    // the newly focused thread's item: Windows caches each host/thread's icon,
+    // and another host may have changed the shared Chinese/Japanese mode while
+    // this one was in the background.
+    if (!needDisableButtons)
+    {
+        pCompositionProcessorEngine->RefreshLanguageBarIcons();
+    }
 }
 
 //+---------------------------------------------------------------------------