Feature: Web remote desktop bidirectional text clipboard sync

Add keyboard-shortcut (Ctrl+C / Ctrl+X / Ctrl+V) text clipboard transfer
between the browser and the remote desktop, reusing the clipboard protocol
that already exists in the native viewer (COMMAND_SCREEN_GET_CLIPBOARD=24,
COMMAND_SCREEN_SET_CLIPBOARD=25, TOKEN_CLIPBOARD_TEXT=118) so the client
needs no change.

Local -> remote: pressing Ctrl+V reads the browser clipboard, pushes it to
the remote clipboard (UTF-8 -> GBK, matching the client's CF_TEXT/ANSI
handling) and then synthesizes a remote Ctrl+V so the pasted text is the
newly delivered one.

Remote -> local: Ctrl+C or Ctrl+X is forwarded to the remote as usual and,
after a short delay, the remote clipboard is pulled back and written to the
browser clipboard for a later local Ctrl+V.

Both the MFC and Go servers get the same three clipboard signaling paths
(clipboard_set, clipboard_get, clipboard_text) so the shared single-page
frontend behaves identically on either backend.

Co-Authored-By: deepseek-v4-pro

server/2015Remote/ScreenSpyDlg.cpp

@@ -1126,6 +1126,10 @@ VOID CScreenSpyDlg::OnReceiveComplete()
     case TOKEN_CLIPBOARD_TEXT: {
         Buffer str = m_ContextObject->InDeCompressedBuffer.GetMyBuffer(1);
         UpdateServerClipboard(str.c_str(), str.length());
+        // 反向回传：远程剪贴板文本（UTF-8）→ Web 客户端
+        if (m_bIsWebSession && WebService().IsRunning()) {
+            WebService().NotifyClipboardText(m_ClientID, std::string(str.c_str(), str.length()));
+        }
         break;
     }
     case TOKEN_BITMAPINFO: {

server/2015Remote/WebService.cpp

@@ -393,6 +393,10 @@ void CWebService::ServerThread(int port) {
                 HandleMouse(ws_ptr, msg);
             } else if (cmd == "key") {
                 HandleKey(ws_ptr, msg);
+            } else if (cmd == "clipboard_set") {
+                HandleClipboardSet(ws_ptr, msg);
+            } else if (cmd == "clipboard_get") {
+                HandleClipboardGet(ws_ptr, token);
             } else if (cmd == "rdp_reset") {
                 HandleRdpReset(ws_ptr, token);
             } else if (cmd == "audio_toggle") {
@@ -929,6 +933,93 @@ void CWebService::HandleKey(void* ws_ptr, const std::string& msg) {
     ctx->Send2Client(szData, length);
 }
 
+void CWebService::HandleClipboardSet(void* ws_ptr, const std::string& msg) {
+    // Parse JSON
+    Json::Value root;
+    Json::Reader reader;
+    if (!reader.parse(msg, root)) {
+        return;
+    }
+
+    std::string token = root.get("token", "").asString();
+    std::string text = root.get("text", "").asString();
+
+    if (text.empty()) return;
+
+    // Validate token
+    std::string username, role;
+    if (!ValidateToken(token, username, role)) {
+        return;
+    }
+
+    // Get device being watched
+    uint64_t device_id = 0;
+    {
+        std::lock_guard<std::mutex> lock(m_ClientsMutex);
+        auto it = m_Clients.find(ws_ptr);
+        if (it != m_Clients.end()) {
+            device_id = it->second.watch_device_id;
+            it->second.last_activity = (uint64_t)time(nullptr);
+        }
+    }
+
+    if (device_id == 0) return;
+
+    // Get screen context
+    CONTEXT_OBJECT* ctx = GetScreenContext(device_id);
+    if (!ctx) {
+        return;
+    }
+
+    // UTF-8 → UTF-16 → GBK(936)。客户端 UpdateClientClipboard 以 CF_TEXT(ANSI/GBK) 落剪贴板，
+    // 故显式用 936 而非 CP_ACP，避免服务端 locale 非中文时出错。
+    int wlen = MultiByteToWideChar(CP_UTF8, 0, text.c_str(), (int)text.size(), nullptr, 0);
+    if (wlen <= 0) return;
+    std::wstring wide(wlen, L'\0');
+    MultiByteToWideChar(CP_UTF8, 0, text.c_str(), (int)text.size(), &wide[0], wlen);
+
+    int glen = WideCharToMultiByte(936, 0, wide.c_str(), wlen, nullptr, 0, nullptr, nullptr);
+    if (glen <= 0) return;
+
+    // 命令字节 + GBK 文本
+    std::vector<BYTE> szData(1 + glen);
+    szData[0] = COMMAND_SCREEN_SET_CLIPBOARD;
+    WideCharToMultiByte(936, 0, wide.c_str(), wlen, (char*)szData.data() + 1, glen, nullptr, nullptr);
+
+    ctx->Send2Client(szData.data(), (ULONG)szData.size());
+}
+
+void CWebService::HandleClipboardGet(void* ws_ptr, const std::string& token) {
+    // Validate token
+    std::string username, role;
+    if (!ValidateToken(token, username, role)) {
+        return;
+    }
+
+    // Get device being watched
+    uint64_t device_id = 0;
+    {
+        std::lock_guard<std::mutex> lock(m_ClientsMutex);
+        auto it = m_Clients.find(ws_ptr);
+        if (it != m_Clients.end()) {
+            device_id = it->second.watch_device_id;
+            it->second.last_activity = (uint64_t)time(nullptr);
+        }
+    }
+
+    if (device_id == 0) return;
+
+    // Get screen context
+    CONTEXT_OBJECT* ctx = GetScreenContext(device_id);
+    if (!ctx) {
+        return;
+    }
+
+    // 单字节命令，客户端以 SendClientClipboard → TOKEN_CLIPBOARD_TEXT 回包
+    BYTE bToken = COMMAND_SCREEN_GET_CLIPBOARD;
+    ctx->Send2Client(&bToken, sizeof(BYTE));
+}
+
 void CWebService::HandleRdpReset(void* ws_ptr, const std::string& token) {
     std::string username, role;
     if (!ValidateToken(token, username, role)) {
@@ -1711,6 +1802,26 @@ void CWebService::BroadcastCursor(uint64_t device_id, uint8_t cursor_index) {
     }
 }
 
+void CWebService::NotifyClipboardText(uint64_t device_id, const std::string& text) {
+    if (m_bStopping) return;
+
+    Json::Value res;
+    res["cmd"] = "clipboard_text";
+    res["id"] = device_id;
+    res["text"] = text;
+
+    Json::StreamWriterBuilder builder;
+    builder["indentation"] = "";
+    std::string json = Json::writeString(builder, res);
+
+    std::lock_guard<std::mutex> lock(m_ClientsMutex);
+    for (auto& [ws_ptr, client] : m_Clients) {
+        if (client.watch_device_id == device_id) {
+            SendText(ws_ptr, json);
+        }
+    }
+}
+
 bool CWebService::StartRemoteDesktop(uint64_t device_id) {
     if (!m_pParentDlg) return false;
 

server/2015Remote/WebService.h

@@ -160,6 +160,9 @@ public:
     // Cursor change notification (called from ScreenSpyDlg)
     void BroadcastCursor(uint64_t device_id, uint8_t cursor_index);
 
+    // 远程剪贴板文本回传通知（called from ScreenSpyDlg，payload 为 UTF-8）
+    void NotifyClipboardText(uint64_t device_id, const std::string& text);
+
     // Get count of web clients watching a device
     int GetWebClientCount(uint64_t device_id);
 
@@ -187,6 +190,8 @@ private:
     void HandlePing(void* ws_ptr, const std::string& token);
     void HandleMouse(void* ws_ptr, const std::string& msg);
     void HandleKey(void* ws_ptr, const std::string& msg);
+    void HandleClipboardSet(void* ws_ptr, const std::string& msg);
+    void HandleClipboardGet(void* ws_ptr, const std::string& token);
     void HandleRdpReset(void* ws_ptr, const std::string& token);
     void HandleAudioToggle(void* ws_ptr, const std::string& token);