diff --git a/src/libs/clangbackendipc/clangbackendipc-lib.pri b/src/libs/clangbackendipc/clangbackendipc-lib.pri
index cc11840a043..3084a13761b 100644
--- a/src/libs/clangbackendipc/clangbackendipc-lib.pri
+++ b/src/libs/clangbackendipc/clangbackendipc-lib.pri
@@ -46,7 +46,8 @@ SOURCES += $$PWD/ipcserverinterface.cpp \
     $$PWD/requestdiagnosticsmessage.cpp \
     $$PWD/registerunsavedfilesforeditormessage.cpp \
     $$PWD/unregisterunsavedfilesforeditormessage.cpp \
-    $$PWD/updatetranslationunitsforeditormessage.cpp
+    $$PWD/updatetranslationunitsforeditormessage.cpp \
+    $$PWD/updatevisibletranslationunitsmessage.cpp
 
 HEADERS += \
     $$PWD/ipcserverinterface.h \
@@ -87,6 +88,7 @@ HEADERS += \
     $$PWD/requestdiagnosticsmessage.h \
     $$PWD/registerunsavedfilesforeditormessage.h \
     $$PWD/unregisterunsavedfilesforeditormessage.h \
-    $$PWD/updatetranslationunitsforeditormessage.h
+    $$PWD/updatetranslationunitsforeditormessage.h \
+    $$PWD/updatevisibletranslationunitsmessage.h
 
 contains(QT_CONFIG, reduce_exports):CONFIG += hide_symbols
diff --git a/src/libs/clangbackendipc/cmbmessages.cpp b/src/libs/clangbackendipc/cmbmessages.cpp
index 04af03c5e7d..d275de5353d 100644
--- a/src/libs/clangbackendipc/cmbmessages.cpp
+++ b/src/libs/clangbackendipc/cmbmessages.cpp
@@ -49,6 +49,7 @@
 #include "translationunitdoesnotexistmessage.h"
 #include "unregisterunsavedfilesforeditormessage.h"
 #include "updatetranslationunitsforeditormessage.h"
+#include "updatevisibletranslationunitsmessage.h"
 
 #include <QDataStream>
 
@@ -82,6 +83,8 @@ void Messages::registerMessages()
     registerMetaType<RequestDiagnosticsMessage>();
     registerMetaType<DiagnosticsChangedMessage>();
 
+    registerMetaType<UpdateVisibleTranslationUnitsMessage>();
+
     registerMetaType<CompleteCodeMessage>();
     registerMetaType<CodeCompletedMessage>();
     registerMetaType<CodeCompletion>();
diff --git a/src/libs/clangbackendipc/ipcclientinterface.h b/src/libs/clangbackendipc/ipcclientinterface.h
index 32d17e4c60d..5600e130763 100644
--- a/src/libs/clangbackendipc/ipcclientinterface.h
+++ b/src/libs/clangbackendipc/ipcclientinterface.h
@@ -50,6 +50,7 @@ class DiagnosticsChangedMessage;
 class RequestDiagnosticsMessage;
 class RegisterUnsavedFilesForEditorMessage;
 class UnregisterUnsavedFilesForEditorMessage;
+class UpdateVisibleTranslationUnitsMessage;
 
 class CMBIPC_EXPORT IpcClientInterface : public IpcInterface
 {
diff --git a/src/libs/clangbackendipc/ipcserverinterface.cpp b/src/libs/clangbackendipc/ipcserverinterface.cpp
index 92ba85a6de7..93717dfa33a 100644
--- a/src/libs/clangbackendipc/ipcserverinterface.cpp
+++ b/src/libs/clangbackendipc/ipcserverinterface.cpp
@@ -39,6 +39,7 @@
 #include "requestdiagnosticsmessage.h"
 #include "unregisterunsavedfilesforeditormessage.h"
 #include "updatetranslationunitsforeditormessage.h"
+#include "updatevisibletranslationunitsmessage.h"
 
 #include <QDebug>
 #include <QVariant>
@@ -57,6 +58,8 @@ void IpcServerInterface::dispatch(const QVariant &message)
     static const int unregisterUnsavedFilesForEditorMessageType = QMetaType::type("ClangBackEnd::UnregisterUnsavedFilesForEditorMessage");
     static const int completeCodeMessageType = QMetaType::type("ClangBackEnd::CompleteCodeMessage");
     static const int requestDiagnosticsMessageType = QMetaType::type("ClangBackEnd::RequestDiagnosticsMessage");
+    static const int updateVisibleTranslationUnitsMessageType = QMetaType::type("ClangBackEnd::UpdateVisibleTranslationUnitsMessage");
+
 
     int type = message.userType();
 
@@ -80,6 +83,8 @@ void IpcServerInterface::dispatch(const QVariant &message)
         completeCode(message.value<CompleteCodeMessage>());
     else if (type == requestDiagnosticsMessageType)
         requestDiagnostics(message.value<RequestDiagnosticsMessage>());
+    else if (type == updateVisibleTranslationUnitsMessageType)
+        updateVisibleTranslationUnits(message.value<UpdateVisibleTranslationUnitsMessage>());
     else
         qWarning() << "Unknown IpcServerMessage";
 }
diff --git a/src/libs/clangbackendipc/ipcserverinterface.h b/src/libs/clangbackendipc/ipcserverinterface.h
index 0682970412c..98d1441c0d5 100644
--- a/src/libs/clangbackendipc/ipcserverinterface.h
+++ b/src/libs/clangbackendipc/ipcserverinterface.h
@@ -54,6 +54,7 @@ public:
     virtual void unregisterUnsavedFilesForEditor(const UnregisterUnsavedFilesForEditorMessage &message) = 0;
     virtual void completeCode(const CompleteCodeMessage &message) = 0;
     virtual void requestDiagnostics(const RequestDiagnosticsMessage &message) = 0;
+    virtual void updateVisibleTranslationUnits(const UpdateVisibleTranslationUnitsMessage &message) = 0;
 
     void addClient(IpcClientInterface *client);
     void removeClient(IpcClientInterface *client);
diff --git a/src/libs/clangbackendipc/ipcserverproxy.cpp b/src/libs/clangbackendipc/ipcserverproxy.cpp
index a1d9d978be5..fa5777267c8 100644
--- a/src/libs/clangbackendipc/ipcserverproxy.cpp
+++ b/src/libs/clangbackendipc/ipcserverproxy.cpp
@@ -42,6 +42,7 @@
 #include <requestdiagnosticsmessage.h>
 #include <unregisterunsavedfilesforeditormessage.h>
 #include <updatetranslationunitsforeditormessage.h>
+#include <updatevisibletranslationunitsmessage.h>
 
 #include <QLocalServer>
 #include <QLocalSocket>
@@ -119,5 +120,10 @@ void IpcServerProxy::requestDiagnostics(const ClangBackEnd::RequestDiagnosticsMe
     writeMessageBlock.write(QVariant::fromValue(message));
 }
 
+void IpcServerProxy::updateVisibleTranslationUnits(const UpdateVisibleTranslationUnitsMessage &message)
+{
+    writeMessageBlock.write(QVariant::fromValue(message));
+}
+
 } // namespace ClangBackEnd
 
diff --git a/src/libs/clangbackendipc/ipcserverproxy.h b/src/libs/clangbackendipc/ipcserverproxy.h
index a3f52ff128c..d4c42887f4f 100644
--- a/src/libs/clangbackendipc/ipcserverproxy.h
+++ b/src/libs/clangbackendipc/ipcserverproxy.h
@@ -65,7 +65,7 @@ public:
     void unregisterUnsavedFilesForEditor(const UnregisterUnsavedFilesForEditorMessage &message) override;
     void completeCode(const CompleteCodeMessage &message) override;
     void requestDiagnostics(const RequestDiagnosticsMessage &message) override;
-
+    void updateVisibleTranslationUnits(const UpdateVisibleTranslationUnitsMessage &message) override;
     void readMessages();
 
     void resetCounter();
diff --git a/src/libs/clangbackendipc/updatevisibletranslationunitsmessage.cpp b/src/libs/clangbackendipc/updatevisibletranslationunitsmessage.cpp
new file mode 100644
index 00000000000..8e383fa86c1
--- /dev/null
+++ b/src/libs/clangbackendipc/updatevisibletranslationunitsmessage.cpp
@@ -0,0 +1,116 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company.  For licensing terms and
+** conditions see http://www.qt.io/terms-conditions.  For further information
+** use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 or version 3 as published by the Free
+** Software Foundation and appearing in the file LICENSE.LGPLv21 and
+** LICENSE.LGPLv3 included in the packaging of this file.  Please review the
+** following information to ensure the GNU Lesser General Public License
+** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, The Qt Company gives you certain additional
+** rights.  These rights are described in The Qt Company LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+****************************************************************************/
+#include "updatevisibletranslationunitsmessage.h"
+
+#include "container_common.h"
+
+#include <QDataStream>
+#include <QDebug>
+
+#include <algorithm>
+#include <iterator>
+#include <ostream>
+
+namespace ClangBackEnd {
+
+UpdateVisibleTranslationUnitsMessage::UpdateVisibleTranslationUnitsMessage(
+        const Utf8String &currentEditorFilePath,
+        const Utf8StringVector &visibleEditorFilePaths)
+    : currentEditorFilePath_(currentEditorFilePath),
+      visibleEditorFilePaths_(visibleEditorFilePaths)
+{
+}
+
+const Utf8String &UpdateVisibleTranslationUnitsMessage::currentEditorFilePath() const
+{
+    return currentEditorFilePath_;
+}
+
+const Utf8StringVector &UpdateVisibleTranslationUnitsMessage::visibleEditorFilePaths() const
+{
+    return visibleEditorFilePaths_;
+}
+
+QDataStream &operator<<(QDataStream &out, const UpdateVisibleTranslationUnitsMessage &message)
+{
+    out << message.currentEditorFilePath_;
+    out << message.visibleEditorFilePaths_;
+
+    return out;
+}
+
+QDataStream &operator>>(QDataStream &in, UpdateVisibleTranslationUnitsMessage &message)
+{
+    in >> message.currentEditorFilePath_;
+    in >> message.visibleEditorFilePaths_;
+
+    return in;
+}
+
+bool operator==(const UpdateVisibleTranslationUnitsMessage &first, const UpdateVisibleTranslationUnitsMessage &second)
+{
+    return first.currentEditorFilePath_ == second.currentEditorFilePath_
+        && first.visibleEditorFilePaths_ == second.visibleEditorFilePaths_;
+}
+
+bool operator<(const UpdateVisibleTranslationUnitsMessage &first, const UpdateVisibleTranslationUnitsMessage &second)
+{
+    return first.currentEditorFilePath_ < second.currentEditorFilePath_
+        && compareContainer(first.visibleEditorFilePaths_, second.visibleEditorFilePaths_);
+}
+
+QDebug operator<<(QDebug debug, const UpdateVisibleTranslationUnitsMessage &message)
+{
+    debug.nospace() << "UpdateVisibleTranslationUnitsMessage(";
+
+    debug.nospace() << message.currentEditorFilePath()  << ", ";
+
+    for (const Utf8String &visibleEditorFilePath : message.visibleEditorFilePaths())
+        debug.nospace() << visibleEditorFilePath << ", ";
+
+    debug.nospace() << ")";
+
+    return debug;
+}
+
+void PrintTo(const UpdateVisibleTranslationUnitsMessage &message, ::std::ostream* os)
+{
+    *os << "UpdateVisibleTranslationUnitsMessage(";
+
+    *os << message.currentEditorFilePath().constData()  << ", ";
+
+    auto visiblePaths = message.visibleEditorFilePaths();
+
+    std::copy(visiblePaths.cbegin(), visiblePaths.cend(), std::ostream_iterator<Utf8String>(*os, ", "));
+
+    *os << ")";
+}
+
+} // namespace ClangBackEnd
diff --git a/src/libs/clangbackendipc/updatevisibletranslationunitsmessage.h b/src/libs/clangbackendipc/updatevisibletranslationunitsmessage.h
new file mode 100644
index 00000000000..3383ccc616f
--- /dev/null
+++ b/src/libs/clangbackendipc/updatevisibletranslationunitsmessage.h
@@ -0,0 +1,72 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company.  For licensing terms and
+** conditions see http://www.qt.io/terms-conditions.  For further information
+** use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 or version 3 as published by the Free
+** Software Foundation and appearing in the file LICENSE.LGPLv21 and
+** LICENSE.LGPLv3 included in the packaging of this file.  Please review the
+** following information to ensure the GNU Lesser General Public License
+** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, The Qt Company gives you certain additional
+** rights.  These rights are described in The Qt Company LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+****************************************************************************/
+#ifndef CLANGBACKEND_UPDATEVISIBLETRANSLATIONUNITSMESSAGE_H
+#define CLANGBACKEND_UPDATEVISIBLETRANSLATIONUNITSMESSAGE_H
+
+#include <clangbackendipc_global.h>
+
+#include <utf8stringvector.h>
+
+#include <QMetaType>
+
+namespace ClangBackEnd {
+
+class CMBIPC_EXPORT UpdateVisibleTranslationUnitsMessage
+{
+    friend CMBIPC_EXPORT QDataStream &operator<<(QDataStream &out, const UpdateVisibleTranslationUnitsMessage &message);
+    friend CMBIPC_EXPORT QDataStream &operator>>(QDataStream &in, UpdateVisibleTranslationUnitsMessage &message);
+    friend CMBIPC_EXPORT bool operator==(const UpdateVisibleTranslationUnitsMessage &first, const UpdateVisibleTranslationUnitsMessage &second);
+    friend CMBIPC_EXPORT bool operator<(const UpdateVisibleTranslationUnitsMessage &first, const UpdateVisibleTranslationUnitsMessage &second);
+
+public:
+    UpdateVisibleTranslationUnitsMessage() = default;
+    UpdateVisibleTranslationUnitsMessage(const Utf8String &currentEditorFilePath,
+                                         const Utf8StringVector &visibleEditorFilePaths);
+
+    const Utf8String &currentEditorFilePath() const;
+    const Utf8StringVector &visibleEditorFilePaths() const;
+
+private:
+    Utf8String currentEditorFilePath_;
+    Utf8StringVector visibleEditorFilePaths_;
+};
+
+CMBIPC_EXPORT QDataStream &operator<<(QDataStream &out, const UpdateVisibleTranslationUnitsMessage &message);
+CMBIPC_EXPORT QDataStream &operator>>(QDataStream &in, UpdateVisibleTranslationUnitsMessage &message);
+CMBIPC_EXPORT bool operator==(const UpdateVisibleTranslationUnitsMessage &first, const UpdateVisibleTranslationUnitsMessage &second);
+CMBIPC_EXPORT bool operator<(const UpdateVisibleTranslationUnitsMessage &first, const UpdateVisibleTranslationUnitsMessage &second);
+
+CMBIPC_EXPORT QDebug operator<<(QDebug debug, const UpdateVisibleTranslationUnitsMessage &message);
+void PrintTo(const UpdateVisibleTranslationUnitsMessage &message, ::std::ostream* os);
+} // namespace ClangBackEnd
+
+Q_DECLARE_METATYPE(ClangBackEnd::UpdateVisibleTranslationUnitsMessage)
+
+#endif // CLANGBACKEND_UPDATEVISIBLETRANSLATIONUNITSMESSAGE_H
diff --git a/src/libs/sqlite/utf8string.cpp b/src/libs/sqlite/utf8string.cpp
index c8cbaea2230..9fb92b5d39d 100644
--- a/src/libs/sqlite/utf8string.cpp
+++ b/src/libs/sqlite/utf8string.cpp
@@ -269,6 +269,14 @@ void PrintTo(const Utf8String &text, ::std::ostream* os)
     *os << "\"" << text.toByteArray().data() << "\"";
 }
 
+std::ostream& operator<<(std::ostream &os, const Utf8String &utf8String)
+{
+    using std::ostream;
+    os << utf8String.constData();
+
+    return os;
+}
+
 uint qHash(const Utf8String &utf8String)
 {
     return qHash(utf8String.byteArray);
diff --git a/src/libs/sqlite/utf8string.h b/src/libs/sqlite/utf8string.h
index c6adfc93716..6158f8b690d 100644
--- a/src/libs/sqlite/utf8string.h
+++ b/src/libs/sqlite/utf8string.h
@@ -36,6 +36,8 @@
 #include <QByteArray>
 #include <QMetaType>
 
+#include <iosfwd>
+
 class Utf8StringVector;
 class Utf8String;
 
@@ -120,6 +122,7 @@ SQLITE_EXPORT QDataStream &operator<<(QDataStream &datastream, const Utf8String
 SQLITE_EXPORT QDataStream &operator>>(QDataStream &datastream, Utf8String &text);
 SQLITE_EXPORT QDebug operator<<(QDebug debug, const Utf8String &text);
 SQLITE_EXPORT void PrintTo(const Utf8String &text, ::std::ostream* os);
+SQLITE_EXPORT std::ostream& operator<<(std::ostream &os, const Utf8String &utf8String);
 
 SQLITE_EXPORT uint qHash(const Utf8String &utf8String);
 
diff --git a/src/tools/clangbackend/ipcsource/clangipcserver.cpp b/src/tools/clangbackend/ipcsource/clangipcserver.cpp
index 320c982c88e..31c3ae481f3 100644
--- a/src/tools/clangbackend/ipcsource/clangipcserver.cpp
+++ b/src/tools/clangbackend/ipcsource/clangipcserver.cpp
@@ -54,6 +54,7 @@
 #include <translationunitdoesnotexistmessage.h>
 #include <unregisterunsavedfilesforeditormessage.h>
 #include <updatetranslationunitsforeditormessage.h>
+#include <updatevisibletranslationunitsmessage.h>
 
 #include <QCoreApplication>
 #include <QDebug>
@@ -243,6 +244,18 @@ void ClangIpcServer::requestDiagnostics(const RequestDiagnosticsMessage &message
     }
 }
 
+void ClangIpcServer::updateVisibleTranslationUnits(const UpdateVisibleTranslationUnitsMessage &message)
+{
+    TIME_SCOPE_DURATION("ClangIpcServer::updateVisibleTranslationUnits");
+
+    try {
+        translationUnits.setCurrentEditor(message.currentEditorFilePath());
+        translationUnits.setVisibleEditors(message.visibleEditorFilePaths());
+    }  catch (const std::exception &exception) {
+        qWarning() << "Error in ClangIpcServer::updateVisibleTranslationUnits:" << exception.what();
+    }
+}
+
 const TranslationUnits &ClangIpcServer::translationUnitsForTestOnly() const
 {
     return translationUnits;
diff --git a/src/tools/clangbackend/ipcsource/clangipcserver.h b/src/tools/clangbackend/ipcsource/clangipcserver.h
index d4e5c6442ac..bfb1313e64f 100644
--- a/src/tools/clangbackend/ipcsource/clangipcserver.h
+++ b/src/tools/clangbackend/ipcsource/clangipcserver.h
@@ -61,6 +61,7 @@ public:
     void unregisterUnsavedFilesForEditor(const UnregisterUnsavedFilesForEditorMessage &message) override;
     void completeCode(const CompleteCodeMessage &message) override;
     void requestDiagnostics(const RequestDiagnosticsMessage &message) override;
+    void updateVisibleTranslationUnits(const UpdateVisibleTranslationUnitsMessage &message) override;
 
     const TranslationUnits &translationUnitsForTestOnly() const;
 
diff --git a/tests/unit/echoserver/echoipcserver.cpp b/tests/unit/echoserver/echoipcserver.cpp
index c9dbfb42e88..fe1e79180f3 100644
--- a/tests/unit/echoserver/echoipcserver.cpp
+++ b/tests/unit/echoserver/echoipcserver.cpp
@@ -43,6 +43,7 @@
 #include "requestdiagnosticsmessage.h"
 #include "unregisterunsavedfilesforeditormessage.h"
 #include "updatetranslationunitsforeditormessage.h"
+#include "updatevisibletranslationunitsmessage.h"
 
 #include <QCoreApplication>
 #include <QDebug>
@@ -106,6 +107,11 @@ void EchoIpcServer::requestDiagnostics(const RequestDiagnosticsMessage &message)
     echoMessage(QVariant::fromValue(message));
 }
 
+void EchoIpcServer::updateVisibleTranslationUnits(const UpdateVisibleTranslationUnitsMessage &message)
+{
+    echoMessage(QVariant::fromValue(message));
+}
+
 void EchoIpcServer::echoMessage(const QVariant &message)
 {
     client()->echo(EchoMessage(message));
diff --git a/tests/unit/echoserver/echoipcserver.h b/tests/unit/echoserver/echoipcserver.h
index cb3c55d2bb4..f7710f6f3dc 100644
--- a/tests/unit/echoserver/echoipcserver.h
+++ b/tests/unit/echoserver/echoipcserver.h
@@ -49,6 +49,7 @@ public:
     void unregisterUnsavedFilesForEditor(const UnregisterUnsavedFilesForEditorMessage &message) override;
     void completeCode(const CompleteCodeMessage &message) override;
     void requestDiagnostics(const RequestDiagnosticsMessage &message) override;
+    void updateVisibleTranslationUnits(const UpdateVisibleTranslationUnitsMessage &message) override;
 
 private:
     void echoMessage(const QVariant &message);
diff --git a/tests/unit/unittest/clangipcservertest.cpp b/tests/unit/unittest/clangipcservertest.cpp
index be19eab6eed..2f0711832b0 100644
--- a/tests/unit/unittest/clangipcservertest.cpp
+++ b/tests/unit/unittest/clangipcservertest.cpp
@@ -47,6 +47,7 @@
 #include <projectpartsdonotexistmessage.h>
 #include <translationunitdoesnotexistmessage.h>
 #include <updatetranslationunitsforeditormessage.h>
+#include <updatevisibletranslationunitsmessage.h>
 
 #include <QBuffer>
 #include <QFile>
@@ -76,6 +77,7 @@ using ClangBackEnd::ProjectPartContainer;
 using ClangBackEnd::TranslationUnitDoesNotExistMessage;
 using ClangBackEnd::ProjectPartsDoNotExistMessage;
 using ClangBackEnd::UpdateTranslationUnitsForEditorMessage;
+using ClangBackEnd::UpdateVisibleTranslationUnitsMessage;
 
 MATCHER_P5(HasDirtyTranslationUnit,
            filePath,
@@ -135,11 +137,13 @@ protected:
     void registerProjectPart();
     void changeProjectPartArguments();
     void changeProjectPartArgumentsToWrongValues();
+    void updateVisibilty(const Utf8String &currentEditor, const Utf8String &additionalVisibleEditor);
     static const Utf8String unsavedContent(const QString &unsavedFilePath);
 
 protected:
     MockIpcClient mockIpcClient;
     ClangBackEnd::ClangIpcServer clangServer;
+    const ClangBackEnd::TranslationUnits &translationUnits = clangServer.translationUnitsForTestOnly();
     const Utf8String projectPartId = Utf8StringLiteral("pathToProjectPart.pro");
     const Utf8String functionTestFilePath = Utf8StringLiteral(TESTDATA_DIR"/complete_extractor_function.cpp");
     const Utf8String variableTestFilePath = Utf8StringLiteral(TESTDATA_DIR"/complete_extractor_variable.cpp");
@@ -148,53 +152,6 @@ protected:
     const Utf8String parseErrorTestFilePath = Utf8StringLiteral(TESTDATA_DIR"/complete_translationunit_parse_error.cpp");
 };
 
-
-void ClangIpcServer::SetUp()
-{
-    clangServer.addClient(&mockIpcClient);
-    registerProjectPart();
-    registerFiles();
-}
-
-void ClangIpcServer::registerFiles()
-{
-    RegisterTranslationUnitForEditorMessage message({FileContainer(functionTestFilePath, projectPartId, unsavedContent(unsavedTestFilePath), true),
-                                                     FileContainer(variableTestFilePath, projectPartId)});
-
-    clangServer.registerTranslationUnitsForEditor(message);
-}
-
-void ClangIpcServer::registerProjectPart()
-{
-    RegisterProjectPartsForEditorMessage message({ProjectPartContainer(projectPartId)});
-
-    clangServer.registerProjectPartsForEditor(message);
-}
-
-void ClangIpcServer::changeProjectPartArguments()
-{
-    RegisterProjectPartsForEditorMessage message({ProjectPartContainer(projectPartId, {Utf8StringLiteral("-DArgumentDefinition")})});
-
-    clangServer.registerProjectPartsForEditor(message);
-}
-
-void ClangIpcServer::changeProjectPartArgumentsToWrongValues()
-{
-    RegisterProjectPartsForEditorMessage message({ProjectPartContainer(projectPartId, {Utf8StringLiteral("-blah")})});
-
-    clangServer.registerProjectPartsForEditor(message);
-}
-
-const Utf8String ClangIpcServer::unsavedContent(const QString &unsavedFilePath)
-{
-    QFile unsavedFileContentFile(unsavedFilePath);
-    bool isOpen = unsavedFileContentFile.open(QIODevice::ReadOnly | QIODevice::Text);
-    if (!isOpen)
-        ADD_FAILURE() << "File with the unsaved content cannot be opened!";
-
-    return Utf8String::fromByteArray(unsavedFileContentFile.readAll());
-}
-
 TEST_F(ClangIpcServer, GetCodeCompletion)
 {
     CompleteCodeMessage completeCodeMessage(functionTestFilePath,
@@ -426,6 +383,86 @@ TEST_F(ClangIpcServer, TranslationUnitAfterCreationNeedsNoReparseAndHasNewDiagno
     ASSERT_THAT(clangServer, HasDirtyTranslationUnit(functionTestFilePath, projectPartId, 0U, false, true));
 }
 
+TEST_F(ClangIpcServer, SetCurrentAndVisibleEditor)
+{
+    auto functionTranslationUnit = translationUnits.translationUnit(functionTestFilePath, projectPartId);
+    auto variableTranslationUnit = translationUnits.translationUnit(variableTestFilePath, projectPartId);
+
+    updateVisibilty(functionTestFilePath, variableTestFilePath);
+
+    ASSERT_TRUE(functionTranslationUnit.isUsedByCurrentEditor());
+    ASSERT_TRUE(functionTranslationUnit.isVisibleInEditor());
+    ASSERT_TRUE(variableTranslationUnit.isVisibleInEditor());
+}
+
+TEST_F(ClangIpcServer, IsNotCurrentCurrentAndVisibleEditorAnymore)
+{
+    auto functionTranslationUnit = translationUnits.translationUnit(functionTestFilePath, projectPartId);
+    auto variableTranslationUnit = translationUnits.translationUnit(variableTestFilePath, projectPartId);
+    updateVisibilty(functionTestFilePath, variableTestFilePath);
+
+    updateVisibilty(variableTestFilePath, Utf8String());
+
+    ASSERT_FALSE(functionTranslationUnit.isUsedByCurrentEditor());
+    ASSERT_FALSE(functionTranslationUnit.isVisibleInEditor());
+    ASSERT_TRUE(variableTranslationUnit.isUsedByCurrentEditor());
+    ASSERT_TRUE(variableTranslationUnit.isVisibleInEditor());
+}
+
+void ClangIpcServer::SetUp()
+{
+    clangServer.addClient(&mockIpcClient);
+    registerProjectPart();
+    registerFiles();
+}
+
+void ClangIpcServer::registerFiles()
+{
+    RegisterTranslationUnitForEditorMessage message({FileContainer(functionTestFilePath, projectPartId, unsavedContent(unsavedTestFilePath), true),
+                                                     FileContainer(variableTestFilePath, projectPartId)});
+
+    clangServer.registerTranslationUnitsForEditor(message);
+}
+
+void ClangIpcServer::registerProjectPart()
+{
+    RegisterProjectPartsForEditorMessage message({ProjectPartContainer(projectPartId)});
+
+    clangServer.registerProjectPartsForEditor(message);
+}
+
+void ClangIpcServer::changeProjectPartArguments()
+{
+    RegisterProjectPartsForEditorMessage message({ProjectPartContainer(projectPartId, {Utf8StringLiteral("-DArgumentDefinition")})});
+
+    clangServer.registerProjectPartsForEditor(message);
+}
+
+void ClangIpcServer::changeProjectPartArgumentsToWrongValues()
+{
+    RegisterProjectPartsForEditorMessage message({ProjectPartContainer(projectPartId, {Utf8StringLiteral("-blah")})});
+
+    clangServer.registerProjectPartsForEditor(message);
+}
+
+void ClangIpcServer::updateVisibilty(const Utf8String &currentEditor, const Utf8String &additionalVisibleEditor)
+{
+    UpdateVisibleTranslationUnitsMessage message(currentEditor,
+                                                 {currentEditor, additionalVisibleEditor});
+
+    clangServer.updateVisibleTranslationUnits(message);
+}
+
+const Utf8String ClangIpcServer::unsavedContent(const QString &unsavedFilePath)
+{
+    QFile unsavedFileContentFile(unsavedFilePath);
+    bool isOpen = unsavedFileContentFile.open(QIODevice::ReadOnly | QIODevice::Text);
+    if (!isOpen)
+        ADD_FAILURE() << "File with the unsaved content cannot be opened!";
+
+    return Utf8String::fromByteArray(unsavedFileContentFile.readAll());
+}
+
 TEST_F(ClangIpcServer, TranslationUnitAfterUpdateNeedsReparseAndHasNewDiagnostics)
 {
     const auto fileContainer = FileContainer(functionTestFilePath, projectPartId,unsavedContent(unsavedTestFilePath), true, 1);
diff --git a/tests/unit/unittest/clientserverinprocesstest.cpp b/tests/unit/unittest/clientserverinprocesstest.cpp
index 87632e2c069..0b5bb27d114 100644
--- a/tests/unit/unittest/clientserverinprocesstest.cpp
+++ b/tests/unit/unittest/clientserverinprocesstest.cpp
@@ -53,6 +53,7 @@
 #include <translationunitdoesnotexistmessage.h>
 #include <unregisterunsavedfilesforeditormessage.h>
 #include <updatetranslationunitsforeditormessage.h>
+#include <updatevisibletranslationunitsmessage.h>
 #include <writemessageblock.h>
 
 #include <QBuffer>
@@ -232,6 +233,19 @@ TEST_F(ClientServerInProcess, SendUnregisterProjectPartsForEditorMessage)
     scheduleServerMessages();
 }
 
+TEST_F(ClientServerInProcess, UpdateVisibleTranslationUnitsMessage)
+{
+    ClangBackEnd::UpdateVisibleTranslationUnitsMessage message(Utf8StringLiteral(TESTDATA_DIR"/fileone.cpp"),
+                                                               {Utf8StringLiteral(TESTDATA_DIR"/fileone.cpp"),
+                                                                Utf8StringLiteral(TESTDATA_DIR"/filetwo.cpp")});
+
+    EXPECT_CALL(mockIpcServer, updateVisibleTranslationUnits(message))
+        .Times(1);
+
+    serverProxy.updateVisibleTranslationUnits(message);
+    scheduleServerMessages();
+}
+
 TEST_F(ClientServerInProcess, SendTranslationUnitDoesNotExistMessage)
 {
     ClangBackEnd::TranslationUnitDoesNotExistMessage message(fileContainer);
diff --git a/tests/unit/unittest/mockipcserver.h b/tests/unit/unittest/mockipcserver.h
index 31591c28c0d..83f9870b4d6 100644
--- a/tests/unit/unittest/mockipcserver.h
+++ b/tests/unit/unittest/mockipcserver.h
@@ -60,6 +60,8 @@ public:
                  void(const ClangBackEnd::CompleteCodeMessage &message));
     MOCK_METHOD1(requestDiagnostics,
                  void(const ClangBackEnd::RequestDiagnosticsMessage &message));
+    MOCK_METHOD1(updateVisibleTranslationUnits,
+                 void(const ClangBackEnd::UpdateVisibleTranslationUnitsMessage &message));
 };
 
 #endif // MOCKIPCSERVER_H