diff --git a/bin/app/data/gui/code_view/images/pattern.png b/bin/app/data/gui/code_view/images/pattern.png
new file mode 100644
index 00000000..2f424187
Binary files /dev/null and b/bin/app/data/gui/code_view/images/pattern.png differ
diff --git a/src/app/qt/element/QtCodeFile.cpp b/src/app/qt/element/QtCodeFile.cpp
index ea5863bb..83b0416d 100644
--- a/src/app/qt/element/QtCodeFile.cpp
+++ b/src/app/qt/element/QtCodeFile.cpp
@@ -4,6 +4,8 @@
 #include <QPushButton>
 #include <QVBoxLayout>
 
+#include "utility/file/FileSystem.h"
+#include "utility/logging/logging.h"
 #include "utility/messaging/type/MessageActivateFile.h"
 #include "utility/messaging/type/MessageShowFile.h"
 #include "utility/messaging/type/MessageShowSnippets.h"
@@ -19,6 +21,7 @@ QtCodeFile::QtCodeFile(const FilePath& filePath, QtCodeFileList* parent)
 	: QFrame(parent)
 	, m_parent(parent)
 	, m_filePath(filePath)
+	, m_updateTitleBarFunctor(std::bind(&QtCodeFile::doUpdateTitleBar, this))
 {
 	setObjectName("code_file");
 
@@ -28,15 +31,15 @@ QtCodeFile::QtCodeFile(const FilePath& filePath, QtCodeFileList* parent)
 	layout->setAlignment(Qt::AlignTop);
 	setLayout(layout);
 
-	QPushButton* titleWidget = new QPushButton(this);
-	titleWidget->setObjectName("title_widget");
-	layout->addWidget(titleWidget);
+	m_titleBar = new QPushButton(this);
+	m_titleBar->setObjectName("title_widget");
+	layout->addWidget(m_titleBar);
 
 	QHBoxLayout* titleLayout = new QHBoxLayout();
 	titleLayout->setMargin(0);
 	titleLayout->setSpacing(0);
 	titleLayout->setAlignment(Qt::AlignLeft);
-	titleWidget->setLayout(titleLayout);
+	m_titleBar->setLayout(titleLayout);
 
 	m_title = new QPushButton(filePath.fileName().c_str(), this);
 	m_title->setObjectName("title_label");
@@ -54,7 +57,7 @@ QtCodeFile::QtCodeFile(const FilePath& filePath, QtCodeFileList* parent)
 
 	titleLayout->addWidget(m_title);
 
-	titleWidget->setMinimumHeight(m_title->height() + 4);
+	m_titleBar->setMinimumHeight(m_title->height() + 4);
 
 	m_referenceCount = new QLabel(this);
 	m_referenceCount->setObjectName("references_label");
@@ -85,7 +88,7 @@ QtCodeFile::QtCodeFile(const FilePath& filePath, QtCodeFileList* parent)
 	m_snippetButton->setEnabled(false);
 	m_maximizeButton->setEnabled(false);
 
-	connect(titleWidget, SIGNAL(clicked()), this, SLOT(clickedTitleBar()));
+	connect(m_titleBar, SIGNAL(clicked()), this, SLOT(clickedTitleBar()));
 	connect(m_title, SIGNAL(clicked()), this, SLOT(clickedTitle()));
 	connect(m_minimizeButton, SIGNAL(clicked()), this, SLOT(clickedMinimizeButton()));
 	connect(m_snippetButton, SIGNAL(clicked()), this, SLOT(clickedSnippetButton()));
@@ -105,6 +108,12 @@ QtCodeFile::~QtCodeFile()
 {
 }
 
+void QtCodeFile::setModificationTime(TimePoint modificationTime)
+{
+	m_modificationTime = modificationTime;
+	updateTitleBar();
+}
+
 const FilePath& QtCodeFile::getFilePath() const
 {
 	return m_filePath;
@@ -386,6 +395,11 @@ void QtCodeFile::clickedMaximizeButton()
 	m_minimizePlaceholder->hide();
 }
 
+void QtCodeFile::handleMessage(MessageWindowFocus* message)
+{
+	updateTitleBar();
+}
+
 void QtCodeFile::updateSnippets()
 {
 	int maxDigits = 1;
@@ -420,3 +434,22 @@ void QtCodeFile::updateRefCount(int refCount)
 		m_referenceCount->hide();
 	}
 }
+
+void QtCodeFile::updateTitleBar()
+{
+	m_updateTitleBarFunctor();
+}
+
+void QtCodeFile::doUpdateTitleBar()
+{
+	// cannot use m_filePath.exists() here since it is only checked when FilePath is constructed.
+	if ((!FileSystem::exists(m_filePath.str())) ||
+		(FileSystem::getLastWriteTime(m_filePath) > m_modificationTime))
+	{
+		m_title->setStyleSheet("background-image: url(data/gui/code_view/images/pattern.png);");
+	}
+	else
+	{ 
+		m_title->setStyleSheet("");
+	}
+}
diff --git a/src/app/qt/element/QtCodeFile.h b/src/app/qt/element/QtCodeFile.h
index 7a938c65..bde81574 100644
--- a/src/app/qt/element/QtCodeFile.h
+++ b/src/app/qt/element/QtCodeFile.h
@@ -8,7 +8,11 @@
 #include <QFrame>
 
 #include "utility/file/FilePath.h"
+#include "utility/TimePoint.h"
 #include "utility/types.h"
+#include "utility/messaging/MessageListener.h"
+#include "utility/messaging/type/MessageWindowFocus.h"
+#include "qt/utility/QtThreadedFunctor.h"
 
 class QLabel;
 class QPushButton;
@@ -19,6 +23,7 @@ class TokenLocationFile;
 
 class QtCodeFile
 	: public QFrame
+	, MessageListener<MessageWindowFocus>
 {
 	Q_OBJECT
 
@@ -26,6 +31,8 @@ public:
 	QtCodeFile(const FilePath& filePath, QtCodeFileList* parent);
 	virtual ~QtCodeFile();
 
+	void setModificationTime(TimePoint modificationTime);
+
 	const FilePath& getFilePath() const;
 	std::string getFileName() const;
 	Id getFocusedTokenId() const;
@@ -67,11 +74,18 @@ private slots:
 	void clickedMaximizeButton();
 
 private:
+	virtual void handleMessage(MessageWindowFocus* message);
+
 	void updateSnippets();
 	void updateRefCount(int refCount);
+	void updateTitleBar();
+	void doUpdateTitleBar();
+
+	QtThreadedFunctor<> m_updateTitleBarFunctor;
 
 	QtCodeFileList* m_parent;
 
+	QPushButton* m_titleBar;
 	QPushButton* m_title;
 	QLabel* m_referenceCount;
 
@@ -85,6 +99,7 @@ private:
 	QWidget* m_minimizePlaceholder;
 
 	const FilePath m_filePath;
+	TimePoint m_modificationTime;
 	std::shared_ptr<TokenLocationFile> m_locationFile;
 };
 
diff --git a/src/app/qt/element/QtCodeFileList.cpp b/src/app/qt/element/QtCodeFileList.cpp
index 13c49fd2..9f191603 100644
--- a/src/app/qt/element/QtCodeFileList.cpp
+++ b/src/app/qt/element/QtCodeFileList.cpp
@@ -47,6 +47,7 @@ void QtCodeFileList::addCodeSnippet(
 	const std::string& code,
 	std::shared_ptr<TokenLocationFile> locationFile,
 	int refCount,
+	TimePoint modificationTime,
 	bool insert
 ){
 	QtCodeFile* file = getFile(locationFile);
@@ -60,12 +61,14 @@ void QtCodeFileList::addCodeSnippet(
 	{
 		file->addCodeSnippet(startLineNumber, title, titleId, code, locationFile, refCount);
 	}
+	file->setModificationTime(modificationTime);
 }
 
-void QtCodeFileList::addFile(std::shared_ptr<TokenLocationFile> locationFile, int refCount)
+void QtCodeFileList::addFile(std::shared_ptr<TokenLocationFile> locationFile, int refCount, TimePoint modificationTime)
 {
 	QtCodeFile* file = getFile(locationFile);
 	file->setLocationFile(locationFile, refCount);
+	file->setModificationTime(modificationTime);
 }
 
 void QtCodeFileList::clearCodeSnippets()
diff --git a/src/app/qt/element/QtCodeFileList.h b/src/app/qt/element/QtCodeFileList.h
index 8025c313..9a369026 100644
--- a/src/app/qt/element/QtCodeFileList.h
+++ b/src/app/qt/element/QtCodeFileList.h
@@ -7,6 +7,7 @@
 #include <QFrame>
 #include <QScrollArea>
 
+#include "utility/TimePoint.h"
 #include "utility/types.h"
 
 class QtCodeFile;
@@ -33,10 +34,11 @@ public:
 		const std::string& code,
 		std::shared_ptr<TokenLocationFile> locationFile,
 		int refCount,
+		TimePoint modificationTime,
 		bool insert = false
 	);
 
-	void addFile(std::shared_ptr<TokenLocationFile> locationFile, int refCount);
+	void addFile(std::shared_ptr<TokenLocationFile> locationFile, int refCount, TimePoint modificationTime);
 
 	void clearCodeSnippets();
 
diff --git a/src/app/qt/view/QtCodeView.cpp b/src/app/qt/view/QtCodeView.cpp
index 0cd87b97..fec7f032 100644
--- a/src/app/qt/view/QtCodeView.cpp
+++ b/src/app/qt/view/QtCodeView.cpp
@@ -96,7 +96,7 @@ void QtCodeView::doShowCodeSnippets(const std::vector<CodeSnippetParams>& snippe
 	{
 		if (params.isCollapsed)
 		{
-			m_widget->addFile(params.locationFile, params.refCount);
+			m_widget->addFile(params.locationFile, params.refCount, params.modificationTime);
 		}
 		else
 		{
@@ -106,7 +106,8 @@ void QtCodeView::doShowCodeSnippets(const std::vector<CodeSnippetParams>& snippe
 				params.titleId,
 				params.code,
 				params.locationFile,
-				params.refCount
+				params.refCount,
+				params.modificationTime
 			);
 		}
 	}
@@ -116,15 +117,16 @@ void QtCodeView::doShowCodeSnippets(const std::vector<CodeSnippetParams>& snippe
 
 void QtCodeView::doAddCodeSnippets(const std::vector<CodeSnippetParams>& snippets)
 {
-	for (const CodeSnippetParams& snippet : snippets)
+	for (const CodeSnippetParams& params : snippets)
 	{
 		m_widget->addCodeSnippet(
-			snippet.startLineNumber,
-			snippet.title,
-			snippet.titleId,
-			snippet.code,
-			snippet.locationFile,
-			snippet.refCount,
+			params.startLineNumber,
+			params.title,
+			params.titleId,
+			params.code,
+			params.locationFile,
+			params.refCount,
+			params.modificationTime,
 			true
 		);
 	}
@@ -134,7 +136,7 @@ void QtCodeView::doAddCodeSnippets(const std::vector<CodeSnippetParams>& snippet
 
 void QtCodeView::doShowCodeFile(const CodeSnippetParams& params)
 {
-	m_widget->addCodeSnippet(1, params.title, 0, params.code, params.locationFile, -1);
+	m_widget->addCodeSnippet(1, params.title, 0, params.code, params.locationFile, -1, params.modificationTime);
 }
 
 void QtCodeView::doShowFirstActiveSnippet()
diff --git a/src/lib/CMakeLists.txt b/src/lib/CMakeLists.txt
index 0c8bac6f..1f0320fc 100644
--- a/src/lib/CMakeLists.txt
+++ b/src/lib/CMakeLists.txt
@@ -302,6 +302,8 @@ add_files(
 	utility/ConfigManager.cpp
 	utility/ConfigManager.h
 	utility/Property.h
+	utility/TimePoint.cpp
+	utility/TimePoint.h
 	utility/types.h
 	utility/utility.cpp
 	utility/utility.h
diff --git a/src/lib/component/controller/CodeController.cpp b/src/lib/component/controller/CodeController.cpp
index d2c995a1..d5d262d9 100644
--- a/src/lib/component/controller/CodeController.cpp
+++ b/src/lib/component/controller/CodeController.cpp
@@ -121,6 +121,7 @@ void CodeController::handleMessage(MessageShowFile* message)
 	std::shared_ptr<TextAccess> textAccess = m_storageAccess->getFileContent(message->filePath);
 	params.code = textAccess->getText();
 
+	params.modificationTime = m_storageAccess->getFileModificationTime(message->filePath);
 	params.locationFile = m_storageAccess->getTokenLocationsForFile(message->filePath.str());
 
 	getView()->showCodeFile(params);
@@ -194,6 +195,7 @@ std::vector<CodeView::CodeSnippetParams> CodeController::getSnippetsForActiveTok
 				CodeView::CodeSnippetParams params;
 				params.locationFile = file;
 				params.refCount = file->getUnscopedStartTokenLocationCount();
+				params.modificationTime = m_storageAccess->getFileModificationTime(file->getFilePath());
 
 				params.isCollapsed = true;
 				snippets.push_back(params);
@@ -259,6 +261,8 @@ std::vector<CodeView::CodeSnippetParams> CodeController::getSnippetsForFile(std:
 		params.refCount = file->getUnscopedStartTokenLocationCount();
 		params.startLineNumber = std::max<int>(1, range.start.row - (range.start.strong ? 0 : snippetExpandRange));
 		params.endLineNumber = std::min<int>(textAccess->getLineCount(), range.end.row + (range.end.strong ? 0 : snippetExpandRange));
+		params.modificationTime = m_storageAccess->getFileModificationTime(file->getFilePath());
+
 
 		std::shared_ptr<TokenLocationFile> tempFile =
 			m_storageAccess->getTokenLocationsForLinesInFile(file->getFilePath().str(), params.startLineNumber, params.endLineNumber);
diff --git a/src/lib/component/view/CodeView.h b/src/lib/component/view/CodeView.h
index 17d0eb44..413342ca 100644
--- a/src/lib/component/view/CodeView.h
+++ b/src/lib/component/view/CodeView.h
@@ -5,6 +5,7 @@
 
 #include "component/view/View.h"
 #include "data/location/TokenLocationFile.h"
+#include "utility/TimePoint.h"
 #include "utility/types.h"
 
 class CodeController;
@@ -26,6 +27,7 @@ public:
 		std::string code;
 
 		Id titleId;
+		TimePoint modificationTime;
 
 		std::shared_ptr<TokenLocationFile> locationFile;
 
diff --git a/src/lib/data/Storage.cpp b/src/lib/data/Storage.cpp
index 94eba30f..1aa3cdd4 100644
--- a/src/lib/data/Storage.cpp
+++ b/src/lib/data/Storage.cpp
@@ -5,6 +5,7 @@
 
 #include "utility/file/FileSystem.h"
 #include "utility/logging/logging.h"
+#include "utility/TimePoint.h"
 #include "utility/utility.h"
 #include "utility/utilityString.h"
 
@@ -1219,6 +1220,11 @@ std::shared_ptr<TextAccess> Storage::getFileContent(const FilePath& filePath) co
 	return m_sqliteStorage.getFileContentByPath(filePath.str());
 }
 
+TimePoint Storage::getFileModificationTime(const FilePath& filePath) const
+{
+	return TimePoint(m_sqliteStorage.getFileByPath(filePath.str()).modificationTime);
+}
+
 Id Storage::addNodeHierarchy(Node::NodeType nodeType, NameHierarchy nameHierarchy, bool defined, bool distinct)
 {
 	std::vector<Id> nameIds = addNameHierarchyElements(nameHierarchy);
diff --git a/src/lib/data/Storage.h b/src/lib/data/Storage.h
index abd16a8d..c59b24f3 100644
--- a/src/lib/data/Storage.h
+++ b/src/lib/data/Storage.h
@@ -161,8 +161,7 @@ public:
 	virtual std::shared_ptr<TokenLocationFile> getTokenLocationOfParentScope(const TokenLocation* child) const;
 
 	virtual std::shared_ptr<TextAccess> getFileContent(const FilePath& filePath) const;
-
-
+	virtual TimePoint getFileModificationTime(const FilePath& filePath) const;
 
 private:
 	Id addNodeHierarchy(Node::NodeType nodeType, NameHierarchy nameHierarchy, bool defined, bool distinct = false);
diff --git a/src/lib/data/access/StorageAccess.h b/src/lib/data/access/StorageAccess.h
index 2047ca77..8463879c 100644
--- a/src/lib/data/access/StorageAccess.h
+++ b/src/lib/data/access/StorageAccess.h
@@ -17,6 +17,7 @@ class TextAccess;
 class TokenLocation;
 class TokenLocationCollection;
 class TokenLocationFile;
+class TimePoint;
 
 class StorageAccess
 {
@@ -56,6 +57,7 @@ public:
 	virtual std::shared_ptr<TokenLocationFile> getTokenLocationOfParentScope(const TokenLocation* child) const = 0;
 
 	virtual std::shared_ptr<TextAccess> getFileContent(const FilePath& filePath) const = 0;
+	virtual TimePoint getFileModificationTime(const FilePath& filePath) const = 0;
 };
 
 #endif // STORAGE_ACCESS_H
diff --git a/src/lib/data/access/StorageAccessProxy.cpp b/src/lib/data/access/StorageAccessProxy.cpp
index 6cd5218e..de5b5f01 100644
--- a/src/lib/data/access/StorageAccessProxy.cpp
+++ b/src/lib/data/access/StorageAccessProxy.cpp
@@ -6,6 +6,7 @@
 
 #include "utility/logging/logging.h"
 #include "utility/file/FileInfo.h"
+#include "utility/TimePoint.h"
 
 StorageAccessProxy::StorageAccessProxy()
 	: m_subject(nullptr)
@@ -243,3 +244,13 @@ std::shared_ptr<TextAccess> StorageAccessProxy::getFileContent(const FilePath& f
 
 	return nullptr;
 }
+
+TimePoint StorageAccessProxy::getFileModificationTime(const FilePath& filePath) const
+{
+	if (hasSubject())
+	{
+		return m_subject->getFileModificationTime(filePath);
+	}
+
+	return TimePoint(boost::posix_time::not_a_date_time);
+}
diff --git a/src/lib/data/access/StorageAccessProxy.h b/src/lib/data/access/StorageAccessProxy.h
index 24b892fd..4b434afb 100644
--- a/src/lib/data/access/StorageAccessProxy.h
+++ b/src/lib/data/access/StorageAccessProxy.h
@@ -47,6 +47,7 @@ public:
 	virtual std::shared_ptr<TokenLocationFile> getTokenLocationOfParentScope(const TokenLocation* child) const;
 
 	virtual std::shared_ptr<TextAccess> getFileContent(const FilePath& filePath) const;
+	virtual TimePoint getFileModificationTime(const FilePath& filePath) const;
 
 private:
 	StorageAccess* m_subject;
diff --git a/src/lib/utility/TimePoint.cpp b/src/lib/utility/TimePoint.cpp
new file mode 100644
index 00000000..9d7e37aa
--- /dev/null
+++ b/src/lib/utility/TimePoint.cpp
@@ -0,0 +1,21 @@
+#include "TimePoint.h"
+
+TimePoint::TimePoint()
+	: m_time(boost::posix_time::not_a_date_time)
+{
+}
+
+TimePoint::TimePoint(boost::posix_time::ptime t)
+	: m_time(t)
+{
+}
+
+//TimePoint::TimePoint(time_t t)
+//{
+// needs an implementation
+//}
+
+TimePoint::TimePoint(std::string s)
+{
+	m_time = boost::posix_time::time_from_string(s);
+}
diff --git a/src/lib/utility/TimePoint.h b/src/lib/utility/TimePoint.h
new file mode 100644
index 00000000..53086a6c
--- /dev/null
+++ b/src/lib/utility/TimePoint.h
@@ -0,0 +1,25 @@
+#ifndef TIME_POINT_H
+#define TIME_POINT_H
+
+#include "boost/date_time/posix_time/posix_time.hpp"
+
+class TimePoint
+{
+public:
+	TimePoint();
+	TimePoint(boost::posix_time::ptime t);
+	//TimePoint(time_t t);
+	TimePoint(std::string s);
+
+	inline bool operator==(const TimePoint& rhs){ return m_time == rhs.m_time; }
+	inline bool operator!=(const TimePoint& rhs){ return m_time != rhs.m_time; }
+	inline bool operator<(const TimePoint& rhs){ return m_time < rhs.m_time; }
+	inline bool operator>(const TimePoint& rhs){ return m_time > rhs.m_time; }
+	inline bool operator<=(const TimePoint& rhs){ return m_time <= rhs.m_time; }
+	inline bool operator>=(const TimePoint& rhs){ return m_time >= rhs.m_time; }
+
+private:
+	boost::posix_time::ptime m_time;
+};
+
+#endif // TIME_POINT_H
diff --git a/src/lib/utility/file/FileSystem.cpp b/src/lib/utility/file/FileSystem.cpp
index e3c07d79..a75b5d71 100644
--- a/src/lib/utility/file/FileSystem.cpp
+++ b/src/lib/utility/file/FileSystem.cpp
@@ -94,6 +94,17 @@ std::vector<FileInfo> FileSystem::getFileInfosFromPaths(
 	return files;
 }
 
+TimePoint FileSystem::getLastWriteTime(const FilePath& filePath)
+{
+	boost::posix_time::ptime lastWriteTime;
+	if (FileSystem::exists(filePath.str()))
+	{
+		std::time_t t = boost::filesystem::last_write_time(filePath.path());
+		lastWriteTime = boost::posix_time::from_time_t(t);
+	}
+	return TimePoint(lastWriteTime);
+}
+
 std::string FileSystem::getTimeStringNow() // TODO: move to utility
 {
 	return boost::posix_time::to_iso_string(boost::posix_time::second_clock::universal_time());
diff --git a/src/lib/utility/file/FileSystem.h b/src/lib/utility/file/FileSystem.h
index 8df7936f..79eebb5a 100644
--- a/src/lib/utility/file/FileSystem.h
+++ b/src/lib/utility/file/FileSystem.h
@@ -5,6 +5,7 @@
 #include <vector>
 
 #include "utility/file/FileInfo.h"
+#include "utility/TimePoint.h"
 
 class FileSystem
 {
@@ -19,6 +20,7 @@ public:
 	static std::vector<FileInfo> getFileInfosFromPaths(
 		const std::vector<FilePath>& paths, const std::vector<std::string>& fileExtensions);
 
+	static TimePoint getLastWriteTime(const FilePath& filePath);
 	static std::string getTimeStringNow();
 
 	static std::vector<FilePath> getSubDirectories(const FilePath& path);