ui: Change screen scaling on Linux (issue #518, #523)

* Set environment variables QT_AUTO_SCREEN_SCALE_FACTOR and QT_SCALE_FACTOR on Linux on app start
* Added ScreenAutoScaling and ScreenScaleFactor to ApplicationSettings with dropdown boxes in the preferences
  only visible on Linux
* Removed QtFontPicker and QtTextEncodingPicker
* Moved logging into preferences category "output"

fortune cookie message = You will have a peace of mind when you talk to an old friend

bin/app/user/ApplicationSettings_template.xml

@@ -29,10 +29,16 @@
 		<scroll_speed><!-- DECIMAL: multiplier for default scroll speed in views --></scroll_speed>
 
 		<logging_enabled><!-- BOOL: define if console and file logging is enabled --></logging_enabled>
+		<verbose_indexer_logging_enabled><!-- BOOL: define if verbose indexer logging is enabled --></verbose_indexer_logging_enabled>
 
 		<graph_controls_visible><!-- BOOL: define if the graph controls are visible or collapsed --></graph_controls_visible>
 	</application>
 
+	<screen>
+		<auto_scaling><!-- INTEGER: 0 or 1 if auto scaling is enabled, -1 for system setting --></auto_scaling>
+		<scale_factor><!-- DECIMAL: defines highDPI scale factor, < 0 uses system setting --></scale_factor>
+	</screen>
+
 	<indexing>
 		<indexer_thread_count><!-- INTEGER: number of threads indexing the source code --></indexer_thread_count>
 		<multi_process_indexing><!-- BOOL: use different processes instead of threads during indexing --></multi_process_indexing>

src/app/main.cpp

@@ -187,15 +187,17 @@ QCoreApplication* createApplication(int &argc, char *argv[], bool noGUI = false)
 
 int main(int argc, char *argv[])
 {
-#ifdef __linux__
-	if (std::getenv("SOURCETRAIL_VIA_SCRIPT") == nullptr)
+	if (utility::getOsType() == OS_LINUX && std::getenv("SOURCETRAIL_VIA_SCRIPT") == nullptr)
 	{
 		std::cout << "ERROR: Please run Sourcetrail via the Sourcetrail.sh script!" << std::endl;
 	}
-#endif
 
 	QApplication::setApplicationName("Sourcetrail");
-	QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling, true);
+
+	if (utility::getOsType() != OS_LINUX)
+	{
+		QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling, true);
+	}
 
 	Version version(
 		VERSION_YEAR,

src/lib/settings/ApplicationSettings.cpp

@@ -225,6 +225,26 @@ void ApplicationSettings::setGraphControlsVisible(bool visible)
 	setValue<bool>("application/graph_controls_visible", visible);
 }
 
+int ApplicationSettings::getScreenAutoScaling() const
+{
+	return getValue<int>("screen/auto_scaling", 1);
+}
+
+void ApplicationSettings::setScreenAutoScaling(int autoScaling)
+{
+	setValue<int>("screen/auto_scaling", autoScaling);
+}
+
+float ApplicationSettings::getScreenScaleFactor() const
+{
+	return getValue<float>("screen/scale_factor", -1.0);
+}
+
+void ApplicationSettings::setScreenScaleFactor(float scaleFactor)
+{
+	setValue<float>("screen/scale_factor", scaleFactor);
+}
+
 bool ApplicationSettings::getLoggingEnabled() const
 {
 	return getValue<bool>("application/logging_enabled", false);
@@ -265,16 +285,6 @@ int ApplicationSettings::getLogFilter() const
 	return getValue<int>("application/log_filter", Logger::LOG_WARNINGS | Logger::LOG_ERRORS);
 }
 
-std::vector<FilePath> ApplicationSettings::getIndexingFilePaths() const
-{
-	return getPathValues("application/state/indexing_paths/indexing_path");
-}
-
-bool ApplicationSettings::setIndexingFilePaths(const std::vector<FilePath>& indexingFiles)
-{
-	return setPathValues("application/state/indexing_paths/indexing_path", indexingFiles);
-}
-
 int ApplicationSettings::getIndexerThreadCount() const
 {
 	return getValue<int>("indexing/indexer_thread_count", 0);

src/lib/settings/ApplicationSettings.h

@@ -62,6 +62,13 @@ public:
 	bool getGraphControlsVisible() const;
 	void setGraphControlsVisible(bool visible);
 
+	// screen
+	int getScreenAutoScaling() const;
+	void setScreenAutoScaling(int autoScaling);
+
+	float getScreenScaleFactor() const;
+	void setScreenScaleFactor(float scaleFactor);
+
 	// logging
 	bool getLoggingEnabled() const;
 	void setLoggingEnabled(bool loggingEnabled);
@@ -75,9 +82,6 @@ public:
 	int getStatusFilter() const;
 	void setStatusFilter(int mask);
 
-	std::vector<FilePath> getIndexingFilePaths() const;
-	bool setIndexingFilePaths(const std::vector<FilePath>& indexingFiles);
-
 	// indexing
 	int getIndexerThreadCount() const;
 	void setIndexerThreadCount(const int count);

src/lib/utility/ConfigManager.cpp

@@ -66,7 +66,9 @@ bool ConfigManager::getValue(const std::string& key, float& value) const
 	std::string valueString;
 	if (getValue(key, valueString))
 	{
-		value = static_cast<float>(atof(valueString.c_str()));
+		std::stringstream ss;
+		ss << valueString;
+		ss >> value;
 		return true;
 	}
 	return false;
@@ -91,8 +93,8 @@ bool ConfigManager::getValues(const std::string& key, std::vector<std::string>&
 
 	if (ret.first != ret.second)
 	{
-		std::multimap<std::string, std::string>::const_iterator cit = ret.first;
-		for(;cit!=ret.second;++cit)
+		for (std::multimap<std::string, std::string>::const_iterator cit = ret.first;
+			cit != ret.second; ++cit)
 		{
 			values.push_back(cit->second);
 		}
@@ -171,7 +173,9 @@ void ConfigManager::setValue(const std::string& key, const int value)
 
 void ConfigManager::setValue(const std::string& key, const float value)
 {
-	setValue(key, std::to_string(value));
+	std::stringstream ss;
+	ss << value;
+	setValue(key, ss.str());
 }
 
 void ConfigManager::setValue(const std::string& key, const bool value)
@@ -183,11 +187,11 @@ void ConfigManager::setValues(const std::string& key, const std::vector<std::str
 {
 	std::multimap<std::string, std::string>::iterator it = m_values.find(key);
 
-	if(it != m_values.end())
+	if (it != m_values.end())
 	{
 		m_values.erase(key);
 	}
-	for(std::string s : values)
+	for (std::string s : values)
 	{
 		m_values.emplace(key, s);
 	}
@@ -196,7 +200,7 @@ void ConfigManager::setValues(const std::string& key, const std::vector<std::str
 void ConfigManager::setValues(const std::string& key, const std::vector<int>& values)
 {
 	std::vector<std::string> stringValues;
-	for(int i : values)
+	for (int i : values)
 	{
 		stringValues.push_back(std::to_string(i));
 	}
@@ -206,7 +210,7 @@ void ConfigManager::setValues(const std::string& key, const std::vector<int>& va
 void ConfigManager::setValues(const std::string& key, const std::vector<float>& values)
 {
 	std::vector<std::string> stringValues;
-	for(float f : values)
+	for (float f : values)
 	{
 		stringValues.push_back(std::to_string(f));
 	}
@@ -216,7 +220,7 @@ void ConfigManager::setValues(const std::string& key, const std::vector<float>&
 void ConfigManager::setValues(const std::string& key, const std::vector<bool>& values)
 {
 	std::vector<std::string> stringValues;
-	for(bool b : values)
+	for (bool b : values)
 	{
 		stringValues.push_back(std::string(b ? "1" : "0"));
 	}
@@ -267,7 +271,7 @@ bool ConfigManager::load(const std::shared_ptr<TextAccess> textAccess)
 	{
 		TiXmlHandle docHandle(&doc);
 		TiXmlNode *rootNode = docHandle.FirstChild("config").ToNode();
-		if(rootNode == nullptr)
+		if (rootNode == nullptr)
 		{
 			LOG_ERROR("No rootelement 'config' in the configfile");
 			return false;
@@ -316,7 +320,7 @@ bool ConfigManager::createXmlDocument(bool saveAsFile, const std::string filepat
 	TiXmlElement *root = new TiXmlElement("config");
 	doc.LinkEndChild(root);
 
-	for(std::multimap<std::string,std::string>::iterator it = m_values.begin(); it != m_values.end(); ++it)
+	for (std::multimap<std::string,std::string>::iterator it = m_values.begin(); it != m_values.end(); ++it)
 	{
 		if (!it->first.size() || !it->second.size())
 		{
@@ -345,7 +349,7 @@ bool ConfigManager::createXmlDocument(bool saveAsFile, const std::string filepat
 		child->LinkEndChild(text);
 	}
 
-	if(saveAsFile)
+	if (saveAsFile)
 	{
 		success = doc.SaveFile(filepath.c_str());
 	}

src/lib_gui/CMakeLists.txt

@@ -34,8 +34,6 @@ add_files(
 	qt/element/QtCodeSnippet.h
 	qt/element/QtDirectoryListBox.cpp
 	qt/element/QtDirectoryListBox.h
-	qt/element/QtFontPicker.cpp
-	qt/element/QtFontPicker.h
 	qt/element/QtHelpButton.cpp
 	qt/element/QtHelpButton.h
 	qt/element/QtHistoryList.cpp
@@ -60,8 +58,6 @@ add_files(
 	qt/element/QtStatusBar.h
 	qt/element/QtTable.cpp
 	qt/element/QtTable.h
-	qt/element/QtTextEncodingPicker.cpp
-	qt/element/QtTextEncodingPicker.h
 	qt/element/QtTooltip.cpp
 	qt/element/QtTooltip.h
 	qt/element/QtUndoRedo.cpp

src/lib_gui/platform_includes/includesLinux.h

@@ -11,8 +11,35 @@
 #include "utility/ResourcePaths.h"
 #include "utility/UserPaths.h"
 
+#include "settings/ApplicationSettings.h"
+
 void setupPlatform(int argc, char *argv[])
 {
+	std::string home = std::getenv("HOME");
+	UserPaths::setUserDataPath(FilePath(home + "/.config/sourcetrail/"));
+
+	// Set QT screen scaling factor
+	ApplicationSettings appSettings;
+	appSettings.load(UserPaths::getAppSettingsPath());
+
+	qputenv("QT_AUTO_SCREEN_SCALE_FACTOR_SOURCETRAIL", qgetenv("QT_AUTO_SCREEN_SCALE_FACTOR"));
+	qputenv("QT_SCALE_FACTOR_SOURCETRAIL", qgetenv("QT_SCALE_FACTOR"));
+
+	int autoScaling = appSettings.getScreenAutoScaling();
+	if (autoScaling != -1)
+	{
+		QByteArray bytes;
+		bytes.setNum(autoScaling);
+		qputenv("QT_AUTO_SCREEN_SCALE_FACTOR", bytes);
+	}
+
+	float scaleFactor = appSettings.getScreenScaleFactor();
+	if (scaleFactor > 0.0)
+	{
+		QByteArray bytes;
+		bytes.setNum(scaleFactor);
+		qputenv("QT_SCALE_FACTOR", bytes);
+	}
 }
 
 void setupApp(int argc, char *argv[])
@@ -26,8 +53,6 @@ void setupApp(int argc, char *argv[])
 	QDir coatiDir((userdir + "/.config/coati").c_str());
 	userdir.append("/.config/sourcetrail/");
 
-	UserPaths::setUserDataPath(FilePath(userdir));
-
 	QString userDataPath(userdir.c_str());
 	QDir dataDir(userdir.c_str());
 	if (!dataDir.exists())

src/lib_gui/platform_includes/includesMac.h

@@ -12,10 +12,11 @@
 #include "utility/ResourcePaths.h"
 #include "utility/UserPaths.h"
 
-bool appIsMacBundle = false;
 
 void setupPlatform(int argc, char *argv[])
 {
+	UserPaths::setUserDataPath(FilePath("./user/"));
+
 	// ----------------------------------------------------------------------------
 	// This makes relative paths work in C++ in Xcode by changing directory to the Resources folder inside the .app bundle
 	// source: http://stackoverflow.com/questions/516200/relative-paths-not-working-in-xcode-c
@@ -81,19 +82,12 @@ void setupPlatform(int argc, char *argv[])
 
 	// ----------------------------------------------------------------------------
 	UserPaths::setUserDataPath(FilePath(dataPath.toStdString() + "/"));
-
-	appIsMacBundle = true;
 }
 
 void setupApp(int argc, char *argv[])
 {
 	FilePath path(QDir::currentPath().toStdString());
 	AppPath::setAppPath(path.getAbsolute().str() + "/");
-
-	if (!appIsMacBundle)
-	{
-		UserPaths::setUserDataPath(FilePath("./user/"));
-	}
 }
 
 #endif // INCLUDES_MAC_H

src/lib_gui/qt/element/QtFontPicker.cpp

@@ -1,34 +0,0 @@
-#include "qt/element/QtFontPicker.h"
-
-#include <QHBoxLayout>
-#include <QFontComboBox>
-
-QtFontPicker::QtFontPicker(QWidget *parent)
-	: QWidget(parent)
-{
-	setObjectName("picker");
-
-	QBoxLayout* layout = new QHBoxLayout();
-	layout->setSpacing(0);
-	layout->setContentsMargins(1, 1, 1, 1);
-	layout->setAlignment(Qt::AlignTop);
-
-	m_box = new QFontComboBox();
-	m_box->setFontFilters(QFontComboBox::MonospacedFonts);
-	m_box->setEditable(false);
-
-	layout->addWidget(m_box);
-
-	setLayout(layout);
-	setSizePolicy(sizePolicy().horizontalPolicy(), QSizePolicy::Fixed);
-}
-
-QString QtFontPicker::getText()
-{
-	return m_box->currentText();
-}
-
-void QtFontPicker::setText(QString text)
-{
-	m_box->setCurrentText(text);
-}

src/lib_gui/qt/element/QtFontPicker.h

@@ -1,23 +0,0 @@
-#ifndef QT_FONT_PICKER_H
-#define QT_FONT_PICKER_H
-
-#include <QWidget>
-
-class QFontComboBox;
-
-class QtFontPicker
-	: public QWidget
-{
-	Q_OBJECT
-
-public:
-	QtFontPicker(QWidget *parent);
-
-	QString getText();
-	void setText(QString text);
-
-private:
-	QFontComboBox* m_box;
-};
-
-#endif // QT_FONT_PICKER_H

src/lib_gui/qt/element/QtTextEncodingPicker.cpp

@@ -1,39 +0,0 @@
-#include "qt/element/QtTextEncodingPicker.h"
-
-#include <QHBoxLayout>
-#include <QTextCodec>
-#include <QFontComboBox>
-
-QtTextEncodingPicker::QtTextEncodingPicker(QWidget *parent)
-	: QWidget(parent)
-{
-	setObjectName("picker");
-
-	QBoxLayout* layout = new QHBoxLayout();
-	layout->setSpacing(0);
-	layout->setContentsMargins(1, 1, 1, 1);
-	layout->setAlignment(Qt::AlignTop);
-
-	m_box = new QComboBox();
-	for (int mib : QTextCodec::availableMibs())
-	{
-		m_box->addItem(QTextCodec::codecForMib(mib)->name());
-	}
-	m_box->setEditable(false);
-
-	layout->addWidget(m_box);
-
-	setLayout(layout);
-	setSizePolicy(sizePolicy().horizontalPolicy(), QSizePolicy::Fixed);
-}
-
-QString QtTextEncodingPicker::getText()
-{
-	return m_box->currentText();
-}
-
-void QtTextEncodingPicker::setText(QString text)
-{
-	m_box->setCurrentText(text);
-}
-

src/lib_gui/qt/element/QtTextEncodingPicker.h

@@ -1,23 +0,0 @@
-#ifndef QT_TEXT_ENCODING_PICKER_H
-#define QT_TEXT_ENCODING_PICKER_H
-
-#include <QWidget>
-
-class QComboBox;
-
-class QtTextEncodingPicker
-	: public QWidget
-{
-	Q_OBJECT
-
-public:
-	QtTextEncodingPicker(QWidget *parent);
-
-	QString getText();
-	void setText(QString text);
-
-private:
-	QComboBox* m_box;
-};
-
-#endif // QT_TEXT_ENCODING_PICKER_H

src/lib_gui/qt/window/QtPreferencesWindow.cpp

@@ -6,6 +6,7 @@
 #include "utility/messaging/type/MessageScrollSpeedChange.h"
 
 #include "Application.h"
+#include "component/view/DialogView.h"
 #include "qt/window/project_wizzard/QtProjectWizzardContentPaths.h"
 #include "qt/window/project_wizzard/QtProjectWizzardContentPreferences.h"
 #include "qt/window/project_wizzard/QtProjectWizzardContentGroup.h"
@@ -22,6 +23,9 @@ QtPreferencesWindow::QtPreferencesWindow(QWidget* parent)
 	m_appSettings.setSourcetrailPort(appSettings->getSourcetrailPort());
 	m_appSettings.setPluginPort(appSettings->getPluginPort());
 
+	m_appSettings.setScreenAutoScaling(appSettings->getScreenAutoScaling());
+	m_appSettings.setScreenScaleFactor(appSettings->getScreenScaleFactor());
+
 
 	QtProjectWizzardContentGroup* summary = new QtProjectWizzardContentGroup(this);
 	summary->setIsForm(true);
@@ -62,24 +66,39 @@ void QtPreferencesWindow::handleNext()
 
 	saveContent();
 
-	bool appSettingsChanged = !(m_appSettings == *ApplicationSettings::getInstance().get());
+	Application* app = Application::getInstance().get();
+	ApplicationSettings* appSettings = ApplicationSettings::getInstance().get();
 
-	if (m_appSettings.getScrollSpeed() != ApplicationSettings::getInstance()->getScrollSpeed())
+	bool needsRestart =
+		m_appSettings.getScreenAutoScaling() != appSettings->getScreenAutoScaling() ||
+		m_appSettings.getScreenScaleFactor() != appSettings->getScreenScaleFactor();
+
+	if (needsRestart)
 	{
-		MessageScrollSpeedChange(ApplicationSettings::getInstance()->getScrollSpeed()).dispatch();
+		app->getDialogView()->confirm(
+			"Please restart the application for all changes to take effect."
+		);
 	}
 
-	if (m_appSettings.getSourcetrailPort() != ApplicationSettings::getInstance()->getSourcetrailPort() ||
-		m_appSettings.getPluginPort() != ApplicationSettings::getInstance()->getPluginPort())
+
+	bool appSettingsChanged = !(m_appSettings == *appSettings);
+
+	if (m_appSettings.getScrollSpeed() != appSettings->getScrollSpeed())
+	{
+		MessageScrollSpeedChange(appSettings->getScrollSpeed()).dispatch();
+	}
+
+	if (m_appSettings.getSourcetrailPort() != appSettings->getSourcetrailPort() ||
+		m_appSettings.getPluginPort() != appSettings->getPluginPort())
 	{
 		MessagePluginPortChange().dispatch();
 	}
 
-	Application::getInstance()->loadSettings();
+	app->loadSettings();
 
 	if (appSettingsChanged)
 	{
-		Project* currentProject = Application::getInstance()->getCurrentProject().get();
+		Project* currentProject = app->getCurrentProject().get();
 		if (currentProject)
 		{
 			MessageLoadProject(currentProject->getProjectSettingsFilePath(), true).dispatch();

src/lib_gui/qt/window/project_wizzard/QtProjectWizzardContentPreferences.cpp

@@ -1,7 +1,12 @@
 #include "qt/window/project_wizzard/QtProjectWizzardContentPreferences.h"
 
-#include "qt/element/QtFontPicker.h"
-#include "qt/element/QtTextEncodingPicker.h"
+#include <QCheckBox>
+#include <QComboBox>
+#include <QFontComboBox>
+#include <QLabel>
+#include <QLineEdit>
+#include <QTextCodec>
+
 #include "qt/utility/utilityQt.h"
 #include "settings/ApplicationSettings.h"
 #include "utility/file/FileSystem.h"
@@ -17,8 +22,11 @@ QtProjectWizzardContentPreferences::QtProjectWizzardContentPreferences(
 	: QtProjectWizzardContent(window)
 	, m_oldColorSchemeIndex(-1)
 	, m_newColorSchemeIndex(-1)
+	, m_screenAutoScaling(nullptr)
+	, m_screenScaleFactor(nullptr)
 {
-	m_colorSchemePaths = FileSystem::getFilePathsFromDirectory(ResourcePaths::getColorSchemesPath(), std::vector<std::string>(1, ".xml"));
+	m_colorSchemePaths =
+		FileSystem::getFilePathsFromDirectory(ResourcePaths::getColorSchemesPath(), std::vector<std::string>(1, ".xml"));
 }
 
 QtProjectWizzardContentPreferences::~QtProjectWizzardContentPreferences()
@@ -37,10 +45,9 @@ void QtProjectWizzardContentPreferences::populate(QGridLayout* layout, int& row)
 	addTitle("USER INTERFACE", layout, row);
 
 	// font face
-	m_fontFace = new QtFontPicker(this);
-	m_fontFace->setObjectName("name");
-	m_fontFace->setAttribute(Qt::WA_MacShowFocusRect, 0);
-
+	m_fontFace = new QFontComboBox(this);
+	m_fontFace->setFontFilters(QFontComboBox::MonospacedFonts);
+	m_fontFace->setEditable(false);
 	addLabelAndWidget("Font Face", m_fontFace, layout, row);
 	row++;
 
@@ -51,12 +58,11 @@ void QtProjectWizzardContentPreferences::populate(QGridLayout* layout, int& row)
 	m_tabWidth = addComboBox("Tab Width", 1, 16, "", layout, row);
 
 	// text encoding
-	m_textEncoding = new QtTextEncodingPicker(this);
-	m_textEncoding->setObjectName("text encoding");
-	m_textEncoding->setAttribute(Qt::WA_MacShowFocusRect, 0);
-
-	addLabelAndWidget("Text Encoding", m_textEncoding, layout, row);
-	row++;
+	m_textEncoding = addComboBox("Text Encoding", "", layout, row);
+	for (int mib : QTextCodec::availableMibs())
+	{
+		m_textEncoding->addItem(QTextCodec::codecForMib(mib)->name());
+	}
 
 	// color scheme
 	m_colorSchemes = addComboBox("Color Scheme", "", layout, row);
@@ -64,7 +70,8 @@ void QtProjectWizzardContentPreferences::populate(QGridLayout* layout, int& row)
 	{
 		m_colorSchemes->insertItem(i, m_colorSchemePaths[i].withoutExtension().fileName().c_str());
 	}
-	connect(m_colorSchemes, static_cast<void (QComboBox::*)(int)>(&QComboBox::activated), this, &QtProjectWizzardContentPreferences::colorSchemeChanged);
+	connect(m_colorSchemes, static_cast<void (QComboBox::*)(int)>(&QComboBox::activated),
+		this, &QtProjectWizzardContentPreferences::colorSchemeChanged);
 
 	// animations
 	m_useAnimations = addCheckBox("Animations", "Enable animations",
@@ -74,22 +81,69 @@ void QtProjectWizzardContentPreferences::populate(QGridLayout* layout, int& row)
 	m_showBuiltinTypes = addCheckBox("Built-in Types", "Show built-in types in graph when referenced",
 		"<p>Enable display of referenced built-in types in the graph view.</p>", layout, row);
 
-	// logging
-	m_loggingEnabled = addCheckBox("Logging", "Enable console and file logging",
-		"<p>Show logs in the console and save this information in files.</p>", layout, row);
-	connect(m_loggingEnabled, &QCheckBox::clicked, this, &QtProjectWizzardContentPreferences::loggingEnabledChanged);
-
-	m_verboseIndexerLoggingEnabled = addCheckBox(
-		"Indexer Logging",
-		"Enable verbose indexer logging",
-		"<p>Enable additional logs of abstract syntax tree traversal during indexing. This information can help "
-		"tracking down crashes that occurr during indexing.</p>"
-		"<p><b>Warning</b>: This slows down indexing performance a lot.</p>",
-		layout, row
-	);
-
 	addGap(layout, row);
 
+
+	// Linux UI scale
+	if (utility::getOsType() == OS_LINUX)
+	{
+		// screen
+		addTitle("SCREEN", layout, row);
+
+		QLabel* hint = new QLabel("<changes need restart>");
+		hint->setStyleSheet("color: grey");
+		layout->addWidget(hint, row-1, QtProjectWizzardWindow::BACK_COL, Qt::AlignRight);
+
+		// auto scaling
+		m_screenAutoScalingInfoLabel = new QLabel("");
+		m_screenAutoScaling = addComboBoxWithWidgets(
+			"Auto Scaling to DPI",
+			"<p>Define if automatic scaling to screen DPI resolution is active. "
+			"This setting manipulates the environment flag QT_AUTO_SCREEN_SCALE_FACTOR of the Qt framework "
+			"(<a href=\"http://doc.qt.io/qt-5/highdpi.html\">http://doc.qt.io/qt-5/highdpi.html</a>). "
+			"Choose 'system' to stick to the setting of your current environment.</p>"
+			"<p>Changes to this setting require a restart of the application to take effect.</p>",
+			{ m_screenAutoScalingInfoLabel },
+			layout,
+			row
+		);
+		m_screenAutoScaling->addItem("system", -1);
+		m_screenAutoScaling->addItem("off", 0);
+		m_screenAutoScaling->addItem("on", 1);
+		connect(m_screenAutoScaling, static_cast<void (QComboBox::*)(int)>(&QComboBox::activated),
+			this, &QtProjectWizzardContentPreferences::uiAutoScalingChanges);
+
+		// scale factor
+		m_screenScaleFactorInfoLabel = new QLabel("");
+		m_screenScaleFactor = addComboBoxWithWidgets(
+			"Scale Factor",
+			"<p>Define a screen scale factor for the user interface of the application. "
+			"This setting manipulates the environment flag QT_SCALE_FACTOR of the Qt framework "
+			"(<a href=\"http://doc.qt.io/qt-5/highdpi.html\">http://doc.qt.io/qt-5/highdpi.html</a>). "
+			"Choose 'system' to stick to the setting of your current environment.</p>"
+			"<p>Changes to this setting require a restart of the application to take effect.</p>",
+			{ m_screenScaleFactorInfoLabel },
+			layout,
+			row
+		);
+		m_screenScaleFactor->addItem("system", -1.0);
+		m_screenScaleFactor->addItem("25%", 0.25);
+		m_screenScaleFactor->addItem("50%", 0.5);
+		m_screenScaleFactor->addItem("75%", 0.75);
+		m_screenScaleFactor->addItem("100%", 1.0);
+		m_screenScaleFactor->addItem("125%", 1.25);
+		m_screenScaleFactor->addItem("150%", 1.5);
+		m_screenScaleFactor->addItem("175%", 1.75);
+		m_screenScaleFactor->addItem("200%", 2.0);
+		m_screenScaleFactor->addItem("250%", 2.5);
+		m_screenScaleFactor->addItem("300%", 3.0);
+		m_screenScaleFactor->addItem("400%", 4.0);
+		connect(m_screenScaleFactor, static_cast<void (QComboBox::*)(int)>(&QComboBox::activated),
+			this, &QtProjectWizzardContentPreferences::uiScaleFactorChanges);
+
+		addGap(layout, row);
+	}
+
 	// Controls
 	addTitle("CONTROLS", layout, row);
 
@@ -112,6 +166,25 @@ void QtProjectWizzardContentPreferences::populate(QGridLayout* layout, int& row)
 
 	addGap(layout, row);
 
+	// output
+	addTitle("OUTPUT", layout, row);
+
+	// logging
+	m_loggingEnabled = addCheckBox("Logging", "Enable console and file logging",
+		"<p>Show logs in the console and save this information in files.</p>", layout, row);
+	connect(m_loggingEnabled, &QCheckBox::clicked, this, &QtProjectWizzardContentPreferences::loggingEnabledChanged);
+
+	m_verboseIndexerLoggingEnabled = addCheckBox(
+		"Indexer Logging",
+		"Enable verbose indexer logging",
+		"<p>Enable additional logs of abstract syntax tree traversal during indexing. This information can help "
+		"tracking down crashes that occurr during indexing.</p>"
+		"<p><b>Warning</b>: This slows down indexing performance a lot.</p>",
+		layout, row
+	);
+
+	addGap(layout, row);
+
 	// Network
 	addTitle("NETWORK", layout, row);
 
@@ -128,7 +201,8 @@ void QtProjectWizzardContentPreferences::populate(QGridLayout* layout, int& row)
 		"<p>Port number that Sourcetrail uses to listen for incoming messages from plugins.</p>", layout, row);
 
 	// Sourcetrail port
-	m_pluginPort = addLineEdit("Plugin Port", "<p>Port number that Sourcetrail uses to sends outgoing messages to plugins.</p>", layout, row);
+	m_pluginPort = addLineEdit("Plugin Port",
+		"<p>Port number that Sourcetrail uses to sends outgoing messages to plugins.</p>", layout, row);
 
 	addGap(layout, row);
 
@@ -136,38 +210,24 @@ void QtProjectWizzardContentPreferences::populate(QGridLayout* layout, int& row)
 	addTitle("INDEXING", layout, row);
 
 	// indexer threads
-	const int minThreadCount = 0;
-	const int maxThreadCount = 24;
-
-	m_threads = new QComboBox(this);
-	connect(m_threads, static_cast<void (QComboBox::*)(int)>(&QComboBox::activated), this, &QtProjectWizzardContentPreferences::indexerThreadsChanges);
-	for (int i = minThreadCount; i <= maxThreadCount; i++)
-	{
-		m_threads->insertItem(i, QString::number(i));
-	}
-
 	m_threadsInfoLabel = new QLabel("");
 	utility::setWidgetRetainsSpaceWhenHidden(m_threadsInfoLabel);
-
-	QHBoxLayout* hlayout = new QHBoxLayout();
-	hlayout->setContentsMargins(0, 0, 0, 0);
-	hlayout->addWidget(m_threads);
-	hlayout->addWidget(m_threadsInfoLabel);
-
-	QWidget* threadsWidget = new QWidget();
-	threadsWidget->setLayout(hlayout);
-
-	addLabelAndWidget("Indexer Threads", threadsWidget, layout, row, Qt::AlignLeft);
-	addHelpButton(
+	m_threads = addComboBoxWithWidgets(
 		"Indexer Threads",
+		0,
+		24,
 		"<p>Set the number of threads used to work on indexing your project in parallel.</p>"
 		"<p>When setting this value to 0 Sourcetrail tries to use the ideal thread count for your computer.</p>",
-		layout, row
+		{ m_threadsInfoLabel },
+		layout,
+		row
 	);
-	row++;
+	connect(m_threads, static_cast<void (QComboBox::*)(int)>(&QComboBox::activated),
+		this, &QtProjectWizzardContentPreferences::indexerThreadsChanges);
 
 	// multi process indexing
-	m_multiProcessIndexing = addCheckBox("Multi Process<br />C/C++ Indexing", "Run C/C++ indexer threads in different process",
+	m_multiProcessIndexing = addCheckBox("Multi Process<br />C/C++ Indexing",
+		"Run C/C++ indexer threads in different process",
 		"<p>Enable C/C++ indexer threads to run in different process.</p>"
 		"<p>This prevents the application from crashing due to unforseen exceptions while indexing.</p>",
 		layout, row);
@@ -201,12 +261,13 @@ void QtProjectWizzardContentPreferences::populate(QGridLayout* layout, int& row)
 			break;
 		}
 
-		const std::string javaArchitectureString = utility::getApplicationArchitectureType() == APPLICATION_ARCHITECTURE_X86_32 ? "32 Bit" : "64 Bit";
+		const std::string javaArchitectureString =
+			utility::getApplicationArchitectureType() == APPLICATION_ARCHITECTURE_X86_32 ? "32 Bit" : "64 Bit";
 
 		addLabelAndWidget(
 			("Java Path (" + javaArchitectureString + ")").c_str(),
-			m_javaPath, 
-			layout, 
+			m_javaPath,
+			layout,
 			row
 		);
 
@@ -247,7 +308,8 @@ void QtProjectWizzardContentPreferences::populate(QGridLayout* layout, int& row)
 		addHelpButton(
 			"JRE System Library",
 			"<p>Only required for indexing Java projects.</p>"
-			"<p>Add the jar files of your JRE System Library. These jars can be found inside your JRE install directory.</p>", layout, row);
+			"<p>Add the jar files of your JRE System Library. These jars can be found inside your JRE install directory.</p>",
+			layout, row);
 
 		m_jreSystemLibraryPaths = new QtDirectoryListBox(this, title);
 
@@ -296,12 +358,12 @@ void QtProjectWizzardContentPreferences::load()
 {
 	ApplicationSettings* appSettings = ApplicationSettings::getInstance().get();
 
-	m_fontFace->setText(QString::fromStdString(appSettings->getFontName()));
+	m_fontFace->setCurrentText(QString::fromStdString(appSettings->getFontName()));
 
 	m_fontSize->setCurrentIndex(appSettings->getFontSize() - appSettings->getFontSizeMin());
 	m_tabWidth->setCurrentIndex(appSettings->getCodeTabWidth() - 1);
 
-	m_textEncoding->setText(QString::fromStdString(appSettings->getTextEncoding()));
+	m_textEncoding->setCurrentText(QString::fromStdString(appSettings->getTextEncoding()));
 
 	FilePath colorSchemePath = appSettings->getColorSchemePath();
 	for (size_t i = 0; i < m_colorSchemePaths.size(); i++)
@@ -318,13 +380,25 @@ void QtProjectWizzardContentPreferences::load()
 	m_useAnimations->setChecked(appSettings->getUseAnimations());
 	m_showBuiltinTypes->setChecked(appSettings->getShowBuiltinTypesInGraph());
 
-	m_loggingEnabled->setChecked(appSettings->getLoggingEnabled());
-	m_verboseIndexerLoggingEnabled->setChecked(appSettings->getVerboseIndexerLoggingEnabled());
-	m_verboseIndexerLoggingEnabled->setEnabled(m_loggingEnabled->isChecked());
+	if (m_screenAutoScaling)
+	{
+		m_screenAutoScaling->setCurrentIndex(m_screenAutoScaling->findData(appSettings->getScreenAutoScaling()));
+		uiAutoScalingChanges(m_screenAutoScaling->currentIndex());
+	}
+
+	if (m_screenScaleFactor)
+	{
+		m_screenScaleFactor->setCurrentIndex(m_screenScaleFactor->findData(appSettings->getScreenScaleFactor()));
+		uiScaleFactorChanges(m_screenScaleFactor->currentIndex());
+	}
 
 	m_scrollSpeed->setText(QString::number(appSettings->getScrollSpeed(), 'f', 1));
 	m_graphZooming->setChecked(appSettings->getControlsGraphZoomOnMouseWheel());
 
+	m_loggingEnabled->setChecked(appSettings->getLoggingEnabled());
+	m_verboseIndexerLoggingEnabled->setChecked(appSettings->getVerboseIndexerLoggingEnabled());
+	m_verboseIndexerLoggingEnabled->setEnabled(m_loggingEnabled->isChecked());
+
 	m_automaticUpdateCheck->setChecked(appSettings->getAutomaticUpdateCheck());
 
 	m_sourcetrailPort->setText(QString::number(appSettings->getSourcetrailPort()));
@@ -353,12 +427,12 @@ void QtProjectWizzardContentPreferences::save()
 {
 	ApplicationSettings* appSettings = ApplicationSettings::getInstance().get();
 
-	appSettings->setFontName(m_fontFace->getText().toStdString());
+	appSettings->setFontName(m_fontFace->currentText().toStdString());
 
 	appSettings->setFontSize(m_fontSize->currentIndex() + appSettings->getFontSizeMin());
 	appSettings->setCodeTabWidth(m_tabWidth->currentIndex() + 1);
 
-	appSettings->setTextEncoding(m_textEncoding->getText().toStdString());
+	appSettings->setTextEncoding(m_textEncoding->currentText().toStdString());
 
 	appSettings->setColorSchemePath(m_colorSchemePaths[m_colorSchemes->currentIndex()]);
 	m_oldColorSchemeIndex = -1;
@@ -366,14 +440,24 @@ void QtProjectWizzardContentPreferences::save()
 	appSettings->setUseAnimations(m_useAnimations->isChecked());
 	appSettings->setShowBuiltinTypesInGraph(m_showBuiltinTypes->isChecked());
 
-	appSettings->setLoggingEnabled(m_loggingEnabled->isChecked());
-	appSettings->setVerboseIndexerLoggingEnabled(m_verboseIndexerLoggingEnabled->isChecked());
+	if (m_screenAutoScaling)
+	{
+		appSettings->setScreenAutoScaling(m_screenAutoScaling->currentData().toInt());
+	}
+
+	if (m_screenScaleFactor)
+	{
+		appSettings->setScreenScaleFactor(m_screenScaleFactor->currentData().toDouble());
+	}
 
 	float scrollSpeed = m_scrollSpeed->text().toFloat();
 	if (scrollSpeed) appSettings->setScrollSpeed(scrollSpeed);
 
 	appSettings->setControlsGraphZoomOnMouseWheel(m_graphZooming->isChecked());
 
+	appSettings->setLoggingEnabled(m_loggingEnabled->isChecked());
+	appSettings->setVerboseIndexerLoggingEnabled(m_verboseIndexerLoggingEnabled->isChecked());
+
 	appSettings->setAutomaticUpdateCheck(m_automaticUpdateCheck->isChecked());
 
 	int sourcetrailPort = m_sourcetrailPort->text().toInt();
@@ -425,7 +509,8 @@ void QtProjectWizzardContentPreferences::javaPathDetectionClicked()
 
 void QtProjectWizzardContentPreferences::jreSystemLibraryPathsDetectionClicked()
 {
-	std::vector<FilePath> paths = m_jreSystemLibraryPathsDetector->getPaths(m_jreSystemLibraryPathsDetectorBox->currentText().toStdString());
+	std::vector<FilePath> paths =
+		m_jreSystemLibraryPathsDetector->getPaths(m_jreSystemLibraryPathsDetectorBox->currentText().toStdString());
 	std::vector<FilePath> oldPaths = m_jreSystemLibraryPaths->getList();
 	m_jreSystemLibraryPaths->setList(utility::unique(utility::concat(oldPaths, paths)));
 }
@@ -448,7 +533,8 @@ void QtProjectWizzardContentPreferences::indexerThreadsChanges(int index)
 {
 	if (index == 0)
 	{
-		m_threadsInfoLabel->setText(("detected " + std::to_string(utility::getIdealThreadCount()) + " threads to be ideal.").c_str());
+		m_threadsInfoLabel->setText(
+			("detected " + std::to_string(utility::getIdealThreadCount()) + " threads to be ideal.").c_str());
 		m_threadsInfoLabel->show();
 	}
 	else
@@ -457,6 +543,50 @@ void QtProjectWizzardContentPreferences::indexerThreadsChanges(int index)
 	}
 }
 
+void QtProjectWizzardContentPreferences::uiAutoScalingChanges(int index)
+{
+	if (index == 0)
+	{
+		QString autoScale(qgetenv("QT_AUTO_SCREEN_SCALE_FACTOR_SOURCETRAIL"));
+		if (autoScale == "1")
+		{
+			autoScale = "on";
+		}
+		else
+		{
+			autoScale = "off";
+		}
+
+		m_screenAutoScalingInfoLabel->setText("detected: '" + autoScale + "'");
+		m_screenAutoScalingInfoLabel->show();
+	}
+	else
+	{
+		m_screenAutoScalingInfoLabel->hide();
+	}
+}
+
+void QtProjectWizzardContentPreferences::uiScaleFactorChanges(int index)
+{
+	if (index == 0)
+	{
+		QString scale = "100";
+		bool ok;
+		double scaleFactor = qgetenv("QT_SCALE_FACTOR_SOURCETRAIL").toDouble(&ok);
+		if (ok)
+		{
+			scale = QString::number(int(scaleFactor * 100));
+		}
+
+		m_screenScaleFactorInfoLabel->setText("detected: '" + scale + "%'");
+		m_screenScaleFactorInfoLabel->show();
+	}
+	else
+	{
+		m_screenScaleFactorInfoLabel->hide();
+	}
+}
+
 void QtProjectWizzardContentPreferences::addJavaPathDetection(QGridLayout* layout, int& row)
 {
 	std::vector<std::string> detectorNames = m_javaPathDetector->getWorkingDetectorNames();
@@ -608,6 +738,35 @@ QComboBox* QtProjectWizzardContentPreferences::addComboBox(
 	return comboBox;
 }
 
+QComboBox* QtProjectWizzardContentPreferences::addComboBoxWithWidgets(
+	QString label, QString helpText, std::vector<QWidget*> widgets, QGridLayout* layout, int& row)
+{
+	QComboBox* comboBox = new QComboBox(this);
+
+	QHBoxLayout* hlayout = new QHBoxLayout();
+	hlayout->setContentsMargins(0, 0, 0, 0);
+	hlayout->addWidget(comboBox);
+
+	for (QWidget* widget : widgets)
+	{
+		hlayout->addWidget(widget);
+	}
+
+	QWidget* container = new QWidget();
+	container->setLayout(hlayout);
+
+	addLabelAndWidget(label, container, layout, row, Qt::AlignLeft);
+
+	if (helpText.size())
+	{
+		addHelpButton(label, helpText, layout, row);
+	}
+
+	row++;
+
+	return comboBox;
+}
+
 QComboBox* QtProjectWizzardContentPreferences::addComboBox(
 	QString label, int min, int max, QString helpText, QGridLayout* layout, int& row)
 {
@@ -624,6 +783,22 @@ QComboBox* QtProjectWizzardContentPreferences::addComboBox(
 	return comboBox;
 }
 
+QComboBox* QtProjectWizzardContentPreferences::addComboBoxWithWidgets(
+	QString label, int min, int max, QString helpText, std::vector<QWidget*> widgets, QGridLayout* layout, int& row)
+{
+	QComboBox* comboBox = addComboBoxWithWidgets(label, helpText, widgets, layout, row);
+
+	if (min != max)
+	{
+		for (int i = min; i <= max; i++)
+		{
+			comboBox->insertItem(i, QString::number(i));
+		}
+	}
+
+	return comboBox;
+}
+
 QLineEdit* QtProjectWizzardContentPreferences::addLineEdit(QString label, QString helpText, QGridLayout* layout, int& row)
 {
 	QLineEdit* lineEdit = new QLineEdit(this);

src/lib_gui/qt/window/project_wizzard/QtProjectWizzardContentPreferences.h

@@ -1,18 +1,17 @@
 #ifndef QT_PROJECT_WIZZARD_CONTENT_PREFERENCES_H
 #define QT_PROJECT_WIZZARD_CONTENT_PREFERENCES_H
 
-#include <QCheckBox>
-#include <QComboBox>
-#include <QLabel>
-#include <QLineEdit>
-
 #include "qt/element/QtLocationPicker.h"
 #include "qt/element/QtDirectoryListBox.h"
 #include "qt/window/project_wizzard/QtProjectWizzardContent.h"
 #include "utility/path_detector/CombinedPathDetector.h"
 
-class QtFontPicker;
-class QtTextEncodingPicker;
+class QCheckBox;
+class QComboBox;
+class QFontComboBox;
+class QLabel;
+class QLineEdit;
+
 
 class QtProjectWizzardContentPreferences
 	: public QtProjectWizzardContent
@@ -37,6 +36,8 @@ private slots:
 	void mavenPathDetectionClicked();
 	void loggingEnabledChanged();
 	void indexerThreadsChanges(int index);
+	void uiAutoScalingChanges(int index);
+	void uiScaleFactorChanges(int index);
 
 private:
 	void addJavaPathDetection(QGridLayout* layout, int& row);
@@ -50,13 +51,17 @@ private:
 
 	QCheckBox* addCheckBox(QString label, QString text, QString helpText, QGridLayout* layout, int& row);
 	QComboBox* addComboBox(QString label, QString helpText, QGridLayout* layout, int& row);
+	QComboBox* addComboBoxWithWidgets(
+		QString label, QString helpText, std::vector<QWidget*> widgets, QGridLayout* layout, int& row);
 	QComboBox* addComboBox(QString label, int min, int max, QString helpText, QGridLayout* layout, int& row);
+	QComboBox* addComboBoxWithWidgets(
+		QString label, int min, int max, QString helpText, std::vector<QWidget*> widgets, QGridLayout* layout, int& row);
 	QLineEdit* addLineEdit(QString label, QString helpText, QGridLayout* layout, int& row);
 
-	QtFontPicker* m_fontFace;
+	QFontComboBox* m_fontFace;
 	QComboBox* m_fontSize;
 	QComboBox* m_tabWidth;
-	QtTextEncodingPicker* m_textEncoding;
+	QComboBox* m_textEncoding;
 
 	QComboBox* m_colorSchemes;
 	std::vector<FilePath> m_colorSchemePaths;
@@ -66,12 +71,18 @@ private:
 	QCheckBox* m_useAnimations;
 	QCheckBox* m_showBuiltinTypes;
 
-	QCheckBox* m_loggingEnabled;
-	QCheckBox* m_verboseIndexerLoggingEnabled;
+	QComboBox* m_screenAutoScaling;
+	QLabel* m_screenAutoScalingInfoLabel;
+
+	QComboBox* m_screenScaleFactor;
+	QLabel* m_screenScaleFactorInfoLabel;
 
 	QLineEdit* m_scrollSpeed;
 	QCheckBox* m_graphZooming;
 
+	QCheckBox* m_loggingEnabled;
+	QCheckBox* m_verboseIndexerLoggingEnabled;
+
 	QCheckBox* m_automaticUpdateCheck;
 
 	QLineEdit* m_sourcetrailPort;