ProjectExplorer: Don't save defaults to settings

Writes less settings and makes it possible to change defaults in the
future.

Task-number: QTCREATORBUG-24762
Change-Id: I73873b3684827b4fe27cfa5ea2f62a76003f9750
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>

20 files changed, 247 insertions, 120 deletions

diff --git a/src/plugins/classview/classviewnavigationwidgetfactory.cpp b/src/plugins/classview/classviewnavigationwidgetfactory.cpp
index aaaa4295d3..217fedea9a 100644
--- a/src/plugins/classview/classviewnavigationwidgetfactory.cpp
+++ b/src/plugins/classview/classviewnavigationwidgetfactory.cpp
@@ -75,7 +75,9 @@ static QString settingsPrefix(int position)
 
 //! Flat mode settings
 
-void NavigationWidgetFactory::saveSettings(QSettings *settings, int position, QWidget *widget)
+void NavigationWidgetFactory::saveSettings(Utils::QtcSettings *settings,
+                                           int position,
+                                           QWidget *widget)
 {
     auto pw = qobject_cast<NavigationWidget *>(widget);
     QTC_ASSERT(pw, return);
diff --git a/src/plugins/classview/classviewnavigationwidgetfactory.h b/src/plugins/classview/classviewnavigationwidgetfactory.h
index 31f664476d..e067e9ee00 100644
--- a/src/plugins/classview/classviewnavigationwidgetfactory.h
+++ b/src/plugins/classview/classviewnavigationwidgetfactory.h
@@ -41,7 +41,7 @@ public:
     Core::NavigationView createWidget() override;
 
     //! \implements Core::INavigationWidgetFactory::saveSettings
-    void saveSettings(QSettings *settings, int position, QWidget *widget) override;
+    void saveSettings(Utils::QtcSettings *settings, int position, QWidget *widget) override;
 
     //! \implements Core::INavigationWidgetFactory::restoreSettings
     void restoreSettings(QSettings *settings, int position, QWidget *widget) override;
diff --git a/src/plugins/coreplugin/inavigationwidgetfactory.cpp b/src/plugins/coreplugin/inavigationwidgetfactory.cpp
index 7e36dbdd08..63ed236e11 100644
--- a/src/plugins/coreplugin/inavigationwidgetfactory.cpp
+++ b/src/plugins/coreplugin/inavigationwidgetfactory.cpp
@@ -156,7 +156,9 @@ QKeySequence INavigationWidgetFactory::activationSequence() const
 
     \sa INavigationWidgetFactory::restoreSettings()
 */
-void INavigationWidgetFactory::saveSettings(QSettings * /* settings */, int /* position */, QWidget * /* widget */)
+void INavigationWidgetFactory::saveSettings(Utils::QtcSettings * /* settings */,
+                                            int /* position */,
+                                            QWidget * /* widget */)
 {
 }
 
diff --git a/src/plugins/coreplugin/inavigationwidgetfactory.h b/src/plugins/coreplugin/inavigationwidgetfactory.h
index 802f1ca5d8..cd918de6f3 100644
--- a/src/plugins/coreplugin/inavigationwidgetfactory.h
+++ b/src/plugins/coreplugin/inavigationwidgetfactory.h
@@ -39,6 +39,10 @@ class QToolButton;
 class QWidget;
 QT_END_NAMESPACE
 
+namespace Utils {
+class QtcSettings;
+}
+
 namespace Core {
 
 struct NavigationView
@@ -75,7 +79,7 @@ public:
     // Similar to how IView
     virtual NavigationView createWidget() = 0;
 
-    virtual void saveSettings(QSettings *settings, int position, QWidget *widget);
+    virtual void saveSettings(Utils::QtcSettings *settings, int position, QWidget *widget);
     virtual void restoreSettings(QSettings *settings, int position, QWidget *widget);
 
 private:
diff --git a/src/plugins/coreplugin/navigationsubwidget.cpp b/src/plugins/coreplugin/navigationsubwidget.cpp
index 9f340ddf71..bb439d4eff 100644
--- a/src/plugins/coreplugin/navigationsubwidget.cpp
+++ b/src/plugins/coreplugin/navigationsubwidget.cpp
@@ -170,7 +170,7 @@ void NavigationSubWidget::saveSettings()
     if (!m_navigationWidget || !factory())
         return;
 
-    QSettings *settings = Core::ICore::settings();
+    QtcSettings *settings = Core::ICore::settings();
     settings->beginGroup(m_parentWidget->settingsGroup());
     factory()->saveSettings(settings, position(), m_navigationWidget);
     settings->endGroup();
diff --git a/src/plugins/cppeditor/cppincludehierarchy.cpp b/src/plugins/cppeditor/cppincludehierarchy.cpp
index 8ea60a7609..f3a038c50d 100644
--- a/src/plugins/cppeditor/cppincludehierarchy.cpp
+++ b/src/plugins/cppeditor/cppincludehierarchy.cpp
@@ -48,6 +48,7 @@
 #include <utils/fileutils.h>
 #include <utils/navigationtreeview.h>
 #include <utils/qtcassert.h>
+#include <utils/qtcsettings.h>
 #include <utils/utilsicons.h>
 
 #include <QCoreApplication>
@@ -546,7 +547,7 @@ static CppIncludeHierarchyWidget *hierarchyWidget(QWidget *widget)
     return hierarchyWidget;
 }
 
-void CppIncludeHierarchyFactory::saveSettings(QSettings *settings, int position, QWidget *widget)
+void CppIncludeHierarchyFactory::saveSettings(QtcSettings *settings, int position, QWidget *widget)
 {
     hierarchyWidget(widget)->saveSettings(settings, position);
 }
diff --git a/src/plugins/cppeditor/cppincludehierarchy.h b/src/plugins/cppeditor/cppincludehierarchy.h
index 99310a8904..ee20f470b7 100644
--- a/src/plugins/cppeditor/cppincludehierarchy.h
+++ b/src/plugins/cppeditor/cppincludehierarchy.h
@@ -72,7 +72,7 @@ public:
     CppIncludeHierarchyFactory();
 
     Core::NavigationView createWidget() override;
-    void saveSettings(QSettings *settings, int position, QWidget *widget) override;
+    void saveSettings(Utils::QtcSettings *settings, int position, QWidget *widget) override;
     void restoreSettings(QSettings *settings, int position, QWidget *widget) override;
 };
 
diff --git a/src/plugins/projectexplorer/appoutputpane.cpp b/src/plugins/projectexplorer/appoutputpane.cpp
index 658028b2b7..8eb808111f 100644
--- a/src/plugins/projectexplorer/appoutputpane.cpp
+++ b/src/plugins/projectexplorer/appoutputpane.cpp
@@ -510,15 +510,27 @@ void AppOutputPane::setSettings(const AppOutputSettings &settings)
     updateFromSettings();
 }
 
+const AppOutputPaneMode kRunOutputModeDefault = AppOutputPaneMode::PopupOnFirstOutput;
+const AppOutputPaneMode kDebugOutputModeDefault = AppOutputPaneMode::FlashOnOutput;
+const bool kCleanOldOutputDefault = false;
+const bool kMergeChannelsDefault = false;
+const bool kWrapOutputDefault = true;
+
 void AppOutputPane::storeSettings() const
 {
-    QSettings * const s = Core::ICore::settings();
-    s->setValue(POP_UP_FOR_RUN_OUTPUT_KEY, int(m_settings.runOutputMode));
-    s->setValue(POP_UP_FOR_DEBUG_OUTPUT_KEY, int(m_settings.debugOutputMode));
-    s->setValue(CLEAN_OLD_OUTPUT_KEY, m_settings.cleanOldOutput);
-    s->setValue(MERGE_CHANNELS_KEY, m_settings.mergeChannels);
-    s->setValue(WRAP_OUTPUT_KEY, m_settings.wrapOutput);
-    s->setValue(MAX_LINES_KEY, m_settings.maxCharCount / 100);
+    Utils::QtcSettings *const s = Core::ICore::settings();
+    s->setValueWithDefault(POP_UP_FOR_RUN_OUTPUT_KEY,
+                           int(m_settings.runOutputMode),
+                           int(kRunOutputModeDefault));
+    s->setValueWithDefault(POP_UP_FOR_DEBUG_OUTPUT_KEY,
+                           int(m_settings.debugOutputMode),
+                           int(kDebugOutputModeDefault));
+    s->setValueWithDefault(CLEAN_OLD_OUTPUT_KEY, m_settings.cleanOldOutput, kCleanOldOutputDefault);
+    s->setValueWithDefault(MERGE_CHANNELS_KEY, m_settings.mergeChannels, kMergeChannelsDefault);
+    s->setValueWithDefault(WRAP_OUTPUT_KEY, m_settings.wrapOutput, kWrapOutputDefault);
+    s->setValueWithDefault(MAX_LINES_KEY,
+                           m_settings.maxCharCount / 100,
+                           Core::Constants::DEFAULT_MAX_CHAR_COUNT);
 }
 
 void AppOutputPane::loadSettings()
@@ -527,13 +539,12 @@ void AppOutputPane::loadSettings()
     const auto modeFromSettings = [s](const QString key, AppOutputPaneMode defaultValue) {
         return static_cast<AppOutputPaneMode>(s->value(key, int(defaultValue)).toInt());
     };
-    m_settings.runOutputMode = modeFromSettings(POP_UP_FOR_RUN_OUTPUT_KEY,
-                                                AppOutputPaneMode::PopupOnFirstOutput);
+    m_settings.runOutputMode = modeFromSettings(POP_UP_FOR_RUN_OUTPUT_KEY, kRunOutputModeDefault);
     m_settings.debugOutputMode = modeFromSettings(POP_UP_FOR_DEBUG_OUTPUT_KEY,
-                                                  AppOutputPaneMode::FlashOnOutput);
-    m_settings.cleanOldOutput = s->value(CLEAN_OLD_OUTPUT_KEY, false).toBool();
-    m_settings.mergeChannels = s->value(MERGE_CHANNELS_KEY, false).toBool();
-    m_settings.wrapOutput = s->value(WRAP_OUTPUT_KEY, true).toBool();
+                                                  kDebugOutputModeDefault);
+    m_settings.cleanOldOutput = s->value(CLEAN_OLD_OUTPUT_KEY, kCleanOldOutputDefault).toBool();
+    m_settings.mergeChannels = s->value(MERGE_CHANNELS_KEY, kMergeChannelsDefault).toBool();
+    m_settings.wrapOutput = s->value(WRAP_OUTPUT_KEY, kWrapOutputDefault).toBool();
     m_settings.maxCharCount = s->value(MAX_LINES_KEY,
                                        Core::Constants::DEFAULT_MAX_CHAR_COUNT).toInt() * 100;
 }
diff --git a/src/plugins/projectexplorer/compileoutputwindow.cpp b/src/plugins/projectexplorer/compileoutputwindow.cpp
index 6bd7f7aba8..2f322a660a 100644
--- a/src/plugins/projectexplorer/compileoutputwindow.cpp
+++ b/src/plugins/projectexplorer/compileoutputwindow.cpp
@@ -305,21 +305,26 @@ void CompileOutputWindow::updateFilter()
                                            filterUsesRegexp(), filterIsInverted());
 }
 
+const bool kPopUpDefault = false;
+const bool kWrapOutputDefault = true;
+
 void CompileOutputWindow::loadSettings()
 {
     QSettings * const s = Core::ICore::settings();
-    m_settings.popUp = s->value(POP_UP_KEY, false).toBool();
-    m_settings.wrapOutput = s->value(WRAP_OUTPUT_KEY, true).toBool();
+    m_settings.popUp = s->value(POP_UP_KEY, kPopUpDefault).toBool();
+    m_settings.wrapOutput = s->value(WRAP_OUTPUT_KEY, kWrapOutputDefault).toBool();
     m_settings.maxCharCount = s->value(MAX_LINES_KEY,
                                        Core::Constants::DEFAULT_MAX_CHAR_COUNT).toInt() * 100;
 }
 
 void CompileOutputWindow::storeSettings() const
 {
-    QSettings * const s = Core::ICore::settings();
-    s->setValue(POP_UP_KEY, m_settings.popUp);
-    s->setValue(WRAP_OUTPUT_KEY, m_settings.wrapOutput);
-    s->setValue(MAX_LINES_KEY, m_settings.maxCharCount / 100);
+    Utils::QtcSettings *const s = Core::ICore::settings();
+    s->setValueWithDefault(POP_UP_KEY, m_settings.popUp, kPopUpDefault);
+    s->setValueWithDefault(WRAP_OUTPUT_KEY, m_settings.wrapOutput, kWrapOutputDefault);
+    s->setValueWithDefault(MAX_LINES_KEY,
+                           m_settings.maxCharCount / 100,
+                           Core::Constants::DEFAULT_MAX_CHAR_COUNT);
 }
 
 class CompileOutputSettingsWidget : public Core::IOptionsPageWidget
diff --git a/src/plugins/projectexplorer/devicesupport/devicesettingswidget.cpp b/src/plugins/projectexplorer/devicesupport/devicesettingswidget.cpp
index f33607b5c9..12c9e4e53c 100644
--- a/src/plugins/projectexplorer/devicesupport/devicesettingswidget.cpp
+++ b/src/plugins/projectexplorer/devicesupport/devicesettingswidget.cpp
@@ -219,7 +219,7 @@ void DeviceSettingsWidget::updateDeviceFromUi()
 
 void DeviceSettingsWidget::saveSettings()
 {
-    ICore::settings()->setValue(QLatin1String(LastDeviceIndexKey), currentIndex());
+    ICore::settings()->setValueWithDefault(LastDeviceIndexKey, currentIndex(), 0);
     DeviceManager::replaceInstance();
 }
 
diff --git a/src/plugins/projectexplorer/foldernavigationwidget.cpp b/src/plugins/projectexplorer/foldernavigationwidget.cpp
index b7d399720c..c3987e1e48 100644
--- a/src/plugins/projectexplorer/foldernavigationwidget.cpp
+++ b/src/plugins/projectexplorer/foldernavigationwidget.cpp
@@ -903,15 +903,28 @@ Core::NavigationView FolderNavigationWidgetFactory::createWidget()
     return n;
 }
 
-void FolderNavigationWidgetFactory::saveSettings(QSettings *settings, int position, QWidget *widget)
+const bool kHiddenFilesDefault = false;
+const bool kAutoSyncDefault = true;
+const bool kShowBreadCrumbsDefault = true;
+const bool kRootAutoSyncDefault = true;
+
+void FolderNavigationWidgetFactory::saveSettings(Utils::QtcSettings *settings,
+                                                 int position,
+                                                 QWidget *widget)
 {
     auto fnw = qobject_cast<FolderNavigationWidget *>(widget);
     QTC_ASSERT(fnw, return);
     const QString base = kSettingsBase + QString::number(position);
-    settings->setValue(base + kHiddenFilesKey, fnw->hiddenFilesFilter());
-    settings->setValue(base + kSyncKey, fnw->autoSynchronization());
-    settings->setValue(base + kShowBreadCrumbs, fnw->isShowingBreadCrumbs());
-    settings->setValue(base + kSyncRootWithEditor, fnw->rootAutoSynchronization());
+    settings->setValueWithDefault(base + kHiddenFilesKey,
+                                  fnw->hiddenFilesFilter(),
+                                  kHiddenFilesDefault);
+    settings->setValueWithDefault(base + kSyncKey, fnw->autoSynchronization(), kAutoSyncDefault);
+    settings->setValueWithDefault(base + kShowBreadCrumbs,
+                                  fnw->isShowingBreadCrumbs(),
+                                  kShowBreadCrumbsDefault);
+    settings->setValueWithDefault(base + kSyncRootWithEditor,
+                                  fnw->rootAutoSynchronization(),
+                                  kRootAutoSyncDefault);
 }
 
 void FolderNavigationWidgetFactory::restoreSettings(QSettings *settings, int position, QWidget *widget)
@@ -919,10 +932,12 @@ void FolderNavigationWidgetFactory::restoreSettings(QSettings *settings, int pos
     auto fnw = qobject_cast<FolderNavigationWidget *>(widget);
     QTC_ASSERT(fnw, return);
     const QString base = kSettingsBase + QString::number(position);
-    fnw->setHiddenFilesFilter(settings->value(base + kHiddenFilesKey, false).toBool());
-    fnw->setAutoSynchronization(settings->value(base + kSyncKey, true).toBool());
-    fnw->setShowBreadCrumbs(settings->value(base + kShowBreadCrumbs, true).toBool());
-    fnw->setRootAutoSynchronization(settings->value(base + kSyncRootWithEditor, true).toBool());
+    fnw->setHiddenFilesFilter(settings->value(base + kHiddenFilesKey, kHiddenFilesDefault).toBool());
+    fnw->setAutoSynchronization(settings->value(base + kSyncKey, kAutoSyncDefault).toBool());
+    fnw->setShowBreadCrumbs(
+        settings->value(base + kShowBreadCrumbs, kShowBreadCrumbsDefault).toBool());
+    fnw->setRootAutoSynchronization(
+        settings->value(base + kSyncRootWithEditor, kRootAutoSyncDefault).toBool());
 }
 
 void FolderNavigationWidgetFactory::insertRootDirectory(const RootDirectory &directory)
diff --git a/src/plugins/projectexplorer/foldernavigationwidget.h b/src/plugins/projectexplorer/foldernavigationwidget.h
index f871fb2aaa..a69ddedf47 100644
--- a/src/plugins/projectexplorer/foldernavigationwidget.h
+++ b/src/plugins/projectexplorer/foldernavigationwidget.h
@@ -39,6 +39,7 @@ class IEditor;
 namespace Utils {
 class NavigationTreeView;
 class FileCrumbLabel;
+class QtcSettings;
 }
 
 QT_BEGIN_NAMESPACE
@@ -70,7 +71,7 @@ public:
     FolderNavigationWidgetFactory();
 
     Core::NavigationView createWidget() override;
-    void saveSettings(QSettings *settings, int position, QWidget *widget) override;
+    void saveSettings(Utils::QtcSettings *settings, int position, QWidget *widget) override;
     void restoreSettings(QSettings *settings, int position, QWidget *widget) override;
 
     static void insertRootDirectory(const RootDirectory &directory);
diff --git a/src/plugins/projectexplorer/kitchooser.cpp b/src/plugins/projectexplorer/kitchooser.cpp
index 469dc9cf71..8b6b6ecb05 100644
--- a/src/plugins/projectexplorer/kitchooser.cpp
+++ b/src/plugins/projectexplorer/kitchooser.cpp
@@ -92,7 +92,7 @@ void KitChooser::onActivated()
     Id id = Id::fromSetting(m_chooser->currentData());
     if (m_hasStartupKit && m_chooser->currentIndex() == 0)
         id = Id(); // Special value to indicate startup kit.
-    ICore::settings()->setValue(lastKitKey, id.toSetting());
+    ICore::settings()->setValueWithDefault(lastKitKey, id.toSetting(), Id().toSetting());
     emit activated();
 }
 
diff --git a/src/plugins/projectexplorer/projectexplorer.cpp b/src/plugins/projectexplorer/projectexplorer.cpp
index 3552d8d471..3f9a969f29 100644
--- a/src/plugins/projectexplorer/projectexplorer.cpp
+++ b/src/plugins/projectexplorer/projectexplorer.cpp
@@ -262,6 +262,8 @@ const char DEFAULT_BUILD_DIRECTORY_TEMPLATE[] = "../%{JS: Util.asciify(\"build-%
 const char DEFAULT_BUILD_DIRECTORY_TEMPLATE_KEY_OLD[] = "Directories/BuildDirectory.Template"; // TODO: Remove in ~4.16
 const char DEFAULT_BUILD_DIRECTORY_TEMPLATE_KEY[] = "Directories/BuildDirectory.TemplateV2";
 
+const char RECENTPROJECTS_FILE_NAMES_KEY[] = "ProjectExplorer/RecentProjects/FileNames";
+const char RECENTPROJECTS_DISPLAY_NAMES_KEY[] = "ProjectExplorer/RecentProjects/DisplayNames";
 const char BUILD_BEFORE_DEPLOY_SETTINGS_KEY[] = "ProjectExplorer/Settings/BuildBeforeDeploy";
 const char DEPLOY_BEFORE_RUN_SETTINGS_KEY[] = "ProjectExplorer/Settings/DeployBeforeRun";
 const char SAVE_BEFORE_BUILD_SETTINGS_KEY[] = "ProjectExplorer/Settings/SaveBeforeBuild";
@@ -1481,10 +1483,9 @@ bool ProjectExplorerPlugin::initialize(const QStringList &arguments, QString *er
     });
 
     QSettings *s = ICore::settings();
-    const QStringList fileNames =
-            s->value(QLatin1String("ProjectExplorer/RecentProjects/FileNames")).toStringList();
-    const QStringList displayNames =
-            s->value(QLatin1String("ProjectExplorer/RecentProjects/DisplayNames")).toStringList();
+    const QStringList fileNames = s->value(Constants::RECENTPROJECTS_FILE_NAMES_KEY).toStringList();
+    const QStringList displayNames = s->value(Constants::RECENTPROJECTS_DISPLAY_NAMES_KEY)
+                                         .toStringList();
     if (fileNames.size() == displayNames.size()) {
         for (int i = 0; i < fileNames.size(); ++i) {
             dd->m_recentProjects.append(qMakePair(fileNames.at(i), displayNames.at(i)));
@@ -1502,38 +1503,59 @@ bool ProjectExplorerPlugin::initialize(const QStringList &arguments, QString *er
                 = static_cast<BuildBeforeRunMode>(buildBeforeDeploy.toInt());
     }
 
-    dd->m_projectExplorerSettings.deployBeforeRun =
-            s->value(Constants::DEPLOY_BEFORE_RUN_SETTINGS_KEY, true).toBool();
-    dd->m_projectExplorerSettings.saveBeforeBuild =
-            s->value(Constants::SAVE_BEFORE_BUILD_SETTINGS_KEY, false).toBool();
-    dd->m_projectExplorerSettings.useJom = s->value(Constants::USE_JOM_SETTINGS_KEY, true).toBool();
-    dd->m_projectExplorerSettings.autorestoreLastSession =
-            s->value(Constants::AUTO_RESTORE_SESSION_SETTINGS_KEY, false).toBool();
-    dd->m_projectExplorerSettings.addLibraryPathsToRunEnv =
-            s->value(Constants::ADD_LIBRARY_PATHS_TO_RUN_ENV_SETTINGS_KEY, true).toBool();
-    dd->m_projectExplorerSettings.prompToStopRunControl =
-            s->value(Constants::PROMPT_TO_STOP_RUN_CONTROL_SETTINGS_KEY, false).toBool();
-    dd->m_projectExplorerSettings.automaticallyCreateRunConfigurations =
-            s->value(Constants::AUTO_CREATE_RUN_CONFIGS_SETTINGS_KEY, true).toBool();
+    static const ProjectExplorerSettings defaultSettings;
+
+    dd->m_projectExplorerSettings.deployBeforeRun
+        = s->value(Constants::DEPLOY_BEFORE_RUN_SETTINGS_KEY, defaultSettings.deployBeforeRun)
+              .toBool();
+    dd->m_projectExplorerSettings.saveBeforeBuild
+        = s->value(Constants::SAVE_BEFORE_BUILD_SETTINGS_KEY, defaultSettings.saveBeforeBuild)
+              .toBool();
+    dd->m_projectExplorerSettings.useJom
+        = s->value(Constants::USE_JOM_SETTINGS_KEY, defaultSettings.useJom).toBool();
+    dd->m_projectExplorerSettings.autorestoreLastSession
+        = s->value(Constants::AUTO_RESTORE_SESSION_SETTINGS_KEY,
+                   defaultSettings.autorestoreLastSession)
+              .toBool();
+    dd->m_projectExplorerSettings.addLibraryPathsToRunEnv
+        = s->value(Constants::ADD_LIBRARY_PATHS_TO_RUN_ENV_SETTINGS_KEY,
+                   defaultSettings.addLibraryPathsToRunEnv)
+              .toBool();
+    dd->m_projectExplorerSettings.prompToStopRunControl
+        = s->value(Constants::PROMPT_TO_STOP_RUN_CONTROL_SETTINGS_KEY,
+                   defaultSettings.prompToStopRunControl)
+              .toBool();
+    dd->m_projectExplorerSettings.automaticallyCreateRunConfigurations
+        = s->value(Constants::AUTO_CREATE_RUN_CONFIGS_SETTINGS_KEY,
+                   defaultSettings.automaticallyCreateRunConfigurations)
+              .toBool();
     dd->m_projectExplorerSettings.environmentId =
             QUuid(s->value(Constants::ENVIRONMENT_ID_SETTINGS_KEY).toByteArray());
     if (dd->m_projectExplorerSettings.environmentId.isNull())
         dd->m_projectExplorerSettings.environmentId = QUuid::createUuid();
     int tmp = s->value(Constants::STOP_BEFORE_BUILD_SETTINGS_KEY,
-                            Utils::HostOsInfo::isWindowsHost() ? 1 : 0).toInt();
+                       int(defaultSettings.stopBeforeBuild))
+                  .toInt();
     if (tmp < 0 || tmp > int(StopBeforeBuild::SameApp))
-        tmp = Utils::HostOsInfo::isWindowsHost() ? 1 : 0;
+        tmp = int(defaultSettings.stopBeforeBuild);
     dd->m_projectExplorerSettings.stopBeforeBuild = StopBeforeBuild(tmp);
-    dd->m_projectExplorerSettings.terminalMode = static_cast<TerminalMode>(s->value(
-        Constants::TERMINAL_MODE_SETTINGS_KEY, int(TerminalMode::Off)).toInt());
+    dd->m_projectExplorerSettings.terminalMode = static_cast<TerminalMode>(
+        s->value(Constants::TERMINAL_MODE_SETTINGS_KEY, int(defaultSettings.terminalMode)).toInt());
     dd->m_projectExplorerSettings.closeSourceFilesWithProject
-            = s->value(Constants::CLOSE_FILES_WITH_PROJECT_SETTINGS_KEY, true).toBool();
+        = s->value(Constants::CLOSE_FILES_WITH_PROJECT_SETTINGS_KEY,
+                   defaultSettings.closeSourceFilesWithProject)
+              .toBool();
     dd->m_projectExplorerSettings.clearIssuesOnRebuild
-            = s->value(Constants::CLEAR_ISSUES_ON_REBUILD_SETTINGS_KEY, true).toBool();
+        = s->value(Constants::CLEAR_ISSUES_ON_REBUILD_SETTINGS_KEY,
+                   defaultSettings.clearIssuesOnRebuild)
+              .toBool();
     dd->m_projectExplorerSettings.abortBuildAllOnError
-            = s->value(Constants::ABORT_BUILD_ALL_ON_ERROR_SETTINGS_KEY, true).toBool();
+        = s->value(Constants::ABORT_BUILD_ALL_ON_ERROR_SETTINGS_KEY,
+                   defaultSettings.abortBuildAllOnError)
+              .toBool();
     dd->m_projectExplorerSettings.lowBuildPriority
-            = s->value(Constants::LOW_BUILD_PRIORITY_SETTINGS_KEY, false).toBool();
+        = s->value(Constants::LOW_BUILD_PRIORITY_SETTINGS_KEY, defaultSettings.lowBuildPriority)
+              .toBool();
 
     dd->m_buildPropertiesSettings.buildDirectoryTemplateOld
             = s->value(Constants::DEFAULT_BUILD_DIRECTORY_TEMPLATE_KEY_OLD).toString();
@@ -2119,7 +2141,7 @@ void ProjectExplorerPluginPrivate::savePersistentSettings()
         SessionManager::save();
     }
 
-    QSettings *s = ICore::settings();
+    QtcSettings *s = ICore::settings();
     if (SessionManager::isDefaultVirgin()) {
         s->remove(Constants::STARTUPSESSION_KEY);
     } else {
@@ -2137,45 +2159,79 @@ void ProjectExplorerPluginPrivate::savePersistentSettings()
         displayNames << (*it).second;
     }
 
-    s->setValue(QLatin1String("ProjectExplorer/RecentProjects/FileNames"), fileNames);
-    s->setValue(QLatin1String("ProjectExplorer/RecentProjects/DisplayNames"), displayNames);
-
-    s->setValue(Constants::BUILD_BEFORE_DEPLOY_SETTINGS_KEY, int(dd->m_projectExplorerSettings.buildBeforeDeploy));
-    s->setValue(Constants::DEPLOY_BEFORE_RUN_SETTINGS_KEY, dd->m_projectExplorerSettings.deployBeforeRun);
-    s->setValue(Constants::SAVE_BEFORE_BUILD_SETTINGS_KEY, dd->m_projectExplorerSettings.saveBeforeBuild);
-    s->setValue(Constants::USE_JOM_SETTINGS_KEY, dd->m_projectExplorerSettings.useJom);
-    s->setValue(Constants::AUTO_RESTORE_SESSION_SETTINGS_KEY, dd->m_projectExplorerSettings.autorestoreLastSession);
-    s->setValue(Constants::ADD_LIBRARY_PATHS_TO_RUN_ENV_SETTINGS_KEY, dd->m_projectExplorerSettings.addLibraryPathsToRunEnv);
-    s->setValue(Constants::PROMPT_TO_STOP_RUN_CONTROL_SETTINGS_KEY, dd->m_projectExplorerSettings.prompToStopRunControl);
-    s->setValue(Constants::TERMINAL_MODE_SETTINGS_KEY,
-                int(dd->m_projectExplorerSettings.terminalMode));
-    s->setValue(Constants::CLOSE_FILES_WITH_PROJECT_SETTINGS_KEY,
-                dd->m_projectExplorerSettings.closeSourceFilesWithProject);
-    s->setValue(Constants::CLEAR_ISSUES_ON_REBUILD_SETTINGS_KEY,
-                dd->m_projectExplorerSettings.clearIssuesOnRebuild);
-    s->setValue(Constants::ABORT_BUILD_ALL_ON_ERROR_SETTINGS_KEY,
-                dd->m_projectExplorerSettings.abortBuildAllOnError);
-    s->setValue(Constants::LOW_BUILD_PRIORITY_SETTINGS_KEY,
-                dd->m_projectExplorerSettings.lowBuildPriority);
-    s->setValue(Constants::AUTO_CREATE_RUN_CONFIGS_SETTINGS_KEY,
-                dd->m_projectExplorerSettings.automaticallyCreateRunConfigurations);
-    s->setValue(Constants::ENVIRONMENT_ID_SETTINGS_KEY, dd->m_projectExplorerSettings.environmentId.toByteArray());
-    s->setValue(Constants::STOP_BEFORE_BUILD_SETTINGS_KEY, int(dd->m_projectExplorerSettings.stopBeforeBuild));
+    s->setValueWithDefault(Constants::RECENTPROJECTS_FILE_NAMES_KEY, fileNames);
+    s->setValueWithDefault(Constants::RECENTPROJECTS_DISPLAY_NAMES_KEY, displayNames);
+
+    static const ProjectExplorerSettings defaultSettings;
+
+    s->setValueWithDefault(Constants::BUILD_BEFORE_DEPLOY_SETTINGS_KEY,
+                           int(dd->m_projectExplorerSettings.buildBeforeDeploy),
+                           int(defaultSettings.buildBeforeDeploy));
+    s->setValueWithDefault(Constants::DEPLOY_BEFORE_RUN_SETTINGS_KEY,
+                           dd->m_projectExplorerSettings.deployBeforeRun,
+                           defaultSettings.deployBeforeRun);
+    s->setValueWithDefault(Constants::SAVE_BEFORE_BUILD_SETTINGS_KEY,
+                           dd->m_projectExplorerSettings.saveBeforeBuild,
+                           defaultSettings.saveBeforeBuild);
+    s->setValueWithDefault(Constants::USE_JOM_SETTINGS_KEY,
+                           dd->m_projectExplorerSettings.useJom,
+                           defaultSettings.useJom);
+    s->setValueWithDefault(Constants::AUTO_RESTORE_SESSION_SETTINGS_KEY,
+                           dd->m_projectExplorerSettings.autorestoreLastSession,
+                           defaultSettings.autorestoreLastSession);
+    s->setValueWithDefault(Constants::ADD_LIBRARY_PATHS_TO_RUN_ENV_SETTINGS_KEY,
+                           dd->m_projectExplorerSettings.addLibraryPathsToRunEnv,
+                           defaultSettings.addLibraryPathsToRunEnv);
+    s->setValueWithDefault(Constants::PROMPT_TO_STOP_RUN_CONTROL_SETTINGS_KEY,
+                           dd->m_projectExplorerSettings.prompToStopRunControl,
+                           defaultSettings.prompToStopRunControl);
+    s->setValueWithDefault(Constants::TERMINAL_MODE_SETTINGS_KEY,
+                           int(dd->m_projectExplorerSettings.terminalMode),
+                           int(defaultSettings.terminalMode));
+    s->setValueWithDefault(Constants::CLOSE_FILES_WITH_PROJECT_SETTINGS_KEY,
+                           dd->m_projectExplorerSettings.closeSourceFilesWithProject,
+                           defaultSettings.closeSourceFilesWithProject);
+    s->setValueWithDefault(Constants::CLEAR_ISSUES_ON_REBUILD_SETTINGS_KEY,
+                           dd->m_projectExplorerSettings.clearIssuesOnRebuild,
+                           defaultSettings.clearIssuesOnRebuild);
+    s->setValueWithDefault(Constants::ABORT_BUILD_ALL_ON_ERROR_SETTINGS_KEY,
+                           dd->m_projectExplorerSettings.abortBuildAllOnError,
+                           defaultSettings.abortBuildAllOnError);
+    s->setValueWithDefault(Constants::LOW_BUILD_PRIORITY_SETTINGS_KEY,
+                           dd->m_projectExplorerSettings.lowBuildPriority,
+                           defaultSettings.lowBuildPriority);
+    s->setValueWithDefault(Constants::AUTO_CREATE_RUN_CONFIGS_SETTINGS_KEY,
+                           dd->m_projectExplorerSettings.automaticallyCreateRunConfigurations,
+                           defaultSettings.automaticallyCreateRunConfigurations);
+    s->setValueWithDefault(Constants::ENVIRONMENT_ID_SETTINGS_KEY,
+                           dd->m_projectExplorerSettings.environmentId.toByteArray());
+    s->setValueWithDefault(Constants::STOP_BEFORE_BUILD_SETTINGS_KEY,
+                           int(dd->m_projectExplorerSettings.stopBeforeBuild),
+                           int(defaultSettings.stopBeforeBuild));
 
     // Store this in the Core directory scope for backward compatibility!
-    s->setValue(Constants::DEFAULT_BUILD_DIRECTORY_TEMPLATE_KEY_OLD,
-                dd->m_buildPropertiesSettings.buildDirectoryTemplateOld);
-    s->setValue(Constants::DEFAULT_BUILD_DIRECTORY_TEMPLATE_KEY,
-                dd->m_buildPropertiesSettings.buildDirectoryTemplate);
-
-    s->setValue(Constants::SEPARATE_DEBUG_INFO_SETTINGS_KEY,
-                dd->m_buildPropertiesSettings.separateDebugInfo.toVariant());
-    s->setValue(Constants::QML_DEBUGGING_SETTINGS_KEY,
-                dd->m_buildPropertiesSettings.qmlDebugging.toVariant());
-    s->setValue(Constants::QT_QUICK_COMPILER_SETTINGS_KEY,
-                dd->m_buildPropertiesSettings.qtQuickCompiler.toVariant());
-
-    s->setValue(Constants::CUSTOM_PARSER_COUNT_KEY, dd->m_customParsers.count());
+    if (dd->m_buildPropertiesSettings.buildDirectoryTemplate
+        == Constants::DEFAULT_BUILD_DIRECTORY_TEMPLATE) {
+        s->remove(Constants::DEFAULT_BUILD_DIRECTORY_TEMPLATE_KEY_OLD);
+        s->remove(Constants::DEFAULT_BUILD_DIRECTORY_TEMPLATE_KEY);
+    } else {
+        s->setValue(Constants::DEFAULT_BUILD_DIRECTORY_TEMPLATE_KEY_OLD,
+                    dd->m_buildPropertiesSettings.buildDirectoryTemplateOld);
+        s->setValue(Constants::DEFAULT_BUILD_DIRECTORY_TEMPLATE_KEY,
+                    dd->m_buildPropertiesSettings.buildDirectoryTemplate);
+    }
+
+    s->setValueWithDefault(Constants::SEPARATE_DEBUG_INFO_SETTINGS_KEY,
+                           dd->m_buildPropertiesSettings.separateDebugInfo.toVariant(),
+                           TriState::Default.toVariant());
+    s->setValueWithDefault(Constants::QML_DEBUGGING_SETTINGS_KEY,
+                           dd->m_buildPropertiesSettings.qmlDebugging.toVariant(),
+                           TriState::Default.toVariant());
+    s->setValueWithDefault(Constants::QT_QUICK_COMPILER_SETTINGS_KEY,
+                           dd->m_buildPropertiesSettings.qtQuickCompiler.toVariant(),
+                           TriState::Default.toVariant());
+
+    s->setValueWithDefault(Constants::CUSTOM_PARSER_COUNT_KEY, dd->m_customParsers.count(), 0);
     for (int i = 0; i < dd->m_customParsers.count(); ++i) {
         s->setValue(Constants::CUSTOM_PARSER_PREFIX_KEY + QString::number(i),
                     dd->m_customParsers.at(i).toMap());
diff --git a/src/plugins/projectexplorer/projectexplorersettings.h b/src/plugins/projectexplorer/projectexplorersettings.h
index 496bc3e26a..b5cbd7db3f 100644
--- a/src/plugins/projectexplorer/projectexplorersettings.h
+++ b/src/plugins/projectexplorer/projectexplorersettings.h
@@ -25,8 +25,10 @@
 
 #pragma once
 
+#include "projectexplorerconstants.h"
+
 #include <coreplugin/coreconstants.h>
-#include <projectexplorer/projectexplorerconstants.h>
+#include <utils/hostosinfo.h>
 
 #include <QUuid>
 
@@ -53,7 +55,9 @@ public:
     bool clearIssuesOnRebuild = true;
     bool abortBuildAllOnError = true;
     bool lowBuildPriority = false;
-    StopBeforeBuild stopBeforeBuild = StopBeforeBuild::None;
+    StopBeforeBuild stopBeforeBuild = Utils::HostOsInfo::isWindowsHost()
+                                          ? StopBeforeBuild::SameProject
+                                          : StopBeforeBuild::None;
     TerminalMode terminalMode = TerminalMode::Off;
 
     // Add a UUid which is used to identify the development environment.
diff --git a/src/plugins/projectexplorer/projecttreewidget.cpp b/src/plugins/projectexplorer/projecttreewidget.cpp
index 353d50716c..6b15b6f13a 100644
--- a/src/plugins/projectexplorer/projecttreewidget.cpp
+++ b/src/plugins/projectexplorer/projecttreewidget.cpp
@@ -635,16 +635,32 @@ NavigationView ProjectTreeWidgetFactory::createWidget()
     return n;
 }
 
-void ProjectTreeWidgetFactory::saveSettings(QSettings *settings, int position, QWidget *widget)
+const bool kProjectFilterDefault = false;
+const bool kHideGeneratedFilesDefault = true;
+const bool kHideDisabledFilesDefault = false;
+const bool kTrimEmptyDirsDefault = true;
+const bool kSyncDefault = true;
+
+void ProjectTreeWidgetFactory::saveSettings(QtcSettings *settings, int position, QWidget *widget)
 {
     auto ptw = qobject_cast<ProjectTreeWidget *>(widget);
     Q_ASSERT(ptw);
     const QString baseKey = QLatin1String("ProjectTreeWidget.") + QString::number(position);
-    settings->setValue(baseKey + QLatin1String(".ProjectFilter"), ptw->projectFilter());
-    settings->setValue(baseKey + QLatin1String(".GeneratedFilter"), ptw->generatedFilesFilter());
-    settings->setValue(baseKey + ".DisabledFilesFilter", ptw->disabledFilesFilter());
-    settings->setValue(baseKey + QLatin1String(".TrimEmptyDirsFilter"), ptw->trimEmptyDirectoriesFilter());
-    settings->setValue(baseKey + QLatin1String(".SyncWithEditor"), ptw->autoSynchronization());
+    settings->setValueWithDefault(baseKey + ".ProjectFilter",
+                                  ptw->projectFilter(),
+                                  kProjectFilterDefault);
+    settings->setValueWithDefault(baseKey + ".GeneratedFilter",
+                                  ptw->generatedFilesFilter(),
+                                  kHideGeneratedFilesDefault);
+    settings->setValueWithDefault(baseKey + ".DisabledFilesFilter",
+                                  ptw->disabledFilesFilter(),
+                                  kHideDisabledFilesDefault);
+    settings->setValueWithDefault(baseKey + ".TrimEmptyDirsFilter",
+                                  ptw->trimEmptyDirectoriesFilter(),
+                                  kTrimEmptyDirsDefault);
+    settings->setValueWithDefault(baseKey + ".SyncWithEditor",
+                                  ptw->autoSynchronization(),
+                                  kSyncDefault);
 }
 
 void ProjectTreeWidgetFactory::restoreSettings(QSettings *settings, int position, QWidget *widget)
@@ -652,9 +668,16 @@ void ProjectTreeWidgetFactory::restoreSettings(QSettings *settings, int position
     auto ptw = qobject_cast<ProjectTreeWidget *>(widget);
     Q_ASSERT(ptw);
     const QString baseKey = QLatin1String("ProjectTreeWidget.") + QString::number(position);
-    ptw->setProjectFilter(settings->value(baseKey + QLatin1String(".ProjectFilter"), false).toBool());
-    ptw->setGeneratedFilesFilter(settings->value(baseKey + QLatin1String(".GeneratedFilter"), true).toBool());
-    ptw->setDisabledFilesFilter(settings->value(baseKey + ".DisabledFilesFilter", false).toBool());
-    ptw->setTrimEmptyDirectories(settings->value(baseKey + QLatin1String(".TrimEmptyDirsFilter"), true).toBool());
-    ptw->setAutoSynchronization(settings->value(baseKey +  QLatin1String(".SyncWithEditor"), true).toBool());
+    ptw->setProjectFilter(
+        settings->value(baseKey + QLatin1String(".ProjectFilter"), kProjectFilterDefault).toBool());
+    ptw->setGeneratedFilesFilter(
+        settings->value(baseKey + QLatin1String(".GeneratedFilter"), kHideGeneratedFilesDefault)
+            .toBool());
+    ptw->setDisabledFilesFilter(
+        settings->value(baseKey + ".DisabledFilesFilter", kHideDisabledFilesDefault).toBool());
+    ptw->setTrimEmptyDirectories(
+        settings->value(baseKey + QLatin1String(".TrimEmptyDirsFilter"), kTrimEmptyDirsDefault)
+            .toBool());
+    ptw->setAutoSynchronization(
+        settings->value(baseKey + QLatin1String(".SyncWithEditor"), kSyncDefault).toBool());
 }
diff --git a/src/plugins/projectexplorer/projecttreewidget.h b/src/plugins/projectexplorer/projecttreewidget.h
index aa612fdf7e..c9afb44fab 100644
--- a/src/plugins/projectexplorer/projecttreewidget.h
+++ b/src/plugins/projectexplorer/projecttreewidget.h
@@ -114,7 +114,7 @@ public:
 
     Core::NavigationView createWidget() override;
     void restoreSettings(QSettings *settings, int position, QWidget *widget) override;
-    void saveSettings(QSettings *settings, int position, QWidget *widget) override;
+    void saveSettings(Utils::QtcSettings *settings, int position, QWidget *widget) override;
 };
 
 } // namespace Internal
diff --git a/src/plugins/projectexplorer/toolchainmanager.cpp b/src/plugins/projectexplorer/toolchainmanager.cpp
index e16f642952..546f553b0c 100644
--- a/src/plugins/projectexplorer/toolchainmanager.cpp
+++ b/src/plugins/projectexplorer/toolchainmanager.cpp
@@ -105,7 +105,8 @@ ToolChainManager::ToolChainManager(QObject *parent) :
     connect(this, &ToolChainManager::toolChainUpdated, this, &ToolChainManager::toolChainsChanged);
 
     QSettings * const s = Core::ICore::settings();
-    d->m_detectionSettings.detectX64AsX32 = s->value(DETECT_X64_AS_X32_KEY, false).toBool();
+    d->m_detectionSettings.detectX64AsX32
+        = s->value(DETECT_X64_AS_X32_KEY, ToolchainDetectionSettings().detectX64AsX32).toBool();
 }
 
 ToolChainManager::~ToolChainManager()
@@ -137,8 +138,10 @@ void ToolChainManager::saveToolChains()
     QTC_ASSERT(d->m_accessor, return);
 
     d->m_accessor->saveToolChains(d->m_toolChains, Core::ICore::dialogParent());
-    QSettings * const s = Core::ICore::settings();
-    s->setValue(DETECT_X64_AS_X32_KEY, d->m_detectionSettings.detectX64AsX32);
+    QtcSettings *const s = Core::ICore::settings();
+    s->setValueWithDefault(DETECT_X64_AS_X32_KEY,
+                           d->m_detectionSettings.detectX64AsX32,
+                           ToolchainDetectionSettings().detectX64AsX32);
 }
 
 QList<ToolChain *> ToolChainManager::toolChains(const ToolChain::Predicate &predicate)
diff --git a/src/plugins/texteditor/outlinefactory.cpp b/src/plugins/texteditor/outlinefactory.cpp
index 87a162e0d1..7c7e644b18 100644
--- a/src/plugins/texteditor/outlinefactory.cpp
+++ b/src/plugins/texteditor/outlinefactory.cpp
@@ -250,7 +250,7 @@ Core::NavigationView OutlineFactory::createWidget()
     return n;
 }
 
-void OutlineFactory::saveSettings(QSettings *settings, int position, QWidget *widget)
+void OutlineFactory::saveSettings(Utils::QtcSettings *settings, int position, QWidget *widget)
 {
     auto widgetStack = qobject_cast<OutlineWidgetStack *>(widget);
     Q_ASSERT(widgetStack);
diff --git a/src/plugins/texteditor/outlinefactory.h b/src/plugins/texteditor/outlinefactory.h
index 83d6e00522..0f72bcf6e5 100644
--- a/src/plugins/texteditor/outlinefactory.h
+++ b/src/plugins/texteditor/outlinefactory.h
@@ -79,7 +79,7 @@ public:
 
     // from INavigationWidgetFactory
     Core::NavigationView createWidget() override;
-    void saveSettings(QSettings *settings, int position, QWidget *widget) override;
+    void saveSettings(Utils::QtcSettings *settings, int position, QWidget *widget) override;
     void restoreSettings(QSettings *settings, int position, QWidget *widget) override;
 
 signals: