Cpp: Use new settings API

Avoid writing defaults to the settings.

Task-number: QTCREATORBUG-24430
Change-Id: I8e1d5a5b8ca21ef96a68a4d71a7d97d138bd186b
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

10 files changed, 241 insertions, 154 deletions

diff --git a/src/plugins/cppeditor/cppincludehierarchy.cpp b/src/plugins/cppeditor/cppincludehierarchy.cpp
index f3a038c50de..2a9e9b7cfee 100644
--- a/src/plugins/cppeditor/cppincludehierarchy.cpp
+++ b/src/plugins/cppeditor/cppincludehierarchy.cpp
@@ -447,16 +447,18 @@ void CppIncludeHierarchyWidget::perform()
     showIncludeHierarchy();
 }
 
+const bool kSyncDefault = false;
+
 void CppIncludeHierarchyWidget::saveSettings(QSettings *settings, int position)
 {
     const QString key = QString("IncludeHierarchy.%1.SyncWithEditor").arg(position);
-    settings->setValue(key, m_toggleSync->isChecked());
+    QtcSettings::setValueWithDefault(settings, key, m_toggleSync->isChecked(), kSyncDefault);
 }
 
 void CppIncludeHierarchyWidget::restoreSettings(QSettings *settings, int position)
 {
     const QString key = QString("IncludeHierarchy.%1.SyncWithEditor").arg(position);
-    m_toggleSync->setChecked(settings->value(key).toBool());
+    m_toggleSync->setChecked(settings->value(key, kSyncDefault).toBool());
 }
 
 void CppIncludeHierarchyWidget::onItemActivated(const QModelIndex &index)
diff --git a/src/plugins/cppeditor/cppinsertvirtualmethods.cpp b/src/plugins/cppeditor/cppinsertvirtualmethods.cpp
index 49da4a8a772..7b2c36145c9 100644
--- a/src/plugins/cppeditor/cppinsertvirtualmethods.cpp
+++ b/src/plugins/cppeditor/cppinsertvirtualmethods.cpp
@@ -297,6 +297,13 @@ QStringList sortedAndTrimmedStringListWithoutEmptyElements(const QStringList &li
 namespace CppEditor {
 namespace Internal {
 
+const bool kInsertVirtualKeywordDefault = false;
+const bool kHideReimplementedFunctionsDefault = false;
+const bool kInsertOVerrideReplacementDefault = false;
+const int kOverrideReplacementIndexDefault = 0;
+const InsertVirtualMethodsDialog::ImplementationMode kImplementationModeDefault
+    = InsertVirtualMethodsDialog::ModeOnlyDeclarations;
+
 class VirtualMethodsSettings
 {
 public:
@@ -304,37 +311,50 @@ public:
     {
         QSettings *s = Core::ICore::settings();
         s->beginGroup(group());
-        insertVirtualKeyword = s->value(insertVirtualKeywordKey(), false).toBool();
-        hideReimplementedFunctions = s->value(hideReimplementedFunctionsKey(), false).toBool();
-        insertOverrideReplacement = s->value(insertOverrideReplacementKey(), false).toBool();
-        overrideReplacementIndex = s->value(overrideReplacementIndexKey(), 0).toInt();
+        insertVirtualKeyword = s->value(insertVirtualKeywordKey(), kInsertVirtualKeywordDefault)
+                                   .toBool();
+        hideReimplementedFunctions
+            = s->value(hideReimplementedFunctionsKey(), kHideReimplementedFunctionsDefault).toBool();
+        insertOverrideReplacement
+            = s->value(insertOverrideReplacementKey(), kInsertOVerrideReplacementDefault).toBool();
+        overrideReplacementIndex
+            = s->value(overrideReplacementIndexKey(), kOverrideReplacementIndexDefault).toInt();
         userAddedOverrideReplacements = s->value(userAddedOverrideReplacementsKey()).toStringList();
         implementationMode = static_cast<InsertVirtualMethodsDialog::ImplementationMode>(
-                    s->value(implementationModeKey(), 1).toInt());
+            s->value(implementationModeKey(), int(kImplementationModeDefault)).toInt());
         s->endGroup();
     }
 
     void write() const
     {
-        QSettings *s = Core::ICore::settings();
+        Utils::QtcSettings *s = Core::ICore::settings();
         s->beginGroup(group());
-        s->setValue(insertVirtualKeywordKey(), insertVirtualKeyword);
-        s->setValue(hideReimplementedFunctionsKey(), hideReimplementedFunctions);
-        s->setValue(insertOverrideReplacementKey(), insertOverrideReplacement);
-        s->setValue(overrideReplacementIndexKey(), overrideReplacementIndex);
-        s->setValue(userAddedOverrideReplacementsKey(), userAddedOverrideReplacements);
-        s->setValue(implementationModeKey(), implementationMode);
+        s->setValueWithDefault(insertVirtualKeywordKey(),
+                               insertVirtualKeyword,
+                               kInsertVirtualKeywordDefault);
+        s->setValueWithDefault(hideReimplementedFunctionsKey(),
+                               hideReimplementedFunctions,
+                               kHideReimplementedFunctionsDefault);
+        s->setValueWithDefault(insertOverrideReplacementKey(),
+                               insertOverrideReplacement,
+                               kInsertOVerrideReplacementDefault);
+        s->setValueWithDefault(overrideReplacementIndexKey(),
+                               overrideReplacementIndex,
+                               kOverrideReplacementIndexDefault);
+        s->setValueWithDefault(userAddedOverrideReplacementsKey(), userAddedOverrideReplacements);
+        s->setValueWithDefault(implementationModeKey(),
+                               int(implementationMode),
+                               int(kImplementationModeDefault));
         s->endGroup();
     }
 
     QString overrideReplacement; // internal
     QStringList userAddedOverrideReplacements;
-    InsertVirtualMethodsDialog::ImplementationMode implementationMode =
-            InsertVirtualMethodsDialog::ModeOnlyDeclarations;
-    int overrideReplacementIndex = 0;
-    bool insertVirtualKeyword = false;
-    bool hideReimplementedFunctions = false;
-    bool insertOverrideReplacement = false;
+    InsertVirtualMethodsDialog::ImplementationMode implementationMode = kImplementationModeDefault;
+    int overrideReplacementIndex = kOverrideReplacementIndexDefault;
+    bool insertVirtualKeyword = kInsertVirtualKeywordDefault;
+    bool hideReimplementedFunctions = kHideReimplementedFunctionsDefault;
+    bool insertOverrideReplacement = kInsertOVerrideReplacementDefault;
 
 private:
     using _ = QLatin1String;
diff --git a/src/plugins/cppeditor/cppquickfixsettings.cpp b/src/plugins/cppeditor/cppquickfixsettings.cpp
index a2ec232097c..6d016d6e203 100644
--- a/src/plugins/cppeditor/cppquickfixsettings.cpp
+++ b/src/plugins/cppeditor/cppquickfixsettings.cpp
@@ -25,8 +25,11 @@
 
 #include "cppquickfixsettings.h"
 #include "cppeditorconstants.h"
+
 #include <coreplugin/icore.h>
 #include <cpptools/cppcodestylesettings.h>
+#include <utils/qtcsettings.h>
+
 #include <QRegularExpression>
 
 namespace CppEditor {
@@ -54,81 +57,66 @@ void CppQuickFixSettings::loadGlobalSettings()
 
 void CppQuickFixSettings::loadSettingsFrom(QSettings *s)
 {
-    s->beginGroup(QLatin1String(Constants::QUICK_FIX_SETTINGS_ID));
-    getterOutsideClassFrom = s->value(QLatin1String(
-                                          Constants::QUICK_FIX_SETTING_GETTER_OUTSIDE_CLASS_FROM),
-                                      getterOutsideClassFrom)
+    CppQuickFixSettings def;
+    s->beginGroup(Constants::QUICK_FIX_SETTINGS_ID);
+    getterOutsideClassFrom = s->value(Constants::QUICK_FIX_SETTING_GETTER_OUTSIDE_CLASS_FROM,
+                                      def.getterOutsideClassFrom)
                                  .toInt();
-    getterInCppFileFrom = s->value(QLatin1String(
-                                       Constants::QUICK_FIX_SETTING_GETTER_IN_CPP_FILE_FROM),
-                                   getterInCppFileFrom)
+    getterInCppFileFrom = s->value(Constants::QUICK_FIX_SETTING_GETTER_IN_CPP_FILE_FROM,
+                                   def.getterInCppFileFrom)
                               .toInt();
-    setterOutsideClassFrom = s->value(QLatin1String(
-                                          Constants::QUICK_FIX_SETTING_SETTER_OUTSIDE_CLASS_FROM),
-                                      setterOutsideClassFrom)
+    setterOutsideClassFrom = s->value(Constants::QUICK_FIX_SETTING_SETTER_OUTSIDE_CLASS_FROM,
+                                      def.setterOutsideClassFrom)
                                  .toInt();
-    setterInCppFileFrom = s->value(QLatin1String(
-                                       Constants::QUICK_FIX_SETTING_SETTER_IN_CPP_FILE_FROM),
-                                   setterInCppFileFrom)
+    setterInCppFileFrom = s->value(Constants::QUICK_FIX_SETTING_SETTER_IN_CPP_FILE_FROM,
+                                   def.setterInCppFileFrom)
                               .toInt();
-    getterAttributes = s->value(QLatin1String(Constants::QUICK_FIX_SETTING_GETTER_ATTRIBUTES),
-                                getterAttributes)
-                           .toString();
-    getterNameTemplate = s->value(QLatin1String(Constants::QUICK_FIX_SETTING_GETTER_NAME_TEMPLATE),
-                                  getterNameTemplate)
+    getterAttributes
+        = s->value(Constants::QUICK_FIX_SETTING_GETTER_ATTRIBUTES, def.getterAttributes).toString();
+    getterNameTemplate = s->value(Constants::QUICK_FIX_SETTING_GETTER_NAME_TEMPLATE,
+                                  def.getterNameTemplate)
                              .toString();
-    setterNameTemplate = s->value(QLatin1String(Constants::QUICK_FIX_SETTING_SETTER_NAME_TEMPLATE),
-                                  setterNameTemplate)
+    setterNameTemplate = s->value(Constants::QUICK_FIX_SETTING_SETTER_NAME_TEMPLATE,
+                                  def.setterNameTemplate)
                              .toString();
-    setterParameterNameTemplate = s->value(QLatin1String(
-                                               Constants::QUICK_FIX_SETTING_SETTER_PARAMETER_NAME),
-                                           setterParameterNameTemplate)
+    setterParameterNameTemplate = s->value(Constants::QUICK_FIX_SETTING_SETTER_PARAMETER_NAME,
+                                           def.setterParameterNameTemplate)
                                       .toString();
-    resetNameTemplate = s->value(QLatin1String(Constants::QUICK_FIX_SETTING_RESET_NAME_TEMPLATE),
-                                 resetNameTemplate)
+    resetNameTemplate = s->value(Constants::QUICK_FIX_SETTING_RESET_NAME_TEMPLATE,
+                                 def.resetNameTemplate)
                             .toString();
-    signalNameTemplate = s->value(QLatin1String(Constants::QUICK_FIX_SETTING_SIGNAL_NAME_TEMPLATE),
-                                  signalNameTemplate)
+    signalNameTemplate = s->value(Constants::QUICK_FIX_SETTING_SIGNAL_NAME_TEMPLATE,
+                                  def.signalNameTemplate)
                              .toString();
-    signalWithNewValue = s->value(QLatin1String(Constants::QUICK_FIX_SETTING_SIGNAL_WITH_NEW_VALUE),
-                                  signalWithNewValue)
+    signalWithNewValue = s->value(Constants::QUICK_FIX_SETTING_SIGNAL_WITH_NEW_VALUE,
+                                  def.signalWithNewValue)
                              .toBool();
-    setterAsSlot = s->value(QLatin1String(Constants::QUICK_FIX_SETTING_SETTER_AS_SLOT), setterAsSlot)
-                       .toBool();
+    setterAsSlot = s->value(Constants::QUICK_FIX_SETTING_SETTER_AS_SLOT, def.setterAsSlot).toBool();
     cppFileNamespaceHandling = static_cast<MissingNamespaceHandling>(
-        s->value(QLatin1String(Constants::QUICK_FIX_SETTING_CPP_FILE_NAMESPACE_HANDLING),
-                 static_cast<int>(cppFileNamespaceHandling))
+        s->value(Constants::QUICK_FIX_SETTING_CPP_FILE_NAMESPACE_HANDLING,
+                 static_cast<int>(def.cppFileNamespaceHandling))
             .toInt());
-    memberVariableNameTemplate
-        = s->value(QLatin1String(Constants::QUICK_FIX_SETTING_MEMBER_VARIABEL_NAME_TEMPLATE),
-                   memberVariableNameTemplate)
-              .toString();
-    valueTypes = s->value(QLatin1String(Constants::QUICK_FIX_SETTING_VALUE_TYPES), valueTypes)
-                     .toStringList();
-    int size = s->beginReadArray(QLatin1String(Constants::QUICK_FIX_SETTING_CUSTOM_TEMPLATES));
+    memberVariableNameTemplate = s->value(Constants::QUICK_FIX_SETTING_MEMBER_VARIABEL_NAME_TEMPLATE,
+                                          def.memberVariableNameTemplate)
+                                     .toString();
+    valueTypes = s->value(Constants::QUICK_FIX_SETTING_VALUE_TYPES, def.valueTypes).toStringList();
+    customTemplates = def.customTemplates;
+    int size = s->beginReadArray(Constants::QUICK_FIX_SETTING_CUSTOM_TEMPLATES);
     if (size > 0)
         customTemplates.clear();
 
     for (int i = 0; i < size; ++i) {
         s->setArrayIndex(i);
         CustomTemplate c;
-        c.types = s->value(QLatin1String(Constants::QUICK_FIX_SETTING_CUSTOM_TEMPLATE_TYPES))
-                      .toStringList();
+        c.types = s->value(Constants::QUICK_FIX_SETTING_CUSTOM_TEMPLATE_TYPES).toStringList();
         if (c.types.isEmpty())
             continue;
-        c.equalComparison = s->value(QLatin1String(
-                                         Constants::QUICK_FIX_SETTING_CUSTOM_TEMPLATE_COMPARISON))
+        c.equalComparison = s->value(Constants::QUICK_FIX_SETTING_CUSTOM_TEMPLATE_COMPARISON)
                                 .toString();
-        c.returnType = s->value(QLatin1String(
-                                    Constants::QUICK_FIX_SETTING_CUSTOM_TEMPLATE_RETURN_TYPE))
-                           .toString();
+        c.returnType = s->value(Constants::QUICK_FIX_SETTING_CUSTOM_TEMPLATE_RETURN_TYPE).toString();
         c.returnExpression
-            = s->value(
-                   QLatin1String(Constants::QUICK_FIX_SETTING_CUSTOM_TEMPLATE_RETURN_EXPRESSION))
-                  .toString();
-        c.assignment = s->value(
-                            QLatin1String(Constants::QUICK_FIX_SETTING_CUSTOM_TEMPLATE_ASSIGNMENT))
-                           .toString();
+            = s->value(Constants::QUICK_FIX_SETTING_CUSTOM_TEMPLATE_RETURN_EXPRESSION).toString();
+        c.assignment = s->value(Constants::QUICK_FIX_SETTING_CUSTOM_TEMPLATE_ASSIGNMENT).toString();
         if (c.assignment.isEmpty() && c.returnType.isEmpty() && c.equalComparison.isEmpty())
             continue; // nothing custom here
 
@@ -140,45 +128,86 @@ void CppQuickFixSettings::loadSettingsFrom(QSettings *s)
 
 void CppQuickFixSettings::saveSettingsTo(QSettings *s)
 {
-    s->beginGroup(QLatin1String(Constants::QUICK_FIX_SETTINGS_ID));
-    s->setValue(QLatin1String(Constants::QUICK_FIX_SETTING_GETTER_OUTSIDE_CLASS_FROM),
-                getterOutsideClassFrom);
-    s->setValue(QLatin1String(Constants::QUICK_FIX_SETTING_GETTER_IN_CPP_FILE_FROM),
-                getterInCppFileFrom);
-    s->setValue(QLatin1String(Constants::QUICK_FIX_SETTING_SETTER_OUTSIDE_CLASS_FROM),
-                setterOutsideClassFrom);
-    s->setValue(QLatin1String(Constants::QUICK_FIX_SETTING_SETTER_IN_CPP_FILE_FROM),
-                setterInCppFileFrom);
-
-    s->setValue(QLatin1String(Constants::QUICK_FIX_SETTING_GETTER_ATTRIBUTES), getterAttributes);
-    s->setValue(QLatin1String(Constants::QUICK_FIX_SETTING_GETTER_NAME_TEMPLATE), getterNameTemplate);
-    s->setValue(QLatin1String(Constants::QUICK_FIX_SETTING_SETTER_NAME_TEMPLATE), setterNameTemplate);
-    s->setValue(QLatin1String(Constants::QUICK_FIX_SETTING_RESET_NAME_TEMPLATE), resetNameTemplate);
-    s->setValue(QLatin1String(Constants::QUICK_FIX_SETTING_SIGNAL_NAME_TEMPLATE), signalNameTemplate);
-    s->setValue(QLatin1String(Constants::QUICK_FIX_SETTING_SIGNAL_WITH_NEW_VALUE), signalWithNewValue);
-    s->setValue(QLatin1String(Constants::QUICK_FIX_SETTING_CPP_FILE_NAMESPACE_HANDLING),
-                static_cast<int>(cppFileNamespaceHandling));
-    s->setValue(QLatin1String(Constants::QUICK_FIX_SETTING_MEMBER_VARIABEL_NAME_TEMPLATE),
-                memberVariableNameTemplate);
-    s->setValue(QLatin1String(Constants::QUICK_FIX_SETTING_SETTER_PARAMETER_NAME),
-                setterParameterNameTemplate);
-    s->setValue(QLatin1String(Constants::QUICK_FIX_SETTING_SETTER_AS_SLOT), setterAsSlot);
-    s->setValue(QLatin1String(Constants::QUICK_FIX_SETTING_VALUE_TYPES), valueTypes);
-    s->beginWriteArray(QLatin1String(Constants::QUICK_FIX_SETTING_CUSTOM_TEMPLATES));
-    for (int i = 0; i < static_cast<int>(customTemplates.size()); ++i) {
-        const auto &c = customTemplates[i];
-        s->setArrayIndex(i);
-        s->setValue(QLatin1String(Constants::QUICK_FIX_SETTING_CUSTOM_TEMPLATE_TYPES), c.types);
-        s->setValue(QLatin1String(Constants::QUICK_FIX_SETTING_CUSTOM_TEMPLATE_COMPARISON),
-                    c.equalComparison);
-        s->setValue(QLatin1String(Constants::QUICK_FIX_SETTING_CUSTOM_TEMPLATE_RETURN_TYPE),
-                    c.returnType);
-        s->setValue(QLatin1String(Constants::QUICK_FIX_SETTING_CUSTOM_TEMPLATE_RETURN_EXPRESSION),
-                    c.returnExpression);
-        s->setValue(QLatin1String(Constants::QUICK_FIX_SETTING_CUSTOM_TEMPLATE_ASSIGNMENT),
-                    c.assignment);
+    using Utils::QtcSettings;
+    CppQuickFixSettings def;
+    s->beginGroup(Constants::QUICK_FIX_SETTINGS_ID);
+    QtcSettings::setValueWithDefault(s,
+                                     Constants::QUICK_FIX_SETTING_GETTER_OUTSIDE_CLASS_FROM,
+                                     getterOutsideClassFrom,
+                                     def.getterOutsideClassFrom);
+    QtcSettings::setValueWithDefault(s,
+                                     Constants::QUICK_FIX_SETTING_GETTER_IN_CPP_FILE_FROM,
+                                     getterInCppFileFrom,
+                                     def.getterInCppFileFrom);
+    QtcSettings::setValueWithDefault(s,
+                                     Constants::QUICK_FIX_SETTING_SETTER_OUTSIDE_CLASS_FROM,
+                                     setterOutsideClassFrom,
+                                     def.setterOutsideClassFrom);
+    QtcSettings::setValueWithDefault(s,
+                                     Constants::QUICK_FIX_SETTING_SETTER_IN_CPP_FILE_FROM,
+                                     setterInCppFileFrom,
+                                     def.setterInCppFileFrom);
+
+    QtcSettings::setValueWithDefault(s,
+                                     Constants::QUICK_FIX_SETTING_GETTER_ATTRIBUTES,
+                                     getterAttributes,
+                                     def.getterAttributes);
+    QtcSettings::setValueWithDefault(s,
+                                     Constants::QUICK_FIX_SETTING_GETTER_NAME_TEMPLATE,
+                                     getterNameTemplate,
+                                     def.getterNameTemplate);
+    QtcSettings::setValueWithDefault(s,
+                                     Constants::QUICK_FIX_SETTING_SETTER_NAME_TEMPLATE,
+                                     setterNameTemplate,
+                                     def.setterNameTemplate);
+    QtcSettings::setValueWithDefault(s,
+                                     Constants::QUICK_FIX_SETTING_RESET_NAME_TEMPLATE,
+                                     resetNameTemplate,
+                                     def.resetNameTemplate);
+    QtcSettings::setValueWithDefault(s,
+                                     Constants::QUICK_FIX_SETTING_SIGNAL_NAME_TEMPLATE,
+                                     signalNameTemplate,
+                                     def.signalNameTemplate);
+    QtcSettings::setValueWithDefault(s,
+                                     Constants::QUICK_FIX_SETTING_SIGNAL_WITH_NEW_VALUE,
+                                     signalWithNewValue,
+                                     def.signalWithNewValue);
+    QtcSettings::setValueWithDefault(s,
+                                     Constants::QUICK_FIX_SETTING_CPP_FILE_NAMESPACE_HANDLING,
+                                     int(cppFileNamespaceHandling),
+                                     int(def.cppFileNamespaceHandling));
+    QtcSettings::setValueWithDefault(s,
+                                     Constants::QUICK_FIX_SETTING_MEMBER_VARIABEL_NAME_TEMPLATE,
+                                     memberVariableNameTemplate,
+                                     def.memberVariableNameTemplate);
+    QtcSettings::setValueWithDefault(s,
+                                     Constants::QUICK_FIX_SETTING_SETTER_PARAMETER_NAME,
+                                     setterParameterNameTemplate,
+                                     def.setterParameterNameTemplate);
+    QtcSettings::setValueWithDefault(s,
+                                     Constants::QUICK_FIX_SETTING_SETTER_AS_SLOT,
+                                     setterAsSlot,
+                                     def.setterAsSlot);
+    QtcSettings::setValueWithDefault(s,
+                                     Constants::QUICK_FIX_SETTING_VALUE_TYPES,
+                                     valueTypes,
+                                     def.valueTypes);
+    if (customTemplates == def.customTemplates) {
+        s->remove(Constants::QUICK_FIX_SETTING_CUSTOM_TEMPLATES);
+    } else {
+        s->beginWriteArray(Constants::QUICK_FIX_SETTING_CUSTOM_TEMPLATES);
+        for (int i = 0; i < static_cast<int>(customTemplates.size()); ++i) {
+            const auto &c = customTemplates[i];
+            s->setArrayIndex(i);
+            s->setValue(Constants::QUICK_FIX_SETTING_CUSTOM_TEMPLATE_TYPES, c.types);
+            s->setValue(Constants::QUICK_FIX_SETTING_CUSTOM_TEMPLATE_COMPARISON, c.equalComparison);
+            s->setValue(Constants::QUICK_FIX_SETTING_CUSTOM_TEMPLATE_RETURN_TYPE, c.returnType);
+            s->setValue(Constants::QUICK_FIX_SETTING_CUSTOM_TEMPLATE_RETURN_EXPRESSION,
+                        c.returnExpression);
+            s->setValue(Constants::QUICK_FIX_SETTING_CUSTOM_TEMPLATE_ASSIGNMENT, c.assignment);
+        }
+        s->endArray();
     }
-    s->endArray();
     s->endGroup();
 }
 
diff --git a/src/plugins/cppeditor/cppquickfixsettings.h b/src/plugins/cppeditor/cppquickfixsettings.h
index 2b13f76de02..89d9f2a9f4b 100644
--- a/src/plugins/cppeditor/cppquickfixsettings.h
+++ b/src/plugins/cppeditor/cppquickfixsettings.h
@@ -48,6 +48,14 @@ public:
     }
     struct CustomTemplate
     {
+        bool operator==(const CustomTemplate &b) const
+        {
+            return types == b.types
+                && equalComparison == b.equalComparison
+                && returnExpression == b.returnExpression
+                && returnType == b.returnType
+                && assignment == b.assignment;
+        }
         QStringList types;
         QString equalComparison;
         QString returnExpression;
diff --git a/src/plugins/cpptools/cppfilesettingspage.cpp b/src/plugins/cpptools/cppfilesettingspage.cpp
index 0b711a458bf..4d1d738e8cc 100644
--- a/src/plugins/cpptools/cppfilesettingspage.cpp
+++ b/src/plugins/cpptools/cppfilesettingspage.cpp
@@ -73,40 +73,46 @@ const char *licenseTemplateTemplate = QT_TRANSLATE_NOOP("CppTools::Internal::Cpp
 
 void CppFileSettings::toSettings(QSettings *s) const
 {
-    s->beginGroup(QLatin1String(Constants::CPPTOOLS_SETTINGSGROUP));
-    s->setValue(QLatin1String(headerPrefixesKeyC), headerPrefixes);
-    s->setValue(QLatin1String(sourcePrefixesKeyC), sourcePrefixes);
-    s->setValue(QLatin1String(headerSuffixKeyC), headerSuffix);
-    s->setValue(QLatin1String(sourceSuffixKeyC), sourceSuffix);
-    s->setValue(QLatin1String(headerSearchPathsKeyC), headerSearchPaths);
-    s->setValue(QLatin1String(sourceSearchPathsKeyC), sourceSearchPaths);
-    s->setValue(QLatin1String(Constants::LOWERCASE_CPPFILES_KEY), lowerCaseFiles);
-    s->setValue(QLatin1String(headerPragmaOnceC), headerPragmaOnce);
-    s->setValue(QLatin1String(licenseTemplatePathKeyC), licenseTemplatePath);
+    using Utils::QtcSettings;
+    const CppFileSettings def;
+    s->beginGroup(Constants::CPPTOOLS_SETTINGSGROUP);
+    QtcSettings::setValueWithDefault(s, headerPrefixesKeyC, headerPrefixes, def.headerPrefixes);
+    QtcSettings::setValueWithDefault(s, sourcePrefixesKeyC, sourcePrefixes, def.sourcePrefixes);
+    QtcSettings::setValueWithDefault(s, headerSuffixKeyC, headerSuffix, def.headerSuffix);
+    QtcSettings::setValueWithDefault(s, sourceSuffixKeyC, sourceSuffix, def.sourceSuffix);
+    QtcSettings::setValueWithDefault(s,
+                                     headerSearchPathsKeyC,
+                                     headerSearchPaths,
+                                     def.headerSearchPaths);
+    QtcSettings::setValueWithDefault(s,
+                                     sourceSearchPathsKeyC,
+                                     sourceSearchPaths,
+                                     def.sourceSearchPaths);
+    QtcSettings::setValueWithDefault(s,
+                                     Constants::LOWERCASE_CPPFILES_KEY,
+                                     lowerCaseFiles,
+                                     def.lowerCaseFiles);
+    QtcSettings::setValueWithDefault(s, headerPragmaOnceC, headerPragmaOnce, def.headerPragmaOnce);
+    QtcSettings::setValueWithDefault(s,
+                                     licenseTemplatePathKeyC,
+                                     licenseTemplatePath,
+                                     def.licenseTemplatePath);
     s->endGroup();
 }
 
 void CppFileSettings::fromSettings(QSettings *s)
 {
-    const QStringList defaultHeaderSearchPaths
-            = QStringList({"include", "Include", QDir::toNativeSeparators("../include"),
-                           QDir::toNativeSeparators("../Include")});
-    const QStringList defaultSourceSearchPaths
-            = QStringList({QDir::toNativeSeparators("../src"), QDir::toNativeSeparators("../Src"),
-                           ".."});
-    s->beginGroup(QLatin1String(Constants::CPPTOOLS_SETTINGSGROUP));
-    headerPrefixes = s->value(QLatin1String(headerPrefixesKeyC)).toStringList();
-    sourcePrefixes = s->value(QLatin1String(sourcePrefixesKeyC)).toStringList();
-    headerSuffix = s->value(QLatin1String(headerSuffixKeyC), QLatin1String("h")).toString();
-    sourceSuffix = s->value(QLatin1String(sourceSuffixKeyC), QLatin1String("cpp")).toString();
-    headerSearchPaths = s->value(QLatin1String(headerSearchPathsKeyC), defaultHeaderSearchPaths)
-            .toStringList();
-    sourceSearchPaths = s->value(QLatin1String(sourceSearchPathsKeyC), defaultSourceSearchPaths)
-            .toStringList();
-    const bool lowerCaseDefault = Constants::lowerCaseFilesDefault;
-    lowerCaseFiles = s->value(QLatin1String(Constants::LOWERCASE_CPPFILES_KEY), QVariant(lowerCaseDefault)).toBool();
-    headerPragmaOnce = s->value(headerPragmaOnceC, headerPragmaOnce).toBool();
-    licenseTemplatePath = s->value(QLatin1String(licenseTemplatePathKeyC), QString()).toString();
+    const CppFileSettings def;
+    s->beginGroup(Constants::CPPTOOLS_SETTINGSGROUP);
+    headerPrefixes = s->value(headerPrefixesKeyC, def.headerPrefixes).toStringList();
+    sourcePrefixes = s->value(sourcePrefixesKeyC, def.sourcePrefixes).toStringList();
+    headerSuffix = s->value(headerSuffixKeyC, def.headerSuffix).toString();
+    sourceSuffix = s->value(sourceSuffixKeyC, def.sourceSuffix).toString();
+    headerSearchPaths = s->value(headerSearchPathsKeyC, def.headerSearchPaths).toStringList();
+    sourceSearchPaths = s->value(sourceSearchPathsKeyC, def.sourceSearchPaths).toStringList();
+    lowerCaseFiles = s->value(Constants::LOWERCASE_CPPFILES_KEY, def.lowerCaseFiles).toBool();
+    headerPragmaOnce = s->value(headerPragmaOnceC, def.headerPragmaOnce).toBool();
+    licenseTemplatePath = s->value(licenseTemplatePathKeyC, def.licenseTemplatePath).toString();
     s->endGroup();
 }
 
diff --git a/src/plugins/cpptools/cppfilesettingspage.h b/src/plugins/cpptools/cppfilesettingspage.h
index 4fb2db74b9a..e3533b396fc 100644
--- a/src/plugins/cpptools/cppfilesettingspage.h
+++ b/src/plugins/cpptools/cppfilesettingspage.h
@@ -25,8 +25,12 @@
 
 #pragma once
 
+#include "cpptoolsconstants.h"
+
 #include <coreplugin/dialogs/ioptionspage.h>
 
+#include <QDir>
+
 QT_BEGIN_NAMESPACE
 class QSettings;
 QT_END_NAMESPACE
@@ -37,14 +41,19 @@ namespace Internal {
 struct CppFileSettings
 {
     QStringList headerPrefixes;
-    QString headerSuffix;
-    QStringList headerSearchPaths;
+    QString headerSuffix = "h";
+    QStringList headerSearchPaths = {"include",
+                                     "Include",
+                                     QDir::toNativeSeparators("../include"),
+                                     QDir::toNativeSeparators("../Include")};
     QStringList sourcePrefixes;
-    QString sourceSuffix;
-    QStringList sourceSearchPaths;
+    QString sourceSuffix = "cpp";
+    QStringList sourceSearchPaths = {QDir::toNativeSeparators("../src"),
+                                     QDir::toNativeSeparators("../Src"),
+                                     ".."};
     QString licenseTemplatePath;
     bool headerPragmaOnce = false;
-    bool lowerCaseFiles = false;
+    bool lowerCaseFiles = Constants::LOWERCASE_CPPFILES_DEFAULT;
 
     void toSettings(QSettings *) const;
     void fromSettings(QSettings *);
diff --git a/src/plugins/cpptools/cpptoolsconstants.h b/src/plugins/cpptools/cpptoolsconstants.h
index 752bfbff87a..2a3bfe13a8b 100644
--- a/src/plugins/cpptools/cpptoolsconstants.h
+++ b/src/plugins/cpptools/cpptoolsconstants.h
@@ -49,7 +49,7 @@ const char AMBIGUOUS_HEADER_MIMETYPE[] = "application/vnd.qtc.ambiguousheader";
 // QSettings keys for use by the "New Class" wizards.
 const char CPPTOOLS_SETTINGSGROUP[] = "CppTools";
 const char LOWERCASE_CPPFILES_KEY[] = "LowerCaseFiles";
-enum { lowerCaseFilesDefault = 1 };
+const bool LOWERCASE_CPPFILES_DEFAULT = true;
 const char CPPTOOLS_SORT_EDITOR_DOCUMENT_OUTLINE[] = "SortedMethodOverview";
 const char CPPTOOLS_SHOW_INFO_BAR_FOR_HEADER_ERRORS[] = "ShowInfoBarForHeaderErrors";
 const char CPPTOOLS_SHOW_INFO_BAR_FOR_FOR_NO_PROJECT[] = "ShowInfoBarForNoProject";
diff --git a/src/plugins/cpptools/cpptoolssettings.cpp b/src/plugins/cpptools/cpptoolssettings.cpp
index 72b8453f369..91b22ffa54e 100644
--- a/src/plugins/cpptools/cpptoolssettings.cpp
+++ b/src/plugins/cpptools/cpptoolssettings.cpp
@@ -43,6 +43,9 @@
 #include <QSettings>
 
 static const char idKey[] = "CppGlobal";
+const bool kSortEditorDocumentOutlineDefault = true;
+const bool kShowHeaderErrorInfoBarDefault = true;
+const bool kShowNoProjectInfoBarDefault = true;
 
 using namespace Core;
 using namespace CppTools;
@@ -254,12 +257,16 @@ static QString sortEditorDocumentOutlineKey()
 
 bool CppToolsSettings::sortedEditorDocumentOutline() const
 {
-    return ICore::settings()->value(sortEditorDocumentOutlineKey(), true).toBool();
+    return ICore::settings()
+        ->value(sortEditorDocumentOutlineKey(), kSortEditorDocumentOutlineDefault)
+        .toBool();
 }
 
 void CppToolsSettings::setSortedEditorDocumentOutline(bool sorted)
 {
-    ICore::settings()->setValue(sortEditorDocumentOutlineKey(), sorted);
+    ICore::settings()->setValueWithDefault(sortEditorDocumentOutlineKey(),
+                                           sorted,
+                                           kSortEditorDocumentOutlineDefault);
     emit editorDocumentOutlineSortingChanged(sorted);
 }
 
@@ -272,12 +279,16 @@ static QString showHeaderErrorInfoBarKey()
 
 bool CppToolsSettings::showHeaderErrorInfoBar() const
 {
-    return ICore::settings()->value(showHeaderErrorInfoBarKey(), true).toBool();
+    return ICore::settings()
+        ->value(showHeaderErrorInfoBarKey(), kShowHeaderErrorInfoBarDefault)
+        .toBool();
 }
 
 void CppToolsSettings::setShowHeaderErrorInfoBar(bool show)
 {
-    ICore::settings()->setValue(showHeaderErrorInfoBarKey(), show);
+    ICore::settings()->setValueWithDefault(showHeaderErrorInfoBarKey(),
+                                           show,
+                                           kShowHeaderErrorInfoBarDefault);
     emit showHeaderErrorInfoBarChanged(show);
 }
 
@@ -290,11 +301,13 @@ static QString showNoProjectInfoBarKey()
 
 bool CppToolsSettings::showNoProjectInfoBar() const
 {
-    return ICore::settings()->value(showNoProjectInfoBarKey(), true).toBool();
+    return ICore::settings()->value(showNoProjectInfoBarKey(), kShowNoProjectInfoBarDefault).toBool();
 }
 
 void CppToolsSettings::setShowNoProjectInfoBar(bool show)
 {
-    ICore::settings()->setValue(showNoProjectInfoBarKey(), show);
+    ICore::settings()->setValueWithDefault(showNoProjectInfoBarKey(),
+                                           show,
+                                           kShowNoProjectInfoBarDefault);
     emit showNoProjectInfoBarChanged(show);
 }
diff --git a/src/plugins/designer/cpp/formclasswizardpage.cpp b/src/plugins/designer/cpp/formclasswizardpage.cpp
index 5fd54dbaa0d..0e9386236e1 100644
--- a/src/plugins/designer/cpp/formclasswizardpage.cpp
+++ b/src/plugins/designer/cpp/formclasswizardpage.cpp
@@ -67,7 +67,7 @@ bool FormClassWizardPage::lowercaseHeaderFiles()
     QString lowerCaseSettingsKey = CppTools::Constants::CPPTOOLS_SETTINGSGROUP;
     lowerCaseSettingsKey += '/';
     lowerCaseSettingsKey += CppTools::Constants::LOWERCASE_CPPFILES_KEY;
-    const bool lowerCaseDefault = CppTools::Constants::lowerCaseFilesDefault;
+    const bool lowerCaseDefault = CppTools::Constants::LOWERCASE_CPPFILES_DEFAULT;
     return Core::ICore::settings()->value(lowerCaseSettingsKey, QVariant(lowerCaseDefault)).toBool();
 }
 
diff --git a/src/plugins/qmakeprojectmanager/wizards/qtwizard.cpp b/src/plugins/qmakeprojectmanager/wizards/qtwizard.cpp
index 659d3f1899e..70a489dd07e 100644
--- a/src/plugins/qmakeprojectmanager/wizards/qtwizard.cpp
+++ b/src/plugins/qmakeprojectmanager/wizards/qtwizard.cpp
@@ -112,7 +112,7 @@ bool QtWizard::lowerCaseFiles()
     QString lowerCaseSettingsKey = QLatin1String(CppTools::Constants::CPPTOOLS_SETTINGSGROUP);
     lowerCaseSettingsKey += QLatin1Char('/');
     lowerCaseSettingsKey += QLatin1String(CppTools::Constants::LOWERCASE_CPPFILES_KEY);
-    const bool lowerCaseDefault = CppTools::Constants::lowerCaseFilesDefault;
+    const bool lowerCaseDefault = CppTools::Constants::LOWERCASE_CPPFILES_DEFAULT;
     return Core::ICore::settings()->value(lowerCaseSettingsKey, QVariant(lowerCaseDefault)).toBool();
 }