CppEditor: Show info bar for project-less file

While at it, centralize the code for handling the info bars and actions.

Change-Id: Ied62e3db268aaff3ef87e246bfe2b50399341be3
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/cpptools/cpptoolsconstants.h

@@ -50,6 +50,7 @@ const char LOWERCASE_CPPFILES_KEY[] = "LowerCaseFiles";
 enum { lowerCaseFilesDefault = 1 };
 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";
 const char CPPTOOLS_MODEL_MANAGER_PCH_USAGE[] = "PCHUsage";
 const char CPPTOOLS_INTERPRET_AMBIGIUOUS_HEADERS_AS_C_HEADERS[]
     = "InterpretAmbiguousHeadersAsCHeaders";

src/plugins/cpptools/cpptoolssettings.cpp

@@ -285,3 +285,21 @@ void CppToolsSettings::setShowHeaderErrorInfoBar(bool show)
     ICore::settings()->setValue(showHeaderErrorInfoBarKey(), show);
     emit showHeaderErrorInfoBarChanged(show);
 }
+
+static QString showNoProjectInfoBarKey()
+{
+    return QLatin1String(CppTools::Constants::CPPTOOLS_SETTINGSGROUP)
+         + QLatin1Char('/')
+         + QLatin1String(CppTools::Constants::CPPTOOLS_SHOW_INFO_BAR_FOR_FOR_NO_PROJECT);
+}
+
+bool CppToolsSettings::showNoProjectInfoBar() const
+{
+    return ICore::settings()->value(showNoProjectInfoBarKey(), true).toBool();
+}
+
+void CppToolsSettings::setShowNoProjectInfoBar(bool show)
+{
+    ICore::settings()->setValue(showNoProjectInfoBarKey(), show);
+    emit showNoProjectInfoBarChanged(show);
+}

src/plugins/cpptools/cpptoolssettings.h

@@ -66,9 +66,13 @@ public:
     bool showHeaderErrorInfoBar() const;
     void setShowHeaderErrorInfoBar(bool show);
 
+    bool showNoProjectInfoBar() const;
+    void setShowNoProjectInfoBar(bool show);
+
 signals:
     void editorDocumentOutlineSortingChanged(bool isSorted);
     void showHeaderErrorInfoBarChanged(bool isShown);
+    void showNoProjectInfoBarChanged(bool isShown);
 
 private:
     Internal::CppToolsSettingsPrivate *d;