[TD]fix line standard drop downs

src/Mod/TechDraw/App/LineGenerator.cpp

@@ -55,6 +55,14 @@ using namespace TechDraw;
 using DU = DrawUtil;
 
 LineGenerator::LineGenerator()
+{
+    reloadDescriptions();
+//    m_elementDefs = loadElements();
+//    m_lineDefs = getLineDefinitions();
+//    m_lineDescs = getLineDescriptions();
+}
+
+void LineGenerator::reloadDescriptions()
 {
     m_elementDefs = loadElements();
     m_lineDefs = getLineDefinitions();

src/Mod/TechDraw/App/LineGenerator.h

@@ -63,6 +63,10 @@ public:
     static std::vector<std::string> getAvailableLineStandards();
     static std::string getLineStandardsBody();
 
+    //! if the line standard changes during a lineGenerator's life time
+    //! then the elements and line descriptions need to be reloaded using the
+    //! new standard.
+    void reloadDescriptions();
     //! get line descriptions from memory
     std::vector<std::string> getLoadedDescriptions();
     //! get line descriptions from file

src/Mod/TechDraw/App/Preferences.cpp

@@ -425,6 +425,12 @@ int Preferences::lineStandard()
     return getPreferenceGroup("Standards")->GetInt("LineStandard", 1);
 }
 
+//! update the line standard preference.  used in the preferences dialog.
+void Preferences::setLineStandard(int index)
+{
+    getPreferenceGroup("Standards")->SetInt("LineStandard", index);
+}
+
 std::string Preferences::lineDefinitionLocation()
 {
     std::string defaultDir = App::Application::getResourceDir() + "Mod/TechDraw/LineGroup/";

src/Mod/TechDraw/App/Preferences.h

@@ -107,6 +107,7 @@ public:
     static bool SectionUsePreviousCut();
 
     static int lineStandard();
+    static void setLineStandard(int index);
     static std::string lineDefinitionLocation();
     static std::string lineElementsLocation();