[TD] Balloon, move property LineVisible to View tab and fix a refresh bug.

src/Mod/TechDraw/Gui/QGIViewBalloon.cpp

@@ -766,7 +766,7 @@ void QGIViewBalloon::draw()
     balloonLines->setPath(dLinePath);
 
     // This overwrites the previously created QPainterPath with empty one, in case it should be hidden.  Should be refactored.
-    if (!balloon->LineVisible.getValue()) {
+    if (!vp->LineVisible.getValue()) {
         arrow->hide();
         balloonLines->setPath(QPainterPath());
     }

src/Mod/TechDraw/Gui/ViewProviderBalloon.cpp

@@ -75,6 +75,7 @@ ViewProviderBalloon::ViewProviderBalloon()
     double weight = lg->getWeight("Thin");
     delete lg;                                   //Coverity CID 174670
     ADD_PROPERTY_TYPE(LineWidth,(weight),group,(App::PropertyType)(App::Prop_None),"Leader line width");
+    ADD_PROPERTY_TYPE(LineVisible,(true),group,(App::PropertyType)(App::Prop_None),"Balloon line visible or hidden");
 
     ADD_PROPERTY_TYPE(Color,(PreferencesGui::dimColor()),
                                               group,App::Prop_None,"Color of the balloon");
@@ -148,7 +149,8 @@ void ViewProviderBalloon::onChanged(const App::Property* p)
     if ((p == &Font)  ||
         (p == &Fontsize) ||
         (p == &Color) ||
-        (p == &LineWidth)) {
+        (p == &LineWidth) ||
+        (p == &LineVisible)) {
         QGIView* qgiv = getQView();
         if (qgiv) {
             qgiv->updateView(true);

src/Mod/TechDraw/Gui/ViewProviderBalloon.h

@@ -48,6 +48,7 @@ public:
     App::PropertyFont   Font;
     App::PropertyLength Fontsize;
     App::PropertyLength LineWidth;
+    App::PropertyBool   LineVisible;
     App::PropertyColor  Color;
 
     virtual void attach(App::DocumentObject *);