Bug 83834

This isn't one of the rules in assocwidget, it causes an error message:

umbrello: UMLView::addWidget: Not adding (id=120/type=312/name=new_class_1) because it's already there
umbrello: ERROR: cannot addAssocInViewAndDoc(), deleting

the bug is also present in version 1.3.0 with kde 3.3.
How about having a link option instead of a message one?
The link would be a simple line and multiples messages (in both directions) would be properties of this link, each message represented be an arrow.

CVS commit by okellogg: 

Permit more than one message from one collaborating object to another.
BUG:83834


  M +14 -8     associationwidget.cpp   1.140
  M +5 -0      umlview.cpp   1.207
  M +10 -0     umlview.h   1.72


--- kdesdk/umbrello/umbrello/associationwidget.cpp  #1.139:1.140
@@ -106,16 +106,18 @@ AssociationWidget::AssociationWidget(UML
         mergeAssociationDataIntoUMLRepresentation();
 
-        //collaboration messages need a name label because it's that
-        //which handles the right click menu options
+        // Collaboration messages need a name label because it's that
+        // which lets operator== distinguish them, which in turn
+        // permits us to have more than one message between two objects.
         if (getAssocType() == at_Coll_Message) {
                 // Create a temporary name to bring on setName()
-                ObjectWidget *ow = static_cast<ObjectWidget*>(m_role[B].m_pWidget);
-                QString localIdStr = ID2STR(ow->getLocalID());
-                setName("m" + localIdStr);
-                if (m_pObject)
+                int collabID = m_pView->generateCollaborationId();
+                setName("m" + QString::number(collabID));
+                if (m_pObject) {
                         m_pName->setUMLObject( m_pObject );
-                else
+                } else {
+                        ObjectWidget *ow = static_cast<ObjectWidget*>(m_role[B].m_pWidget);
                         m_pName->setUMLObject( ow->getUMLObject() );
         }
+        }
 }
 
@@ -216,5 +218,9 @@ bool AssociationWidget::operator==(Assoc
         }
 
-        return true;
+        // Two objects in a collaboration can have multiple messages between each other.
+        // Here we depend on the messages having names, and the names must be different.
+        // That is the reason why collaboration messages have strange initial names like
+        // "m29997" or similar.
+        return (getName() == Other.getName());
 }
 

--- kdesdk/umbrello/umbrello/umlview.cpp  #1.206:1.207
@@ -130,4 +130,5 @@ void UMLView::init() {
         m_nCanvasWidth = UMLView::defaultCanvasSize;
         m_nCanvasHeight = UMLView::defaultCanvasSize;
+        m_nCollaborationId = 0;
 
         // Initialize other data
@@ -221,4 +222,8 @@ void UMLView::setName(const QString &nam
 }
 
+int UMLView::generateCollaborationId() {
+        return ++m_nCollaborationId;
+}
+
 void UMLView::print(KPrinter *pPrinter, QPainter & pPainter) {
         int height, width;

--- kdesdk/umbrello/umbrello/umlview.h  #1.71:1.72
@@ -948,4 +948,9 @@ public:
         }
 
+        /**
+         * Used for creating unique name of collaboration messages.
+         */
+        int generateCollaborationId();
+
 protected:
 
@@ -1148,4 +1153,9 @@ protected:
         void forceUpdateWidgetFontMetrics(QPainter *painter);
 
+        /**
+         * Used for creating unique name of collaboration messages.
+         */
+        int m_nCollaborationId;
+
         QPoint m_Pos, m_LineToPos;
         bool m_bCreateObject, m_bDrawRect, m_bDrawSelectedOnly, m_bPaste;