Added highlight of calls within condition statements of if/else blocks

src/common/model/enums.h

@@ -39,6 +39,7 @@ enum class relationship_t {
     kDependency
 };
 
+/// Types of sequence diagram activity elements
 enum class message_t {
     kCall,
     kReturn,
@@ -55,6 +56,13 @@ enum class message_t {
     kNone
 };
 
+/// The scope of the call expression represented in the sequence diagram
+enum class message_scope_t {
+    kNormal,   // This is a regular call expression
+    kCondition // This is a call expression from within a control condition
+               // e.g if(a->is_valid()) { ... }
+};
+
 std::string to_string(relationship_t r);
 
 std::string to_string(access_t r);