add enum Role

This will make it easier to ensure we are always using the appropriate
data type in the DataChanged signal since we won't need to hand pass
i32s around and instead define them once in the function get_role.

src/rust/slide_model.rs

@@ -106,6 +106,24 @@ mod slide_model {
         ActiveChanged,
     }
 
+    enum Role {
+        ActiveRole,
+        SelectedRole,
+        LoopingRole,
+        TextRole,
+    }
+
+    // impl Role {
+    //     pub fn get_role(&self) -> i32 {
+    //         match self {
+    //             Role::ActiveRole => 12,
+    //             Role::SelectedRole => 13,
+    //             Role::LoopingRole => 14,
+    //             Role::TextRole => 1,
+    //         }
+    //     }
+    // }
+
     impl qobject::SlideyMod {
         // #[qinvokable]
         // pub fn add(self: Pin<&mut Self>) {
@@ -662,7 +680,7 @@ mod slide_model {
             let tl = &self.as_ref().index(0, 0, &QModelIndex::default());
             let br = &self.as_ref().index(rc, 0, &QModelIndex::default());
             let mut vector_roles = QVector_i32::default();
-            vector_roles.append(12);
+            vector_roles.append(self.get_role(Role::ActiveRole));
             for slide in self.as_mut().slides_mut().iter_mut() {
                 // println!("slide is deactivating {:?}", i);
                 slide.active = false;
@@ -682,6 +700,16 @@ mod slide_model {
                 false
             }
         }
+
+        fn get_role(&self, role: Role) -> i32 {
+            match role {
+                Role::ActiveRole => 12,
+                Role::SelectedRole => 13,
+                Role::LoopingRole => 14,
+                Role::TextRole => 1,
+                _ => 0,
+            }
+        }
     }
 
     // Create Rust bindings for C++ functions of the base class (QAbstractItemModel)