Merge hierarchy package into transform package (#156)

features/hierarchy/hierarchy.go → features/transform/hierarchy.go

@@ -1,4 +1,4 @@
-package hierarchy
+package transform
 
 import (
 	"github.com/yohamta/donburi"
@@ -12,26 +12,26 @@ type hierarchySystem struct {
 
 // HierarchySystem is a system that removes children of invalid parents.
 var HierarchySystem = &hierarchySystem{
-	query: donburi.NewQuery(filter.Contains(parentComponent)),
+	query: donburi.NewQuery(filter.Contains(hierarchyParentComponent)),
 }
 
-// RemoveChildren removes children of invalid parents.
+// RemoveHierarchyChildren removes children of invalid parents.
 // This function is useful when you want to remove children of invalid parents.
 // You don't need to use this system function when you use
 // hierarchy.RemoveRecursive() or hierarchy.RemoveChildrenRecursive() instead.
-func (hs *hierarchySystem) RemoveChildren(ecs *ecs.ECS) {
+func (hs *hierarchySystem) RemoveHierarchyChildren(ecs *ecs.ECS) {
 	hs.query.Each(ecs.World, func(entry *donburi.Entry) {
 		if !entry.Valid() {
 			return
 		}
-		if pd, ok := getParentData(entry); ok {
+		if pd, ok := getHierarchyParentData(entry); ok {
 			if pd.Parent.Valid() {
 				return
 			}
-			c, ok := GetChildren(entry)
+			c, ok := getHierarchyChildren(entry)
 			if ok {
 				for _, e := range c {
-					RemoveRecursive(e)
+					removeHierarchyRecursive(e)
 				}
 			}
 			entry.Remove()

features/transform/hierarchy_children.go

@@ -0,0 +1,32 @@
+package transform
+
+import (
+	"github.com/yohamta/donburi"
+)
+
+type hierarchyChildrenData struct {
+	Children []*donburi.Entry
+}
+
+var hierarchyChildrenComponent = donburi.NewComponentType[hierarchyChildrenData]()
+
+// getHierarchyChildren returns children of the entry.
+func getHierarchyChildren(entry *donburi.Entry) ([]*donburi.Entry, bool) {
+	if cd, ok := getHierarchyChildrenData(entry); ok {
+		return cd.Children, true
+	}
+	return nil, false
+}
+
+// hasHierarchyChildren returns true if the entry has children.
+func hasHierarchyChildren(entry *donburi.Entry) bool {
+	return entry.HasComponent(hierarchyChildrenComponent)
+}
+
+func getHierarchyChildrenData(entry *donburi.Entry) (*hierarchyChildrenData, bool) {
+	if hasHierarchyChildren(entry) {
+		c := donburi.Get[hierarchyChildrenData](entry, hierarchyChildrenComponent)
+		return c, true
+	}
+	return nil, false
+}