From 409c71bdfd8e0a08fd726225ebdce16bc60a4570 Mon Sep 17 00:00:00 2001
From: AeioMuch <75151379+AeioMuch@users.noreply.github.com>
Date: Mon, 25 Mar 2024 12:13:36 +0100
Subject: [PATCH] Allow batch drag and drop in typed array of Node and
 NodePath.

---
 editor/editor_properties_array_dict.cpp | 102 +++++++++++++++++++++---
 editor/editor_properties_array_dict.h   |   2 +
 2 files changed, 92 insertions(+), 12 deletions(-)

diff --git a/editor/editor_properties_array_dict.cpp b/editor/editor_properties_array_dict.cpp
index a6c7d6b617db..00fe42cb0af1 100644
--- a/editor/editor_properties_array_dict.cpp
+++ b/editor/editor_properties_array_dict.cpp
@@ -483,9 +483,10 @@ bool EditorPropertyArray::_is_drop_valid(const Dictionary &p_drag_data) const {
 	}
 
 	Dictionary drag_data = p_drag_data;
+	const String drop_type = drag_data.get("type", "");
 
-	if (drag_data.has("type") && String(drag_data["type"]) == "files") {
-		Vector<String> files = drag_data["files"];
+	if (drop_type == "files") {
+		PackedStringArray files = drag_data["files"];
 
 		for (int i = 0; i < files.size(); i++) {
 			const String &file = files[i];
@@ -504,6 +505,56 @@ bool EditorPropertyArray::_is_drop_valid(const Dictionary &p_drag_data) const {
 		return true;
 	}
 
+	if (drop_type == "nodes") {
+		Array node_paths = drag_data["nodes"];
+
+		PackedStringArray allowed_subtype_array;
+		if (allowed_type == "NodePath") {
+			if (subtype_hint_string == "NodePath") {
+				return true;
+			} else {
+				for (int j = 0; j < subtype_hint_string.get_slice_count(","); j++) {
+					String ast = subtype_hint_string.get_slice(",", j).strip_edges();
+					allowed_subtype_array.append(ast);
+				}
+			}
+		}
+
+		bool is_drop_allowed = true;
+
+		for (int i = 0; i < node_paths.size(); i++) {
+			const Node *dropped_node = get_node_or_null(node_paths[i]);
+			ERR_FAIL_NULL_V_MSG(dropped_node, false, "Could not get the dropped node by its path.");
+
+			if (allowed_type != "NodePath") {
+				if (!ClassDB::is_parent_class(dropped_node->get_class_name(), allowed_type)) {
+					// Fail if one of the nodes is not of allowed type.
+					return false;
+				}
+			}
+
+			// The array of NodePaths is restricted to specific types using @export_node_path().
+			if (allowed_type == "NodePath" && subtype_hint_string != "NodePath") {
+				if (!allowed_subtype_array.has(dropped_node->get_class_name())) {
+					// The dropped node type was not found in the allowed subtype array, we must check if it inherits one of them.
+					for (const String &ast : allowed_subtype_array) {
+						if (ClassDB::is_parent_class(dropped_node->get_class_name(), ast)) {
+							is_drop_allowed = true;
+							break;
+						} else {
+							is_drop_allowed = false;
+						}
+					}
+					if (!is_drop_allowed) {
+						break;
+					}
+				}
+			}
+		}
+
+		return is_drop_allowed;
+	}
+
 	return false;
 }
 
@@ -515,18 +566,18 @@ void EditorPropertyArray::drop_data_fw(const Point2 &p_point, const Variant &p_d
 	ERR_FAIL_COND(!_is_drop_valid(p_data));
 
 	Dictionary drag_data = p_data;
+	const String drop_type = drag_data.get("type", "");
+	Variant array = object->get_array();
 
-	if (drag_data.has("type") && String(drag_data["type"]) == "files") {
-		Vector<String> files = drag_data["files"];
-
-		Variant array = object->get_array();
+	// Handle the case where array is not initialized yet.
+	if (!array.is_array()) {
+		initialize_array(array);
+	} else {
+		array = array.duplicate();
+	}
 
-		// Handle the case where array is not initialized yet.
-		if (!array.is_array()) {
-			initialize_array(array);
-		} else {
-			array = array.duplicate();
-		}
+	if (drop_type == "files") {
+		PackedStringArray files = drag_data["files"];
 
 		// Loop the file array and add to existing array.
 		for (int i = 0; i < files.size(); i++) {
@@ -540,6 +591,33 @@ void EditorPropertyArray::drop_data_fw(const Point2 &p_point, const Variant &p_d
 
 		emit_changed(get_edited_property(), array);
 	}
+
+	if (drop_type == "nodes") {
+		Array node_paths = drag_data["nodes"];
+		Node *base_node = get_base_node();
+
+		for (int i = 0; i < node_paths.size(); i++) {
+			const NodePath &path = node_paths[i];
+
+			if (subtype == Variant::OBJECT) {
+				array.call("push_back", get_node(path));
+			} else if (subtype == Variant::NODE_PATH) {
+				array.call("push_back", base_node->get_path().rel_path_to(path));
+			}
+		}
+
+		emit_changed(get_edited_property(), array);
+	}
+}
+
+Node *EditorPropertyArray::get_base_node() {
+	Node *base_node = Object::cast_to<Node>(InspectorDock::get_inspector_singleton()->get_edited_object());
+
+	if (!base_node) {
+		base_node = get_tree()->get_edited_scene_root();
+	}
+
+	return base_node;
 }
 
 void EditorPropertyArray::_notification(int p_what) {
diff --git a/editor/editor_properties_array_dict.h b/editor/editor_properties_array_dict.h
index b1bf45f1b760..dae0fc52a644 100644
--- a/editor/editor_properties_array_dict.h
+++ b/editor/editor_properties_array_dict.h
@@ -135,6 +135,8 @@ class EditorPropertyArray : public EditorProperty {
 	void _reorder_button_up();
 	void _create_new_property_slot();
 
+	Node *get_base_node();
+
 protected:
 	Ref<EditorPropertyArrayObject> object;