implement C# interface export

fix: EditorResourcePicker node path not disappearing

core/core_constants.cpp

@@ -676,6 +676,7 @@ void register_global_constants() {
 	BIND_CORE_ENUM_CONSTANT(PROPERTY_HINT_NODE_TYPE);
 	BIND_CORE_ENUM_CONSTANT(PROPERTY_HINT_HIDE_QUATERNION_EDIT);
 	BIND_CORE_ENUM_CONSTANT(PROPERTY_HINT_PASSWORD);
+	BIND_CORE_ENUM_CONSTANT(PROPERTY_HINT_INTERFACE);
 	BIND_CORE_ENUM_CONSTANT(PROPERTY_HINT_MAX);
 
 	BIND_CORE_BITFIELD_FLAG(PROPERTY_USAGE_NONE);

core/object/object.h

@@ -86,6 +86,7 @@ enum PropertyHint {
 	PROPERTY_HINT_HIDE_QUATERNION_EDIT, /// Only Node3D::transform should hide the quaternion editor.
 	PROPERTY_HINT_PASSWORD,
 	PROPERTY_HINT_LAYERS_AVOIDANCE,
+	PROPERTY_HINT_INTERFACE, ///< hint_text="language_name,interface1,interface2,..."
 	PROPERTY_HINT_MAX,
 };
 

core/object/script_language.h

@@ -178,6 +178,7 @@ class Script : public Resource {
 
 	virtual void get_constants(HashMap<StringName, Variant> *p_constants) {}
 	virtual void get_members(HashSet<StringName> *p_constants) {}
+	virtual void get_interfaces(HashSet<StringName> *p_list) {}
 
 	virtual bool is_placeholder_fallback_enabled() const { return false; }
 

doc/classes/@GlobalScope.xml

@@ -2935,7 +2935,12 @@
 		<constant name="PROPERTY_HINT_PASSWORD" value="36" enum="PropertyHint">
 			Hints that a string property is a password, and every character is replaced with the secret character.
 		</constant>
-		<constant name="PROPERTY_HINT_MAX" value="38" enum="PropertyHint">
+		<constant name="PROPERTY_HINT_INTERFACE" value="38" enum="PropertyHint">
+			Hints that an Object property is an instance of a type that implements the specified interface.
+			The language and interfaces must be specified by a comma separated hint string, where the first token is the language name and subsequent tokens are interfaces (e.g. [code]"C#,InterfaceA"[/code]).
+			The inspector will allow any Resource or Node (if the edited object is also a Node) that implements the interface to be selected.
+		</constant>
+		<constant name="PROPERTY_HINT_MAX" value="39" enum="PropertyHint">
 			Represents the size of the [enum PropertyHint] enum.
 		</constant>
 		<constant name="PROPERTY_USAGE_NONE" value="0" enum="PropertyUsageFlags" is_bitfield="true">

editor/editor_data.cpp

@@ -974,6 +974,36 @@ bool EditorData::script_class_is_parent(const String &p_class, const String &p_i
 	return true;
 }
 
+bool EditorData::script_class_implements_interface(const String &p_class, const String &p_interface_hint_string) {
+	Ref<Script> script = script_class_load_script(p_class);
+	return script_object_implements_interface(script, p_interface_hint_string);
+}
+
+bool EditorData::script_object_implements_interface(const Ref<Script> &p_script, const String &p_interface_hint_string) {
+	if (p_script.is_null()) {
+		return false;
+	}
+
+	Vector<String> hint_tokens = p_interface_hint_string.split(",");
+	ERR_FAIL_COND_V_MSG(hint_tokens.size() <= 1, false, "Invalid hint string for PROPERTY_HINT_INTERFACE; should contain the language name and at least one interface name.");
+
+	String language_name = hint_tokens[0];
+	Vector<String> interface_names = hint_tokens.slice(1);
+
+	if (language_name != p_script->get_language()->get_name()) {
+		return false;
+	}
+
+	HashSet<StringName> script_interfaces;
+	p_script->get_interfaces(&script_interfaces);
+	for (const String &E : interface_names) {
+		if (!script_interfaces.has(E)) {
+			return false;
+		}
+	}
+	return true;
+}
+
 StringName EditorData::script_class_get_base(const String &p_class) const {
 	Ref<Script> script = script_class_load_script(p_class);
 	if (script.is_null()) {

editor/editor_data.h

@@ -241,6 +241,8 @@ class EditorData {
 	bool script_class_is_parent(const String &p_class, const String &p_inherits);
 	StringName script_class_get_base(const String &p_class) const;
 	Variant script_class_instance(const String &p_class);
+	bool script_class_implements_interface(const String &p_class, const String &p_interface);
+	bool script_object_implements_interface(const Ref<Script> &p_script, const String &p_interface); // For non global classes
 
 	Ref<Script> script_class_load_script(const String &p_class) const;
 

editor/editor_properties.cpp

@@ -3198,6 +3198,34 @@ void EditorPropertyResource::_resource_changed(const Ref<Resource> &p_resource)
 	}
 }
 
+void EditorPropertyResource::_node_changed(const NodePath &p_path) {
+	// Similar to EditorPropertyNodePath::_node_selected
+	EditorInterfacePicker *interface_picker = Object::cast_to<EditorInterfacePicker>(resource_picker);
+
+	if (!interface_picker) {
+		return;
+	}
+	Node *base_node = Object::cast_to<Node>(get_edited_object());
+	NodePath path = p_path;
+
+	if (!base_node && Object::cast_to<RefCounted>(get_edited_object())) {
+		Node *to_node = get_node(p_path);
+		ERR_FAIL_NULL(to_node);
+		path = get_tree()->get_edited_scene_root()->get_path_to(to_node);
+	}
+
+	if (base_node) { // for AnimationTrackKeyEdit
+		path = base_node->get_path().rel_path_to(p_path);
+	}
+
+	if (!base_node) {
+		emit_changed(get_edited_property(), get_tree()->get_edited_scene_root()->get_node(path));
+	} else {
+		emit_changed(get_edited_property(), base_node->get_node(path));
+	}
+	update_property();
+}
+
 void EditorPropertyResource::_sub_inspector_property_keyed(const String &p_property, const Variant &p_value, bool p_advance) {
 	// The second parameter could be null, causing the event to fire with less arguments, so use the pointer call which preserves it.
 	const Variant args[3] = { String(get_edited_property()) + ":" + p_property, p_value, p_advance };
@@ -3265,13 +3293,18 @@ void EditorPropertyResource::_viewport_selected(const NodePath &p_path) {
 	update_property();
 }
 
-void EditorPropertyResource::setup(Object *p_object, const String &p_path, const String &p_base_type) {
+void EditorPropertyResource::setup(Object *p_object, const String &p_path, const String &p_base_type, const String &p_interface_hint_string) {
 	if (resource_picker) {
 		memdelete(resource_picker);
 		resource_picker = nullptr;
 	}
 
-	if (p_path == "script" && p_base_type == "Script" && Object::cast_to<Node>(p_object)) {
+	if (!p_interface_hint_string.is_empty()) {
+		EditorInterfacePicker *interface_picker = memnew(EditorInterfacePicker);
+		interface_picker->set_is_editing_node(Object::cast_to<Node>(p_object));
+		interface_picker->connect("node_changed", callable_mp(this, &EditorPropertyResource::_node_changed));
+		resource_picker = interface_picker;
+	} else if (p_path == "script" && p_base_type == "Script" && Object::cast_to<Node>(p_object)) {
 		EditorScriptPicker *script_picker = memnew(EditorScriptPicker);
 		script_picker->set_script_owner(Object::cast_to<Node>(p_object));
 		resource_picker = script_picker;
@@ -3288,6 +3321,7 @@ void EditorPropertyResource::setup(Object *p_object, const String &p_path, const
 	}
 
 	resource_picker->set_base_type(p_base_type);
+	resource_picker->set_interface_hint_string(p_interface_hint_string);
 	resource_picker->set_editable(true);
 	resource_picker->set_h_size_flags(SIZE_EXPAND_FILL);
 	add_child(resource_picker);
@@ -3367,6 +3401,13 @@ void EditorPropertyResource::update_property() {
 		}
 	}
 
+	// For interface picker, also set node or null if possible
+	EditorInterfacePicker *interface_picker = Object::cast_to<EditorInterfacePicker>(resource_picker);
+	if (interface_picker) {
+		Node *n = Object::cast_to<Node>(get_edited_property_value());
+		interface_picker->set_edited_property(n); // or null
+	}
+
 	resource_picker->set_edited_resource_no_check(res);
 }
 
@@ -3817,9 +3858,9 @@ EditorProperty *EditorInspectorDefaultPlugin::get_editor_for_property(Object *p_
 				return editor;
 			} else {
 				EditorPropertyResource *editor = memnew(EditorPropertyResource);
-				editor->setup(p_object, p_path, p_hint == PROPERTY_HINT_RESOURCE_TYPE ? p_hint_text : "Resource");
+				editor->setup(p_object, p_path, p_hint == PROPERTY_HINT_RESOURCE_TYPE ? p_hint_text : "Resource", p_hint == PROPERTY_HINT_INTERFACE ? p_hint_text : String());
 
-				if (p_hint == PROPERTY_HINT_RESOURCE_TYPE) {
+				if (p_hint == PROPERTY_HINT_RESOURCE_TYPE || p_hint == PROPERTY_HINT_INTERFACE) {
 					const PackedStringArray open_in_new_inspector = EDITOR_GET("interface/inspector/resources_to_open_in_new_inspector");
 
 					for (const String &type : open_in_new_inspector) {

editor/editor_properties.h

@@ -703,6 +703,7 @@ class EditorPropertyResource : public EditorProperty {
 
 	void _resource_selected(const Ref<Resource> &p_resource, bool p_inspect);
 	void _resource_changed(const Ref<Resource> &p_resource);
+	void _node_changed(const NodePath &p_node_path); // For interface exports
 
 	void _viewport_selected(const NodePath &p_path);
 
@@ -719,7 +720,7 @@ class EditorPropertyResource : public EditorProperty {
 
 public:
 	virtual void update_property() override;
-	void setup(Object *p_object, const String &p_path, const String &p_base_type);
+	void setup(Object *p_object, const String &p_path, const String &p_base_type, const String &p_interface_hint_string = String());
 
 	void collapse_all_folding() override;
 	void expand_all_folding() override;

editor/editor_properties_array_dict.cpp

@@ -313,7 +313,7 @@ void EditorPropertyArray::update_property() {
 	String array_type_name = Variant::get_type_name(array_type);
 	if (array_type == Variant::ARRAY && subtype != Variant::NIL) {
 		String type_name;
-		if (subtype == Variant::OBJECT && (subtype_hint == PROPERTY_HINT_RESOURCE_TYPE || subtype_hint == PROPERTY_HINT_NODE_TYPE)) {
+		if (subtype == Variant::OBJECT && (subtype_hint == PROPERTY_HINT_RESOURCE_TYPE || subtype_hint == PROPERTY_HINT_NODE_TYPE || subtype_hint == PROPERTY_HINT_INTERFACE)) {
 			type_name = subtype_hint_string;
 		} else {
 			type_name = Variant::get_type_name(subtype);

editor/editor_quick_open.cpp

@@ -37,10 +37,11 @@
 Rect2i EditorQuickOpen::prev_rect = Rect2i();
 bool EditorQuickOpen::was_showed = false;
 
-void EditorQuickOpen::popup_dialog(const String &p_base, bool p_enable_multi, bool p_dont_clear) {
+void EditorQuickOpen::popup_dialog(const String &p_base, bool p_enable_multi, bool p_dont_clear, const String &p_interface_hint) {
 	base_type = p_base;
 	allow_multi_select = p_enable_multi;
 	search_options->set_select_mode(allow_multi_select ? Tree::SELECT_MULTI : Tree::SELECT_SINGLE);
+	interface_hint_string = p_interface_hint;
 
 	if (was_showed) {
 		popup(prev_rect);
@@ -75,6 +76,10 @@ void EditorQuickOpen::_build_search_cache(EditorFileSystemDirectory *p_efsd) {
 		// Iterate all possible base types.
 		for (String &parent_type : base_types) {
 			if (ClassDB::is_parent_class(engine_type, parent_type) || EditorNode::get_editor_data().script_class_is_parent(script_type, parent_type)) {
+				if (!interface_hint_string.is_empty() && !EditorNode::get_editor_data().script_class_implements_interface(script_type, interface_hint_string)) {
+					continue;
+				}
+
 				files.push_back(file.substr(6, file.length()));
 
 				// Store refs to used icons.

editor/editor_quick_open.h

@@ -45,6 +45,7 @@ class EditorQuickOpen : public ConfirmationDialog {
 	LineEdit *search_box = nullptr;
 	Tree *search_options = nullptr;
 	String base_type;
+	String interface_hint_string;
 	bool allow_multi_select = false;
 
 	Vector<String> files;
@@ -82,7 +83,7 @@ class EditorQuickOpen : public ConfirmationDialog {
 	String get_selected() const;
 	Vector<String> get_selected_files() const;
 
-	void popup_dialog(const String &p_base, bool p_enable_multi = false, bool p_dontclear = false);
+	void popup_dialog(const String &p_base, bool p_enable_multi = false, bool p_dontclear = false, const String &p_interface_hint = String());
 	EditorQuickOpen();
 };