Moved "Update From Scene" button to multimesh item inspector

editor/instance_library/voxel_instance_library_editor_plugin.cpp

@@ -52,12 +52,8 @@ void VoxelInstanceLibraryEditorPlugin::_notification(int p_what) {
 		// otherwise `add_inspector_plugin` causes ANOTHER editor plugin to leak on exit... Oo
 		add_inspector_plugin(_inspector_plugin);
 
-		_multimesh_item_inspector_plugin.instantiate();
-		add_inspector_plugin(_multimesh_item_inspector_plugin);
-
 	} else if (p_what == NOTIFICATION_EXIT_TREE) {
 		remove_inspector_plugin(_inspector_plugin);
-		remove_inspector_plugin(_multimesh_item_inspector_plugin);
 	}
 }
 
@@ -88,15 +84,6 @@ void VoxelInstanceLibraryEditorPlugin::_on_button_pressed(int id) {
 			ur.commit_action();
 		} break;
 
-		case VoxelInstanceLibraryInspectorPlugin::BUTTON_UPDATE_MULTIMESH_ITEM_FROM_SCENE: {
-			ERR_FAIL_COND(_library.is_null());
-			const int item_id = try_get_selected_item_id();
-			if (item_id != -1) {
-				_item_id_to_update = item_id;
-				_open_scene_dialog->popup_centered_ratio();
-			}
-		} break;
-
 		case VoxelInstanceLibraryInspectorPlugin::BUTTON_ADD_SCENE_ITEM: {
 			_open_scene_dialog->popup_centered_ratio();
 		} break;
@@ -161,10 +148,6 @@ void VoxelInstanceLibraryEditorPlugin::_on_open_scene_dialog_file_selected(Strin
 			add_scene_item(fpath);
 			break;
 
-		case VoxelInstanceLibraryInspectorPlugin::BUTTON_UPDATE_MULTIMESH_ITEM_FROM_SCENE:
-			update_multimesh_item_from_scene(fpath, _item_id_to_update);
-			break;
-
 		default:
 			ERR_PRINT("Invalid menu option");
 			break;
@@ -196,33 +179,6 @@ void VoxelInstanceLibraryEditorPlugin::add_scene_item(String fpath) {
 	ur.commit_action();
 }
 
-void VoxelInstanceLibraryEditorPlugin::update_multimesh_item_from_scene(String fpath, int item_id) {
-	ERR_FAIL_COND(_library.is_null());
-
-	Ref<PackedScene> scene = ResourceLoader::load(fpath);
-	ERR_FAIL_COND(scene.is_null());
-
-	Ref<VoxelInstanceLibraryItem> item_base = _library->get_item(item_id);
-	ERR_FAIL_COND_MSG(item_base.is_null(), "Item not found");
-	Ref<VoxelInstanceLibraryMultiMeshItem> item = item_base;
-	ERR_FAIL_COND_MSG(item.is_null(), "Item not using multimeshes");
-
-	Node *node = scene->instantiate();
-	ERR_FAIL_COND(node == nullptr);
-
-	Variant data_before = item->serialize_multimesh_item_properties();
-	item->setup_from_template(node);
-	Variant data_after = item->serialize_multimesh_item_properties();
-
-	memdelete(node);
-
-	UndoRedo &ur = get_undo_redo();
-	ur.create_action("Update Multimesh Item From Scene");
-	ur.add_do_method(item.ptr(), "_deserialize_multimesh_item_properties", data_after);
-	ur.add_undo_method(item.ptr(), "_deserialize_multimesh_item_properties", data_before);
-	ur.commit_action();
-}
-
 void VoxelInstanceLibraryEditorPlugin::_bind_methods() {
 	// ClassDB::bind_method(D_METHOD("_on_button_pressed", "id"),
 	// &VoxelInstanceLibraryEditorPlugin::_on_button_pressed); ClassDB::bind_method(

editor/instance_library/voxel_instance_library_editor_plugin.h

@@ -3,7 +3,6 @@
 
 #include "../../terrain/instancing/voxel_instance_library.h"
 #include "voxel_instance_library_inspector_plugin.h"
-#include "voxel_instance_library_multimesh_item_inspector_plugin.h"
 #include <editor/editor_plugin.h>
 
 class Control;
@@ -31,7 +30,6 @@ private:
 
 	int try_get_selected_item_id();
 	void add_scene_item(String fpath);
-	void update_multimesh_item_from_scene(String fpath, int item_id);
 
 	void _on_remove_item_confirmed();
 	void _on_open_scene_dialog_file_selected(String fpath);
@@ -47,7 +45,6 @@ private:
 
 	Ref<VoxelInstanceLibrary> _library;
 	Ref<VoxelInstanceLibraryInspectorPlugin> _inspector_plugin;
-	Ref<VoxelInstanceLibraryMultiMeshItemInspectorPlugin> _multimesh_item_inspector_plugin;
 };
 
 } // namespace zylann::voxel

editor/instance_library/voxel_instance_library_inspector_plugin.cpp

@@ -46,14 +46,6 @@ void VoxelInstanceLibraryInspectorPlugin::add_buttons() {
 	spacer->set_h_size_flags(Control::SIZE_EXPAND_FILL);
 	hb->add_child(spacer);
 
-	Button *button_update = memnew(Button);
-	// TODO Move this to multimesh items?
-	button_update->set_text(TTR("Update From Scene..."));
-	button_update->connect("pressed",
-			callable_mp(button_listener, &VoxelInstanceLibraryEditorPlugin::_on_button_pressed)
-					.bind(BUTTON_UPDATE_MULTIMESH_ITEM_FROM_SCENE));
-	hb->add_child(button_update);
-
 	add_custom_control(hb);
 }
 

editor/instance_library/voxel_instance_library_inspector_plugin.h

@@ -10,9 +10,8 @@ class VoxelInstanceLibraryEditorPlugin;
 class VoxelInstanceLibraryInspectorPlugin : public EditorInspectorPlugin {
 	GDCLASS(VoxelInstanceLibraryInspectorPlugin, EditorInspectorPlugin)
 public:
-	enum Buttons {
+	enum Buttons { //
 		BUTTON_ADD_MULTIMESH_ITEM,
-		BUTTON_UPDATE_MULTIMESH_ITEM_FROM_SCENE,
 		BUTTON_ADD_SCENE_ITEM,
 		BUTTON_REMOVE_ITEM
 	};

editor/instance_library/voxel_instance_library_multimesh_item_editor_plugin.cpp

@@ -0,0 +1,87 @@
+#include "voxel_instance_library_multimesh_item_editor_plugin.h"
+#include <editor/editor_file_dialog.h>
+
+namespace zylann::voxel {
+
+VoxelInstanceLibraryMultiMeshItemEditorPlugin::VoxelInstanceLibraryMultiMeshItemEditorPlugin() {
+	Control *base_control = get_editor_interface()->get_base_control();
+
+	_open_scene_dialog = memnew(EditorFileDialog);
+	List<String> extensions;
+	ResourceLoader::get_recognized_extensions_for_type(PackedScene::get_class_static(), &extensions);
+	for (List<String>::Element *E = extensions.front(); E; E = E->next()) {
+		_open_scene_dialog->add_filter("*." + E->get());
+	}
+	_open_scene_dialog->set_file_mode(EditorFileDialog::FILE_MODE_OPEN_FILE);
+	base_control->add_child(_open_scene_dialog);
+	_open_scene_dialog->connect("file_selected",
+			callable_mp(this, &VoxelInstanceLibraryMultiMeshItemEditorPlugin::_on_open_scene_dialog_file_selected));
+}
+
+bool VoxelInstanceLibraryMultiMeshItemEditorPlugin::handles(Object *p_object) const {
+	// TODO Making a plugin handling sub-resources of `VoxelInstanceLibrary` breaks the inspector.
+	// There are also some caveats when using multiple sub-inspectors. To keep supporting multiple sub-inspectors open
+	// inside a library, we cannot rely on `edit` giving us edited resources.
+	// See https://github.com/godotengine/godot/issues/64700
+	return false;
+	// const VoxelInstanceLibraryMultiMeshItem *item = Object::cast_to<VoxelInstanceLibraryMultiMeshItem>(p_object);
+	// return item != nullptr;
+}
+
+void VoxelInstanceLibraryMultiMeshItemEditorPlugin::edit(Object *p_object) {
+	// VoxelInstanceLibraryMultiMeshItem *item = Object::cast_to<VoxelInstanceLibraryMultiMeshItem>(p_object);
+	// _item.reference_ptr(item);
+}
+
+void VoxelInstanceLibraryMultiMeshItemEditorPlugin::make_visible(bool visible) {
+	// if (!visible) {
+	// 	_item.unref();
+	// }
+}
+
+void VoxelInstanceLibraryMultiMeshItemEditorPlugin::_notification(int p_what) {
+	if (p_what == NOTIFICATION_ENTER_TREE) {
+		_inspector_plugin.instantiate();
+		_inspector_plugin->listener = this;
+		add_inspector_plugin(_inspector_plugin);
+
+	} else if (p_what == NOTIFICATION_EXIT_TREE) {
+		remove_inspector_plugin(_inspector_plugin);
+	}
+}
+
+void VoxelInstanceLibraryMultiMeshItemEditorPlugin::_on_update_from_scene_button_pressed(
+		VoxelInstanceLibraryMultiMeshItem *item) {
+	_item.reference_ptr(item);
+	ERR_FAIL_COND(_item.is_null());
+	_open_scene_dialog->popup_centered_ratio();
+}
+
+static void update_multimesh_item_from_scene(
+		VoxelInstanceLibraryMultiMeshItem &item, String scene_file_path, UndoRedo &ur) {
+	Ref<PackedScene> scene = ResourceLoader::load(scene_file_path);
+	ERR_FAIL_COND(scene.is_null());
+
+	Node *node = scene->instantiate();
+	ERR_FAIL_COND(node == nullptr);
+
+	Variant data_before = item.serialize_multimesh_item_properties();
+	item.setup_from_template(node);
+	Variant data_after = item.serialize_multimesh_item_properties();
+
+	memdelete(node);
+
+	ur.create_action("Update Multimesh Item From Scene");
+	ur.add_do_method(&item, "_deserialize_multimesh_item_properties", data_after);
+	ur.add_undo_method(&item, "_deserialize_multimesh_item_properties", data_before);
+	ur.commit_action();
+}
+
+void VoxelInstanceLibraryMultiMeshItemEditorPlugin::_on_open_scene_dialog_file_selected(String fpath) {
+	ERR_FAIL_COND(_item.is_null());
+	update_multimesh_item_from_scene(**_item, fpath, get_undo_redo());
+	// We are done with this item
+	_item.unref();
+}
+
+} // namespace zylann::voxel

editor/instance_library/voxel_instance_library_multimesh_item_editor_plugin.h

@@ -0,0 +1,33 @@
+#ifndef VOXEL_INSTANCE_LIBRARY_MULTIMESH_ITEM_EDITOR_PLUGIN_H
+#define VOXEL_INSTANCE_LIBRARY_MULTIMESH_ITEM_EDITOR_PLUGIN_H
+
+#include "../../terrain/instancing/voxel_instance_library_multimesh_item.h"
+#include "voxel_instance_library_multimesh_item_inspector_plugin.h"
+#include <editor/editor_plugin.h>
+
+namespace zylann::voxel {
+
+class VoxelInstanceLibraryMultiMeshItemEditorPlugin : public EditorPlugin {
+	GDCLASS(VoxelInstanceLibraryMultiMeshItemEditorPlugin, EditorPlugin)
+public:
+	VoxelInstanceLibraryMultiMeshItemEditorPlugin();
+
+	bool handles(Object *p_object) const override;
+	void edit(Object *p_object) override;
+	void make_visible(bool visible) override;
+
+	void _on_update_from_scene_button_pressed(VoxelInstanceLibraryMultiMeshItem *item);
+
+private:
+	void _notification(int p_what);
+
+	void _on_open_scene_dialog_file_selected(String fpath);
+
+	EditorFileDialog *_open_scene_dialog = nullptr;
+	Ref<VoxelInstanceLibraryMultiMeshItem> _item;
+	Ref<VoxelInstanceLibraryMultiMeshItemInspectorPlugin> _inspector_plugin;
+};
+
+} // namespace zylann::voxel
+
+#endif // VOXEL_INSTANCE_LIBRARY_MULTIMESH_ITEM_EDITOR_PLUGIN_H

editor/instance_library/voxel_instance_library_multimesh_item_inspector_plugin.cpp

@@ -1,5 +1,7 @@
 #include "voxel_instance_library_multimesh_item_inspector_plugin.h"
 #include "../../terrain/instancing/voxel_instance_library_multimesh_item.h"
+#include "voxel_instance_library_editor_plugin.h"
+#include "voxel_instance_library_multimesh_item_editor_plugin.h"
 
 namespace zylann::voxel {
 
@@ -11,6 +13,20 @@ void VoxelInstanceLibraryMultiMeshItemInspectorPlugin::parse_group(Object *p_obj
 	const VoxelInstanceLibraryMultiMeshItem *item = Object::cast_to<VoxelInstanceLibraryMultiMeshItem>(p_object);
 	ERR_FAIL_COND(item == nullptr);
 	if (item->get_scene().is_null()) {
+		ERR_FAIL_COND(listener == nullptr);
+		// TODO I preferred  this at the end of the group, but Godot doesn't expose anything to do it.
+		// This is a legacy workflow, we'll see if it can be removed later.
+		Button *button = memnew(Button);
+		button->set_tooltip(TTR("Set properties based on an existing scene. This might copy mesh and material data if "
+								"the scene embeds them. Properties will not update if the scene changes later."));
+		button->set_text(TTR("Update from scene..."));
+		// Using a bind() instead of relying on "currently edited" item in the editor plugin allows to support multiple
+		// sub-inspectors. Plugins are not instanced per-inspected-object, but custom controls are.
+		button->connect("pressed",
+				callable_mp(
+						listener, &VoxelInstanceLibraryMultiMeshItemEditorPlugin::_on_update_from_scene_button_pressed)
+						.bind(item));
+		add_custom_control(button);
 		return;
 	}
 
@@ -20,7 +36,7 @@ void VoxelInstanceLibraryMultiMeshItemInspectorPlugin::parse_group(Object *p_obj
 		add_custom_control(label);
 	}
 	// TODO Button to open scene in editor, since Godot doesn't have that in its resource picker menu?
-	// Perhaps it should rather be a feature request to Godot
+	// Perhaps it should rather be a feature request to Godot.
 	// else if (p_group == VoxelInstanceLibraryMultiMeshItem::SCENE_SETTINGS_GROUP_NAME) {
 	// 	ERR_FAIL_COND(listener == nullptr);
 	// 	Button *button = memnew(Button);

editor/instance_library/voxel_instance_library_multimesh_item_inspector_plugin.h

@@ -5,9 +5,13 @@
 
 namespace zylann::voxel {
 
+class VoxelInstanceLibraryMultiMeshItemEditorPlugin;
+
 class VoxelInstanceLibraryMultiMeshItemInspectorPlugin : public EditorInspectorPlugin {
 	GDCLASS(VoxelInstanceLibraryMultiMeshItemInspectorPlugin, EditorInspectorPlugin)
 public:
+	VoxelInstanceLibraryMultiMeshItemEditorPlugin *listener = nullptr;
+
 	bool can_handle(Object *p_object) override;
 	void parse_group(Object *p_object, const String &p_group) override;
 	bool parse_property(Object *p_object, const Variant::Type p_type, const String &p_path, const PropertyHint p_hint,

register_types.cpp

@@ -55,6 +55,7 @@
 #include "editor/fast_noise_lite/fast_noise_lite_editor_plugin.h"
 #include "editor/graph/voxel_graph_editor_plugin.h"
 #include "editor/instance_library/voxel_instance_library_editor_plugin.h"
+#include "editor/instance_library/voxel_instance_library_multimesh_item_editor_plugin.h"
 #include "editor/instancer/voxel_instancer_editor_plugin.h"
 #include "editor/mesh_sdf/voxel_mesh_sdf_editor_plugin.h"
 #include "editor/terrain/voxel_terrain_editor_plugin.h"
@@ -258,6 +259,7 @@ void initialize_voxel_module(ModuleInitializationLevel p_level) {
 		EditorPlugins::add_by_type<VoxelGraphEditorPlugin>();
 		EditorPlugins::add_by_type<VoxelTerrainEditorPlugin>();
 		EditorPlugins::add_by_type<VoxelInstanceLibraryEditorPlugin>();
+		EditorPlugins::add_by_type<VoxelInstanceLibraryMultiMeshItemEditorPlugin>();
 		EditorPlugins::add_by_type<ZN_FastNoiseLiteEditorPlugin>();
 		EditorPlugins::add_by_type<magica::VoxEditorPlugin>();
 		EditorPlugins::add_by_type<VoxelInstancerEditorPlugin>();