EditorInspectorPlugin._parse_property gets called on all plugins when inspecting an array inspector, regardless of can_handle

[Zylann]

Godot version

Godot 4 beta11

System information

Windows 10 64 bits NVIDIA GeForce GTX 1060

Issue description

I have an inspector plugin that only handles a custom object type, but found out that _parse_property gets called on it every time I open an array inspector. I did not expect that because in can_handle I return false already. But another problem is, there is no way to actually specify if an inspector plugin can handle non-object types.

Another of my inspector plugins does not fail, but instead gets triggered unwantedly: it replaces AABB properties with a custom one that works differently. But as a result, it also triggers in Variant array inspectors where items are AABBs.

I'm not sure if it is a design issue or a documentation issue, because if it is the latter, it means every plugin has to check if the object is valid in this method, regardless of can_handle (I don't know if other methods are in this case too?).

Call stack:

_err_print_error(const char * p_function, const char * p_file, int p_line, const char * p_error, const char * p_message, bool p_editor_notify, ErrorHandlerType p_type) Line 86 (core\error\error_macros.cpp:86)
_err_print_error(const char * p_function, const char * p_file, int p_line, const char * p_error, bool p_editor_notify, ErrorHandlerType p_type) Line 78 (core\error\error_macros.cpp:78)
zylann::voxel::VoxelInstanceLibraryMultiMeshItemInspectorPlugin::parse_property(Object * p_object, const Variant::Type p_type, const String & p_path, const PropertyHint p_hint, const String & p_hint_text, const unsigned int p_usage, const bool p_wide) Line 77 (modules\voxel\editor\instance_library\voxel_instance_library_multimesh_item_inspector_plugin.cpp:77)
EditorInspector::instantiate_property_editor(Object * p_object, const Variant::Type p_type, const String & p_path, const PropertyHint p_hint, const String & p_hint_text, const unsigned int p_usage, const bool p_wide) Line 2444 (editor\editor_inspector.cpp:2444)
EditorPropertyArray::update_property() Line 355 (editor\editor_properties_array_dict.cpp:355)
EditorPropertyArray::_edit_pressed() Line 547 (editor\editor_properties_array_dict.cpp:547)
call_with_variant_args_helper<EditorPropertyArray>(EditorPropertyArray * p_instance, void(EditorPropertyArray::*)() p_method, const Variant * * p_args, Callable::CallError & r_error, IndexSequence<> __formal) Line 267 (core\variant\binder_common.h:267)
call_with_variant_args<EditorPropertyArray>(EditorPropertyArray * p_instance, void(EditorPropertyArray::*)() p_method, const Variant * * p_args, int p_argcount, Callable::CallError & r_error) Line 377 (core\variant\binder_common.h:377)
CallableCustomMethodPointer<EditorPropertyArray>::call(const Variant * * p_arguments, int p_argcount, Variant & r_return_value, Callable::CallError & r_call_error) Line 105 (core\object\callable_method_pointer.h:105)
Callable::callp(const Variant * * p_arguments, int p_argcount, Variant & r_return_value, Callable::CallError & r_call_error) Line 51 (core\variant\callable.cpp:51)
Object::emit_signalp(const StringName & p_name, const Variant * * p_args, int p_argcount) Line 1047 (core\object\object.cpp:1047)
Object::emit_signal<>(const StringName & p_name) Line 869 (core\object\object.h:869)
BaseButton::_pressed() Line 139 (scene\gui\base_button.cpp:139)
BaseButton::on_action_event(Ref<InputEvent> p_event) Line 174 (scene\gui\base_button.cpp:174)
BaseButton::gui_input(const Ref<InputEvent> & p_event) Line 69 (scene\gui\base_button.cpp:69)
Control::_call_gui_input(const Ref<InputEvent> & p_event) Line 1736 (scene\gui\control.cpp:1736)
Viewport::_gui_call_input(Control * p_control, const Ref<InputEvent> & p_input) Line 1333 (scene\main\viewport.cpp:1333)
Viewport::_gui_input_event(Ref<InputEvent> p_event) Line 1607 (scene\main\viewport.cpp:1607)
Viewport::push_input(const Ref<InputEvent> & p_event, bool p_local_coords) Line 2801 (scene\main\viewport.cpp:2801)
Window::_window_input(const Ref<InputEvent> & p_ev) Line 1331 (scene\main\window.cpp:1331)

I don't know if it's the only place, but this happens because of this:

godot/editor/editor_properties_array_dict.cpp

Line 355 in f73cb4c

prop = EditorInspector::instantiate_property_editor(nullptr, value_type, "", subtype_hint, subtype_hint_string, PROPERTY_USAGE_NONE);

Which then results in this:

godot/editor/editor_inspector.cpp

Lines 2441 to 2443 in f73cb4c

	EditorProperty *EditorInspector::instantiate_property_editor(Object *p_object, const Variant::Type p_type, const String &p_path, PropertyHint p_hint, const String &p_hint_text, const uint32_t p_usage, const bool p_wide) {
	for (int i = inspector_plugin_count - 1; i >= 0; i--) {
	inspector_plugins[i]->parse_property(p_object, p_type, p_path, p_hint, p_hint_text, p_usage, p_wide);

Specifically in array and dict sub-inspectors, can_handle is not even checked (and in fact it can't because it only receives objects) then parse_property is called with a null object on ALL inspector plugins. This does not happen for properties of objects.

Steps to reproduce

Make an EditorInspectorPlugin that implements _parse_property, for example:

@tool
extends EditorInspectorPlugin

func _can_handle(object):
	return object is Sprite2D:

func _parse_property(object, type, name, hint_type, hint_string, usage_flags, wide):
	if not (object is Sprite2D):
		push_error(str("Passed ", object, " to inspector plugin that only handles Sprite2D"))
	return false

Make an EditorPlugin to register it.
Enable the plugin.
Create a Line2D node.
In the inspector, add points to the Line2D node, then expand the points property.
Observe errors.

Minimal reproduction project

EditorInspectorPluginVariantType.zip

[SneaK1ng]

Maybe should call can_handle() before calling parse_property()?

[Zylann]

Just bumped again into a similar issue, but this time when clicking on a VisualShader Compare node. Apparently my plugin's parse_property is also called for properties of this object even though it does not handle that object...

[uguu-org]

I also ran into an unexpected call of _parse_property, not with arrays but with AnimationTree. I found that things were fine until I added an AnimationNodeTransition.

Attached is a reduced scene to reproduce the error.
inspector_test.zip

Click on AnimationTree to observe something like these in the output:

Ignored AnimationTree:<AnimationTree#1703608902859> (AnimationTree)
Unexpected call to handle AnimationTree:<AnimationTree#1703608902859>
[]

The first line says _can_handle is called, the next line says _parse_property is still called regardless, and the third line says the calling stack is empty.

[Zylann]

Still hitting this in latest 4.1.1, my inspector plugin parse_property is called for instances of VisualShaderNodeColorFunc when I create a ColorFunc node in a Visual Shader, despite my plugin not handling that type. Everytime I create a node in VisualShader, actually.
The reason is similar to my first post, except there doesn't seem to be any array involved here.

[isaaccp]

Still happening at HEAD. I have a custom look up for StringNames in different namespaces and it's impossible to invoke the right one when they are in an Array due to this issue :/

Also, I thought I would work around this issue by returning false in _parse_property(), which should cause the inspector to keep the original property editor instead of replacing it, but it doesn't seem to work like that for Arrays either, I guess due to the same difference in how arrays are treated.