Plugin for adding custom property editors on inspector. This plugins allows adding custom property editors to [EditorInspector]. Plugins are registered via [method EditorPlugin.add_inspector_plugin]. When an object is edited, the [method can_handle] function is called and must return [code]true[/code] if the object type is supported. If supported, the function [method parse_begin] will be called, allowing to place custom controls at the beginning of the class. Subsequently, the [method parse_category] and [method parse_property] are called for every category and property. They offer the ability to add custom controls to the inspector too. Finally [method parse_end] will be called. On each of these calls, the "add" functions can be called. Adds a custom control, not necessarily a property editor. Adds a property editor, this must inherit [EditorProperty]. Adds an editor that allows modifying multiple properties, this must inherit [EditorProperty]. Returns [code]true[/code] if this object can be handled by this plugin. Called to allow adding controls at the beginning of the list. Called to allow adding controls at the beginning of the category. Called to allow adding controls at the end of the list. Called to allow adding property specific editors to the inspector. Usually these inherit [EditorProperty]. Returning [code]true[/code] removes the built-in editor for this property, otherwise allows to insert a custom editor before the built-in one.