Manages the SceneTree selection in the editor. This object manages the SceneTree selection in the editor. [b]Note:[/b] This class shouldn't be instantiated directly. Instead, access the singleton using [method EditorInterface.get_selection]. Adds a node to the selection. [b]Note:[/b] The newly selected node will not be automatically edited in the inspector. If you want to edit a node, use [method EditorInterface.edit_node]. Clear the selection. Gets the list of selected nodes. Gets the list of selected nodes, optimized for transform operations (i.e. moving them, rotating, etc). This list avoids situations where a node is selected and also child/grandchild. Removes a node from the selection. Emitted when the selection changes.