Version: 2018.3 (switch to 2019.1)
  • C#
Experimental: this API is experimental and might be changed or removed in the future.


class in UnityEngine.Experimental.UIElements


Inherits from:Experimental.UIElements.Focusable


Implemented in:UnityEngine.UIElementsModule

Implements interfaces:IStyle, ITransform, IUIElementDataWatch, IVisualElementScheduler

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Base class for objects that are part of the UIElements visual tree.

VisualElement contains several features that are common to all controls in UIElements, such as layout, styling and event handling. Several other classes derive from it to implement custom rendering and define behaviour for controls.

Static Properties

defaultFocusIndexThe default focus index for newly created elements.


childCount Number of child elements in this object's contentContainer
clippingOptionsShould this element clip painting to its boundaries.
contentContainer child elements are added to this element, usually this
dataWatchAccess to this element data watch interface.
enabledInHierarchyReturns true if the VisualElement is enabled in its own hierarchy.
enabledSelfReturns true if the VisualElement is enabled locally.
persistenceKeyUsed for view data persistence (ie. tree expanded states, scroll position, zoom level).
scheduleRetrieves this VisualElement's IVisualElementScheduler
shadow Access to this element physical hierarchy
styleReference to the style object of this element.
this[int] Access to this element physical hierarchy
tooltipText to display inside an information box after the user hovers the element for a small amount of time.
userDataThis property can be used to associate application-specific user data with this VisualElement.

Public Methods

AddAdd an element to this element's contentContainer
AddStyleSheetPathAdds this stylesheet file to this element list of applied styles
BringToFrontBrings this element to the end of its parent children list. The element will be visually in front of any overlapping sibling elements.
ChildrenReturns the elements from its contentContainer
ClearRemove all child elements from this element's contentContainer
ContainsReturns true if the element is a direct child of this VisualElement
ElementAtRetrieves the child element at position
EnableInClassListEnables or disables the class with the given name.
FindAncestorUserDataSearchs up the hierachy of this VisualElement and retrieves stored userData, if any is found.
FindCommonAncestorFinds the lowest commont ancestor between two VisualElements inside the VisualTree hierarchy
GetEnumeratorAllows to iterate into this elements children
GetFirstAncestorOfTypeWalks up the hierarchy, starting from this element's parent, and returns the first VisualElement of this type
GetFirstOfTypeWalks up the hierarchy, starting from this element, and returns the first VisualElement of this type
GetFullHierarchicalPersistenceKeyCombine this VisualElement's VisualElement.persistenceKey with those of its parents to create a more unique key for use with VisualElement.GetOrCreatePersistentData.
GetOrCreatePersistentDataTakes a reference to an existing persisted object and a key and returns the object either filled with the persisted state or as-is.
HasStyleSheetPathChecks if this stylesheet file is in this element list of applied styles
IndexOfRetrieves the child index of the specified VisualElement.
InsertInsert an element into this element's contentContainer
MarkDirtyRepaintTriggers a repaint of the VisualElement on the next frame.
OnPersistentDataReadyCalled when the persistent data is accessible and/or when the data or persistence key have changed (VisualElement is properly parented).
OverwriteFromPersistedDataOverwrite object from the persistent data store.
PlaceBehindPlaces this element right before the sibling element in their parent children list. If the element and the sibling position overlap, the element will be visually behind of its sibling.
PlaceInFrontPlaces this element right after the sibling element in their parent children list. If the element and the sibling position overlap, the element will be visually in front of its sibling.
RemoveRemoves this child from the hierarchy
RemoveAtRemove the child element located at this position from this element's contentContainer
RemoveFromHierarchyRemoves this element from its parent hierarchy
RemoveStyleSheetPathRemoves this stylesheet file from this element list of applied styles
SavePersistentDataWrite persistence data to file.
SendEventSends an event to the event handler.
SendToBackSends this element to the beginning of its parent children list. The element will be visually behind any overlapping sibling elements.
SetEnabledChanges whether the current VisualElement is enabled or not. When disabled, a VisualElement does not receive most events.
SortReorders child elements from this VisualElement contentContainer.
ToggleInClassListToggles between adding and removing the given class name from the class list.

Protected Methods

OnStyleResolvedCallback when the styles of an object have changed.

Inherited Members


canGrabFocusReturn true if the element can be focused.
focusControllerReturn the focus controller for this element.
focusIndexAn integer used to sort focusables in the focus ring. A negative value means that the element can not be focused.

Public Methods

HandleEventHandle an event, most often by executing the callbacks associated with the event.
HasBubbleUpHandlersReturn true if event handlers for the event propagation BubbleUp phase have been attached on this object.
HasTrickleDownHandlersReturns true if event handlers, for the event propagation TrickleDown phase, are attached to this object.
RegisterCallbackAdds an event handler to the instance. If the event handler has already been registered for the same phase (either TrickleDown or BubbleUp) then this method has no effect.
UnregisterCallbackRemove callback from the instance.
BlurTell the element to release the focus.
FocusAttempt to give the focus to this element.

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