UI Toolkit sends an event when a user interacts with elements from UI(User Interface) Allows a user to interact with your application. More info
See in Glossary Toolkit and changes the state of those elements. For example, the following actions all have associated:
The event design is similar to the Event interface for HTML elements.
Event types fit into a hierarchy based on the EventBase class. Each event family implements an interface that defines the common characteristics for all events of the same family. For example, BlurEvent and FocusEvent use the FocusEventBase class.
Select any of the event types listed below for more information on the event, its parent class, and links to the API documentation.
The following table is a simple overview of each event type. For more information on an event, see the pages listed above.
| Event type | Description | Trickles down | Bubbles up | Cancellable | |
|---|---|---|---|---|---|
| Capture events | |||||
| MouseCaptureEvent | Sent when an element takes the mouse capture. | Yes | Yes | ||
| MouseCaptureOutEvent | Sent when an element releases or otherwise loses the mouse capture. | Yes | Yes | ||
| PointerCaptureEvent | Sent when an element captures a pointer. | Yes | Yes | ||
| PointerCaptureOutEvent | Sent when an element releases a pointer. | Yes | Yes | ||
| Change events | |||||
| ChangeEvent | A generic event sent when the value of an element changes. | Yes | Yes | ||
| Command events | |||||
| ValidateCommandEvent | IMGUI sends this event while it determines whether the command will be handled by an element in the panel. | Yes | Yes | Yes | |
| ExecuteCommandEvent | IMGUI sends this event when an element in the panel should execute a command. | Yes | Yes | Yes | |
| Drag events | |||||
| DragExitedEvent | Sent when the drag and drop process ends. | Yes | Yes | ||
| DragUpdatedEvent | Sent when the dragged element moves over a drop target. | Yes | Yes | Yes | |
| DragPerformEvent | Sent when the dragged element drops onto an acceptable target. | Yes | Yes | Yes | |
| DragEnterEvent | The dragged element entered a new VisualElement. This event is sent when the drag operation begins. |
Yes | |||
| DragLeaveEvent | The dragged element exited the current drop target. This event is sent when the drag operation ends. | Yes | |||
| Focus events | |||||
| FocusOutEvent | Sent before an element loses focus. | Yes | Yes | ||
| FocusInEvent | Sent before an element gains focus. | Yes | Yes | ||
| BlurEvent | Sent after an element has lost focus. | Yes | |||
| FocusEvent | Sent after an element has gained focus. | Yes | |||
| IMGUI events | |||||
| IMGUIEvent | Sent to encapsulate IMGUI-specific events. | Yes | Yes | Yes | |
| Input events | |||||
| InputEvent | Sent when data is input to a visual element, typically a control. | ||||
| Keyboard events | |||||
| KeyDownEvent | Sent when the user presses a key on the keyboard. | Yes | Yes | Yes | |
| KeyUpEvent | Sent when the user releases a key on the keyboard. | Yes | Yes | Yes | |
| Layout events | |||||
| GeometryChangedEvent | Event sent when either the position or the dimensions of an element changes. | ||||
| Mouse events | |||||
| MouseDownEvent | Sent when the user presses a mouse button. | Yes | Yes | Yes | |
| MouseUpEvent | Sent when the user releases a mouse button. | Yes | Yes | Yes | |
| MouseMoveEvent | Sent when the user moves the mouse. | Yes | Yes | Yes | |
| WheelEvent | Sent when the user activates the mouse wheel. | Yes | Yes | Yes | |
| MouseEnterWindowEvent | Sent when the mouse enters a window. | Yes | |||
| MouseLeaveWindowEvent | Sent when the mouse leaves a window. | Yes | |||
| MouseEnterEvent | Sent when the mouse enters an element or one of its descendants. | Yes | Yes | ||
| MouseLeaveEvent | Sent when the mouse leaves an element or one of its descendants. | Yes | Yes | ||
| MouseOverEvent | Sent when the mouse enters an element. | Yes | Yes | Yes | |
| MouseOutEvent | Sent when the mouse leaves an element. | Yes | Yes | Yes | |
| ContextClickEvent (obsolete) | Sent when the user presses and releases the third mouse button. Exists for backwards compatibility with IMGUI. | Yes | Yes | Yes | |
| Pointer events | |||||
| PointerDownEvent | Sent when you press a pointer. | Yes | Yes | Yes | |
| PointerUpEvent | Sent when you release a pointer. | Yes | Yes | Yes | |
| PointerMoveEvent | Sent when the pointer changes state. | Yes | Yes | Yes | |
| PointerEnterEvent | Sent when the pointer enters a visual element, or one of its descendants. | Yes | Yes | ||
| PointerLeaveEvent | Sent when the pointer leaves a visual element and all of its descendants. | Yes | Yes | ||
| PointerOverEvent | Sent when the pointer enters a visual element. | Yes | Yes | Yes | |
| PointerOutEvent | Sent when the pointer leaves a visual element. | Yes | Yes | Yes | |
| PointerStationaryEvent | Sent when a pointer type (like a stylus or finger) doesn’t change for a set amount of time determined by the operating system. | Yes | Yes | Yes | |
| PointerCancelEvent | Sent when a pointer action is cancelled by the operating system. | Yes | Yes | Yes | |
| Panel events | |||||
| AttachToPanelEvent | Sent right after an element attaches to a panel. | ||||
| DetachFromPanelEvent | Sent just before an element detaches from a panel. | ||||
| Tooltip events | |||||
| TooltipEvent | Tooltip is sent just before a tooltip is displayed. | Yes | Yes | Yes |