onrelease

OnRelease is an event name used in user interface programming to denote the moment a user finishes pressing or touching a control. The exact meaning and behavior vary by framework, but it generally represents the end of a press gesture, such as releasing a mouse button or lifting a finger from a touch surface. It is often used to model a completed click or tap action, and may be paired with a corresponding press or down event.

Historically, some environments, notably certain ActionScript and Flash-based UI components, exposed an onRelease handler on interactive objects like buttons. In those contexts the handler fired when the user released the input over the control, completing a press action.

In modern web and cross-platform development, there is no universal onRelease event. Web platforms typically rely on mouseup or pointerup events to detect the release portion of a gesture, while higher-level frameworks may offer onRelease as an alias or as part of a component’s API. The exact semantics—such as whether release must occur inside the control’s boundaries—depend on the framework or library in use.

Implementation considerations include accessibility and consistency with other input methods. Ensure that keyboard activation triggers a release-like effect for screen readers, and be aware that some environments may distinguish releases that occur inside versus outside the control’s area. Developers should consult framework-specific documentation to map onRelease to the appropriate underlying events or callbacks.

See also: onPress, onClick, onPointerUp, onMouseUp.