# mouseUp(atPositionX:positionY:activePart:modifiers:forceUpdate:at:) Provides information when the left mouse button is released. ``` func mouseUp(atPositionX mousePositionX: Double, positionY mousePositionY: Double, activePart: Int, modifiers: FxModifierKeys, forceUpdate: UnsafeMutablePointer!, at time: CMTime) ``` ## Parameters `mousePositionX` X position of the pointer (in `drawingCoordinates` space). `mousePositionY` Y position of the pointer (in `drawingCoordinates` space). `activePart` The active part of the control that currently contains the pointer. `modifiers` The keyboard modifiers currently pressed. `forceUpdate` Set to `YES` if the filter/generator associated with this control needs to be re-calculated; `NO` otherwise. `time` The current time when the mouse button was released. ## Discussion Depending on the host application, the time value may be relative to the start of the timeline or to the start of the clip. See the header file `FxPlug/FxHostCapabilities.h`. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)