When you handle pointer input, you might want the control to capture a pointer. When a visual element captures a pointer, Unity sends all the events associated with the pointer to the visual element regardless of whether the pointer hovers over the visual element. For example, if you create a control that receives drag events and captures the pointer, the control still receives drag events regardless of the pointer location.

The

Manipulator

class provides a convenient way to capture the pointer. The class is a base class for all manipulators. A manipulator is a class that handles pointer input and sends events to a visual element. For example, the

Clickable

class is a manipulator that sends a

PointerDownEvent

when the user clicks on a visual element. After a

PointerDownEvent

, some elements must capture the pointer position to ensure it receives all subsequent pointer events, even when the cursor is no longer hovering over the element. For example, when you click on a button, slider, or scroll bar.

To capture the pointer, call

PointerCaptureHelper.CapturePointer

.

To release the pointer, call

PointerCaptureHelper.ReleasePointer

. If another element is already capturing the pointer when you call , the element receives a

PointerCaptureOutEvent

event and loses the capture.

Only one element in the application can have the capture at any moment. While an element has the capture, it's the target of all subsequent pointer events except mouse wheel events. This only applies to pointer events that don't already have a set target and rely on the dispatch process to determine the target.

For more information, see the Capture events.