Instance Method


Asks the delegate whether a preview interaction is allowed to begin.


optional func previewInteractionShouldBegin(_ previewInteraction: UIPreviewInteraction) -> Bool



The preview interaction that is responding to user input

Return Value

true if the preview interaction should continue into the preview and commit phases; otherwise false.


If you don't implement this optional method, the default return value of true is assumed.

When false, no further delegate calls are made for the specified preview interaction until the user restarts the 3D Touch interaction.

See Also

Preview Interaction Delegate Methods

func previewInteraction(UIPreviewInteraction, didUpdatePreviewTransition: CGFloat, ended: Bool)

Informs the delegate of the progress through the preview phase of the preview interaction.


func previewInteraction(UIPreviewInteraction, didUpdateCommitTransition: CGFloat, ended: Bool)

Informs the delegate of the preview interaction's progress through the commit phase.

func previewInteractionDidCancel(UIPreviewInteraction)

Informs the delegate that the specified preview interaction was canceled.