sourceRect
The rectangle, in the source view’s coordinate system, that responds to a 3D Touch by a user and remains visually sharp while surrounding content blurs.
Declaration
var sourceRect: CGRect { get set }Discussion
Use this property if you want to specify a preview indication area that is different than the bounds of the view in the sourceView property. Set this property’s value in your object’s previewingContext(_:viewControllerForLocation:) method.
The default value of this property corresponds to the bounds of the view in the sourceView property.
For example, if your source view is a table view, you can set the sourceRect property to the frame of the row under the user’s touch. The row then remains visually sharp when a user presses it, while surrounding content blurs, thereby indicating to the user that it is the row being touched that has a preview available.
You can change the value of this property at runtime.