Implemented UIPanGestureRecognizer for positionBar

[anovoselskyi]

Implemented positionBar moving to make ability easily seek within the selected ranges to see what content you have selected to trim

[SergeyZalozniy]

3px is too narrow for any gesture recognizer. (Apple recommends minimum 32px)
It will be good to add extra code:
public override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? { let frame = positionBar.frame.insetBy(dx: -32, dy: 0) if frame.contains(point) { return positionBar } return super.hitTest(point, with: event) }

[anovoselskyi]

@SergeyZalozniy I agree with you, also from doc the func insetBy(::) adjusting the size of rect by (2dx,2dy), so let frame = positionBar.frame.insetBy(dx: -15, dy: 0) will be most closer to the 32px