How to set minimum and maximum value of pinch gesture recognizer in SWIFT?

Question

I need to set minimum and and maximum value of pinch gesture from 0 to 1 in swift. Is there any way to do that?

Basically what i need is replacing slider into pinch gesture, I have a chart view in my app and there is a slider which is used to change value of chart. Similarly I want to implement pinch gesture instead of slider, More precisely the value must be change accordingly when pinching on the chart. Also I need to limit pinching range into 0 to 1 (Pinch scale).

Answer 1

What you are looking for is not easy to picture, but if you want to allow users to use pinch to zoom a view while keeping the zooming constrained to a minimum and maximum value, you could simply make use of a UIScrollView and make it zoomable, and put some other view inside of it to represent something that needs to be pinched.

For zooming you need to implement a UIScrollViewDelegate and implement viewForZoomingInScrollView:, as explained in the UIScrollView documentation. Set the UIScrollView's minimumZoomScale and maximumZoomScale properties to constrain it. The zoom scale will be within your minimum and maximum range, and you can then convert it to your slider-like value.