Swift - Cropping images *outside* of allowsEditing -

i have very simple project set allows click "browse photo" button. user selects photo photo gallery, , it's displayed on programmatically created uiimageview.

works charm. - missing key functionality required.

i need user able scale image (via pinching , dragging) after displayed within uiimageview. allowsediting = true, lets user crop before. need similar functionality, however, allowing them edit once it's on main ui.

help appreciated. please , thank you!!

import uikit

class viewcontroller: uiviewcontroller {

@iboutlet weak var imageview: uiimageview!   var imageviewlayer: calayer{     return imageview.layer }   override func viewdidload() {     super.viewdidload()     // additional setup after loading view, typically nib.     imageviewlayer.contents = uiimage(named: "ss3.jpg")?.cgimage     imageviewlayer.contentsgravity = kcagravityresizeaspect  }  override func didreceivememorywarning() {     super.didreceivememorywarning()     // dispose of resources can recreated. }    @ibaction func newgesture(sender: anyobject) {     imageviewlayer.transform = catransform3dmakescale(sender.scale, sender.scale, 1) } 

}

i did similar while back. added image uiimageview's layer property, added gesture recognizer view , implemented gesture call backs modifying layer property , not view. adding image uiimageview's layer did trick. side note, add every uiview supported calayer class. has lot of methods , properties dynamically change view, in case done gestures.

as alternative, can use calayer's hittest method instead of implementing call backs gesture recognizers.

edit- sample code

you thing this:

   @iboutlet weak var imageview: uiimageview!      var imageviewlayer: calayer{         return imageview.layer     } 

in viewdidload, set image

imageviewlayer.contents = uiimage(named: "coredatademoapp")?.cgimage imageviewlayer.contentsgravity = kcagravityresizeaspect 

add pinch gesture imageview in storyboard (or programmatically) , in it's call this:

@ibaction func pinchgesturerecognized(sender: anyobject) {    imageviewlayer.transform = catransform3dmakescale(sender.scale, sender.scale, 1)   } 

again give idea of how work , not complete code. hope helps!

this way of doing it:

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