Scale UITextView with pan gesture - swift

Question

I'm making a feature where user can add text sticker, scale and rotate it using pan gesture by dragging on right bottom corner.
I made a custom class inherited from UIView, I put UITextView on it, 3 views on corners for buttons(close, edit and zoom/rotate) and transparent UIView on top for gestures.
Sorry, I have no enough reputation to add images
Text Sticker view structure - https://imgur.com/lDz47fV
My attempt is to use CGAffineTransform on pan gesture. Pan gesture is lying on Rotate Button View (bottom left corner)
#IBAction func resizeGestureRecognizer(_ sender: UIPanGestureRecognizer) {
let touchLocation = sender.location(in: self.superview)
let center = self.center
switch sender.state {
case .began:
self.deltaAngle = CGFloat(atan2f(Float(touchLocation.y - center.y), Float(touchLocation.x - center.x))) - CGAffineTransformGetAngle(self.transform)
self.initialDistance = CGPointGetDistance(point1: center, point2: touchLocation)
//self.initialBounds = self.bounds
case .changed:
let angle = atan2f(Float(touchLocation.y - center.y), Float(touchLocation.x - center.x))
let angleDiff = Float(self.deltaAngle) - angle
let scale = CGPointGetDistance(point1: center, point2: touchLocation) / self.initialDistance
// downscale buttons to ramain same size and rotation
for button in buttonViews {
var t = CGAffineTransform.identity
t = t.rotated(by: CGFloat(angleDiff))
t = t.scaledBy(x: 1/scale, y: 1/scale)
button.transform = t
}
var t = CGAffineTransform.identity
t = t.rotated(by: CGFloat(-angleDiff))
t = t.scaledBy(x: scale, y: scale)
self.transform = t
// textView.layer.shouldRasterize = true
// textView.layer.rasterizationScale = 20
case .ended, .cancelled:
print("ended")
default:
break
}
}
This code works but every time I'm trying to resize or rotate sticker it scale back to original scale. What am I missing?
Result - https://imgur.com/QHPlI93
Also, as a workaround for scaled font quality, I'm using huge fornt size(100) and scale of 0.5 for sticker:
override func awakeFromNib() {
textView.textContainerInset = UIEdgeInsets(top: 10, left: 20, bottom: 10, right: 20)
frameView.layer.cornerRadius = 13
showEditingHandlers = true
textView.becomeFirstResponder()
let scale: CGFloat = 0.5
for button in buttonViews {
var t = CGAffineTransform.identity
t = t.scaledBy(x: 1/scale, y: 1/scale)
button.transform = t
}
var t = CGAffineTransform.identity
t = t.scaledBy(x: scale, y: scale)
self.transform = t
textView.delegate = self
update()
}

Answer 1

Ok, in case someone else will be searching for similar problem, I'll post my solution
I added variables fro scale in top of my class:
var scale: CGFloat = 0
var savedScale: CGFloat = 0.5 // 0.5 becuase I use double font size and scaled my sticker by 0.5 to handle font blur
next, in my gesture handle func I just save last scale like this:
#IBAction func resizeGestureRecognizer(_ sender: UIPanGestureRecognizer) {
let touchLocation = sender.location(in: self.superview)
let center = self.center
switch sender.state {
case .began:
print("saved scale = \(savedScale)")
self.deltaAngle = CGFloat(atan2f(Float(touchLocation.y - center.y), Float(touchLocation.x - center.x))) - CGAffineTransformGetAngle(self.transform)
self.initialDistance = CGPointGetDistance(point1: center, point2: touchLocation)
case .changed:
let angle = atan2f(Float(touchLocation.y - center.y), Float(touchLocation.x - center.x))
let angleDiff = Float(self.deltaAngle) - angle
scale = CGPointGetDistance(point1: center, point2: touchLocation) / self.initialDistance
print("scale: \(scale)")
scale = scale * savedScale // <- added this
// downscale buttons to ramain same size and rotation
for button in buttonViews {
var t = CGAffineTransform.identity
//t = t.rotated(by: CGFloat(angleDiff))
t = t.scaledBy(x: 1/scale, y: 1/scale)
button.transform = t
}
var t = CGAffineTransform.identity
t = t.rotated(by: CGFloat(-angleDiff))
t = t.scaledBy(x: scale, y: scale)
self.transform = t
case .ended, .cancelled:
print("ended")
savedScale = 1 * scale // <- and this
default:
break
}
}