Check if imageView is empty - ios

Question

I have a camera feature in my app and when you take the picture it places that picture into an imageView. I have a button that I've hidden and what I want is for when the image is placed in the imageView for the button to be unhidden.
#IBOutlet weak var imageView: UIImageView!
#IBOutlet weak var toGoFurther: UIButton!
override func viewDidLoad() {
super.viewDidLoad()
toGoFurther.hidden = true
if (self.imageView.image != nil){
toGoFurther.hidden = false
}
let testObject = PFObject(className: "TestObject")
testObject["foo"] = "bar"
testObject.saveInBackgroundWithBlock { (success: Bool, error: NSError?) -> Void in
print("Object has been saved.")
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBAction func continueNextPage(sender: AnyObject) {
}
#IBAction func takePhoto(sender: AnyObject) {
if !UIImagePickerController.isSourceTypeAvailable(UIImagePickerControllerSourceType.Camera){
return
}
let imagePicker = UIImagePickerController()
imagePicker.delegate = self
imagePicker.sourceType = UIImagePickerControllerSourceType.Camera;
//Create camera overlay
let pickerFrame = CGRectMake(0, UIApplication.sharedApplication().statusBarFrame.size.height, imagePicker.view.bounds.width, imagePicker.view.bounds.height - imagePicker.navigationBar.bounds.size.height - imagePicker.toolbar.bounds.size.height)
let squareFrame = CGRectMake(pickerFrame.width/2 - 400/2, pickerFrame.height/2 - 400/2, 640, 640)
UIGraphicsBeginImageContext(pickerFrame.size)
let context = UIGraphicsGetCurrentContext()
CGContextSaveGState(context)
CGContextAddRect(context, CGContextGetClipBoundingBox(context))
CGContextMoveToPoint(context, squareFrame.origin.x, squareFrame.origin.y)
CGContextAddLineToPoint(context, squareFrame.origin.x + squareFrame.width, squareFrame.origin.y)
CGContextAddLineToPoint(context, squareFrame.origin.x + squareFrame.width, squareFrame.origin.y + squareFrame.size.height)
CGContextAddLineToPoint(context, squareFrame.origin.x, squareFrame.origin.y + squareFrame.size.height)
CGContextAddLineToPoint(context, squareFrame.origin.x, squareFrame.origin.y)
CGContextEOClip(context)
CGContextMoveToPoint(context, pickerFrame.origin.x, pickerFrame.origin.y)
CGContextSetRGBFillColor(context, 0, 0, 0, 1)
CGContextFillRect(context, pickerFrame)
CGContextRestoreGState(context)
let overlayImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext();
let overlayView = UIImageView(frame: pickerFrame)
overlayView.image = overlayImage
imagePicker.cameraOverlayView = overlayView
self.presentViewController(imagePicker, animated: true, completion: nil)
}
func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : AnyObject]) {
imageView.image = info[UIImagePickerControllerOriginalImage] as? UIImage
dismissViewControllerAnimated(true, completion: nil)
}

Answer 1

Try putting this in the viewDidAppear method. That should do it.
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
toGoFurther.hidden = self.imageView.image == nil
}

Answer 2

So, you want to unhide your button when image is captured and set on view. You need to do this in your didFinishPickingMediaWithInfo function like this:
func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [NSObject: AnyObject]) {
imageView.image = info[UIImagePickerControllerOriginalImage] as? UIImage
// dissmiss the image picker controller window
self.dismissViewControllerAnimated(true, completion:^{
toGoFurther.hidden = false
})
}