Merge an image and text creating another image in swift 4

Question

I am trying to merge an UIImage and a text of an UITextField creating another Image, but I hadn't any success.

What does my app to do? or should it do?

Basically it takes the image created by the method snapshot, merge that image with a text from UITextField, creating an other image that will be save and shows in a tableView.

But I'm having a lot of trouble making it work.

When I take only the image everything works well. Follow my code.

override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
    guard let touch = touches.first, let startPoint = startPoint else {return}
    let currentPoint = touch.location(in: imageView)
    let frame = rect(from: startPoint, to: currentPoint)

    rectShapeLayer.removeFromSuperlayer()


    if frame.size.width < 1{
        tfText.resignFirstResponder()
    } else {
        let memedImage = getImage(frame: frame, imageView: self.imageView)
        save(imageView: imageView, image: memedImage)
    }
}

func getImage(frame: CGRect, imageView: UIImageView) -> UIImage {

    let cropImage = imageView.snapshot(rect: frame, afterScreenUpdates: true)

    return cropImage

But when I try to create an Image using UIGraphicsBeginImageContextWithOptions to merge it with a textField, I fail.

Follow my code

   override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
    guard let touch = touches.first, let startPoint = startPoint else {return}
    let currentPoint = touch.location(in: imageView)
    let frame = rect(from: startPoint, to: currentPoint)

    rectShapeLayer.removeFromSuperlayer()


    if frame.size.width < 1{
        tfText.resignFirstResponder()
    } else {
        let memedImage = getImage(frame: frame, imageView: self.imageView)
        save(imageView: imageView, image: memedImage)
    }
}

func getImage(frame: CGRect, imageView: UIImageView) -> UIImage {

    let cropImage = imageView.snapshot(rect: frame, afterScreenUpdates: true)

    UIGraphicsBeginImageContextWithOptions(cropImage.size, false, 0.0)

    cropImage.draw(in: frame)
    tfText.drawText(in: frame)

    let newImage = UIGraphicsGetImageFromCurrentImageContext()!
    UIGraphicsEndImageContext()

    return newImage
}

Let me show you some screenshots of the my app.

First creating only image.

Now when I try to merge the text and image.

Please, look at the debug area.

The images are created, but they don’t show up on the tableView.

What am I doing wrong?

UPDATE THE QUESTION

With the code above my memedImage is empty. "Thanks Rob"

So, I changed my previous getImage(_:) to:

   func getANewImage(frame: CGRect, imageView: UIImageView, textField: UITextField) -> UIImage{

    let cropImage = imageView.snapshot(rect: frame, afterScreenUpdates: true)

    let newImageView = UIImageView(image: cropImage)

    UIGraphicsBeginImageContextWithOptions(newImageView.frame.size, false, 0.0)

    let context = UIGraphicsGetCurrentContext()!

    context.translateBy(x: newImageView.frame.origin.x, y: newImageView.frame.origin.y)
    newImageView.layer.render(in: context)
    textField.layer.render(in: context)

    let newImage = UIGraphicsGetImageFromCurrentImageContext()!
    UIGraphicsEndImageContext()

    return newImage
}

That way I almost got... I created a new image with the textField, but the textField changed its position, it should be in the center.

With .draw does't work, but with layer.render works almost well.

Answer 1

I almost didn't have help with that question, only a litte hint of the my friend Rob. Thank you again Rob.

Likely, I found out how to fix the problem with the TextField position and I'd like to share the solution.

func getImage(frame: CGRect, imageView: UIImageView, textField: UITextField) -> UIImage{

    //Get the new image after snapshot method
    let cropImage = imageView.snapshot(rect: frame, afterScreenUpdates: true)

    //Create new imageView with the cropImage
    let newImageView = UIImageView(image: cropImage)

    //Origin point of the Snapshot Frame.
    let frameOriginX = frame.origin.x
    let frameOriginY = frame.origin.y

    UIGraphicsBeginImageContextWithOptions(newImageView.frame.size, false, cropImage.scale)
    let context = UIGraphicsGetCurrentContext()!

    //Render the "cropImage" in the CGContext
    newImageView.layer.render(in: context)

    //Position of the TextField
    let tf_X = textField.frame.origin.x - frameOriginX
    let tf_Y = textField.frame.origin.y - frameOriginY

    //Context Translate with TextField position
    context.translateBy(x: tf_X, y: tf_Y)

    //Render the "TextField" in the CGContext
    textField.layer.render(in: context)

    //Create newImage
    let newImage = UIGraphicsGetImageFromCurrentImageContext()!
    UIGraphicsEndImageContext()

    return newImage
}

Of course this code can be optimized, but it worked very well for me.