Camera Quickstart - sammanthp007/Linux-Kernel-Development GitHub Wiki

Overview

This is a quickstart guide for using the taking a photo or picking an image from the camera roll using the stock camera and camera roll. In both cases, we'll modally present the UIImagePickerController class which has a delegate. The delegate has a method which is called after a user takes/picks a picture.

Taking a Picture

Step 1: Declare that your class implements the required protocols

• Add UIImagePickerControllerDelegate and UINavigationControllerDelegate when defining your class or as an extension of your view controller class.

  class PhotoMapViewController: UIViewController, UIImagePickerControllerDelegate, UINavigationControllerDelegate {
  ...
  }
  

Step 2: Instantiate a UIImagePickerController

let vc = UIImagePickerController()
vc.delegate = self
vc.allowsEditing = true
vc.sourceType = UIImagePickerControllerSourceType.camera

self.present(vc, animated: true, completion: nil)

NOTE: The Xcode simulator does not support taking pictures, so you may want to check that the camera is indeed supported on the device before trying to present it.

if UIImagePickerController.isSourceTypeAvailable(.camera) {
   print("Camera is available 📸")
   vc.sourceType = .camera
} else {
   print("Camera 🚫 available so we will use photo library instead")
   vc.sourceType = .photoLibrary
}

Step 3: Implement the delegate method

func imagePickerController(_ picker: UIImagePickerController, 
didFinishPickingMediaWithInfo info: [String : Any]) {
    // Get the image captured by the UIImagePickerController
    let originalImage = info[UIImagePickerControllerOriginalImage] as! UIImage
    let editedImage = info[UIImagePickerControllerEditedImage] as! UIImage

    // Do something with the images (based on your use case)

    // Dismiss UIImagePickerController to go back to your original view controller
    dismiss(animated: true, completion: nil)
}

When the user finishes taking the picture, UIImagePickerController returns a dictionary that contains the image and some other meta data. The full set of keys are listed here.

Picking a Picture from the Camera Roll

Step 1: Declare that your class implements the required protocols

• Add UIImagePickerControllerDelegate and UINavigationControllerDelegate when defining your class or as an extension of your view controller class.

  class PhotoMapViewController: UIViewController, UIImagePickerControllerDelegate, UINavigationControllerDelegate {
  ...
  }
  

Step 2: Instantiate a UIImagePickerController

let vc = UIImagePickerController()
vc.delegate = self
vc.allowsEditing = true
vc.sourceType = UIImagePickerControllerSourceType.photoLibrary

self.present(vc, animated: true, completion: nil)

Step 3: Implement the delegate method

func imagePickerController(_ picker: UIImagePickerController, 
didFinishPickingMediaWithInfo info: [String : Any]) {
    // Get the image captured by the UIImagePickerController
    let originalImage = info[UIImagePickerControllerOriginalImage] as! UIImage
    let editedImage = info[UIImagePickerControllerEditedImage] as! UIImage

    // Do something with the images (based on your use case)

    // Dismiss UIImagePickerController to go back to your original view controller
    dismiss(animated: true, completion: nil)
}