Configure Transforms

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PhotoEditor SDK supports several configuration options for the TransformToolController allowing flexible adaptation to different needs and use cases. For a detailed explanation on how to configure different editor views, refer to this guide.

`allowedCropRatios`#

The default configuration includes a number of different crop aspect ratios users can choose from. In order to restrict those to specific aspect ratios only, for instance those used by social networks (e.g. Facebook, Twitter, Instagram, Flickr), we can specify aspect ratios as CropAspect object and give it the desired width and height. The localizedName argument to the CropAspect construtor allows using a custom name for the crop ratio. Note that setting the aspect ratio will not affect the resolution of the image.

`allowFreeCrop`#

While it is possible to configure the available preset aspect ratios for cropping, we can also disable free cropping to ensure that photo will always choose one of the available aspect ratios by setting allowFreeCrop to false.

`showResetButton`#

When free crop is enabled, users need a way to reset the applied transform operations. In our example, since we are enforcing a certain set of aspect ratios, we can disable the reset button by setting showResetButton to false.

`outputScaling`#

Sometimes image resolution can't be represented in aspect ratio that is desired. That happen in cases where width and height aren't dividable by the selected aspect ratio widths and heights. For this purpose we have an option to scale the output resolution to match the selected ratio exactly. Default is set to .none which means that no output scaling will be performed. In our example we set it to .scaleUp, which means that the output resolution will be scaled up to the closest resolution that is dividable by the selected ratio.

✨Introduced in PhotoEditor SDK v11.6.0

`forceCropMode`#

Since in this example we enforce a certain set of aspect ratios, we need to ensure that one of the crop options is selected before any other editing operations are applied. To this end we configure the PhotoEditViewController by setting forceCropMode to true. This ensures that the transform tool is presented first if the selected photo does not fit one of the allowed aspect ratios.


import PhotoEditorSDK
import UIKit

class PhotoTransformConfigurationSwift: Example, PhotoEditViewControllerDelegate {
  override func invokeExample() {
    // Create a `Photo` from a URL to an image in the app bundle.
    let photo = Photo(url: Bundle.main.url(forResource: "LA", withExtension: "jpg")!)

    // Create a `Configuration` object.
    let configuration = Configuration { builder in
      // Configure the `TransformToolController` that lets the user
      // crop and rotate the image.
      builder.configureTransformToolController { options in
        // By default the editor has a lot of crop aspects enabled.
        // For this example only a couple are enabled, e.g. if you
        // only allow certain image aspects in your application.
        options.allowedCropRatios = [
          CropAspect(width: 1, height: 1),
          CropAspect(width: 16, height: 9, localizedName: "Landscape")
        ]

        // By default the editor allows to use a free crop ratio.
        // For this example this is disabled to ensure that the image
        // has a suitable ratio.
        options.allowFreeCrop = false

        // By default the editor shows the reset button which resets
        // the applied transform operations. In this example the button
        // is hidden since we are enforcing certain ratios and the user
        // can only select among them anyway.
        options.showResetButton = false

        // By default the editor doesn't apply any output scaling
        // ransform operations. In this example, we are using `scaleUp`
        // that will make sure that image output resolution exactly
        // matches selected aspect ratio.
        options.outputScaling = .scaleUp
      }

      // Configure the `PhotoEditViewController`.
      builder.configurePhotoEditViewController { options in
        // For this example the user is forced to crop the asset to one of
        // the allowed crop aspects specified above, before being able to use other
        // features of the editor. The transform tool will only be presented
        // if the image does not already fit one of those allowed aspect ratios.
        options.forceCropMode = true
      }
    }

    // Create and present the photo editor. Make this class the delegate of it to handle export and cancelation.
    let photoEditViewController = PhotoEditViewController(photoAsset: photo, configuration: configuration)
    photoEditViewController.delegate = self
    photoEditViewController.modalPresentationStyle = .fullScreen
    presentingViewController?.present(photoEditViewController, animated: true, completion: nil)
  }

  // MARK: - PhotoEditViewControllerDelegate

  func photoEditViewControllerShouldStart(_ photoEditViewController: PhotoEditViewController, task: PhotoEditorTask) -> Bool {
    // Implementing this method is optional. You can perform additional validation and interrupt the process by returning `false`.
    true
  }

  func photoEditViewControllerDidFinish(_ photoEditViewController: PhotoEditViewController, result: PhotoEditorResult) {
    // The image has been exported successfully and is passed as an `Data` object in the `result.output.data`.
    // To create an `UIImage` from the output, use `UIImage(data:)`.
    // See other examples about how to save the resulting image.
    presentingViewController?.dismiss(animated: true, completion: nil)
  }

  func photoEditViewControllerDidFail(_ photoEditViewController: PhotoEditViewController, error: PhotoEditorError) {
    // There was an error generating the photo.
    print(error.localizedDescription)
    // Dismissing the editor.
    presentingViewController?.dismiss(animated: true, completion: nil)
  }

  func photoEditViewControllerDidCancel(_ photoEditViewController: PhotoEditViewController) {
    // The user tapped on the cancel button within the editor. Dismissing the editor.
    presentingViewController?.dismiss(animated: true, completion: nil)
  }
}

Configure Transforms

allowedCropRatios#

allowFreeCrop#

showResetButton#

outputScaling#

forceCropMode#

`allowedCropRatios`#

`allowFreeCrop`#

`showResetButton`#

`outputScaling`#

`forceCropMode`#