Mantis

Mantis is an iOS Image cropping library, which mimics the Photo App written in Swift and provides rich cropping interactions for your iOS/Mac app (Catalyst only).

Mantis also provides rich crop shapes from the basic circle/square to polygon to arbitrary paths(We even provide a heart shape ❤️ 😏).

Requirements

• iOS 11.0+
• MacOS 10.15+
• Xcode 10.0+

Install

CocoaPods

pod 'Mantis', '~> 1.9.0'

Carthage

github "guoyingtao/Mantis"

Swift Packages

• Respository: https://github.com/guoyingtao/Mantis.git
• Rules: Version - Exact - 1.9.0

Usage

Basic

• Create a cropViewController in Mantis with default config and default mode

You need set (cropViewController or its navigation controller).modalPresentationStyle = .fullscreen for iOS 13+ when the cropViewController is presented

    let cropViewController = Mantis.cropViewController(image: <Your Image>)
    cropViewController.delegate = self
    <Your ViewController>.present(cropViewController, animated: true)

• The caller needs to conform CropViewControllerDelegate

public protocol CropViewControllerDelegate: class {
    func cropViewControllerDidCrop(_ cropViewController: CropViewController, cropped: UIImage, transformation: Transformation, cropInfo: CropInfo)
    func cropViewControllerDidCancel(_ cropViewController: CropViewController, original: UIImage)
    
    // The implementaion of the following functions are optional
    func cropViewControllerDidFailToCrop(_ cropViewController: CropViewController, original: UIImage)     
    func cropViewControllerDidBeginResize(_ cropViewController: CropViewController)
    func cropViewControllerDidEndResize(_ cropViewController: CropViewController, original: UIImage, cropInfo: CropInfo)    
}

UI mode

• CropViewController has two modes:

  • normal mode

  In normal mode, you can use a set of standard CropViewController photo editing features.

let cropViewController = Mantis.cropViewController(image: <Your Image>)

• customizable mode

This mode includes the standard cropping feature, while enabling users to customize other edit features.

let cropViewController = Mantis.cropCustomizableViewController(image: <Your Image>)

Add your own ratio

            // Add a custom ratio 1:2 for portrait orientation
            let config = Mantis.Config()
            config.addCustomRatio(byVerticalWidth: 1, andVerticalHeight: 2)            
            <Your Crop ViewController> = Mantis.cropViewController(image: <Your Image>, config: config)
            
            // Set the ratioOptions of the config if you don't want to keep all default ratios
            let config = Mantis.Config() 
            //config.ratioOptions = [.original, .square, .custom]
            config.ratioOptions = [.custom]
            config.addCustomRatio(byVerticalWidth: 1, andVerticalHeight: 2)            
            <Your Crop ViewController> = Mantis.cropViewController(image: <Your Image>, config: config)

• If you always want to use only one fixed ratio, set Mantis.Config.presetFixedRatioType = alwaysUsingOnePresetFixedRatio

    <Your Crop ViewController>.config.presetFixedRatioType = .alwaysUsingOnePresetFixedRatio(ratio: 16.0 / 9.0)

When choose alwaysUsingOnePresetFixedRatio, fixed-ratio setting button does not show.

• If you want to hide rotation dial, set Mantis.Config.showRotationDial = false
• If you want to use ratio list instead of presenter, set Mantis.CropToolbarConfig.ratioCandidatesShowType = .alwaysShowRatioList

public enum RatioCandidatesShowType {
    case presentRatioList
    case alwaysShowRatioList
}

• If you build your custom toolbar you can add your own fixed ratio buttons

// set a custom fixed ratio
cropToolbarDelegate?.didSelectRatio(ratio: 9 / 16)

Crop shapes

• If you want to set different crop shape, set Mantis.Config.cropShapeType

public enum CropShapeType {
    case rect
    case square
    case ellipse
    case circle(maskOnly: Bool = false)
    case diamond(maskOnly: Bool = false)
    case heart(maskOnly: Bool = false)
    case polygon(sides: Int, offset: CGFloat = 0, maskOnly: Bool = false)
    case path(points: [CGPoint], maskOnly: Bool = false)
}

Preset transformations

• If you want to apply transformations when showing an image, set Mantis.Config.presetTransformationType

public enum PresetTransformationType {
    case none
    case presetInfo(info: Transformation)
    case presetNormalizedInfo(normailizedInfo: CGRect)
}

Please use the transformation infomation obtained previously from delegate method cropViewControllerDidCrop(_ cropViewController: CropViewController, cropped: UIImage, transformation: Transformation, , cropInfo: CropInfo).

Localization

• UIKit project
  Add more languages support to the Localizaions section for Project Info tab

fig 1

• SwiftUI project
  Please check this link

• Static frameworks If you use static frameworks in CocoaPods, you need to add the code below in order to find the correct resource bundle.

    Mantis.locateResourceBundle(by: Self.self)

• Custom localization tables and bundle

By default mantis will use built in localization tables to get string resources not every language is supported out of the box (see fig 1).

However if your app support multiple languages and those languages are not 'built in', then you can define your own strings table and localize them in the application target or framework. By doing so you'll need to configure Mantis localization.

IMPORTANT! Firstly you'll need to create strings file with these keys:

"Mantis.Done" = "";
"Mantis.Cancel" = "";
"Mantis.Reset" = "";
"Mantis.Original" = "";
"Mantis.Square" = "";

Then you'll need to configure Mantis:

let config = Mantis.Config()
config.localizationConfig.bundle = // a bundle where strings file is located
config.localizationConfig.tableName = // a localizaed strings file name within the bundle

Demo projects

Mantis provide two demo projects

• MantisExample (using Storyboard)
• MantisSwiftUIExample (using SwiftUI)

Credits

• The crop are strongly inspired by TOCropViewController
• The rotation feature is inspired by IGRPhotoTweaks
• The rotation dial is inspired by 10clock
• Thanks Leo Dabus for helping me to solve the problem of cropping an ellipse image with transparent background https://stackoverflow.com/a/59805317/288724
• Icons made by Freepik from www.flaticon.com is licensed by CC 3.0 BY