100 Days of SwiftUI（DAY 66（Project13 part 5））

ActionSheetを使用してフィルターをカスタマイズする
Customizing our filter using ActionSheet

//
//  ContentView.swift
//  Instafilter-2
//
//  Created by Naoki Abe on 2020/08/23.
//  Copyright © 2020 Naoki Abe. All rights reserved.
//

import SwiftUI
import CoreImage
import CoreImage.CIFilterBuiltins

struct ContentView: View {
    
    @State private var image: Image?
    @State private var filterIntensity = 0.5
    @State private var showingImagePicker = false
    @State private var inputImage: UIImage?
    
    //画像を処理
    //@State private var currentFilter = CIFilter.sepiaTone()
    @State private var currentFilter: CIFilter = CIFilter.sepiaTone()
    
    let context = CIContext()
    
    @State private var showingFilterSheet = false

    //画像を処理するメソッド
    func applyProcessing() {
        //currentFilter.intensity = Float(filterIntensity)
        //currentFilter.setValue(filterIntensity, forKey: kCIInputIntensityKey)
        let inputKeys = currentFilter.inputKeys
        if inputKeys.contains(kCIInputIntensityKey) { currentFilter.setValue(filterIntensity, forKey: kCIInputIntensityKey) }
        if inputKeys.contains(kCIInputRadiusKey) { currentFilter.setValue(filterIntensity * 200, forKey: kCIInputRadiusKey) }
        if inputKeys.contains(kCIInputScaleKey) { currentFilter.setValue(filterIntensity * 10, forKey: kCIInputScaleKey) }

        guard let outputImage = currentFilter.outputImage else { return }

        if let cgimg = context.createCGImage(outputImage, from: outputImage.extent) {
            let uiImage = UIImage(cgImage: cgimg)
            image = Image(uiImage: uiImage)
        }
    }
    
    func setFilter(_ filter: CIFilter) {
        currentFilter = filter
        loadImage()
    }
    
    func loadImage() {
        guard let inputImage = inputImage else { return }

        let beginImage = CIImage(image: inputImage)
        currentFilter.setValue(beginImage, forKey: kCIInputImageKey)
        applyProcessing()
    }
    //------------------------------------------------------
    var body: some View {
        //------------------------
        let intensity = Binding<Double>(
            get: {
                self.filterIntensity
            },
            set: {
                self.filterIntensity = $0
                self.applyProcessing()
            }
        )
        //------------------------
        return NavigationView {
            VStack {
                ZStack {
                    Rectangle()
                        .fill(Color.secondary)
                    // display the image
                    if image != nil {
                        image?
                            .resizable()
                            .scaledToFit()
                    } else {
                        Text("Tap to select a picture")
                            .foregroundColor(.white)
                            .font(.headline)
                    }
                }
                .onTapGesture {
                    // select an image
                    self.showingImagePicker = true
                }

                HStack {
                    Text("Intensity")
                    Slider(value: intensity)
                }.padding(.vertical)

                HStack {
                    Button("Change Filter") {
                        // change filter
                        self.showingFilterSheet = true
                    }

                    Spacer()

                    Button("Save") {
                        // save the picture
                    }
                }
            }
            .padding([.horizontal, .bottom])
            .navigationBarTitle("Instafilter")
            .sheet(isPresented: $showingImagePicker, onDismiss: loadImage) {
                ImagePicker(image: self.$inputImage)
            }
            .actionSheet(isPresented: $showingFilterSheet) {
                // action sheet here
                ActionSheet(title: Text("Select a filter"), buttons: [
                    .default(Text("Crystallize")) { self.setFilter(CIFilter.crystallize()) },
                    .default(Text("Edges")) { self.setFilter(CIFilter.edges()) },
                    .default(Text("Gaussian Blur")) { self.setFilter(CIFilter.gaussianBlur()) },
                    .default(Text("Pixellate")) { self.setFilter(CIFilter.pixellate()) },
                    .default(Text("Sepia Tone")) { self.setFilter(CIFilter.sepiaTone()) },
                    .default(Text("Unsharp Mask")) { self.setFilter(CIFilter.unsharpMask()) },
                    .default(Text("Vignette")) { self.setFilter(CIFilter.vignette()) },
                    .cancel()
                ])
            }
        }
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}

UIImageWriteToSavedPhotosAlbum（）を使用してフィルターされた画像を保存する

このプロジェクトを完了するには、[保存]ボタンを有効にして、フィルター処理された写真をユーザーの写真ライブラリに保存し、ユーザーがさらに編集したり、共有したりできるようにします。

Privacy – Photo Library Additions Usage Description
We want to save the filtered photo.

Info.plistを開く
空白スペースを右クリック
[行を追加]を選択します
キー名として「プライバシー-フォトライブラリ追加機能の使用法の説明」を選択します。
「フィルタリングされた写真を保存したい」と入力します。値として。


import UIKit

class ImageSaver: NSObject {
    var successHandler: (() -> Void)?
    var errorHandler: ((Error) -> Void)?
    
    func writeToPhotoAlbum(image: UIImage) {
        UIImageWriteToSavedPhotosAlbum(image, self, #selector(saveError), nil)
    }

    @objc func saveError(_ image: UIImage, didFinishSavingWithError error: Error?, contextInfo: UnsafeRawPointer) {
        // save complete
        if let error = error {
            errorHandler?(error)
        } else {
            successHandler?()
        }
    }
}



//
//  ContentView.swift
//  Instafilter-2
//
//  Created by Naoki Abe on 2020/08/23.
//  Copyright © 2020 Naoki Abe. All rights reserved.
//

import SwiftUI
import CoreImage
import CoreImage.CIFilterBuiltins

struct ContentView: View {
    
    @State private var image: Image?
    @State private var filterIntensity = 0.5
    @State private var showingImagePicker = false
    @State private var inputImage: UIImage?
    
    //画像を処理
    //@State private var currentFilter = CIFilter.sepiaTone()
    @State private var currentFilter: CIFilter = CIFilter.sepiaTone()
    
    let context = CIContext()
    
    @State private var showingFilterSheet = false
    
    @State private var processedImage: UIImage?

    //画像を処理するメソッド
    func applyProcessing() {
        //currentFilter.intensity = Float(filterIntensity)
        //currentFilter.setValue(filterIntensity, forKey: kCIInputIntensityKey)
        let inputKeys = currentFilter.inputKeys
        if inputKeys.contains(kCIInputIntensityKey) { currentFilter.setValue(filterIntensity, forKey: kCIInputIntensityKey) }
        if inputKeys.contains(kCIInputRadiusKey) { currentFilter.setValue(filterIntensity * 200, forKey: kCIInputRadiusKey) }
        if inputKeys.contains(kCIInputScaleKey) { currentFilter.setValue(filterIntensity * 10, forKey: kCIInputScaleKey) }

        guard let outputImage = currentFilter.outputImage else { return }

        if let cgimg = context.createCGImage(outputImage, from: outputImage.extent) {
            let uiImage = UIImage(cgImage: cgimg)
            image = Image(uiImage: uiImage)
            processedImage = uiImage
        }
    }
    
    func setFilter(_ filter: CIFilter) {
        currentFilter = filter
        loadImage()
    }
    
    func loadImage() {
        guard let inputImage = inputImage else { return }

        let beginImage = CIImage(image: inputImage)
        currentFilter.setValue(beginImage, forKey: kCIInputImageKey)
        applyProcessing()
    }
    //------------------------------------------------------
    var body: some View {
        //------------------------
        let intensity = Binding<Double>(
            get: {
                self.filterIntensity
            },
            set: {
                self.filterIntensity = $0
                self.applyProcessing()
            }
        )
        //------------------------
        return NavigationView {
            VStack {
                ZStack {
                    Rectangle()
                        .fill(Color.secondary)
                    // display the image
                    if image != nil {
                        image?
                            .resizable()
                            .scaledToFit()
                    } else {
                        Text("Tap to select a picture")
                            .foregroundColor(.white)
                            .font(.headline)
                    }
                }
                .onTapGesture {
                    // select an image
                    self.showingImagePicker = true
                }

                HStack {
                    Text("Intensity")
                    Slider(value: intensity)
                }.padding(.vertical)

                HStack {
                    Button("Change Filter") {
                        // change filter
                        self.showingFilterSheet = true
                    }

                    Spacer()

                    Button("Save") {
                        guard let processedImage = self.processedImage else { return }

                        let imageSaver = ImageSaver()
                        imageSaver.successHandler = {
                            print("Success!")
                        }
                        imageSaver.errorHandler = {
                            print("Oops: \($0.localizedDescription)")
                        }
                        imageSaver.writeToPhotoAlbum(image: processedImage)
                    }
                }
            }
            .padding([.horizontal, .bottom])
            .navigationBarTitle("Instafilter")
            .sheet(isPresented: $showingImagePicker, onDismiss: loadImage) {
                ImagePicker(image: self.$inputImage)
            }
            .actionSheet(isPresented: $showingFilterSheet) {
                // action sheet here
                ActionSheet(title: Text("Select a filter"), buttons: [
                    .default(Text("Crystallize")) { self.setFilter(CIFilter.crystallize()) },
                    .default(Text("Edges")) { self.setFilter(CIFilter.edges()) },
                    .default(Text("Gaussian Blur")) { self.setFilter(CIFilter.gaussianBlur()) },
                    .default(Text("Pixellate")) { self.setFilter(CIFilter.pixellate()) },
                    .default(Text("Sepia Tone")) { self.setFilter(CIFilter.sepiaTone()) },
                    .default(Text("Unsharp Mask")) { self.setFilter(CIFilter.unsharpMask()) },
                    .default(Text("Vignette")) { self.setFilter(CIFilter.vignette()) },
                    .cancel()
                ])
            }
        }
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}