feat(view, viewmodel, model): 增加 document 和 palette，增加手势
1. 可以从另一个 app 中拖入图片或图片链接作为背景 2. 可以从 palette 中拖入 emoji 3. 可以拖动和双击缩放背景图 Signed-off-by: Ching <loooching@gmail.com>
This commit is contained in:
Ching
parent
b6d09f314e
commit
89d38faea4
@ -8,18 +8,30 @@
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/* Begin PBXBuildFile section */
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24145E7C29A1489700ECB9D1 /* EmojiArtApp.swift in Sources */ = {isa = PBXBuildFile; fileRef = 24145E7B29A1489700ECB9D1 /* EmojiArtApp.swift */; };
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24145E7E29A1489700ECB9D1 /* ContentView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 24145E7D29A1489700ECB9D1 /* ContentView.swift */; };
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24145E7E29A1489700ECB9D1 /* EmojiArtDocumentView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 24145E7D29A1489700ECB9D1 /* EmojiArtDocumentView.swift */; };
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24145E8429A1489800ECB9D1 /* Preview Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 24145E8329A1489800ECB9D1 /* Preview Assets.xcassets */; };
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24145E8B29A1498500ECB9D1 /* EmojiArtModel.swift in Sources */ = {isa = PBXBuildFile; fileRef = 24145E8A29A1498500ECB9D1 /* EmojiArtModel.swift */; };
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24145E8D29A225E900ECB9D1 /* EmojiArtModel.Background.swift in Sources */ = {isa = PBXBuildFile; fileRef = 24145E8C29A225E900ECB9D1 /* EmojiArtModel.Background.swift */; };
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248D14EC29A227C700AE4C0D /* EmojiArtDocument.swift in Sources */ = {isa = PBXBuildFile; fileRef = 248D14EB29A227C700AE4C0D /* EmojiArtDocument.swift */; };
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248D14F029A230FE00AE4C0D /* Constants.swift in Sources */ = {isa = PBXBuildFile; fileRef = 248D14EF29A230FE00AE4C0D /* Constants.swift */; };
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/* End PBXBuildFile section */
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/* Begin PBXFileReference section */
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24145E7829A1489700ECB9D1 /* EmojiArt.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = EmojiArt.app; sourceTree = BUILT_PRODUCTS_DIR; };
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24145E7B29A1489700ECB9D1 /* EmojiArtApp.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = EmojiArtApp.swift; sourceTree = "<group>"; };
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24145E7D29A1489700ECB9D1 /* ContentView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ContentView.swift; sourceTree = "<group>"; };
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24145E7D29A1489700ECB9D1 /* EmojiArtDocumentView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = EmojiArtDocumentView.swift; sourceTree = "<group>"; };
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24145E7F29A1489800ECB9D1 /* Assets.xcassets */ = {isa = PBXFileReference; lastKnownFileType = folder.assetcatalog; path = Assets.xcassets; sourceTree = "<group>"; };
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24145E8129A1489800ECB9D1 /* EmojiArt.entitlements */ = {isa = PBXFileReference; lastKnownFileType = text.plist.entitlements; path = EmojiArt.entitlements; sourceTree = "<group>"; };
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24145E8329A1489800ECB9D1 /* Preview Assets.xcassets */ = {isa = PBXFileReference; lastKnownFileType = folder.assetcatalog; path = "Preview Assets.xcassets"; sourceTree = "<group>"; };
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24145E8A29A1498500ECB9D1 /* EmojiArtModel.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = EmojiArtModel.swift; sourceTree = "<group>"; };
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24145E8C29A225E900ECB9D1 /* EmojiArtModel.Background.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = EmojiArtModel.Background.swift; sourceTree = "<group>"; };
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248D14EB29A227C700AE4C0D /* EmojiArtDocument.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = EmojiArtDocument.swift; sourceTree = "<group>"; };
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248D14EF29A230FE00AE4C0D /* Constants.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Constants.swift; sourceTree = "<group>"; };
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/* Begin PBXFrameworksBuildPhase section */
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@ -52,8 +64,14 @@
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24145E7A29A1489700ECB9D1 /* EmojiArt */ = {
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isa = PBXGroup;
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children = (
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248D14EF29A230FE00AE4C0D /* Constants.swift */,
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24145E7B29A1489700ECB9D1 /* EmojiArtApp.swift */,
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24145E7D29A1489700ECB9D1 /* ContentView.swift */,
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24145E7D29A1489700ECB9D1 /* EmojiArtDocumentView.swift */,
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248D14F129A2435000AE4C0D /* UtilityViews.swift */,
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24145E8A29A1498500ECB9D1 /* EmojiArtModel.swift */,
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248D14F529A243F200AE4C0D /* UtilityExtensions.swift */,
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248D14EB29A227C700AE4C0D /* EmojiArtDocument.swift */,
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24145E8C29A225E900ECB9D1 /* EmojiArtModel.Background.swift */,
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24145E7F29A1489800ECB9D1 /* Assets.xcassets */,
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24145E8129A1489800ECB9D1 /* EmojiArt.entitlements */,
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24145E8229A1489800ECB9D1 /* Preview Content */,
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@ -139,8 +157,14 @@
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isa = PBXSourcesBuildPhase;
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buildActionMask = 2147483647;
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files = (
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24145E7E29A1489700ECB9D1 /* ContentView.swift in Sources */,
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24145E7E29A1489700ECB9D1 /* EmojiArtDocumentView.swift in Sources */,
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24145E7C29A1489700ECB9D1 /* EmojiArtApp.swift in Sources */,
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248D14EC29A227C700AE4C0D /* EmojiArtDocument.swift in Sources */,
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248D14F029A230FE00AE4C0D /* Constants.swift in Sources */,
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24145E8B29A1498500ECB9D1 /* EmojiArtModel.swift in Sources */,
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24145E8D29A225E900ECB9D1 /* EmojiArtModel.Background.swift in Sources */,
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248D14F629A243F200AE4C0D /* UtilityExtensions.swift in Sources */,
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248D14F329A2435000AE4C0D /* UtilityViews.swift in Sources */,
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);
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runOnlyForDeploymentPostprocessing = 0;
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};
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14
EmojiArt/Constants.swift
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14
EmojiArt/Constants.swift
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@ -0,0 +1,14 @@
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//
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// Constants.swift
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// EmojiArt
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//
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// Created by ching on 2023/2/19.
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//
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import Foundation
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import SwiftUI
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struct const {
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static let defaultEmojiFontSize: CGFloat = 40
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}
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@ -1,26 +0,0 @@
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//
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// ContentView.swift
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// EmojiArt
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//
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// Created by ching on 2023/2/19.
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//
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import SwiftUI
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struct ContentView: View {
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var body: some View {
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VStack {
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Image(systemName: "globe")
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.imageScale(.large)
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.foregroundColor(.accentColor)
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Text("Hello, world!")
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}
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.padding()
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}
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}
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struct ContentView_Previews: PreviewProvider {
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static var previews: some View {
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ContentView()
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}
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}
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@ -9,9 +9,10 @@ import SwiftUI
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@main
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struct EmojiArtApp: App {
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let document = EmojiArtDocument()
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var body: some Scene {
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WindowGroup {
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ContentView()
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EmojiArtDocumentView(document: document)
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}
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}
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}
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80
EmojiArt/EmojiArtDocument.swift
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80
EmojiArt/EmojiArtDocument.swift
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@ -0,0 +1,80 @@
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//
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// EmojiArtDocument.swift
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// EmojiArt
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//
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// Created by ching on 2023/2/19.
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//
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import SwiftUI
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class EmojiArtDocument: ObservableObject {
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@Published private(set) var emojiArt: EmojiArtModel {
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didSet {
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if emojiArt.background != oldValue.background {
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fetchBackgoundImageDataIfNecessary()
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}
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}
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}
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init() {
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emojiArt = EmojiArtModel()
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}
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var emojis: [EmojiArtModel.Emoji] { emojiArt.emojis }
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var background: EmojiArtModel.Background { emojiArt.background }
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@Published var backgroundImage: UIImage?
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@Published var backgroundImageFetchStatus = BackgroundImageFetchStatus.idle
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enum BackgroundImageFetchStatus {
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case idle
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case fetching
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}
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// MARK: - Intent(s)
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func setBackground(_ background: EmojiArtModel.Background) {
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emojiArt.background = background
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print("background set to \(background)")
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}
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func addEmoji(_ emoji: String, at location: (x: Int, y: Int), size: CGFloat) {
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emojiArt.addEmoji(emoji, at: location, size: Int(size))
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}
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func moveEmoji(_ emoji: EmojiArtModel.Emoji, by offset: CGSize) {
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if let index = emojiArt.emojis.index(matching: emoji) {
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emojiArt.emojis[index].x += Int(offset.width)
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emojiArt.emojis[index].y += Int(offset.height)
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}
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}
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func scaleEmoji(_ emoji: EmojiArtModel.Emoji, by scale: CGFloat) {
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if let index = emojiArt.emojis.index(matching: emoji) {
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emojiArt.emojis[index].size = Int((CGFloat(emojiArt.emojis[index].size) * scale).rounded(.toNearestOrAwayFromZero))
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}
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}
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private func fetchBackgoundImageDataIfNecessary() {
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backgroundImage = nil
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switch emojiArt.background {
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case .url(let url):
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// fetch url
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backgroundImageFetchStatus = .fetching
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DispatchQueue.global(qos: .userInitiated).async {
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let imageData = try? Data(contentsOf: url)
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DispatchQueue.main.async { [weak self] in
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if self?.emojiArt.background == EmojiArtModel.Background.url(url) {
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self?.backgroundImageFetchStatus = .idle
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if imageData != nil {
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self?.backgroundImage = UIImage(data: imageData!)
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}
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}
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}
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}
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case .imageData(let data):
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backgroundImage = UIImage(data: data)
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case .blank:
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break
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}
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}
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}
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171
EmojiArt/EmojiArtDocumentView.swift
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171
EmojiArt/EmojiArtDocumentView.swift
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@ -0,0 +1,171 @@
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//
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// EmojiArtDocumentView.swift
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// EmojiArt
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//
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// Created by ching on 2023/2/19.
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//
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import SwiftUI
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struct EmojiArtDocumentView: View {
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let testEmojis = "😀😃😄😁😆😅😂🤣🥲🥹☺️😊😇🙂🙃😉😌😍🥰😘😗😙😚😋😛😝😜🤪🤨🧐🤓😎🥸🤩"
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@ObservedObject var document: EmojiArtDocument
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var body: some View {
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VStack(spacing: 0) {
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documentBody
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palette
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}
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}
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var documentBody: some View {
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GeometryReader { geometry in
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ZStack {
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Color.yellow.overlay(
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OptionalImage(uiImage: document.backgroundImage)
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.scaleEffect(zoomScale)
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.position(convertFromEmojiCoordinates((0, 0), in: geometry))
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)
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.gesture(doubleTapToZoom(in: geometry.size))
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if document.backgroundImageFetchStatus == .fetching {
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ProgressView().scaleEffect(2)
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} else {
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ForEach(document.emojis) { emoji in
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Text(emoji.text)
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.font(.system(size: fontSize(for: emoji)))
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.scaleEffect(zoomScale)
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.position(position(for: emoji, in: geometry))
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}
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}
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}
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.clipped()
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.onDrop(of: [.plainText, .url, .image], isTargeted: nil) { providers, location in
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drop(providers: providers, at: location, in: geometry)
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}
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.gesture(panGesture().simultaneously(with: zoomGesture()))
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}
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}
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private func drop(providers: [NSItemProvider], at location: CGPoint, in geometry: GeometryProxy) -> Bool {
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var found = providers.loadObjects(ofType: URL.self) { url in
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document.setBackground(EmojiArtModel.Background.url(url.imageURL))
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}
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if !found {
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found = providers.loadObjects(ofType: UIImage.self) { image in
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if let data = image.jpegData(compressionQuality: 1.0) {
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document.setBackground(.imageData(data))
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}
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}
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}
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if !found {
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found = providers.loadObjects(ofType: String.self) { string in
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if let emoji = string.first, emoji.isEmoji {
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document.addEmoji(
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String(emoji),
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at: convertToEmojiCoordinates(location, in: geometry),
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size: const.defaultEmojiFontSize / zoomScale)
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}
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}
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}
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return found
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}
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private func fontSize(for emoji: EmojiArtModel.Emoji) -> CGFloat {
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CGFloat(emoji.size)
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}
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private func position(for emoji: EmojiArtModel.Emoji, in geometry: GeometryProxy) -> CGPoint {
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convertFromEmojiCoordinates((emoji.x, emoji.y), in: geometry)
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}
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private func convertToEmojiCoordinates(_ location: CGPoint, in geometry: GeometryProxy) -> (x: Int, y: Int) {
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let center = geometry.frame(in: .local).center
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let location = CGPoint(
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x: (location.x - center.x - panOffset.width) / zoomScale,
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y: (location.y - center.y - panOffset.height) / zoomScale)
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return (Int(location.x), Int(location.y))
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}
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private func convertFromEmojiCoordinates(_ location: (x: Int, y: Int), in geometry: GeometryProxy) -> CGPoint {
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let center = geometry.frame(in: .local).center
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return CGPoint(
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x: center.x + CGFloat(location.x) * zoomScale + panOffset.width,
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y: center.y + CGFloat(location.y) * zoomScale + panOffset.height)
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}
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@State private var steadyStatePanOffset: CGSize = .zero
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@GestureState private var gesturePanOffset: CGSize = .zero
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private var panOffset: CGSize {
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(steadyStatePanOffset + gesturePanOffset) * zoomScale
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}
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@State private var steadyStateZoomScale: CGFloat = 1
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@GestureState private var gestureZoomScale: CGFloat = 1
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private var zoomScale: CGFloat {
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steadyStateZoomScale * gestureZoomScale
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}
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private func panGesture() -> some Gesture {
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DragGesture()
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.updating($gesturePanOffset) { latestDragGestureValue, gesturePanOffset, _ in
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gesturePanOffset = latestDragGestureValue.translation / zoomScale
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}
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.onEnded { finalDragGestureValue in
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steadyStatePanOffset = steadyStatePanOffset + (finalDragGestureValue.translation / zoomScale)
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}
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}
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private func zoomGesture() -> some Gesture {
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MagnificationGesture()
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.updating($gestureZoomScale) { latestGestureScale, gestureZoomScale, _ in
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gestureZoomScale = latestGestureScale
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}
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.onEnded { gestureScaleAtEnd in
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steadyStateZoomScale *= gestureScaleAtEnd
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}
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}
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private func doubleTapToZoom(in size: CGSize) -> some Gesture {
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TapGesture(count: 2)
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.onEnded {
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withAnimation {
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zoomToFit(document.backgroundImage, in: size)
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}
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}
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}
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private func zoomToFit(_ image: UIImage?, in size: CGSize) {
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if let image = image, image.size.width > 0, image.size.height > 0, size.width > 0, size.height > 0 {
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let hZoom = size.width / image.size.width
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let vZoom = size.height / image.size.height
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steadyStatePanOffset = .zero
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steadyStateZoomScale = min(hZoom, vZoom)
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}
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}
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var palette: some View {
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SrcollingEmojiView(emojis: testEmojis)
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.font(.system(size: const.defaultEmojiFontSize))
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}
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}
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struct SrcollingEmojiView: View {
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let emojis: String
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var body: some View {
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ScrollView(.horizontal) {
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HStack {
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ForEach(emojis.map { String($0) }, id: \.self) { emoji in
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Text(emoji)
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.onDrag { NSItemProvider(object: emoji as NSString) }
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}
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}
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}
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}
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}
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struct ContentView_Previews: PreviewProvider {
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static var previews: some View {
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EmojiArtDocumentView(document: EmojiArtDocument())
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}
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}
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30
EmojiArt/EmojiArtModel.Background.swift
Normal file
30
EmojiArt/EmojiArtModel.Background.swift
Normal file
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//
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// EmojiArtModel.Background.swift
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// EmojiArt
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//
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// Created by ching on 2023/2/19.
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//
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import Foundation
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extension EmojiArtModel {
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enum Background: Equatable {
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case blank
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case url(URL)
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case imageData(Data)
|
||||
|
||||
var url: URL? {
|
||||
switch self {
|
||||
case .url(let url): return url
|
||||
default: return nil
|
||||
}
|
||||
}
|
||||
|
||||
var imageData: Data? {
|
||||
switch self {
|
||||
case .imageData(let data): return data
|
||||
default: return nil
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
40
EmojiArt/EmojiArtModel.swift
Normal file
40
EmojiArt/EmojiArtModel.swift
Normal file
@ -0,0 +1,40 @@
|
||||
//
|
||||
// EmojiArtModel.swift
|
||||
// EmojiArt
|
||||
//
|
||||
// Created by ching on 2023/2/19.
|
||||
//
|
||||
|
||||
import Foundation
|
||||
|
||||
struct EmojiArtModel {
|
||||
var background: Background = EmojiArtModel.Background.blank
|
||||
var emojis = [Emoji]()
|
||||
|
||||
struct Emoji: Identifiable {
|
||||
let text: String
|
||||
var x: Int
|
||||
var y: Int
|
||||
var size: Int
|
||||
var id: Int
|
||||
|
||||
fileprivate init(text: String, x: Int, y: Int, size: Int, id: Int) {
|
||||
self.text = text
|
||||
self.x = x
|
||||
self.y = y
|
||||
self.size = size
|
||||
self.id = id
|
||||
}
|
||||
}
|
||||
|
||||
init() {
|
||||
|
||||
}
|
||||
|
||||
private var uniqueEmojiId = 0
|
||||
mutating func addEmoji(_ text: String, at location: (x: Int, y: Int), size: Int) {
|
||||
uniqueEmojiId += 1
|
||||
emojis.append(Emoji(text: text, x: location.x, y: location.y, size: size, id: uniqueEmojiId))
|
||||
}
|
||||
|
||||
}
|
||||
254
EmojiArt/UtilityExtensions.swift
Normal file
254
EmojiArt/UtilityExtensions.swift
Normal file
@ -0,0 +1,254 @@
|
||||
//
|
||||
// UtilityExtensions.swift
|
||||
// EmojiArt
|
||||
//
|
||||
// Created by CS193p Instructor on 4/26/21.
|
||||
// Copyright © 2021 Stanford University. All rights reserved.
|
||||
//
|
||||
|
||||
import SwiftUI
|
||||
|
||||
// in a Collection of Identifiables
|
||||
// we often might want to find the element that has the same id
|
||||
// as an Identifiable we already have in hand
|
||||
// we name this index(matching:) instead of firstIndex(matching:)
|
||||
// because we assume that someone creating a Collection of Identifiable
|
||||
// is usually going to have only one of each Identifiable thing in there
|
||||
// (though there's nothing to restrict them from doing so; it's just a naming choice)
|
||||
|
||||
extension Collection where Element: Identifiable {
|
||||
func index(matching element: Element) -> Self.Index? {
|
||||
firstIndex(where: { $0.id == element.id })
|
||||
}
|
||||
}
|
||||
|
||||
// we could do the same thing when it comes to removing an element
|
||||
// but we have to add that to a different protocol
|
||||
// because Collection works for immutable collections of things
|
||||
// the "mutable" one is RangeReplaceableCollection
|
||||
// not only could we add remove
|
||||
// but we could add a subscript which takes a copy of one of the elements
|
||||
// and uses its Identifiable-ness to subscript into the Collection
|
||||
// this is an awesome way to create Bindings into an Array in a ViewModel
|
||||
// (since any Published var in an ObservableObject can be bound to via $)
|
||||
// (even vars on that Published var or subscripts on that var)
|
||||
// (or subscripts on vars on that var, etc.)
|
||||
|
||||
extension RangeReplaceableCollection where Element: Identifiable {
|
||||
mutating func remove(_ element: Element) {
|
||||
if let index = index(matching: element) {
|
||||
remove(at: index)
|
||||
}
|
||||
}
|
||||
|
||||
subscript(_ element: Element) -> Element {
|
||||
get {
|
||||
if let index = index(matching: element) {
|
||||
return self[index]
|
||||
} else {
|
||||
return element
|
||||
}
|
||||
}
|
||||
set {
|
||||
if let index = index(matching: element) {
|
||||
replaceSubrange(index...index, with: [newValue])
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// if you use a Set to represent the selection of emoji in HW5
|
||||
// then you might find this syntactic sugar function to be of use
|
||||
|
||||
extension Set where Element: Identifiable {
|
||||
mutating func toggleMembership(of element: Element) {
|
||||
if let index = index(matching: element) {
|
||||
remove(at: index)
|
||||
} else {
|
||||
insert(element)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// some extensions to String and Character
|
||||
// to help us with managing our Strings of emojis
|
||||
// we want them to be "emoji only"
|
||||
// (thus isEmoji below)
|
||||
// and we don't want them to have repeated emojis
|
||||
// (thus withNoRepeatedCharacters below)
|
||||
|
||||
extension String {
|
||||
var withNoRepeatedCharacters: String {
|
||||
var uniqued = ""
|
||||
for ch in self {
|
||||
if !uniqued.contains(ch) {
|
||||
uniqued.append(ch)
|
||||
}
|
||||
}
|
||||
return uniqued
|
||||
}
|
||||
}
|
||||
|
||||
extension Character {
|
||||
var isEmoji: Bool {
|
||||
// Swift does not have a way to ask if a Character isEmoji
|
||||
// but it does let us check to see if our component scalars isEmoji
|
||||
// unfortunately unicode allows certain scalars (like 1)
|
||||
// to be modified by another scalar to become emoji (e.g. 1️⃣)
|
||||
// so the scalar "1" will report isEmoji = true
|
||||
// so we can't just check to see if the first scalar isEmoji
|
||||
// the quick and dirty here is to see if the scalar is at least the first true emoji we know of
|
||||
// (the start of the "miscellaneous items" section)
|
||||
// or check to see if this is a multiple scalar unicode sequence
|
||||
// (e.g. a 1 with a unicode modifier to force it to be presented as emoji 1️⃣)
|
||||
if let firstScalar = unicodeScalars.first, firstScalar.properties.isEmoji {
|
||||
return (firstScalar.value >= 0x238d || unicodeScalars.count > 1)
|
||||
} else {
|
||||
return false
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// extracting the actual url to an image from a url that might contain other info
|
||||
// (essentially looking for the imgurl key)
|
||||
// imgurl is a "well known" key that can be embedded in a url that says what the actual image url is
|
||||
|
||||
extension URL {
|
||||
var imageURL: URL {
|
||||
for query in query?.components(separatedBy: "&") ?? [] {
|
||||
let queryComponents = query.components(separatedBy: "=")
|
||||
if queryComponents.count == 2 {
|
||||
if queryComponents[0] == "imgurl", let url = URL(string: queryComponents[1].removingPercentEncoding ?? "") {
|
||||
return url
|
||||
}
|
||||
}
|
||||
}
|
||||
return baseURL ?? self
|
||||
}
|
||||
}
|
||||
|
||||
// convenience functions for adding/subtracting CGPoints and CGSizes
|
||||
// might come in handy when doing gesture handling
|
||||
// because we do a lot of converting between coordinate systems and such
|
||||
// notice that type types of the lhs and rhs arguments vary below
|
||||
// thus you can offset a CGPoint by the width and height of a CGSize, for example
|
||||
|
||||
extension DragGesture.Value {
|
||||
var distance: CGSize { location - startLocation }
|
||||
}
|
||||
|
||||
extension CGRect {
|
||||
var center: CGPoint {
|
||||
CGPoint(x: midX, y: midY)
|
||||
}
|
||||
}
|
||||
|
||||
extension CGPoint {
|
||||
static func -(lhs: Self, rhs: Self) -> CGSize {
|
||||
CGSize(width: lhs.x - rhs.x, height: lhs.y - rhs.y)
|
||||
}
|
||||
static func +(lhs: Self, rhs: CGSize) -> CGPoint {
|
||||
CGPoint(x: lhs.x + rhs.width, y: lhs.y + rhs.height)
|
||||
}
|
||||
static func -(lhs: Self, rhs: CGSize) -> CGPoint {
|
||||
CGPoint(x: lhs.x - rhs.width, y: lhs.y - rhs.height)
|
||||
}
|
||||
static func *(lhs: Self, rhs: CGFloat) -> CGPoint {
|
||||
CGPoint(x: lhs.x * rhs, y: lhs.y * rhs)
|
||||
}
|
||||
static func /(lhs: Self, rhs: CGFloat) -> CGPoint {
|
||||
CGPoint(x: lhs.x / rhs, y: lhs.y / rhs)
|
||||
}
|
||||
}
|
||||
|
||||
extension CGSize {
|
||||
// the center point of an area that is our size
|
||||
var center: CGPoint {
|
||||
CGPoint(x: width/2, y: height/2)
|
||||
}
|
||||
static func +(lhs: Self, rhs: Self) -> CGSize {
|
||||
CGSize(width: lhs.width + rhs.width, height: lhs.height + rhs.height)
|
||||
}
|
||||
static func -(lhs: Self, rhs: Self) -> CGSize {
|
||||
CGSize(width: lhs.width - rhs.width, height: lhs.height - rhs.height)
|
||||
}
|
||||
static func *(lhs: Self, rhs: CGFloat) -> CGSize {
|
||||
CGSize(width: lhs.width * rhs, height: lhs.height * rhs)
|
||||
}
|
||||
static func /(lhs: Self, rhs: CGFloat) -> CGSize {
|
||||
CGSize(width: lhs.width/rhs, height: lhs.height/rhs)
|
||||
}
|
||||
}
|
||||
|
||||
// add RawRepresentable protocol conformance to CGSize and CGFloat
|
||||
// so that they can be used with @SceneStorage
|
||||
// we do this by first providing default implementations of rawValue and init(rawValue:)
|
||||
// in RawRepresentable when the thing in question is Codable (which both CGFloat and CGSize are)
|
||||
// then all it takes to make something that is Codable be RawRepresentable is to declare it to be so
|
||||
// (it will then get the default implementions needed to be a RawRepresentable)
|
||||
|
||||
extension RawRepresentable where Self: Codable {
|
||||
public var rawValue: String {
|
||||
if let json = try? JSONEncoder().encode(self), let string = String(data: json, encoding: .utf8) {
|
||||
return string
|
||||
} else {
|
||||
return ""
|
||||
}
|
||||
}
|
||||
public init?(rawValue: String) {
|
||||
if let value = try? JSONDecoder().decode(Self.self, from: Data(rawValue.utf8)) {
|
||||
self = value
|
||||
} else {
|
||||
return nil
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
extension CGSize: RawRepresentable { }
|
||||
extension CGFloat: RawRepresentable { }
|
||||
|
||||
// convenience functions for [NSItemProvider] (i.e. array of NSItemProvider)
|
||||
// makes the code for loading objects from the providers a bit simpler
|
||||
// NSItemProvider is a holdover from the Objective-C (i.e. pre-Swift) world
|
||||
// you can tell by its very name (starts with NS)
|
||||
// so unfortunately, dealing with this API is a little bit crufty
|
||||
// thus I recommend you just accept that these loadObjects functions will work and move on
|
||||
// it's a rare case where trying to dive in and understand what's going on here
|
||||
// would probably not be a very efficient use of your time
|
||||
// (though I'm certainly not going to say you shouldn't!)
|
||||
// (just trying to help you optimize your valuable time this quarter)
|
||||
|
||||
extension Array where Element == NSItemProvider {
|
||||
func loadObjects<T>(ofType theType: T.Type, firstOnly: Bool = false, using load: @escaping (T) -> Void) -> Bool where T: NSItemProviderReading {
|
||||
if let provider = first(where: { $0.canLoadObject(ofClass: theType) }) {
|
||||
provider.loadObject(ofClass: theType) { object, error in
|
||||
if let value = object as? T {
|
||||
DispatchQueue.main.async {
|
||||
load(value)
|
||||
}
|
||||
}
|
||||
}
|
||||
return true
|
||||
}
|
||||
return false
|
||||
}
|
||||
func loadObjects<T>(ofType theType: T.Type, firstOnly: Bool = false, using load: @escaping (T) -> Void) -> Bool where T: _ObjectiveCBridgeable, T._ObjectiveCType: NSItemProviderReading {
|
||||
if let provider = first(where: { $0.canLoadObject(ofClass: theType) }) {
|
||||
let _ = provider.loadObject(ofClass: theType) { object, error in
|
||||
if let value = object {
|
||||
DispatchQueue.main.async {
|
||||
load(value)
|
||||
}
|
||||
}
|
||||
}
|
||||
return true
|
||||
}
|
||||
return false
|
||||
}
|
||||
func loadFirstObject<T>(ofType theType: T.Type, using load: @escaping (T) -> Void) -> Bool where T: NSItemProviderReading {
|
||||
loadObjects(ofType: theType, firstOnly: true, using: load)
|
||||
}
|
||||
func loadFirstObject<T>(ofType theType: T.Type, using load: @escaping (T) -> Void) -> Bool where T: _ObjectiveCBridgeable, T._ObjectiveCType: NSItemProviderReading {
|
||||
loadObjects(ofType: theType, firstOnly: true, using: load)
|
||||
}
|
||||
}
|
||||
65
EmojiArt/UtilityViews.swift
Normal file
65
EmojiArt/UtilityViews.swift
Normal file
@ -0,0 +1,65 @@
|
||||
//
|
||||
// UtilityViews.swift
|
||||
// EmojiArt
|
||||
//
|
||||
// Created by CS193p Instructor on 4/26/21.
|
||||
// Copyright © 2021 Stanford University. All rights reserved.
|
||||
//
|
||||
|
||||
import SwiftUI
|
||||
|
||||
// syntactic sure to be able to pass an optional UIImage to Image
|
||||
// (normally it would only take a non-optional UIImage)
|
||||
|
||||
struct OptionalImage: View {
|
||||
var uiImage: UIImage?
|
||||
|
||||
var body: some View {
|
||||
if uiImage != nil {
|
||||
Image(uiImage: uiImage!)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// syntactic sugar
|
||||
// lots of times we want a simple button
|
||||
// with just text or a label or a systemImage
|
||||
// but we want the action it performs to be animated
|
||||
// (i.e. withAnimation)
|
||||
// this just makes it easy to create such a button
|
||||
// and thus cleans up our code
|
||||
|
||||
struct AnimatedActionButton: View {
|
||||
var title: String? = nil
|
||||
var systemImage: String? = nil
|
||||
let action: () -> Void
|
||||
|
||||
var body: some View {
|
||||
Button {
|
||||
withAnimation {
|
||||
action()
|
||||
}
|
||||
} label: {
|
||||
if title != nil && systemImage != nil {
|
||||
Label(title!, systemImage: systemImage!)
|
||||
} else if title != nil {
|
||||
Text(title!)
|
||||
} else if systemImage != nil {
|
||||
Image(systemName: systemImage!)
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// simple struct to make it easier to show configurable Alerts
|
||||
// just an Identifiable struct that can create an Alert on demand
|
||||
// use .alert(item: $alertToShow) { theIdentifiableAlert in ... }
|
||||
// where alertToShow is a Binding<IdentifiableAlert>?
|
||||
// then any time you want to show an alert
|
||||
// just set alertToShow = IdentifiableAlert(id: "my alert") { Alert(title: ...) }
|
||||
// of course, the string identifier has to be unique for all your different kinds of alerts
|
||||
|
||||
struct IdentifiableAlert: Identifiable {
|
||||
var id: String
|
||||
var alert: () -> Alert
|
||||
}
|
||||
Loading…
x
Reference in New Issue
Block a user