From ac6aa3f9091118f6b1b0c7ac0d46a684afeaed82 Mon Sep 17 00:00:00 2001
From: tsuzukihashi <tsudukihashi0817@gmail.com>
Date: Mon, 5 Jun 2023 09:07:47 +0900
Subject: [PATCH] feat: Add Onboarding Item

---
 .../TsuzuKit/Components/SnapCarousel.swift    | 79 +++++++++++++++++++
 .../Representable/PageControllView.swift      | 44 +++++++++++
 2 files changed, 123 insertions(+)
 create mode 100644 Sources/TsuzuKit/Components/SnapCarousel.swift
 create mode 100644 Sources/TsuzuKit/Representable/PageControllView.swift

diff --git a/Sources/TsuzuKit/Components/SnapCarousel.swift b/Sources/TsuzuKit/Components/SnapCarousel.swift
new file mode 100644
index 0000000..493ed72
--- /dev/null
+++ b/Sources/TsuzuKit/Components/SnapCarousel.swift
@@ -0,0 +1,79 @@
+import SwiftUI
+
+/**
+ 
+ */
+public struct SnapCarousel<Content: View, T: Identifiable>: View {
+    var content: (T) -> Content
+    var items: [T]
+
+    // property
+    var spacing: CGFloat
+    var trailingSpace: CGFloat
+
+    @Binding var index: Int
+
+    public init(
+        spacing: CGFloat = 16,
+        trailingSpace: CGFloat = 100,
+        index: Binding<Int>,
+        items: [T],
+        @ViewBuilder content: @escaping (T) -> Content
+    ) {
+        self.spacing = spacing
+        self.trailingSpace = trailingSpace
+        self._index = index
+        self.items = items
+        self.content = content
+    }
+
+    @GestureState var offset: CGFloat = 0
+    @State var currentIndex: Int = 0
+    @State var isScroll: Bool = false
+
+    public var body: some View {
+        GeometryReader { proxy in
+            let width = proxy.size.width - (trailingSpace - spacing)
+            let adjustMentWidth = (trailingSpace / 2) - spacing
+
+            HStack(spacing: spacing) {
+                ForEach(items) { item in
+                    content(item)
+                        .frame(width: proxy.size.width - trailingSpace)
+                }
+            }
+            .padding(.horizontal, spacing)
+            .offset(x: (CGFloat(currentIndex) * -width) + (currentIndex != 0 ? adjustMentWidth : 0)  + offset)
+            .gesture(
+                DragGesture()
+                    .updating($offset, body: { value, out, _ in
+                        out = value.translation.width
+                    })
+                    .onEnded({ value in
+                        let offsetX = value.translation.width
+                        let progress = -offsetX / width
+                        let roundIndex = progress.rounded()
+
+                        currentIndex = max(min(currentIndex + Int(roundIndex), items.count - 1), 0)
+                        currentIndex = index
+                        isScroll = false
+                    })
+                    .onChanged({ value in
+                        isScroll = true
+                        let offsetX = value.translation.width
+                        let progress = -offsetX / width
+                        let roundIndex = progress.rounded()
+
+                        index = max(min(currentIndex + Int(roundIndex), items.count - 1), 0)
+                    })
+            )
+        }
+        .onChange(of: index, perform: { value in
+            if !isScroll {
+                currentIndex = value
+            }
+        })
+        .animation(.easeInOut, value: offset == 0)
+        .animation(.easeInOut, value: currentIndex)
+    }
+}
diff --git a/Sources/TsuzuKit/Representable/PageControllView.swift b/Sources/TsuzuKit/Representable/PageControllView.swift
new file mode 100644
index 0000000..88293dd
--- /dev/null
+++ b/Sources/TsuzuKit/Representable/PageControllView.swift
@@ -0,0 +1,44 @@
+import SwiftUI
+
+public struct PageControllView: UIViewRepresentable {
+  @Binding var currentPage: Int
+  var numberOfPages: Int = 0
+
+  public init(currentPage: Binding<Int>, numberOfPages: Int) {
+    self._currentPage = currentPage
+    self.numberOfPages = numberOfPages
+  }
+
+  public func makeCoordinator() -> Coordinator {
+    Coordinator(self)
+  }
+
+  public func makeUIView(context: Context) -> UIPageControl {
+    let pageControl = UIPageControl()
+    pageControl.currentPageIndicatorTintColor = .label
+    pageControl.numberOfPages = numberOfPages
+    pageControl.pageIndicatorTintColor = .secondaryLabel
+    pageControl.addTarget(
+      context.coordinator,
+      action: #selector(Coordinator.updateCurrentPage(sender:)),
+      for: .valueChanged
+    )
+    return pageControl
+  }
+
+  public func updateUIView(_ uiView: UIPageControl, context: Context) {
+    uiView.currentPage = currentPage
+  }
+
+  public class Coordinator: NSObject {
+    var pageControl: PageControllView
+
+    init(_ pageControl: PageControllView) {
+      self.pageControl = pageControl
+    }
+
+    @objc func updateCurrentPage(sender: UIPageControl) {
+      pageControl.currentPage = sender.currentPage
+    }
+  }
+}