1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
|
import SwiftUI
struct AsyncImageWithPreview<Placeholder: View>: View {
var url: URL?
@Binding var loadingState: PostLoadingState
var finalLoadingState: PostLoadingState
var postURL: URL?
let placeholder: () -> Placeholder
@State private var currentScale: CGFloat = 1.0
@State private var finalScale: CGFloat = 1.0
@State private var currentOffset: CGSize = .zero
@State private var finalOffset: CGSize = .zero
init(
url: URL?,
loadingStage: Binding<PostLoadingState>,
finalLoadingState: PostLoadingState = .loadingFile,
postURL: URL? = nil,
@ViewBuilder placeholder: @escaping () -> Placeholder = {
GeometryReader { geometry in
ProgressView()
.frame(width: geometry.size.width, height: geometry.size.height)
.position(x: geometry.size.width / 2, y: geometry.size.height / 2)
.padding()
}
}
) {
self.url = url
_loadingState = loadingStage
self.finalLoadingState = finalLoadingState
self.postURL = postURL
self.placeholder = placeholder
}
var body: some View {
GeometryReader { geometry in
AsyncImage(url: url) { image in
image
.resizable()
.scaledToFit()
.onAppear {
loadingState = finalLoadingState
}
.scaleEffect(finalScale * currentScale)
.offset(x: finalOffset.width + currentOffset.width,
y: finalOffset.height + currentOffset.height)
.frame(width: geometry.size.width, height: geometry.size.height)
.position(x: geometry.size.width / 2, y: geometry.size.height / 2)
.gesture(
DragGesture()
.onChanged { value in
let translation = value.translation
let newOffset = CGSize(
width: finalOffset.width + translation.width,
height: finalOffset.height + translation.height
)
let scale = finalScale * currentScale
let imageWidth = geometry.size.width * scale
let imageHeight = geometry.size.height * scale
let maxX = max((imageWidth - geometry.size.width) / 2, 0)
let maxY = max((imageHeight - geometry.size.height) / 2, 0)
let clampedX = min(max(newOffset.width, -maxX), maxX)
let clampedY = min(max(newOffset.height, -maxY), maxY)
currentOffset = CGSize(
width: clampedX - finalOffset.width,
height: clampedY - finalOffset.height
)
}
.onEnded { value in
let translation = value.translation
var newOffset = CGSize(
width: finalOffset.width + translation.width,
height: finalOffset.height + translation.height
)
let scale = finalScale * currentScale
let imageWidth = geometry.size.width * scale
let imageHeight = geometry.size.height * scale
let maxX = max((imageWidth - geometry.size.width) / 2, 0)
let maxY = max((imageHeight - geometry.size.height) / 2, 0)
newOffset.width = min(max(newOffset.width, -maxX), maxX)
newOffset.height = min(max(newOffset.height, -maxY), maxY)
finalOffset = newOffset
currentOffset = .zero
}
)
.simultaneousGesture(
MagnificationGesture()
.onChanged { value in
currentScale = value
}
.onEnded { _ in
finalScale *= currentScale
currentScale = 1.0
let scale = finalScale
let imageWidth = geometry.size.width * scale
let imageHeight = geometry.size.height * scale
let maxX = max((imageWidth - geometry.size.width) / 2, 0)
let maxY = max((imageHeight - geometry.size.height) / 2, 0)
finalOffset.width = min(max(finalOffset.width, -maxX), maxX)
finalOffset.height = min(max(finalOffset.height, -maxY), maxY)
}
)
.highPriorityGesture(
TapGesture(count: 2)
.onEnded {
withAnimation {
finalScale = 1.0
currentScale = 1.0
finalOffset = .zero
currentOffset = .zero
}
}
)
.contextMenu {
#if os(iOS)
Button {
guard let url else { return }
URLSession.shared.dataTask(with: url) { data, _, _ in
guard let data, let uiImage = UIImage(data: data) else { return }
UIImageWriteToSavedPhotosAlbum(uiImage, nil, nil, nil)
}.resume()
} label: {
Label("Save Image", systemImage: "square.and.arrow.down")
}
#endif
#if os(iOS)
Button {
let activityViewController = UIActivityViewController(activityItems: [url ?? URL(string: "")!], applicationActivities: nil)
UIApplication.shared.windows.first?.rootViewController?.present(activityViewController, animated: true)
} label: {
Label("Share Image", systemImage: "square.and.arrow.up")
}
#endif
if let url = postURL {
Button {
#if os(iOS)
UIApplication.shared.open(url)
#else
NSWorkspace.shared.open(url)
#endif
} label: {
Label("Open in Safari", systemImage: "safari")
}
}
}
} placeholder: {
placeholder()
.onAppear {
loadingState = .loadingPreview
}
}
}
}
}
|