ListlessMac/Helpers/PlatformTextFieldWidthModifier.swift (1473B)
1import SwiftUI
2
3private struct TextFieldWidthPreferenceKey: PreferenceKey {
4 static let defaultValue: CGFloat = 0
5
6 static func reduce(value: inout CGFloat, nextValue: () -> CGFloat) {
7 value = max(value, nextValue())
8 }
9}
10
11private struct MacTextFieldWidthModifier: ViewModifier {
12 let text: String
13 let placeholder: String
14
15 @State private var measuredWidth: CGFloat = 60
16
17 func body(content: Content) -> some View {
18 content
19 .frame(width: max(44, measuredWidth + 12), alignment: .leading)
20 .background(widthMeasurer)
21 .onPreferenceChange(TextFieldWidthPreferenceKey.self) { width in
22 if width > 0, width != measuredWidth {
23 measuredWidth = width
24 }
25 }
26 }
27
28 private var widthMeasurer: some View {
29 Text(displayText)
30 .font(.body)
31 .lineLimit(1)
32 .fixedSize()
33 .background(
34 GeometryReader { proxy in
35 Color.clear.preference(
36 key: TextFieldWidthPreferenceKey.self, value: proxy.size.width)
37 }
38 )
39 .hidden()
40 }
41
42 private var displayText: String {
43 text.isEmpty ? placeholder : text
44 }
45}
46
47extension View {
48 func platformTextFieldWidth(text: String, placeholder: String) -> some View {
49 modifier(MacTextFieldWidthModifier(text: text, placeholder: placeholder))
50 }
51}
