Improve SwiftUI previews

Author: 1024jp

CotEditor/Sources/InsetTextField.swift

@@ -8,7 +8,7 @@
 //
 //  ---------------------------------------------------------------------------
 //
-//  © 2022-2023 1024jp
+//  © 2022-2024 1024jp
 //
 //  Licensed under the Apache License, Version 2.0 (the "License");
 //  you may not use this file except in compliance with the License.
@@ -190,7 +190,9 @@ final class PaddingTextField: NSTextField {
 // MARK: - Preview
 
 #Preview {
-    InsetTextField(text: .constant(""), prompt: "Prompt")
+    @State var text = ""
+    
+    return InsetTextField(text: $text, prompt: "Prompt")
         .inset(.leading, 20)
         .frame(width: 160)
 }

CotEditor/Sources/RegexTextField.swift

@@ -8,7 +8,7 @@
 //
 //  ---------------------------------------------------------------------------
 //
-//  © 2023 1024jp
+//  © 2023-2024 1024jp
 //
 //  Licensed under the Apache License, Version 2.0 (the "License");
 //  you may not use this file except in compliance with the License.
@@ -122,6 +122,8 @@ struct RegexTextField: NSViewRepresentable {
 // MARK: - Preview
 
 #Preview {
-    RegexTextField(text: .constant("[^abc]def"))
+    @State var text = "[^abc]def"
+    
+    return RegexTextField(text: $text)
         .leadingInset(20)
 }

CotEditor/Sources/StepperNumberField.swift

@@ -115,10 +115,8 @@ private extension Binding where Value == Int {
 
 // MARK: - Preview
 
-struct StepperNumberField_Previews: PreviewProvider {
+#Preview {
+    @State var value = 4
 
-    static var previews: some View {
-        
-        StepperNumberField(value: .constant(4), in: 0...10)
-    }
+    return StepperNumberField(value: $value, in: 0...10)
 }

CotEditor/Sources/ThemeEditorView.swift

@@ -311,20 +311,24 @@ private extension Theme.Metadata {
 
 // MARK: - Preview
 
-#Preview {
+@available(macOS 14, *)
+#Preview(traits: .fixedLayout(width: 360, height: 280)) {
     ThemeEditorView(ThemeManager.shared.setting(name: "Anura")!, isBundled: false) { _ in }
-        .frame(width: 360, height: 280)
 }
 
 #Preview("Metadata (editable)") {
-    ThemeMetadataView(metadata: .constant(.init(
+    @State var metadata = Theme.Metadata(
         author: "Clarus",
         distributionURL: "https://coteditor.com"
-    )), isEditable: true)
+    )
+    
+    return ThemeMetadataView(metadata: $metadata, isEditable: true)
 }
 
 #Preview("Metadata (fixed)") {
-    ThemeMetadataView(metadata: .constant(.init(
+    @State var metadata = Theme.Metadata(
         author: "Claus"
-    )), isEditable: false)
+    )
+    
+    return ThemeMetadataView(metadata: $metadata, isEditable: false)
 }