First actions for generation view

CHDataManagement/Views/Generation/GenerationIssuesView.swift

@@ -0,0 +1,65 @@
+import SwiftUI
+
+struct GenerationIssuesView<S, T, V>: View where S: Collection, T: Hashable & Comparable, V: View, S.Element == T {
+
+    let text: String
+
+    let statusWhenNonEmpty: IssueStatus
+
+    @Binding
+    var items: S
+
+    let map: (T) -> V
+
+    @State
+    private var showList = false
+
+    var status: IssueStatus {
+        items.isEmpty ? .nominal : statusWhenNonEmpty
+    }
+
+    init(text: String, statusWhenNonEmpty: IssueStatus = .error, items: Binding<S>, map: @escaping (T) -> V) {
+        self.text = text
+        self.statusWhenNonEmpty = statusWhenNonEmpty
+        self._items = items
+        self.map = map
+    }
+
+    var body: some View {
+        HStack {
+            Button(action: showListIfNonEmpty) {
+                Image(systemSymbol: status.symbol)
+                    .foregroundStyle(status.color)
+            }.buttonStyle(.plain)
+            Text("\(items.count) \(text)")
+        }
+        .sheet(isPresented: $showList) {
+            VStack {
+                Text("\(items.count) \(text)")
+                    .font(.title)
+                List(items.sorted(), id: \.self) { item in
+                    map(item)
+                }
+                .frame(minHeight: 400)
+                Button("Close") { showList = false }
+            }.padding()
+        }
+    }
+
+    private func showListIfNonEmpty() {
+        guard !items.isEmpty else {
+            return
+        }
+        showList = true
+    }
+}
+
+extension GenerationIssuesView where S == Set<String>, V == Text {
+
+    init(text: String, statusWhenNonEmpty: IssueStatus = .error, items: Binding<Set<String>>) {
+        self.text = text
+        self.statusWhenNonEmpty = statusWhenNonEmpty
+        self._items = items
+        self.map = { Text($0) }
+    }
+}