Improve lag after editing a step item

LeCountdown/Views/Countdown/CountdownFormView.swift

@@ -50,7 +50,8 @@ struct CountdownFormView : View {
                         Button {
                             self.selectedStepItem = stepItem
                         } label: {
-                            LabeledContent(stepItem.name ?? "", value: stepItem.duration.hourMinuteSecond)
+                            LabeledContent(stepItem.name ?? "",
+                                           value: stepItem.duration.hourMinuteSecond)
                         }
                     }.onDelete { indexSet in
                         self.model.deleteStep(indexSet: indexSet)
@@ -98,10 +99,7 @@ struct CountdownFormView : View {
 
             SoundFormView(model: self.model)
         }
-        .sheet(item: self.$selectedStepItem, onDismiss: {
+        .sheet(item: self.$selectedStepItem) { item in
-            // TODO: improve lag
-            self.model.objectWillChange.send()
-        }) { item in
             StepFormView(stepItem: item)
         }
         
@@ -117,6 +115,22 @@ struct CountdownFormView : View {
     
 }
 
+struct StepItemView: View {
+
+    var stepItem: StepItem
+    @Binding var selectedStepItem: StepItem?
+    
+    var body: some View {
+        Button {
+            self.selectedStepItem = stepItem
+        } label: {
+            LabeledContent(self.stepItem.name ?? "",
+                           value: self.stepItem.duration.hourMinuteSecond)
+        }
+    }
+    
+}
+
 struct CountdownFormView_Previews: PreviewProvider {
     
     static var previews: some View {

LeCountdown/Views/Countdown/StepFormView.swift

@@ -19,6 +19,8 @@ struct StepFormView: View {
     
     var soundModel: SoundModel = SoundModel()
     
+    @EnvironmentObject var model: TimerModel
+
     var body: some View {
         
         NavigationStack {
@@ -72,6 +74,8 @@ struct StepFormView: View {
         self.stepItem.duration = self.duration
         self.stepItem.playableIds = self.soundModel.playableIds
         
+        self.model.objectWillChange.send()
+
         self.dismiss()
     }