UndoController

The controller that allows a user to undo an action within seconds. It looks like the system HUDs.

Installation

Via Swift Package Manager

1. In Xcode 11 or greater select File ▸ Swift Packages ▸ Add Package Dependency.
2. Paste the link to this repo https://github.com/Iaenhaall/UndoController.git and click Next.
3. Define the package options for this package or select the default. Click Next.
4. Xcode downloads the code from GitHub and adds the package to the your project target. Click Finish.

Manually

1. Add UndoController.swift file to your project.

   That's all. There are no dependencies.

Usage

You can clone the repo and run the UndoControllerExample project to explore the UndoController features.

These are the main points to pay attention to.

1. Create an UndoController instance.

   @StateObject private var undoController: UndoController = UndoController()

   If you are not satisfied with the standard indents, use the UndoController(indents:) initializer.

   @StateObject private var undoController: UndoController = UndoController(indents: EdgeInsets(top: 0, leading: 20, bottom: 20, trailing: 20))

2. Add UndoController to the desired View.

   It is recommended to add to the view that occupies the entire screen area. For example, to NavigationView.

   NavigationView {
       List {
           ForEach(names, id: \.self) { name  in
               NavigationLink(destination: Text(name).padding().font(.largeTitle)) {
                   Text(name)
                       .padding()
               }
           }
           .onDelete(perform: delete)
       }
   //  .add(undoController) // The next View in the NavigationView stack overlaps UndoController when the NavigationLink is activated.
   }
   .add(undoController) // Stays above NavigationView when NavigationLink is activated.

   To access UndoController from nested Views, EnvironmentObject wrapper can be used.

   In this case, the UndoController, will be available from any application View.

   struct Application: App {
       @StateObject private var undoController: UndoController = UndoController()
       
       var body: some Scene {
           WindowGroup {
               ContentView()
                   .environmentObject(undoController)
                   .add(undoController)
           }
       }
   }

   Note, in this case the UndoController will overlap Views such as TabView. To avoid this, add the controller only to necessary Views (NavigationView, List, etc.) or increase its indentations. The behavior of the UndoController depends on which View you add it to. For example, when it is added to a NavigationView, it will be displayed above all views in the navigation stack. When it is added to a specific View that is inside the navigation stack, it will only appear above that View.

3. Call the UndoController when needed. In the example, it happens when user deletes a name from the List.

   The Show function accepts the following parameters:

   • time: The UndoController lifetime. The default value is 5 sec.
   • timerAction: The action that will be performed if the UndoController's life time has expired. It can be nil.
   • undoAction: The action that will be performed if a user undoes the action.
   • content: The content that is displayed on the UndoController. The content can be any view, such as Text, Label, VStack, etc.

   Please note that when the Show method is called again (while UndoController is present) the timerAction closure from the previous method call is executed.

   func delete(at offsets: IndexSet) {
       ...
       // Shows UndoController after name is deleted.
       undoController.show(time: 5,
                           undoAction: {
                               // Actions required to undo name deletion.
                           })
       {
           // UndoController context.
           Text("After deletion, the name cannot be restored!")
       }
   }

   To undo actions you can write your own code or use the system UndoManager.