Sample project for testing out focus in SwiftUI and iOS 15
This project was to test out different ways of enabling focus in a SwiftUI app. Specifically I wanted to figure out how to force focus on newly created TextFields
so that when they were added focus was set on them.
The secondary objective was to enable a user to click a button next to an existing text field and return focus to that particular field. The key was that the object
backing each text field also had a UUID associated with the backing string. This UUID is what was being used to track which field got focus.
I looked at 5 ways of accomplishing this.
- Custom
@Environment
of type UUID (ContentViewEnvironment.swift) - Custom
@EnvironmentObject
wrapping a publishedUUID
(ContentViewEnvironmentObject.swift) - Passing a
FocusState<UUID?>.Binding
variable to each view (ContentViewVariablePassing.swift) - Custom
@EnvironmentObejct
wrapping a focus bindingFocusState<UUID?>.Binding
(ContentViewBindingEnvironmentObject.swift) - Custom
@Environment
of typeFocusState<UUID?>.Binding
(ContentViewBindingEnvironment.swift)
What I found is that:
Solution #1 was able to set focus on each new TextField
but was not able to change the focus based on the button click.
Solution #2 enabled both required features but required each TextField
implement onAppear
and onReceive
for the solution to work correctly.
Solution #3 enabled both required features but required that each view store and pass the binding down to subviews even if that view didn’t need the behaviors.
Solution #4 enabled both required features but did not have the detractions of #2 or #3.
Solution #5 I could not get working.