I've got a set of buttons within a SwiftUI View which represent various letters of the alphabet. How can I make the buttons or the view accept external keyboard input, say from an iPad Pro's keyboard, so that instead of having to touch the screen a user with a keyboard can press a key? There's plenty of docs on this for the non-SwiftUI world, but I'm specifically wondering what's the recommended way of doing this in SwiftUI?
Thanks!
Just an idea I would need to explore more (if time).
Is the keyboard attached to a textField ?
If so, did you try to implement in shouldChangeCharactersIn delegate func
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
guard value = aStr.first?.asciiValue else { return false }
let valueForA = 65
let valueFora = 97
switch string:
case "A"... "Z": // some action, based on [value - valueForA])
case "a"... "z": // some action, based on[value - valueFora])
default: return false
}
return true
}I probably should have provided example code. Suppose I have a SwiftUI View like this:
struct MyView: View {
var body: some View {
Button(action: {
print("A")
}) {
Text("A")
}
Button(action: {
print("B")
}) {
Text("B")
}
}
}This accepts touches on A and B presented on the screen and causes the associated action closures to run. How would I accept an external physical keyboard press of A or B to cause the code in the closures to run?
OK.
Those are 2 different system patterns:
- on screen, you tap a button
- on external keyboard, you enter data in a textField
So the point is to intercept those events (typing in a TextField), detect which letter pressed and then trigger the correct action.
May have a look at this discussion about onCommand
I suspect that defining a UIKeyCommand and using .addKeyCommand(_:) to add it to your root controller would be part of this. Then you'd hopefully be able to use .onCommand{} via SwiftUI to register a block to handle the Selector you used when creating the UIKeyCommand instance.
I'll have to see if I can determine how this should work.
Darn. .onCommand{} isn't available on iOS. Le sigh. Looks like a custom solution is required after all.