Capturing Keypresses

General
1

I’m trying to do a thing where the user can select their own shortcut keys, and I want to prompt them with a “press your desired shortcut key now” window.

Then obviously in the main program loop I’ll need to check for those keys.

Targets are Windows and Mac.

Is there a better way to do this other than a gigantic Select Case block testing every combination of keys and modifiers?

Edit: I should add that I think I will already will need to do a big Select Case block in order to get a text description of every key so I can display the user’s choice back to them in the UI.

2

If the items you wish to trigger are menu items you can assign the ShortCut property of the appropriate menu item. The system will then trigger things for you.
https://documentation.xojo.com/api/deprecated/menuitem.html#menuitem-shortcut

If you are just using random keys you could create an array of them (in a set order) and then use IndexOf to see if they are in the set and which it is:

Simple example. The app can respond, by default to L, R, U and D by moving something left right up or down. So we have an array of those letters:

Var aKeys() as String = Array( "L", "R", "U", "D" )

To allow customisation, you can then provide a mechanism to change the letters for elements 0, 1, 2 or 3.

When the user presses a key you can test if it one of the set as follows:

Var theKey as Integer = aKeys.IndexOf( thisKey )

theKey now tells you which of your actions you need to perform. ie 0 for the action that initially was set o “L”, even if they change the letters.

You don’t need a case statement for the descriptions either.

Var aDescriptions() as string = Array( "Move Left", "Move Right", "Move Up", "Move Down" )

Does that make sense?

3

I think the easiest way to do this is in the KeyDown event of a TextField, but some keys don’t register (like Pause/Break). You can position the TextField off-screen if you just want to present a label or other UI design. You’ll want to convert to something readable for the user as you mentioned but, with three CheckBoxes and a TextField, I imagine this giving you the basic means of allowing the user to define key combinations:

Function KeyDown(key As String) Handles KeyDown as Boolean
  me.Text = key.Asc.ToString( "#" )
  shiftCheck.Value = Keyboard.AsyncShiftKey
  controlCheck.Value = Keyboard.AsyncControlKey
  altValue.Check = Keyboard.AsyncAltKey
  
  Return True
End Function

There are a number of other methods, such as polling the Keyboard class using a timer, or via declares into system functions for the target OS. There are some other topics that cover these which you should find pretty quickly in a search for “hotkey”.