Change SpinBox's prefix and suffix to a single format String

[KoBeWi]

Describe the project you are working on

Godot etc.

Describe the problem or limitation you are having in your project

Right now SpinBox has these two properties - suffix and prefix. One is a string that appears before value the other is after value. When the value is changed, these strings are merged to form the final text.

The user has no control over the actual text. You can set just these two strings and they will always appear with with this format: [prefix] [value] [suffix]. You can't remove the spaces. You can't format the value string to pad zeros or decimals or whatever. It's just very rigid.

Describe the feature / enhancement and how it helps to overcome the problem or limitation

Instead of having two properties, let's have one: format.

When format is empty, nothing really happens. The SpinBox will display its numeric value.

When format is non-empty, the SpinBox will display the text as: format % value. This way you have absolute control over how the value is displayed. You can add prefix, suffix, separators, change precision. Basically do anything, the only limitation is that you need to provide exactly one placeholder value, %s, %d or %f. The solution is very flexible overall.

Describe how your proposal will work, with code, pseudo-code, mock-ups, and/or diagrams

When format is non-empty, the SpinBox will display the text as: format % value.

I originally came up with this idea for my SliderLabel custom node. E.g. with format %2.f%% the value is displayed like this:

The value is padded to 2 decimal numbers and adds % prefix without any space.

If this enhancement will not be used often, can it be worked around with a few lines of script?

You can hack this by editing value of SpinBox's LineEdit manually, but this won't even work lol

Is there a reason why this should be core and not an add-on in the asset library?

It's about a core node.

[Calinou]

I wonder if this could also be done for ProgressBar to address #2399 in a more general way. That said, it'd need to support two placeholders to support all use cases outlined in that proposal. We could allow using one or two placeholders in the string, but it wouldn't allow you to reorder them (if you want the total to be displayed before the current value).

[Shadowblitz16]

Yes! please implement this!
I ran into this trying to make a hexadecimal spinbox.

If anybody knows how to do it temperately ping me on the Godot discord, my username is Mr Mustache