Allow checkbox's TextStyle modification

[Mubelotix]

Feature request
Make it possible to change the TextStyle of checkboxes, so that there is a basic font size support before #56.

Solution

Checkbox::new(&mut enabled, "Enable").text_style(TextStyle::Body);

Alternatives
Change the TextStyle::Button font size, but that would break other buttons.

[emilk]

There are many widgets we want to change text styles and text color on. Adding modifiers for them all may be the wrong approach.

An alternative is to instead set a new default in Style. This would also make it more convenient to change it for a lot of checkboxes:

ui.style().override_text_style = Some(TextStyle::Monospace);
ui.checkbox(…);
ui.checkbox(…);

What is the user story behind this? Why would one want to change the text style of only some checkboxes?

PS: I think you linked to the wrong issue

[Mubelotix]

What is the user story behind this?

I don't like how the widgets have larger font than body text. It does not integrate well. Especially since I changed the TextStyle::Button font size to a larger value because I needed to display larger items in a custom panel. I can't wait for #56 to be closed!

An alternative is to instead set a new default in Style. This would also make it more convenient to change it for a lot of checkboxes:

Your suggested solution would solve my problem. However, I wonder how complex a PR adding this would be. There are so many places where text_style is hardcoded. I would have to find and track all of them. Anyway I am already having problem with this in #407. That's why I switched back to a draft PR because as soon as I want to make it reviewable I discover another widget that lacks this feature.

Adding modifiers for them all may be the wrong approach.

Indeed. CSS implemented both solutions and I almost never use the element-specific one. However:

• Sometimes it's better to have it. Otherwise if we had like to change a single checkbox among others we would have to embed it into its own container. That's ugly.
• CSS is very powerful at selecting elements among others. It is not possible with egui yet (but that would be great). So the style-related solution would not be as great as in CSS. But you probably thought about this when you added other style fields.

So why don't we add both solutions? We could even (crazy idea incoming) add non-required methods on the Widget trait. We could include setters for all similar generic properties like text_style and text_color for the sake of completeness. The Widgets would be able to implement these methods if applicable.