Buttons: Add a font size control

[pablinos]

Description

In #20967 we have discussed adding a font size control to the button
block. This explores doing that, by adding fontSize to the block's
supported features.

Unfortunately, in testing with the TwentyTwenty theme, the size is
overridden by the theme's CSS. I've reset this in the block's CSS but
it would probably require theme updates to set the style on
.wp-block-button rather than .wp-block-button__link in order to make
sure this doesn't do something unexpected.

As it stands the default button size will have increased. I'm not sure if it
has other consequences.

How has this been tested?

Just manually for now with the TwentyTwenty theme

Screenshots

Types of changes

This is essentially a new feature. Introducing this capability to an existing block.

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.
• I've updated all React Native files affected by any refactorings/renamings in this PR.

[pablinos]

I've just seen I missed another implementation of this that also adds support for padding controls in #26501.

I'm not sure if we should be adding the styles to the link inside the button, but that does get around the issue I was seeing where the theme is setting the font size of the link.

[skorasaurus]

Thanks for sharing; does this come with the ability to disable that font-size control as well?

[pablinos]

Thanks for sharing; does this come with the ability to disable that font-size control as well?

Do you mean to disable it? If so, then you could hook into blocks.registerBlockType and modify the supports object in the settings.

[apeatling]

Works well and this combined with padding provides much greater button flexibility. 👍

[apeatling]

I think you'll need to update tests first @pablinos

[apeatling]

@pablinos Any plans to pick this one back up or would you prefer we take it over the line?

[pablinos]

I can take a look at the tests today @apeatling. Do you think we should take this approach or go in the direction of #26501? Either way, we should add the padding controls as you mention.

[aristath]

PR should be rebased to fix the merge conflicts 👍

[pablinos]

Finally got around to rebasing this and the tests are passing now. What did you think about my comment here @apeatling? I'm not sure whether changing the default font size for a button is a good thing!

[aristath]

cc @carolinan I don't know if TwentyTwenty-One should be changed if we land this... 🤔

[ntsekouras]

Thanks for your work here @pablinos ! It seems though that this has slipped between the cracks and this landed: #30394 and latter updated as well with the new format for typography support.

I'm closing this but again thanks for your work - really appreciate it!

[pablinos]

No problem @ntsekouras, glad it's been implemented!