Allow disabling the shadow panel

[carolinan]

Description

There is no way to turn off the Shadow panel in Site Editor > Styles > Blocks > Button
If theme.json turns off all presets, the panel still shows, but it has no options.

Step-by-step reproduction instructions

Add the following under settings in theme.json:

	"shadow": {
		"presets": [],
		"defaultPresets": false
	},

Screenshots, screen recording, code snippet

The panel shows but there are no options:

Environment info

No response

Please confirm that you have searched existing issues in the repo.

Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

Yes

Where did you find the "defaultPresets": false option? It doesn't show up in my theme schema yet, or are you suggesting we add this?

One other question, I can't find a disable option for the other options, like border. Should that be added as well? Why only for the shadow? Or am I missing something? :)

[carolinan]

From the shadow PR #46502 and theme.json https://github.com/WordPress/gutenberg/blob/trunk/lib/theme.json#L190

Shadow is enabled by default. Border is opt-in, disabled by default.

[carolinan]

It follows the same pattern as other settings: "defaultPalette": false, "defaultGradients": false. "defaultDuotone": false

[colorful-tones]

I went as far as trying the above and this and the empty shadow panel still shows (as reported by Carolina).

{
    "settings": {
        "blocks": {
            "core/button": {
                "shadow": false
            }
        }
    }
}

[cbirdsong]

This is not specific to the button block. It also shows up on column blocks.

[carolinan]

Yes this issue is a bit out of date since the shadow controls changed in WP 6.5.

[t-hamano]

This issue could not be reproduced in the latest Gutenberg. It seems that we just need to set settings.shadow.defaultPresets to false:

{
	"$schema": "../../schemas/json/theme.json",
	"version": 3,
	"settings": {
		"appearanceTools": true,
		"layout": {
			"contentSize": "840px",
			"wideSize": "1100px"
		},
		"shadow": {
			"defaultPresets": false
		}
	}
}

I would like to close this issue, but please feel free to reopen it at any time if the problem reoccurs.

[carolinan]

I still don't think this is the correct solution since the name of the option is to literally set the default presets to false, not disable the option. 🤷‍♀️

[t-hamano]

I believe what is considered a bug in this issue is that the panel is unintentionally displayed even though there is no preset. This issue has already been resolved.

Furthermore, I believe that the specification that the panel's visibility depends on whether there is a preset is consistent across colors, font sizes, and shadows.

What is the correct solution required here?