1965352 - Add folder picker support to config-based settings

Status: NEW

(Firefox :: Settings UI, enhancement)

Description

[Mark Striemer [:mstriemer]]

Introduce support for moz-input-folder backed inputs in the config-based settings architecture.

The Downloads section can be used as a candidate to replace to use this feature.

Here's an example config that looks like it could work for the Downloads setting.

{
  id: "downloads",
  control: "folder",
  l10nId: "download-save-where",
},

The current Preference binding supports filepaths as a pref storage type, which should mean that the setting can be configured with:

Preferences.addSetting({
  id: "downloads",
  pref: "browser.download.dir",
});

It's possible we may need to convert the read value to a string in a get() method in the addSetting() call.

Acceptance Criteria:

• Config system supports control: "folder" populates a moz-input-folder
• Folder control updates the underlying setting correctly
• Tests for the config options