Settings

A plugin keeps its settings as a JSON object under its id in OxiGuitar’s settings.json:

{
  "view": { "dark_interface": true },
  "yourname.example": { "flats": true }
}

It reads and writes only its own object, through the host:

        let count_tied = host
            .settings()
            .ok()
            .and_then(|s| s.get("count_tied").and_then(|v| v.as_bool()))
            .unwrap_or(false);

    /// Keeps `count_tied` in the plugin's settings, beside whatever else is
    /// there.
    fn save(&self, count_tied: bool) -> Result<(), Error> {
        let mut settings = self.host.settings()?;
        settings.insert("count_tied".into(), count_tied.into());
        self.host.set_settings(&settings)
    }

• settings() returns the object (empty when there is none). It is a serde_json::Map, so add serde_json = "1" to your dependencies.
• set_settings(map) replaces the whole object and saves settings.json at once. Read, change, write: keys you leave out are gone.
• The app and every plugin write through one shared copy of settings.json, so none overwrites another’s keys. A settings.json that couldn’t be read when OxiGuitar started is never written, so settings then last for the session only. set_settings returns an error when the file can’t be written (a full disk, a folder the user can’t write to): handle it (the template tells the footer and carries on).
• Show them in a settings window (interface 1.3): with "settings_window": true in the manifest and Plugin::settings_window returning a Tab, the plugin manager (Tools → Plugins) gives the plugin a Settings… button, which opens a window of the plugin’s widgets: the same widgets as a tab’s, without a canvas. Its on reads the settings, changes them and writes them back. Before 1.3, put them in a tab of your own (Tabs).
• Users can also edit settings.json by hand while OxiGuitar is closed, so read it defensively: a value of the wrong type falls back to your default, as the template’s and_then(|v| v.as_bool()) does.

Settings are for small values, and they are global. What belongs to one track of one score goes in a section of the track dialog instead.

Folders (interface 1.3)

host.folders() hands the plugin its folders, as paths:

The host makes the plugin’s own two folders the first time it asks, and the shared folders a manifest lists when OxiGuitar starts, so the user finds them before any plugin runs. Nothing is ever downloaded into them: OxiGuitar and its plugins download nothing.