#Custom settings panels (SettingsPanel)

GraphicsSettingsPanel, AudioSettingsPanel and InputSettingsPanel share the base SettingsPanel<T>. Use it for a settings screen of your game, for example difficulty or accessibility options.

The base has these members:

How to make a panel:

1. Make a [Serializable] subclass of SettingsOptions with public fields. Use the PropertyGrid attributes: [Category], [Range], [Description], [InspectorName], [EnabledIf].
2. Make a [UxmlElement] partial subclass of SettingsPanel<T>.
3. Override Capture() (the values in effect now), DefaultOptions() and ApplyOptions(options).
4. Call AddGrid() in the constructor for a PropertyGrid of Editing.

[Serializable]
public class GameplayOptions : SettingsOptions
{
    public static GameplayOptions Current = new();

    [Category("Gameplay"), Range(0, 2), Description("0: easy, 2: hard.")]
    public int Difficulty = 1;

    [Category("Gameplay"), InspectorName("Show hints")]
    public bool ShowHints = true;
}

[UxmlElement]
public partial class GameplaySettingsPanel : SettingsPanel<GameplayOptions>
{
    public GameplaySettingsPanel() : base("mygame.gameplay") => AddGrid();

    protected override GameplayOptions Capture() => (GameplayOptions)GameplayOptions.Current.Clone();
    protected override GameplayOptions DefaultOptions() => new();
    protected override void ApplyOptions(GameplayOptions options) => options.CopyTo(GameplayOptions.Current);
}

Tips:

• SettingsOptions copies, compares and saves with JsonUtility. Only the serialized fields count.
• Override ConfirmAsync(old, next) to ask the player before the edits stay. GraphicsSettingsPanel uses it for the display mode.
• A panel without a PropertyGrid adds its own controls to Body, overrides ShowEditing() to show Editing in them, and calls ShowDirty() after an edit. InputSettingsPanel does this.
• SettingsOptions.Load(key) is virtual. Override it when a save must merge into the options, as InputBindingOptions does with the binding ids.
• Call Reload() when the source of Capture() changes, for example after a new Actions asset. It drops the edits and loads the saved options again.
• A screen with several panels, such as the Settings screen of the GameMenu example, sets show-buttons="false" on each panel. Its own Apply button awaits ApplyAsync() of each panel, and its dirty state is true when one IsDirty is true.
• Give the panel a parent that grows. The body has a flex basis of 0 and a minimum height of 120 px, so it scrolls in a short parent. In a TabView, also make the tab content container grow (see Settings.uss in the example).

#Styling