ui::ThemeRequest¶

Header: winui/ui/themes/ThemeSource.hpp.

What an application asks for. Every field left at its default means "follow the system."

Pass one as ui::WindowOptions::theme, or later to Window::set_theme(), and the window resolves the Theme from it, and again whenever the system settings change. resolve_theme() makes a fixed Theme from one.

Example:

int run_app()
{
    ui::ThemeRequest request;
    request.mode            = ui::ThemeMode::Dark;
    request.accent_override = ui::Color::from_argb(0xFFE81123); // brand red instead of the OS accent

    // The system decides everything the request leaves at its default:
    ui::Window app{{.title = "App", .theme = request}};

    // Later, follow the system's light or dark setting again:
    request.mode = ui::ThemeMode::System;
    app.set_theme(request);
    return ui::run(app);
}

Field	Type	Default
`mode`	`ThemeMode`	`ThemeMode::System`	Light, Dark, HighContrast, or System (the default) to follow the system as it changes.
`accent_override`	`std::optional<Color>`		A brand accent to use in place of OsThemeSnapshot::accent. Its lighter and darker shades are derived from it. Ignored by the light-only variants and under high contrast.
`variant`	`ThemeVariant`	`ThemeVariant::System`	ThemeVariant::System, the default, follows `mode`, as do Fluent2, Fluent, Metro and Mdl2. Every other variant opts into a fixed, light-only palette true to its era, which ignores `mode` and `accent_override` since the era has no dark mode. The exception is a `mode` of HighContrast, which swaps in the era's contrast colors and keeps the era's shapes. theme_variant_supports_dark_mode() tells the two sets apart.
`classic_scheme`	`std::optional<ClassicPalette>`		A `ClassicPalette` that replaces the era's default colors when `variant` is Windows9x or Windows3x. "Windows 9x with the Eggplant scheme" is one palette away, since those eras' themes are derived from a ClassicPalette alone. Ignored by every other variant, Luna and Aero included.
`early_scheme`	`std::optional<EarlyPalette>`		The palette for `variant` Windows1x: Windows 1.01 or Windows 2.03, each in a color and a monochrome version. The variant defaults to `EarlyPalette::windows_2x_color()`, and this picks any of the other three. Ignored by every other variant.
`animations`	`AnimationPreference`	`AnimationPreference::System`	Whether controls animate (Theme::animations_enabled): System (the default) follows OsThemeSnapshot::animations_enabled, On and Off override it. Applies to every variant.