show static method

ToastHandle show(BuildContext context, String message, { Duration? duration, ToastSeverity severity = ToastSeverity.info, CellStyle? style, ToastAction? action, Object? id, bool persistent = false, })

Shows message as a toast via the nearest enclosing Toaster. Throws if there is no Toaster above context.

severity picks a default color; style overrides it outright when supplied (merged over the severity's style). An optional action adds a hotkey affordance shown in the toast. Reusing a non-null id replaces that toast in place and starts a fresh lifetime. IDs are scoped to this host and compared with ==. Omitting an ID creates a distinct toast. The returned handle belongs to this exact instance, not to later replacements.

persistent disables expiry; explicit dismissal, replacement, eviction and host disposal still remove the toast. It cannot be combined with an explicit duration. Otherwise null duration inherits the host default. A transient toast must have a positive duration.

Implementation

static ToastHandle show(
  BuildContext context,
  String message, {
  Duration? duration,
  ToastSeverity severity = ToastSeverity.info,
  CellStyle? style,
  ToastAction? action,
  Object? id,
  bool persistent = false,
}) {
  if (persistent && duration != null) {
    throw ArgumentError('A persistent toast cannot have a duration.');
  }
  // An action from a handler: locate the toaster without subscribing the
  // caller to anything (the state never changes identity or notifies).
  final state = context.findAncestorStateOfType<_ToasterState>();
  if (state == null) {
    throw StateError(
      'No Toaster above this BuildContext. Wrap your app in a Toaster.',
    );
  }
  final lifetime = persistent ? null : duration ?? state.widget.duration;
  if (lifetime != null && lifetime <= Duration.zero) {
    throw ArgumentError.value(lifetime, 'duration', 'Must be positive');
  }
  final colors = Theme.of(context).colorScheme;
  final resolved = style == null
      ? _styleForSeverity(severity, colors)
      : _styleForSeverity(severity, colors).merge(style);
  return state._enqueue(message, lifetime, resolved, severity, action, id);
}