Source on GitHub·lib/src/ui_kit/fast_toast/

Overview

Global toasts live on the app-root overlay. Call showToast / showCustomToast without a BuildContext; they are not tied to the navigator stack. Only one toast is visible at a time; extras wait in a FIFO queue.

Topic	Notes
Show API	showToast(message) / showCustomToast(widget)
Host	Wrap MaterialApp.builder with FastToastOverlay
Queue	Single slot, FIFO; pending cap 5, drop-oldest
Theme	FastToastTheme (ThemeExtension) for the text panel only
Not provided	success / error / info types, priority interrupt, progress toasts

TIP

Calls made before FastToastOverlay is mounted enqueue without throwing. See the example app’s ToastExample page for a full demo.

---

Setup

import 'package:flutter/material.dart';
import 'package:fast_package/fast_package.dart';

MaterialApp(
  builder: (context, child) {
    return FastToastOverlay(
      child: child ?? const SizedBox.shrink(),
    );
  },
  // ...
);

---

Examples

import 'package:fast_package/fast_package.dart';

showToast('Saved');

showToast(
  'Network error',
  config: FastToastConfig(
    duration: Duration(seconds: 3),
    position: FastToastPosition.bottom,
    dismissible: true,
  ),
);

showCustomToast(
  Row(
    mainAxisSize: MainAxisSize.min,
    children: [
      Icon(Icons.check_circle, color: Colors.green),
      SizedBox(width: 8),
      Text('Custom content'),
    ],
  ),
);

FastToast.dismiss();
FastToast.dismissAll();

showCustomToast inserts your widget as toast content. The host still owns queue, position, duration, and motion, and does not wrap default panel chrome. The widget is built under the overlay tree (Builder / Theme.of work); do not capture a disposed page BuildContext.

---

Theme setup

FastToastTheme styles the default showToast text panel only:

MaterialApp(
  theme: ThemeData(
    brightness: Brightness.light,
    extensions: const [FastToastTheme.light],
  ),
  darkTheme: ThemeData(
    brightness: Brightness.dark,
    extensions: const [FastToastTheme.dark],
  ),
  builder: (context, child) {
    return FastToastOverlay(child: child ?? const SizedBox.shrink());
  },
);

Resolution order:

1. A FastToastTheme registered on ThemeData
2. Fallback to FastToastTheme.light / dark from ThemeData.brightness

---

API

showToast / showCustomToast

void showToast(String message, {FastToastConfig? config});

void showCustomToast(Widget toast, {FastToastConfig? config});

FastToast

Member	Notes
isShowing	Whether a toast is on screen
pendingCount	Pending items, excluding the visible toast
dismiss()	Exit the current toast, then show the next; no-op when idle
dismissAll()	Clear the queue and remove the current toast immediately

FastToastConfig

Parameter	Default	Notes
duration	2000ms	Time on screen before exit animation
position	FastToastPosition.center	top / center / bottom
dismissible	false	Tap content to dismiss

---

Non-goals

• No FastToastType and no success / error / info helpers
• No Loading coordination and no high-priority interrupt
• No animation enum and no progress toast