🔢 animated_otp_input

A highly customizable, animated, and accessible One-Time Password (OTP) input widget for Flutter. Supports advanced theming, error handling, accessibility, and smooth user experience for OTP, PIN, or verification code entry.

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✨ Features

• 🧩 Customizable OTP length and appearance: Choose the number of fields, field size, spacing, and border style.
• 📋 Smart paste detection: Autofills all fields when a full OTP is pasted.
• 🎯 Auto-focus navigation: Focus automatically shifts as the user types or deletes.
• 🛡️ Obscured input for privacy: Hide digits for PIN entry with a custom obscuring character.
• 🎨 Advanced theming: Use OtpInputTheme to style borders, colors, text, animation, and error messages.
• 🌍 Consistent LTR layout: Always left-to-right for digit entry, even in RTL locales.
• 🧠 Auto-submit support: Easily trigger actions when the OTP is complete via onChanged.
• 🚫 Disable input: Make fields read-only during loading or verification.
• ♿ Accessibility: Semantics labels and hints for screen readers, fully customizable.
• ⚠️ Error handling: Per-field error indication and group-level error messages with custom styles.
• 🌀 Animated focus: Customizable scale, duration, and curve for field focus animations.
• 📳 Haptic feedback: Optionally trigger haptic feedback on success or error, with customizable feedback type for tactile confirmation.

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🚀 Installation

Add the package using the command line:

flutter pub add animated_otp_input

Or manually add to your pubspec.yaml:

dependencies:
  animated_otp_input: ^1.0.6

Then run:

flutter pub get

Import the package:

import 'package:animated_otp_input/animated_otp_input.dart';

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📦 Usage

Basic Example

AnimatedOtpInput(
  length: 6,
  onChanged: (otp) {
    print('Entered OTP: $otp');
  },
)

Error Message Example

AnimatedOtpInput(
  length: 4,
  errorMessage: 'Please fill all fields', // Show error message below the fields
  theme: OtpInputTheme(
    errorMessageStyle: TextStyle(
      color: Colors.deepOrange,
      fontWeight: FontWeight.bold,
      fontSize: 14,
    ),
  ),
  onChanged: (otp) {
    // Show error if not all fields are filled
  },
)

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🧑‍💻 Parameters

Name	Type	Default	Description
length	int	6	Number of OTP digits.
onChanged	void Function(String)?	null	Callback triggered when the OTP value changes.
enabled	bool	true	Enables or disables the input fields.
fieldWidth	double	45	Width of each OTP input field.
fieldSpacing	double	4	Horizontal spacing between input fields.
theme	OtpInputTheme	const OtpInputTheme()	Customize input decoration, text style, colors, animation, errors.
obscureText	bool	false	Whether to obscure each input (e.g., for PIN input).
obscureCharacter	String	'•'	The character used when obscureText is true.
autoFocusFirstField	bool	false	Whether to autofocus the first input field when the widget builds.
errorMessage	String?	null	Group-level error message shown below the fields. If set, empty fields will show error borders and the message will be displayed.
semanticsLabel	String	'OTP digit'	Base label for accessibility (screen readers).
semanticsHint	String?	null	Base hint for accessibility.
enableSuccessHaptic	bool?	true	Enable haptic feedback on successful OTP entry.
enableErrorHaptic	bool?	true	Enable haptic feedback on OTP entry error.
successHapticFeedback	OtpHapticType?	OtpHapticType.light	Custom haptic feedback type for success.
errorHapticFeedback	OtpHapticType?	OtpHapticType.heavy	Custom haptic feedback type for error.

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🎨 Customization

Theming with OtpInputTheme

AnimatedOtpInput(
  length: 4,
  fieldWidth: 48,
  fieldSpacing: 8,
  theme: OtpInputTheme(
    border: OutlineInputBorder(borderRadius: BorderRadius.circular(10)),
    fillColor: Colors.grey.shade100,
    focusedBorder: OutlineInputBorder(
      borderSide: BorderSide(color: Colors.deepPurple),
    ),
    errorBorder: OutlineInputBorder(
      borderSide: BorderSide(color: Colors.red),
    ),
    textStyle: TextStyle(fontSize: 20, fontWeight: FontWeight.bold),
    errorMessageStyle: TextStyle(
      color: Colors.deepOrange,
      fontWeight: FontWeight.bold,
      fontSize: 14,
    ),
    borderSideWidth: 2.0, // Custom border width
    focusedScale: 1.2, // Custom scale animation
    animationDuration: Duration(milliseconds: 300),
    animationCurve: Curves.easeInOut, // Custom animation curve
  ),
)

Enable Obscured Input

AnimatedOtpInput(
  obscureText: true,
  obscureCharacter: '*', // Default: •
)

Disable Input

AnimatedOtpInput(
  enabled: false,
)

Autofocus First Field

AnimatedOtpInput(
  autoFocusFirstField: true,
)

Accessibility Customization

AnimatedOtpInput(
  semanticsLabel: 'Verification digit',
  semanticsHint: 'Enter the digit for verification',
)

Haptic Feedback Customization

You can control the type and intensity of haptic feedback for both success and error events using the following parameters:

• enableSuccessHaptic: Enable/disable haptic feedback when OTP is successfully entered.
• enableErrorHaptic: Enable/disable haptic feedback when an error occurs.
• successHapticFeedback: Choose the feedback type for success (light, medium, heavy, vibrate, none).
• errorHapticFeedback: Choose the feedback type for error (light, medium, heavy, vibrate, none).

Example:

AnimatedOtpInput(
  enableSuccessHaptic: true,
  enableErrorHaptic: true,
  successHapticFeedback: OtpHapticType.medium,
  errorHapticFeedback: OtpHapticType.vibrate,
)

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🧪 Testing

Comprehensive widget tests are included for error indication, error message display, custom error styles, accessibility, animation, and more. See the test/ directory for details.

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📸 Demo

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📄 License

This project is licensed under the MIT License.

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🤝 Contributions

Contributions, issues, and feature requests are welcome!
Feel free to open an issue or submit a pull request.

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⭐ Feedback

If you find this package helpful, please give it a ⭐ on pub.flutter-io.cn and share it with others.