📱 Instagram Like Animation Button

A fully customizable, OOP-based Flutter package that replicates the Instagram Reels double-tap heart animation — the heart pops up at the tap position, rotates, and flies to a target widget.

---

✨ Features

Feature	Description
🎯 Fly-to-Target	Heart flies from double-tap position to any target widget
🎨 Custom Gradients	Use any gradient on the heart icon
🔧 Custom Widget Builder	Replace the heart with your own widget (emoji, icon, lottie, etc.)
📳 Haptic Control	Enable/disable/change haptic feedback type (light, medium, heavy, none)
⚡ Animation Config	Customize duration, curves, scale, rotation, timing — 16 parameters
🎭 Full OOP	Mixins, extensions, models, services — clean architecture
📦 Zero Dependencies	Only depends on Flutter SDK
🔁 DoubleTapDetector	Built-in gesture handler with position data

---

🚀 Getting Started

Installation

Add to your pubspec.yaml:

dependencies:
  instagram_like_animation_button: ^4.0.0

Or with a Git reference:

dependencies:
  instagram_like_animation_button:
    git:
      url: https://github.com/iambhabha/instagram_like_animation_button.git

Then run:

flutter pub get

Import

import 'package:instagram_like_animation_button/instagram_like_animation_button.dart';

---

📖 Quick Start

class _MyPageState extends State<MyPage> {
  final GlobalKey likeKey = GlobalKey();
  bool isLiked = false;
  TapDownDetails? tapDetails;

  @override
  Widget build(BuildContext context) {
    return DoubleTapDetector(
      onDoubleTap: (details) => setState(() => tapDetails = details),
      child: Stack(
        children: [
          // Your content (image, video, reels, etc.)
          Container(color: Colors.black),

          // Target icon with GlobalKey
          InkWell(
            key: likeKey,
            onTap: () => setState(() => isLiked = !isLiked),
            child: Icon(
              Icons.favorite,
              color: isLiked ? Colors.red : Colors.white,
            ),
          ),

          // Animation layer
          if (tapDetails != null)
            ReelAnimationLike(
              key: ValueKey(tapDetails),
              likeKey: likeKey,
              position: tapDetails!.globalPosition,
              onLikeCall: () => setState(() => isLiked = true),
              onCompleteAnimation: () => setState(() => tapDetails = null),
            ),
        ],
      ),
    );
  }
}

---

🏗️ Architecture

lib/
├── instagram_like_animation_button.dart    ← Barrel export (single import)
└── src/
    ├── core/
    │   ├── enums.dart                      ← HapticFeedbackType
    │   └── typedefs.dart                   ← AnimationWidgetBuilder, callbacks
    ├── config/
    │   └── like_animation_config.dart      ← 16 configurable animation params
    ├── mixins/
    │   └── haptic_feedback_mixin.dart      ← Haptic feedback mixin
    ├── extensions/
    │   ├── global_key_extensions.dart      ← GlobalKey.centerPosition, etc.
    │   └── offset_extensions.dart          ← Offset.deltaTo()
    ├── models/
    │   └── like_animation_style.dart       ← Gradient, color, icon size
    ├── resources/
    │   ├── asset_res.dart                  ← Asset path constants
    │   ├── color_res.dart                  ← Color constants
    │   └── style_res.dart                  ← Theme gradient
    ├── services/
    │   ├── haptic_manager.dart             ← Singleton haptic service
    │   └── debounce_action.dart            ← Singleton debounce service
    └── widgets/
        ├── reel_animation_like.dart        ← Main animation widget ⭐
        ├── heart_widget.dart               ← Default heart icon
        ├── gradient_icon.dart              ← Gradient ShaderMask wrapper
        └── double_tap_detector.dart        ← Double-tap gesture handler

---

📚 API Reference

ReelAnimationLike — Main Widget ⭐

The core widget. Place in a Stack — it animates from position → likeKey target.

Parameter	Type	Required	Description
likeKey	GlobalKey	✅	Target widget key
position	Offset	✅	Tap position (global)
config	LikeAnimationConfig	❌	Animation parameters
style	LikeAnimationStyle	❌	Visual style
builder	AnimationWidgetBuilder?	❌	Custom widget builder
onLikeCall	VoidCallback?	❌	Called on like
onCompleteAnimation	VoidCallback?	❌	Called on animation end
leftRightPosition	double	❌	X offset adjustment
topBottomPosition	double	❌	Y offset adjustment

ReelAnimationLike(
  likeKey: targetKey,
  position: tapPosition,
  config: const LikeAnimationConfig(
    duration: Duration(milliseconds: 800),
    hapticType: HapticFeedbackType.medium,
    scaleMax: 2.0,
  ),
  style: const LikeAnimationStyle(
    gradient: LinearGradient(colors: [Colors.pink, Colors.orange]),
    iconSize: Size(60, 60),
  ),
  onLikeCall: () => print('Liked!'),
)

Important

🎯 Position Fine-Tuning — leftRightPosition & topBottomPosition

If the animation's starting position doesn't look accurate (heart appears slightly off from the tap point), you can adjust it using these two parameters:

Parameter	What It Does	When to Use
leftRightPosition	Shifts the animation horizontally (X-axis)	Heart appears too far left/right from tap
topBottomPosition	Shifts the animation vertically (Y-axis)	Heart appears too high/low from tap

Why is this needed? Every app has different layouts — AppBar, BottomNavigationBar, SafeArea, padding, etc. These affect where the tap coordinates land vs where the animation renders in the Stack. These offsets let you compensate for that difference.

How to use:

ReelAnimationLike(
  likeKey: likeKey,
  position: tapDetails!.globalPosition,

  // 👇 Adjust these values until the heart appears exactly at the tap point
  leftRightPosition: 8,    // shift 8px to the left
  topBottomPosition: 65,   // shift 65px up (e.g., AppBar height)

  onLikeCall: () {},
)

Quick guide:

• topBottomPosition: 56 → standard AppBar height
• topBottomPosition: 80 → AppBar + status bar
• leftRightPosition: 0 → no horizontal adjustment needed (most cases)

💡 Tip: Start with 0 for both, double-tap on screen, and see where the heart appears. Then adjust the values until it lands exactly on your finger tap position.

---

LikeAnimationConfig — Animation Parameters

Immutable config with copyWith() support. 16 customizable properties:

Property	Type	Default	Description
duration	Duration	600ms	Total animation duration
scaleBegin	double	0.0	Starting scale
scaleMax	double	1.5	Peak scale (pop size)
scaleEnd	double	0.7	Final scale
scaleCurveUp	Curve	easeOut	Scale-up curve
scaleCurveDown	Curve	bounceIn	Scale-down curve
scaleUpWeight	double	30	Scale-up timing weight
scaleDownWeight	double	100	Scale-down timing weight
initialOffset	Offset	(0, -50)	Offset from tap
holdWeight	double	50	Hold phase weight
flyWeight	double	50	Fly phase weight
flyCurve	Curve	easeInOut	Flight curve
rotationRange	double	0.5	Max rotation (radians)
hapticType	HapticFeedbackType	light	Haptic feedback type
fadeDuration	Duration	500ms	Fade-out duration
completionDelay	Duration	500ms	Delay before onComplete

// Disable haptic, fast animation
const config = LikeAnimationConfig(
  duration: Duration(milliseconds: 400),
  hapticType: HapticFeedbackType.none,
  scaleMax: 2.0,
);

// Modify existing config
final modified = config.copyWith(hapticType: HapticFeedbackType.heavy);

---

LikeAnimationStyle — Visual Style

Property	Type	Default	Description
gradient	Gradient?	theme gradient	Gradient overlay
iconColor	Color?	#FF2D55	Icon tint color
iconSize	Size	80×80	Icon dimensions

const style = LikeAnimationStyle(
  gradient: LinearGradient(colors: [Colors.purple, Colors.blue]),
  iconColor: Colors.pink,
  iconSize: Size(50, 50),
);

---

DoubleTapDetector — Gesture Handler

Detects double-taps with position data (Flutter's onDoubleTap doesn't provide this).

DoubleTapDetector(
  onDoubleTap: (details) => print(details.globalPosition),
  onTap: () => print('Single tap'),
  behavior: HitTestBehavior.opaque,
  child: YourContent(),
)

---

HapticFeedbackType — Enum

Value	Description
none	❌ No haptic
light	💫 Light tap (default)
medium	📳 Medium tap
heavy	💥 Heavy tap
selection	🔘 Selection click
vibrate	📱 Standard vibration

---

HeartWidget — Default Icon

HeartWidget(
  style: LikeAnimationStyle(iconColor: Colors.pink, iconSize: Size(60, 60)),
)

GradientIcon — Gradient Wrapper

GradientIcon(
  gradient: LinearGradient(colors: [Colors.red, Colors.orange]),
  child: Icon(Icons.favorite, size: 48),
)

---

Extensions

// GlobalKeyX — on GlobalKey
final Offset? pos    = myKey.globalPosition;    // top-left
final Offset? center = myKey.centerPosition;    // center
final Size?   size   = myKey.widgetSize;         // size

// OffsetX — on Offset
final delta = tapPosition.deltaTo(targetPosition);

Services

// HapticManager (singleton)
HapticManager.instance.trigger(HapticFeedbackType.light);
HapticManager.instance.light();
HapticManager.instance.medium();

// DebounceAction (singleton)
DebounceAction.instance.call(() => print('Done'), milliseconds: 500);
DebounceAction.instance.cancel();

Resources

AssetRes.icFillHeart    // 'assets/ic_fill_heart.png'
AssetRes.icHeart        // 'assets/ic_heart.png'

ColorRes.likeRed        // #FF2D55
ColorRes.whitePure      // #FFFFFF
ColorRes.blackPure      // #000000

StyleRes.themeGradient   // Default LinearGradient

---

🧩 Custom Widget Builder

Replace the default heart with any widget — emoji, Lottie, custom icon:

ReelAnimationLike(
  likeKey: likeKey,
  position: tapPosition,
  builder: (context, scale, rotation, opacity) {
    return Opacity(
      opacity: opacity,
      child: Transform.scale(
        scale: scale.value,
        child: Transform.rotate(
          angle: rotation.value,
          child: Text('🔥', style: TextStyle(fontSize: 60)),
        ),
      ),
    );
  },
  onLikeCall: () {},
)

---

🎮 Full Example

See the complete working example in example/lib/main.dart.

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

class ReelPage extends StatefulWidget {
  const ReelPage({super.key});

  @override
  State<ReelPage> createState() => _ReelPageState();
}

class _ReelPageState extends State<ReelPage> {
  final GlobalKey likeKey = GlobalKey();
  bool isLiked = false;
  TapDownDetails? tapDetails;

  @override
  Widget build(BuildContext context) {
    return DoubleTapDetector(
      onDoubleTap: (details) => setState(() => tapDetails = details),
      child: Stack(
        children: [
          Container(color: Colors.black), // Your video/image

          // Right-side icons (like Instagram Reels)
          Positioned(
            right: 16,
            bottom: 100,
            child: InkWell(
              key: likeKey,
              onTap: () => setState(() => isLiked = !isLiked),
              child: Image.asset(
                isLiked ? AssetRes.icFillHeart : AssetRes.icHeart,
                width: 28, height: 28,
                color: isLiked ? ColorRes.likeRed : ColorRes.whitePure,
                package: 'instagram_like_animation_button',
              ),
            ),
          ),

          // Animation
          if (tapDetails != null)
            ReelAnimationLike(
              key: ValueKey(tapDetails),
              likeKey: likeKey,
              position: tapDetails!.globalPosition,
              config: const LikeAnimationConfig(
                hapticType: HapticFeedbackType.light,
              ),
              style: const LikeAnimationStyle(iconSize: Size(50, 50)),
              onLikeCall: () {
                if (!isLiked) setState(() => isLiked = true);
              },
              onCompleteAnimation: () => setState(() => tapDetails = null),
            ),
        ],
      ),
    );
  }
}

---

📋 Requirements

	Version
Flutter	≥1.17.0
Dart	^3.10.7

📄 License

MIT License — see LICENSE for details.

🤝 Contributing

Contributions are welcome! Please open an issue or submit a pull request.

---

Made with ❤️ by @iambhabha