flutter_helper_kit

A production-ready Flutter utility kit — extensions, widgets, animations, responsive sizing, and utils in one package with zero external dependencies (Flutter SDK only).

Consolidates helpers previously spread across custom_helper folders (Paydrop, WhereToNow, etc.) into a single maintainable package.

Platforms: Android · iOS · Web · macOS · Windows · Linux

---

Installation

dependencies:
  flutter_helper_kit: ^1.0.6

flutter pub add flutter_helper_kit

import 'package:flutter_helper_kit/flutter_helper_kit.dart';

Modular imports (smaller compile surface)

import 'package:flutter_helper_kit/flutter_helper_kit_extensions.dart';
import 'package:flutter_helper_kit/flutter_helper_kit_widgets.dart';
import 'package:flutter_helper_kit/flutter_helper_kit_animation.dart';
import 'package:flutter_helper_kit/flutter_helper_kit_responsive.dart';
import 'package:flutter_helper_kit/flutter_helper_kit_utils.dart';

---

Package structure

Every feature maps to a lib/ path. Use this table to find the right file.

Module	Source path	Key APIs
Extensions	lib/extensions/	String, Color, DateTime, List, Map, Widget, Context, Alignment, Type conversion
Widgets	lib/widgets/	AppButton, SliderButton, ReadMore, FlutterTag, Sharp corners, Pagination, etc.
Animation	lib/animation/	75+ animateWidget*, list animations, AnimatedGestureDetector
App Responsive	lib/app_responsive/	ScreenUtilInit, .w, .h, .sp, .r, RPadding, RSizedBox
Reactive	lib/reactive/	RxDateTime, RxnDateTime (ValueNotifier-based)
Utils	lib/utils/	timeAgoCalculated, RandomImage, SystemUiUtils, MapCustomInfoWindow
Formatters	lib/text_field/	NoLeadingSpaceFormatter, NoSpaceFormatter
Custom Painter	lib/custom_painter/	GoogleLogoWidget

Full single import via flutter_helper_kit.dart.

---

Example app

Runnable demos for every module — each screen shows source file + API names.

cd example
flutter run

See example/README.md for catalog structure and how to add new demos.

---

Quick start

Responsive sizing (app_responsive/)

ScreenUtilInit(
  designSize: const Size(360, 690),
  builder: (_, child) => MaterialApp(home: child),
  child: Builder(
    builder: (context) => Container(
      width: 200.w,
      height: 80.h,
      child: Text('Hello', style: TextStyle(fontSize: 16.sp)),
    ),
  ),
);

API	File
.w, .h, .sp, .r, .sw, .sh	app_responsive/size_extension.dart
ScreenUtilInit	app_responsive/screenutil_init.dart
RPadding, RSizedBox	app_responsive/r_padding.dart, r_sized_box.dart

Widget animations (animation/)

Text('Hello')
  .animateWidgetElasticEntry()
  .animateWidgetGlassReveal();

// List item stagger
ListTile(title: Text('Item'))
  .animateListEntry(index: 0);

// Tap feedback
AnimatedGestureDetector(
  effectPreset: TapEffect.bounce,
  onTap: () {},
  child: Icon(Icons.favorite),
);

API	File
animateWidget* (75+ methods)	animation/widget_animation_extensions.dart
animateList*	animation/list_item_animations.dart
AnimatedGestureDetector	animation/animated_gesture_detector.dart
animateSheetReveal	animation/animations_bottom_sheet.dart

Extensions

'edit_item'.toSnakeCase();           // string_case.dart
'user@mail.com'.isValidateEmail();  // validation.dart
1.50.toStringAsSmartRounded();       // smart_round_to_string.dart
Colors.blue.withColorOpacity(0.5);   // color_extension.dart
DateTime.now().timeAgo();            // date_extension.dart
'42'.toInt();                        // type_conversion.dart (on Object?)
context.showSnackBar(title: Text('Hi')); // build_context_extension.dart

Widgets

// Slider with shimmer label
SliderButton(
  width: 300,
  label: Text('Slide to confirm'),
  action: () async => true,
);

// Password strength meter
PasswordStrengthIndicator(textController: controller);

// Enhanced read-more with regex annotations
ReadMoreTextEnhanced(longText, trimLines: 3, annotations: [...]);

// iOS-style sheets (pass BuildContext)
AppCupertinoActionSheet.showActionSheet(
  context: context,
  actions: [ActionSheetItem(value: 'a', label: 'Option A')],
);

// Animated digit counter
UniversalDigitCounter(value: 12345, type: DigitAnimationType.simple);

// Ticket shape clipper
TicketClipper(
  clipper: PointedEdgeClipper(),
  child: Container(color: Colors.orange),
);

// Infinite scroll list
ListViewPagination(
  itemCount: items.length,
  hasNext: hasMore,
  nextData: fetchMore,
  itemBuilder: (_, i) => ListTile(title: Text(items[i])),
);

Widget	File
AppButton	widgets/app_button.dart
SliderButton	widgets/slider_button.dart
PasswordStrengthIndicator	widgets/password_strength_indicator/
ReadMoreText / ReadMoreTextEnhanced	widgets/read_more_text.dart, read_more_enhanced.dart
FlutterTag	widgets/flutter_tag/
SharpBorderRadius, SharpClipRect	widgets/sharp_corners/
ListViewPagination	widgets/list_view_pagination.dart
CenterTextDivider, CustomBanner	widgets/center_text_divider.dart, custom_banner.dart
AvatarGlow, OutlineGlow	widgets/avatar_glow/
TicketClipper	widgets/ticket_clippers/
UniversalDigitCounter	widgets/rolling_digit/

Reactive datetime (reactive/)

final rx = RxDateTime.now();
rx.addDuration(const Duration(hours: 1));
print(rx.format('yyyy-MM-dd'));
print(rx.timeAgo());

No GetX required — built on ValueNotifier<DateTime>.

Utils

timeAgoCalculated(DateTime.now().subtract(Duration(minutes: 5)));
RandomImage.picsumImage(300, 200);
RandomPicsumImage.image(width: 400, height: 300);
SystemUiUtils.setStatusBarColor(Colors.deepPurple);

Util	File
timeAgoCalculated	utils/ago_time.dart
RandomImage	utils/random_image.dart
RandomPicsumImage	utils/random_picsum_image.dart
SystemUiUtils	utils/system_ui_utils.dart
MapCustomInfoWindow	utils/map_custom_info_window.dart
showDialogWithCloseIcon	utils/close_icon_show_dialog.dart
Validator	utils/password_validator.dart
Numeral	utils/numberal_utils.dart

Map info window (callback adapter)

No google_maps_flutter dependency in this package. Use CallbackMapInfoWindowAdapter:

final adapter = CallbackMapInfoWindowAdapter(
  onGetScreenCoordinate: (latLng) async {
    final coord = await googleMapController.getScreenCoordinate(
      LatLng(latLng.latitude, latLng.longitude),
    );
    return MapScreenCoordinate(coord.x, coord.y);
  },
);
controller.mapAdapter = adapter;

Text field formatters

TextField(
  inputFormatters: [
    NoLeadingSpaceFormatter(),
    NoSpaceFormatter(),
  ],
);

---

Extensions reference

String — extensions/string/

• string_extension.dart — isEmptyOrNull, capitalize, reversed, parsing helpers
• string_case.dart — toSnakeCase, toCamelCase, toPascalCase, toKebabCase, toTitleCase
• validation.dart — isValidateEmail, validatePhone, extractPhoneNumber, URL/password checks

Color — extensions/color/color_extension.dart

• toHex, createMaterialColor, lighten, darken, withColorOpacity, isDark, isLight

DateTime — extensions/date/

• date_extension.dart — timeAgo, isToday, isYesterday, timezone helpers
• date_format.dart — format(pattern:), formatTime()

List / Map / Set / Iterable — extensions/list/, map/, set/

• firstOrNull, lastWhereOrNull, separatorEvery, getOrDefault, validate

Number — extensions/number/

• integer_extension.dart, double_extension.dart, number_extension.dart
• smart_round_to_string.dart — toStringAsSmartRounded()
• height(), width(), circularBorderRadius spacing helpers

Widget / Context — extensions/widget/, context/

• paddingAll, withSize, visible, expanded, centered
• width, height, showSnackBar, theme, platform checks

Other

• alignment/alignment_extensions.dart — isTop, isBottom, isLeft, isRight
• type_conversion.dart — toInt, toDouble, toBool, toStr on Object?
• bool/bool_extensions.dart — validate, toggle, toInt
• duration/duration_extensions.dart — .delay
• function/scope_functions_extension.dart — let, also, run, takeIf
• random/random_extension.dart — random helpers on math.Random

---

Widgets reference

UI & feedback

Widget	File	Description
FlutterToast	flutter_toast.dart	Toast messages
CustomIndicator	custom_indicator.dart	Loading overlay
UnFocusable	hide_keyboard.dart	Dismiss keyboard on outside tap
DoublePressBackWidget	double_press_back_widget.dart	Press back twice to exit
TapSafeGesture	tap_safe_gesture.dart	Debounced async tap
TextShimmer, ProfileShimmer, …	simmer.dart	Shimmer placeholders

Layout & display

Widget	File
Space, SliverSpace	space/space.dart, sliver_space.dart
SeparatedColumn	separated_column.dart
FlutterListView	flutter_list_view.dart
DashDivider	dash_divider.dart
DottedBorderWidget	dotted_border_widget.dart
GradientText	gradient_text.dart
Marquee	marquee_widget.dart
TextAvatar, TextIcon	text_avatar.dart, text_icon_widget.dart
WidgetHelper	widget_helper.dart

Forms & input

Widget	File
RoundedCheckBox	rounded_checkbox_widget.dart
RatingBarWidget	rating_bar_widget.dart
TimerBuilder	timer_builder.dart

---

Typedefs

Callback types in utils/type_def.dart:

FutureVoidCallback, StringCallback, IntArgVoidCallback, DoubleCallback, and more.

---

Migration from custom_helper

Before	After
import '.../custom_helper.dart'	import 'package:flutter_helper_kit/flutter_helper_kit.dart'
Get.context in Cupertino dialogs	Pass context: parameter
Rx<DateTime> (GetX)	RxDateTime / RxnDateTime
Google Maps LatLng in info window	MapLatLng + MapInfoWindowAdapter

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Screenshots

Flutter Toast

Tap Safe Gesture

Avatar Glow

Outline Avatar Glow

Avatar Glow MultiColor

Outline Avatar Glow MultiColor

App Button

Marquee

RatingBar

Read More Text

Rounded Check Box

Text Icon

showDialogWithCloseIcon

Sharp Borders

Flutter Tag

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Contributing

• Issues & features: GitHub Issues
• New widget/API: add under lib/, export in flutter_helper_kit.dart, register demo in example/lib/catalog/example_catalog.dart
• Contact: sachin4kmt@gmail.com

If this package helps your project, consider giving it a star on GitHub.