responsive_spacing_plus

Lightweight responsive toolkit for Flutter (mobile, tablet, desktop). It provides device-type detection, screen metrics, and convenient scaling helpers for typography, spacing, icons/images, padding, and radius. It also includes design-size extensions (.w, .h, .sp, .r), a value picker per device type, and a simple builder widget.

Features

• Device classification via width breakpoints (Mobile / Tablet / Desktop)
• Screen metrics: width, height, status bar height, AppBar height, diagonal
• Scaled sizes for: font, spacing, icons/images, padding, radius
• Design-size helpers: .w .h .sp .r
• ResponsiveBuilder widget and ResponsiveValue<T> for per-device choices
• Configurable design size, breakpoints, and max text scale factor

Getting started

1. Add dependency in pubspec.yaml:

dependencies:
  flutter:
    sdk: flutter
  responsive_spacing_plus: ^0.0.1

2. Import:

import 'package:responsive_spacing_plus/responsive_spacing_plus.dart';

3. (Optional) Initialize global config once if you want to override defaults:

void main() {
	Responsive.init(
		config: const ResponsiveConfig(
			designWidth: 375,
			designHeight: 812,
			maxTextScaleFactor: 2.0,
			breakpoints: ResponsiveBreakpoints(mobileMax: 600, tabletMax: 1024),
		),
	);
	runApp(const MyApp());
}

Usage

Font, spacing, and icons

Text(
	'Hello',
	style: TextStyle(fontSize: context.font(16)), // ~16 on 375px width, scales up
)

SizedBox(height: context.space(12));

Icon(Icons.star, size: context.iconSize(20));

Padding and radius

Container(
	padding: context.pad(const EdgeInsets.symmetric(horizontal: 16, vertical: 12)),
	decoration: BoxDecoration(
		color: Colors.blue,
		borderRadius: BorderRadius.circular(context.radius(12)),
	),
)

Design units to logical pixels

// With 375x812 as the reference design:
SizedBox(width: 100.w(context), height: 44.h(context));
Text('Title', style: TextStyle(fontSize: 14.sp(context)));

Pick a value based on device type

final crossAxisCount = ResponsiveValue<int>(
	mobile: 2,
	tablet: 3,
	desktop: 5,
	fallback: 2,
).resolve(context);

ResponsiveBuilder

ResponsiveBuilder(
	builder: (context, constraints, device) {
		if (device == DeviceType.desktop) {
			return const DesktopLayout();
		} else if (device == DeviceType.tablet) {
			return const TabletLayout();
		}
		return const MobileLayout();
	},
)

Optional: Suggest a textScaleFactor globally

MaterialApp(
	builder: (context, child) {
		final tsf = Responsive.textScaleFactor(context);
		return MediaQuery(
			data: MediaQuery.of(context).copyWith(textScaler: TextScaler.linear(tsf)),
			child: child ?? const SizedBox.shrink(),
		);
	},
	home: ...,
)

Screenshots

Captured from the example/ app and stored under images/ in this package:

images/
	mobile_font.png
	mobile_grid.png
	tablet_grid.png
	taplet_font.png

Embedded below (relative paths work on pub.dev):

How to capture on Windows while the example is running:

# Run the example on Chrome (easy to resize) or on an emulator
cd example
flutter run -d chrome   # or: flutter run -d emulator-5554

# Take screenshots (OS tool)
# Press Win+Shift+S and select the app area, then save to images/*.png

# Or via Flutter (requires a connected device/emulator):
flutter screenshot --out=../images/overview.png

Try the package locally and take screenshots

This repository includes an example/ Flutter app demonstrating the API.

Run the example (Windows PowerShell):

cd example
flutter pub get
# Pick one of your available devices (Chrome/emulator/Windows app):
flutter devices
flutter run -d chrome
# or: flutter run -d windows
# or: flutter run -d <emulator-id>

Take screenshots:

• Use your OS tools (Windows: Snipping Tool / Win+Shift+S) while the app is running.
• Or use Flutter CLI with a connected device:

flutter screenshot --out=screen1.png

Tips:

• Resize the app window (on desktop) or test various devices (on Chrome/emulators) to capture different layouts.
• Ensure you capture examples of typography scaling, spacing, and grid changes.

Publishing to pub.dev (brief)

1. Ensure LICENSE, README.md, and CHANGELOG.md exist and are up to date.
2. Update pubspec.yaml with proper name, description, version and optionally homepage/repository.
3. Dry run:

flutter pub publish --dry-run

4. Publish:

flutter pub publish

Follow semantic versioning for subsequent releases and keep the changelog updated.

Contributing

Issues and PRs are welcome.