📱 custom_responsive

A lightweight Bootstrap-style 12-column responsive grid system for Flutter.

custom_responsive helps you build adaptive layouts using responsive column spans, offsets, nested grids, sliver support, and width-aware builders without manually handling screen sizes.

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🚀 Features

• 12-column responsive grid system
• Breakpoint-based layout control (S, M, XM, L, XL)
• Column offsets for precise positioning
• Nested responsive grids
• Width-aware builders
• Sliver support
• Scrollable or shrink-wrapped layouts
• Custom padding, margin, and color styling
• Lazy or eager rendering options

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📦 Installation

Add the package to your pubspec.yaml:

dependencies:
  custom_responsive: ^1.0.0

Then run:

flutter pub get

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📏 Breakpoints

Breakpoint	Width
S	< 600
M	600 - 904
XM	905 - 1239
L	1240 - 1439
XL	≥ 1440

Values automatically cascade to larger breakpoints when not provided.

Example:

CustomDiv(
  colS: 12,
  colM: 6,
)

is equivalent to:

CustomDiv(
  colS: 12,
  colM: 6,
  colXM: 6,
  colL: 6,
  colXL: 6,
)

---

🧱 Basic Usage

import 'package:custom_responsive/custom_responsive.dart';

CustomResponsive(
  children: [
    CustomDiv(
      colS: 12,
      colM: 6,
      colL: 4,
      child: Container(
        height: 100,
        color: Colors.red,
      ),
    ),
    CustomDiv(
      colS: 12,
      colM: 6,
      colL: 8,
      child: Container(
        height: 100,
        color: Colors.blue,
      ),
    ),
  ],
)

---

↔️ Column Offsets

Offsets allow you to shift items horizontally within the grid.

CustomResponsive(
  children: [
    CustomDiv(
      colS: 6,
      offsetS: 3,
      child: Container(
        height: 100,
        color: Colors.green,
      ),
    ),
  ],
)

---

🪆 Nested Grids

Create responsive layouts inside other responsive layouts.

CustomResponsive(
  children: [
    CustomDiv(
      colS: 12,
      children: [
        CustomDiv(
          colS: 12,
          colM: 6,
          child: Text("Left"),
        ),
        CustomDiv(
          colS: 12,
          colM: 6,
          child: Text("Right"),
        ),
      ],
    ),
  ],
)

---

📐 Width-Aware Builders

Use childBuilder when a widget needs to know its allocated width.

CustomDiv(
  colS: 12,
  colM: 6,
  childBuilder: (width) {
    return Text(
      "Available width: ${width.toStringAsFixed(0)}",
    );
  },
)

---

🧪 Responsive Spacer

Create responsive vertical spacing using CustomDiv.space.

CustomResponsive(
  children: [
    CustomDiv(
      colS: 12,
      child: Text("Section A"),
    ),

    CustomDiv.space(24),

    CustomDiv(
      colS: 12,
      child: Text("Section B"),
    ),
  ],
)

You can enable or disable the spacer for specific breakpoints:

CustomDiv.space(
  24,
  s: true,
  m: false,
  l: true,
)

---

📜 Scroll Behavior

Shrink Wrapped (Default)

Uses a regular Column and sizes itself to its content.

CustomResponsive(
  children: [...],
)

Eager Scrollable

Uses SingleChildScrollView and builds all rows immediately.

CustomResponsive(
  shrinkWrap: false,
  children: [...],
)

Lazy Scrollable

Uses ListView.builder and lazily builds rows.

CustomResponsive(
  shrinkWrap: false,
  useBuilder: true,
  children: [...],
)

---

🪝 Sliver Support

Use SliverCustomResponsive inside a CustomScrollView.

CustomScrollView(
  slivers: [
    SliverCustomResponsive(
      children: [
        CustomDiv(
          colS: 12,
          colM: 6,
          child: Container(
            height: 100,
            color: Colors.orange,
          ),
        ),
        CustomDiv(
          colS: 12,
          colM: 6,
          child: Container(
            height: 100,
            color: Colors.purple,
          ),
        ),
      ],
    ),
  ],
)

---

🧠 Responsive Utilities

getResponsiveValue

Returns a value based on the current breakpoint.

final columns = getResponsiveValue<int>(
  context: context,
  valueS: 12,
  valueM: 6,
  valueL: 4,
);

getResponsiveColumnWidth

Returns the pixel width occupied by a responsive column span.

final width = getResponsiveColumnWidth(
  context: context,
  valueS: 12,
  valueM: 6,
  valueL: 4,
);

---

📌 Notes

• The grid uses a 12-column layout system.
• Column values are automatically clamped to the range 0-12.
• Offsets are automatically clamped to valid values.
• Items automatically wrap to a new row when the current row exceeds 12 columns.
• Nested grids are fully supported.

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📜 License

MIT License. See the LICENSE file for details.

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💬 Feedback & Contributions

Issues, feature requests, and pull requests are welcome.

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Made with ❤️ by Amaan