intrinsic_dimension 0.1.0

A widget that offers the dimensions (width and height) and the start offset of the widget you return from a builder callback function.

example/lib/main.dart

import 'package:flutter/material.dart';

import 'package:intrinsic_dimension/intrinsic_dimension.dart';

void main() => runApp(const MyApp());

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Intrinsic Dimension Example',
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Intrinsic Dimension Example'),
        ),
        body: Padding(
          padding: const EdgeInsets.all(16),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              IntrinsicDimension(
                builder: (context, width, height, startOffset) {
                  return Row(
                    children: [
                      Container(
                        width: 2,
                        height: height,
                        color: Colors.black,
                      ),
                      const SizedBox(width: 8),
                      Expanded(
                        child: Column(
                          crossAxisAlignment: CrossAxisAlignment.start,
                          children: [
                            const Text(
                              'Vertical line with the same height as the widget using a Container',
                            ),
                            Text(
                              'Offset from top left corner (0, 0): $startOffset',
                            ),
                          ],
                        ),
                      ),
                    ],
                  );
                },
              ),
              const SizedBox(height: 32),
              IntrinsicDimension(
                builder: (context, width, height, startOffset) {
                  return Row(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    mainAxisSize: MainAxisSize.min,
                    children: [
                      CustomPaint(
                        key: ValueKey(width),
                        painter: _LinePainter(
                          firstOffset: const Offset(0, 0),
                          secondOffset: Offset(width, 0),
                        ),
                      ),
                      const SizedBox(width: 8),
                      Column(
                        crossAxisAlignment: CrossAxisAlignment.start,
                        children: [
                          const Text(
                            'Horizontal line with the same width\nas the widget usign a LinePainter',
                          ),
                          Text(
                            'Offset from top left corner (0, 0):\n$startOffset',
                          ),
                        ],
                      ),
                    ],
                  );
                },
              ),
              const SizedBox(height: 32),
              IntrinsicDimension(
                builder: (context, width, height, startOffset) {
                  return Row(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    mainAxisSize: MainAxisSize.min,
                    children: [
                      Column(
                        key: ValueKey(width),
                        children: [
                          CustomPaint(
                            painter: _LinePainter(
                              firstOffset: const Offset(0, 0),
                              secondOffset: Offset(width, height),
                            ),
                          ),
                          CustomPaint(
                            painter: _LinePainter(
                              firstOffset: Offset(width, 0),
                              secondOffset: Offset(0, height),
                            ),
                          ),
                        ],
                      ),
                      const SizedBox(width: 8),
                      const SizedBox(
                        width: 100,
                        height: 100,
                      ),
                    ],
                  );
                },
              ),
            ],
          ),
        ),
      ),
    );
  }
}

class _LinePainter extends CustomPainter {
  const _LinePainter({
    required this.firstOffset,
    required this.secondOffset,
  });

  final Offset firstOffset;
  final Offset secondOffset;

  @override
  void paint(Canvas canvas, Size size) {
    final paint = Paint()..color = Colors.black;
    canvas.drawLine(firstOffset, secondOffset, paint);
  }

  @override
  bool shouldRepaint(oldDelegate) => false;
}