healthrian_render_canvas 0.0.1

A library to render JSON descriptions onto a Canvas.

healthrian_render_canvas

A library to render JSON descriptions onto a Canvas.

This package provides the HealthrianRenderCanvas class, which takes a JSON map describing drawing elements (rectangles, text, lines, etc.) and renders them into a PNG image (Uint8List).

Features

• Parse JSON drawing instructions.
• Support for:
  • Rectangles
  • Text (with custom fonts and weights)
  • Lines and Polylines
  • Circles
  • ECG grids/waveforms
  • Images (Base64 encoded)
• Output to Uint8List (PNG format).

Usage

import 'package:healthrian_render_canvas/healthrian_render_canvas.dart';

final canvas = HealthrianRenderCanvas(width: 2480, height: 3508); // A4 300dpi example
final jsonData = {
  'document': {
    'layers': [
      {
        'elements': [
          {
            'type': 'rectangle',
            'x': 10,
            'y': 10,
            'width': 100,
            'height': 50,
            'fill': '#FF0000'
          }
        ]
      }
    ]
  }
};

final pngBytes = await canvas.render(jsonData);