// Automatic FlutterFlow imports\nimport '/backend/schema/structs/index.dart';\nimport '/flutter_flow/flutter_flow_theme.dart';\nimport '/flutter_flow/flutter_flow_util.dart';\nimport '/custom_code/widgets/index.dart'; // Imports other custom widgets\nimport '/custom_code/actions/index.dart'; // Imports custom actions\nimport '/flutter_flow/custom_functions.dart'; // Imports custom functions\nimport 'package:flutter/material.dart';\n// Begin custom widget code\n// DO NOT REMOVE OR MODIFY THE CODE ABOVE!\n\nimport 'dart:typed_data';\nimport 'package:flutter/cupertino.dart';\nimport 'package:flutter_svg/flutter_svg.dart';\nimport 'package:hand_signature/signature.dart';\n\nHandSignatureControl control = new HandSignatureControl(\n  threshold: 0.01,\n  smoothRatio: 0.65,\n  velocityRange: 2.0,\n);\n\nValueNotifier<String?> svg = ValueNotifier<String?>(null);\n\nValueNotifier<ByteData?> rawImage = ValueNotifier<ByteData?>(null);\n\nValueNotifier<ByteData?> rawImageFit = ValueNotifier<ByteData?>(null);\n\nclass Assinaturas extends StatefulWidget {\n  const Assinaturas({\n    Key? key,\n    this.width,\n    this.height,\n  }) : super(key: key);\n\n  final double? width;\n  final double? height;\n\n  @override\n  _AssinaturasState createState() => _AssinaturasState();\n}\n\nclass _AssinaturasState extends State<Assinaturas> {\n  @override\n  Widget build(BuildContext context) {\n    return Container(\n      width: widget.width,\n      height: widget.height,\n      child: Stack(\n        children: <Widget>[\n          Column(\n            children: <Widget>[\n              Expanded(\n                child: Center(\n                  child: AspectRatio(\n                    aspectRatio: 2.0,\n                    child: Stack(\n                      children: <Widget>[\n                        Container(\n                          constraints: BoxConstraints.expand(),\n                          color: Colors.white,\n                          child: HandSignature(\n                            control: control,\n                            type: SignatureDrawType.shape,\n                          ),\n                        ),\n                      ],\n                    ),\n                  ),\n                ),\n              ),\n              Row(\n                children: <Widget>[\n                  CupertinoButton(\n                    onPressed: () {\n                      control.clear();\n                      svg.value = null;\n                      rawImage.value = null;\n                      rawImageFit.value = null;\n                    },\n                    child: Text('clear'),\n                  ),\n                  CupertinoButton(\n                    onPressed: () async {\n                      svg.value = control.toSvg(\n                        color: Colors.blueGrey,\n                        type: SignatureDrawType.shape,\n                        fit: true,\n                      );\n\n                      rawImage.value = await control.toImage(\n                        color: Colors.blueAccent,\n                        background: Colors.greenAccent,\n                        fit: false,\n                      );\n\n                      rawImageFit.value = await control.toImage(\n                        color: Colors.black,\n                        background: Colors.greenAccent,\n                        fit: true,\n                      );\n                    },\n                    child: Text('export'),\n                  ),\n                ],\n              ),\n              SizedBox(\n                height: 16.0,\n              ),\n            ],\n          ),\n          Align(\n            alignment: Alignment.bottomRight,\n            child: Column(\n              mainAxisSize: MainAxisSize.min,\n              children: <Widget>[\n                _buildImageView(),\n                _buildScaledImageView(),\n                _buildSvgView(),\n              ],\n            ),\n          ),\n        ],\n      ),\n    );\n  }\n\n  Widget _buildImageView() => Container(\n        width: 192.0,\n        height: 96.0,\n        decoration: BoxDecoration(\n          border: Border.all(),\n          color: Colors.white30,\n        ),\n        child: ValueListenableBuilder<ByteData?>(\n          valueListenable: rawImage,\n          builder: (context, data, child) {\n            if (data == null) {\n              return Container(\n                color: Colors.red,\n                child: Center(\n                  child: Text('not signed yet (png)\\nscaleToFill: false'),\n                ),\n              );\n            } else {\n              return Padding(\n                padding: EdgeInsets.all(8.0),\n                child: Image.memory(data.buffer.asUint8List()),\n              );\n            }\n          },\n        ),\n      );\n\n  Widget _buildScaledImageView() => Container(\n        width: 192.0,\n        height: 96.0,\n        decoration: BoxDecoration(\n          border: Border.all(),\n          color: Colors.white30,\n        ),\n        child: ValueListenableBuilder<ByteData?>(\n          valueListenable: rawImageFit,\n          builder: (context, data, child) {\n            if (data == null) {\n              return Container(\n                color: Colors.red,\n                child: Center(\n                  child: Text('not signed yet (png)\\nscaleToFill: true'),\n                ),\n              );\n            } else {\n              return Container(\n                padding: EdgeInsets.all(8.0),\n                color: Colors.orange,\n                child: Image.memory(data.buffer.asUint8List()),\n              );\n            }\n          },\n        ),\n      );\n\n  Widget _buildSvgView() => Container(\n        width: 192.0,\n        height: 96.0,\n        decoration: BoxDecoration(\n          border: Border.all(),\n          color: Colors.white30,\n        ),\n        child: ValueListenableBuilder<String?>(\n          valueListenable: svg,\n          builder: (context, data, child) {\n            if (data == null) {\n              return Container(\n                color: Colors.red,\n                child: Center(\n                  child: Text('not signed yet (svg)'),\n                ),\n              );\n            }\n\n            return Padding(\n              padding: EdgeInsets.all(8.0),\n              child: SvgPicture.string(\n                data,\n                placeholderBuilder: (_) => Container(\n                  color: Colors.lightBlueAccent,\n                  child: Center(\n                    child: Text('parsing data(svg)'),\n                  ),\n                ),\n              ),\n            );\n          },\n        ),\n      );\n}
Dependecies:

hand_signature: ^3.0.1
flutter_svg: ^2.0.7
Struggling to use pub.dev custom widgets
