Flutter Zoomable Widget

Question

What I want to build is a widget that can make its child widget zoomable similar to the zoomable behavior.

Gestures I want to cover are

1. Pinch To Zoom

Answer 1

I loved de resolution, you should put that in a packged in pub, you can even put some custom options, in my code I put doubletap to reset the zoom and locked the rotation.

import 'package:flutter/material.dart';
import 'package:matrix_gesture_detector/matrix_gesture_detector.dart';

class ZoomableWidget extends StatefulWidget {
  final Widget child;

  const ZoomableWidget({Key key, this.child}) : super(key: key);
  @override
  _ZoomableWidgetState createState() => _ZoomableWidgetState();
}

class _ZoomableWidgetState extends State {
  Matrix4 matrix = Matrix4.identity();
  Matrix4 zerada =  Matrix4.identity();

  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      onDoubleTap: (){
        setState(() {
          matrix = zerada;
        });
      },
      child: MatrixGestureDetector(
        shouldRotate: false,
        onMatrixUpdate: (Matrix4 m, Matrix4 tm, Matrix4 sm, Matrix4 rm) {
          setState(() {
            matrix = m;
          });
        },
        child: Transform(
          transform: matrix,
          child: widget.child,
        ),
      ),
    );
  }
}