CODEWITHSUNDEEP
flutter
arunin25
arunin25

Reputation: 21

how to add pinch zoom functionality in flutter qr code scanner?

I am developing qr code scanner app using qr_code_scanner flutter package.I am unable to add the pinch zoom functionality on that. Is there anyway to add this functionality or other qr code scanner package which supports pinch zoom function? Please help me on this.

Upvotes: 2

Views: 734

Answers (1)

Jimmy
Jimmy

Reputation: 116

InteractiveViewer can help you to implement pinch, zoom. Check this out: https://api.flutter.dev/flutter/widgets/InteractiveViewer-class.html

If you need double tap to zoom, wrap InteractiveViewer with GestureDetector and implement onDoubleTap

onDoubleTapDown: _handleDoubleTapDown,
              onDoubleTap: () {
                kLogger.i('--> on double tap');
                _handleDoubleTap();
              },
_____

void _handleDoubleTapDown(TapDownDetails details) {
    _doubleTapDetails = details;
}

void _handleDoubleTap() {
    if (_transformationController.value != Matrix4.identity()) {
    _transformationController.value = Matrix4.identity();
} else {
      final position = _doubleTapDetails.localPosition;
      // For a 3x zoom
      _transformationController.value = Matrix4.identity()
        ..translate(-position.dx * 2, -position.dy * 2)
        ..scale(3.0);
      // Fox a 2x zoom
      // ..translate(-position.dx, -position.dy)
      // ..scale(2.0);
    }
}

Upvotes: 2

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