Flutter show image only if it exists in array

Question

Inside my widget I have some images. These images have a position. I would like to check if an image with a certain position exists, show it. Else the child of my GestureDetector should simply be nothing.

This is what I tried:

child: GestureDetector(
        onTap: () => print("tapped 1"),
        onScaleStart: (details) {
          _startingFocalPoint.value = details.focalPoint;
          _previousOffset.value = _offset.value;
          _previousZoom.value = _zoom.value;
        },
        onScaleUpdate: (details) {
          _zoom.value = _previousZoom.value * details.scale;
          final Offset normalizedOffset =
              (_startingFocalPoint.value - _previousOffset.value) /
                  _previousZoom.value;
          _offset.value =
              details.focalPoint - normalizedOffset * _zoom.value;
        },
        child: widget.images.where(
                    (image) => image.position == ImagePosition.ONE) !=
                null
            ? ClipPath(
                clipper: _Position1ClipperImage(),
                child: Transform(
                  transform: Matrix4.identity()
                    ..translate(_offset.value.dx, _offset.value.dy)
                    ..scale(_zoom.value),
                  child: Image.asset(
                      widget.images
                          .firstWhere(
                            (image) => image.position == ImagePosition.ONE,
                          )
                          .path,
                      width: widget.width,
                      height: widget.width,
                      fit: BoxFit.fill),
                ),
              )
            : null,
      ),

But if there is no image with ImagePosition.ONE , I get a Bad State: No elemnt- Error.

What am I missing here?

Let me know if you need any more details!

What you exactly want to do? You want to check image Position or image nullability? — Kudos, Mar 19 '21 at 15:18
@Kudos If the image exists, there should be a child with that image. Else there should be no child. I updated my qeustion — Chris, Mar 19 '21 at 15:26

score 0 · Answer 1 · answered Mar 19 '21 at 15:50

0

Try to update : null at the end with : SizedBox.shrink(). I think the problem is that you are giving a null as a child to the GestureDetector in case there is no image

answered Mar 19 '21 at 15:50

dariowskii

285
2
9

Can you share the stacktrace? – dariowskii Mar 19 '21 at 15:57

score 0 · Answer 2 · answered Mar 19 '21 at 16:06

0

I'm not actually because not having all the stack trace of your error but try replacing null by empty Container() if still not work please provide all your stacktrace for further help

answered Mar 19 '21 at 16:06

sherlock holmes

76
1
4

Flutter show image only if it exists in array

2 Answers2