Flutter load image with slider laggy - flutter

Question

I would like to develop a slider to adjust the brightness of the image instantly.
Just like want Instagram did.
I adopted StreamBuilder to retrieve the image after the brightness is adjusted.
But the image keeps showing image -> black -> image -> black when I am moving the slider.
And the slider is laggy, keep jumping when I move.
Show Image code:
child: StreamBuilder(
stream: _imageRefresher.imageRefreshStream,
initialData: widget.post.imagesFileList[0].imageFile,
builder: (context, snap) {
return PageView.builder(
controller: PageController(
initialPage: 0
),
scrollDirection: Axis.horizontal,
itemCount: widget.post.imagesFileList.length,
onPageChanged: (index) {
setState(() {
listIndex = index;
print(listIndex);
});
},
itemBuilder: (BuildContext context, int index) {
return Hero(
tag: 'heroFeatured$index',
child: Container(
decoration: new BoxDecoration(
image: new DecorationImage(
fit: BoxFit.cover,
image: FileImage(snap.data)
),
),
),
);
},
);
}
)
Slider code:
child:Slider(
label: 'Brightness',
min: -100,
max: 100,
value: widget.post.imagesFileList[listIndex].brightness,
onChanged: (value) {
print(value);
setState(() {
widget.post.imagesFileList[listIndex].brightness = value;
});
_imageRefresher.updatePicutre(widget.post.imagesFileList[listIndex].imagePath, value);
//updatePicutre(widget.post.imagesFileList[listIndex].brightness, value);
},
),
StreamController code:
class ImageRefresher {
StreamController<File> _controller;
final File imageFile;
ImageRefresher({this.imageFile}){
_controller = StreamController();
}
Stream<File> get imageRefreshStream => _controller.stream;
void updatePicutre(String imagePath, double brightness) async{
File f = await FlutterNativeImage.adjustBrightness(imagePath, brightness);
_controller.sink.add(f);
}
dispose() {
_controller.close();
}
}

Answer 1

I think StreamBuildier wasn't designed to support image updates. Check out the Texture class from Flutter dev it might be better suited for this.
https://api.flutter.dev/flutter/widgets/Texture-class.html