ImageProcess/native_vision/lib/widget/edge_detection_shape.dart

import 'dart:math';
import 'dart:ui';

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

import '../edge_painter.dart';
import 'magnifier.dart';
import 'touch_bubble.dart';

class EdgeDetectionShape extends StatefulWidget {
  const EdgeDetectionShape(
      {Key? key,
      required this.renderedImageSize,
      required this.originalImageSize,
      required this.edgeDetectionResult})
      : super(key: key);

  final Size renderedImageSize;
  final Size originalImageSize;
  final EdgeDetectionResult edgeDetectionResult;

  @override
  State createState() => _EdgeDetectionShapeState();
}

class _EdgeDetectionShapeState extends State<EdgeDetectionShape> {
  late double edgeDraggerSize;

  late EdgeDetectionResult edgeDetectionResult;
  late List<Offset> points;

  late double renderedImageWidth;
  late double renderedImageHeight;
  late double top;
  late double left;

  Offset? currentDragPosition;

  @override
  void didChangeDependencies() {
    double shortestSide = min(
        MediaQuery.of(context).size.width, MediaQuery.of(context).size.height);
    edgeDraggerSize = shortestSide / 12;
    super.didChangeDependencies();
  }

  @override
  void initState() {
    edgeDetectionResult = widget.edgeDetectionResult;
    _calculateDimensionValues();

    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Magnifier(
        visible: currentDragPosition != null,
        position: currentDragPosition,
        child: Stack(
          children: [
            _getTouchBubbles(),
            CustomPaint(
                painter: EdgePainter(
                    points: points,
                    color: Theme.of(context)
                        .colorScheme
                        .secondary
                        .withOpacity(0.5)))
          ],
        ));
  }

  void _calculateDimensionValues() {
    top = 0.0;
    left = 0.0;

    double widthFactor =
        widget.renderedImageSize.width / widget.originalImageSize.width;
    double heightFactor =
        widget.renderedImageSize.height / widget.originalImageSize.height;
    double sizeFactor = min(widthFactor, heightFactor);

    renderedImageHeight = widget.originalImageSize.height * sizeFactor;
    top = ((widget.renderedImageSize.height - renderedImageHeight) / 2);

    renderedImageWidth = widget.originalImageSize.width * sizeFactor;
    left = ((widget.renderedImageSize.width - renderedImageWidth) / 2);
  }

  Offset _getNewPositionAfterDrag(
      Offset position, double renderedImageWidth, double renderedImageHeight) {
    return Offset(
        position.dx / renderedImageWidth, position.dy / renderedImageHeight);
  }

  Offset _clampOffset(Offset givenOffset) {
    double absoluteX = givenOffset.dx * renderedImageWidth;
    double absoluteY = givenOffset.dy * renderedImageHeight;

    return Offset(absoluteX.clamp(0.0, renderedImageWidth) / renderedImageWidth,
        absoluteY.clamp(0.0, renderedImageHeight) / renderedImageHeight);
  }

  Widget _getTouchBubbles() {
    points = [
      Offset(left + edgeDetectionResult.topLeft.dx * renderedImageWidth,
          top + edgeDetectionResult.topLeft.dy * renderedImageHeight),
      Offset(left + edgeDetectionResult.topRight.dx * renderedImageWidth,
          top + edgeDetectionResult.topRight.dy * renderedImageHeight),
      Offset(left + edgeDetectionResult.bottomRight.dx * renderedImageWidth,
          top + (edgeDetectionResult.bottomRight.dy * renderedImageHeight)),
      Offset(left + edgeDetectionResult.bottomLeft.dx * renderedImageWidth,
          top + edgeDetectionResult.bottomLeft.dy * renderedImageHeight),
      Offset(left + edgeDetectionResult.topLeft.dx * renderedImageWidth,
          top + edgeDetectionResult.topLeft.dy * renderedImageHeight),
    ];

    onDragFinished() {
      currentDragPosition = null;
      setState(() {});
    }

    return SizedBox(
      width: widget.renderedImageSize.width,
      height: widget.renderedImageSize.height,
      child: Stack(
        children: [
          Positioned(
              left: points[0].dx - (edgeDraggerSize / 2),
              top: points[0].dy - (edgeDraggerSize / 2),
              child: TouchBubble(
                  size: edgeDraggerSize,
                  onDrag: (position) {
                    setState(() {
                      currentDragPosition = Offset(points[0].dx, points[0].dy);
                      Offset newTopLeft = _getNewPositionAfterDrag(
                          position, renderedImageWidth, renderedImageHeight);
                      edgeDetectionResult.topLeft = _clampOffset(
                          edgeDetectionResult.topLeft + newTopLeft);
                    });
                  },
                  onDragFinished: onDragFinished)),
          Positioned(
              left: points[1].dx - (edgeDraggerSize / 2),
              top: points[1].dy - (edgeDraggerSize / 2),
              child: TouchBubble(
                  size: edgeDraggerSize,
                  onDrag: (position) {
                    setState(() {
                      Offset newTopRight = _getNewPositionAfterDrag(
                          position, renderedImageWidth, renderedImageHeight);
                      edgeDetectionResult.topRight = _clampOffset(
                          edgeDetectionResult.topRight + newTopRight);
                      currentDragPosition = Offset(points[1].dx, points[1].dy);
                    });
                  },
                  onDragFinished: onDragFinished)),
          Positioned(
              left: points[2].dx - (edgeDraggerSize / 2),
              top: points[2].dy - (edgeDraggerSize / 2),
              child: TouchBubble(
                  size: edgeDraggerSize,
                  onDrag: (position) {
                    setState(() {
                      Offset newBottomRight = _getNewPositionAfterDrag(
                          position, renderedImageWidth, renderedImageHeight);
                      edgeDetectionResult.bottomRight = _clampOffset(
                          edgeDetectionResult.bottomRight + newBottomRight);
                      currentDragPosition = Offset(points[2].dx, points[2].dy);
                    });
                  },
                  onDragFinished: onDragFinished)),
          Positioned(
              left: points[3].dx - (edgeDraggerSize / 2),
              top: points[3].dy - (edgeDraggerSize / 2),
              child: TouchBubble(
                  size: edgeDraggerSize,
                  onDrag: (position) {
                    setState(() {
                      Offset newBottomLeft = _getNewPositionAfterDrag(
                          position, renderedImageWidth, renderedImageHeight);
                      edgeDetectionResult.bottomLeft = _clampOffset(
                          edgeDetectionResult.bottomLeft + newBottomLeft);
                      currentDragPosition = Offset(points[3].dx, points[3].dy);
                    });
                  },
                  onDragFinished: onDragFinished)),
        ],
      ),
    );
  }
}