I am creating a waste management app where user can take image then this Image is shown in a screen where user can draw rectangles around trash. I am using Stack with Custom Paints for doing this. But I am not able to get position of rectangles because this image is then to be sent to a ML model for further evolution. I am using GetX

Here is my code snippet:

body: SizedBox(
        width: double.maxFinite,
        child: GetBuilder(builder: (DetectTrashController controller) {
          return Stack(
            children: [
              GestureDetector(
                onPanStart: (details) {
                  controller.startDrawing(details.localPosition);
                },
                onPanUpdate: (details) {
                  controller.updateDrawing(details.localPosition);
                },
                onPanEnd: (details) {
                  controller.endDrawing();
                },
                child: Stack(
                  children: [
                    Image.file(
                      fit: BoxFit.cover,
                      height: double.maxFinite,
                      width: double.maxFinite,
                      File(controller.imagePath!),
                    ),
                    SizedBox(
                      height: controller.image!.height.toDouble(),
                      width: controller.image!.width.toDouble(),
                      child: CustomPaint(
                        key: controller.widgetKey,
                        painter: RectanglePainter(
                          controller.rectangles,
                          controller.currentRect,
                          controller.image!,
                        ),
                        size: Size.infinite,
                      ),
                    ),
                    Padding(
                      padding: const EdgeInsets.all(8),
                      child: Align(
                        alignment: Alignment.topLeft,
                        child: InkWell(
                          onTap: () {
                            controller.toggleDrawing();
                          },
                          child: Container(
                              height: 31.v,
                              width: 161.h,
                              color: whiteColor,
                              child: Obx(
                                () => Row(
                                  mainAxisAlignment:
                                      MainAxisAlignment.spaceEvenly,
                                  children: [
                                    Checkbox(
                                      checkColor: whiteColor,
                                      fillColor: MaterialStatePropertyAll(
                                          controller.drawingEnabled.value
                                              ? Colors.black
                                              : null),
                                      shape: controller.drawingEnabled.value
                                          ? const CircleBorder()
                                          : null,
                                      value: controller.drawingEnabled.value,
                                      onChanged: (value) {
                                        controller.toggleDrawing();
                                      },
                                    ),
                                    Text(controller.drawingEnabled.value
                                        ? "Cancel Selection"
                                        : "Draw Selection"),
                                  ],
                                ),
                              )),
                        ),
                      ),
                    ),
                  ],
                ),
              ),
              Padding(
                padding: EdgeInsets.only(bottom: 10.v),
                child: Align(
                  alignment: Alignment.bottomCenter,
                  child: CustomElevetedButton(
                    onPressed: () {},
                    backgroundColor: primaryColor,
                    child: "Update",
                    size: Size(189.h, 40.v),
                  ),
                ),
              )
            ],
          );
        }),
      ),

CustomPaint Class

class RectanglePainter extends CustomPainter {
  final List<Rectangle> rectangles;
  final Rect? currentRect;
  

  RectanglePainter(this.rectangles, this.currentRect,);

  @override
  void paint(Canvas canvas, Size size) {
    final paint = Paint()
      ..color = Colors.red
      ..strokeWidth = 2
      ..style = PaintingStyle.stroke;
  

    // Draw existing rectangles
    for (var rectangle in rectangles) {
      canvas.drawRect(rectangle.rect, paint);
    }

    // Draw the current rectangle being dragged
    if (currentRect != null) {
      canvas.drawRect(currentRect!, paint);
    }
  }

  @override
  bool shouldRepaint(covariant CustomPainter oldDelegate) {
    return true; // Repaint every time to reflect changes
  }
}

OutPut

Output