Stave doesn't render dead-center

[heyaphra]

Summary

While the widget is behaving as expected (the bottom staff line renders at (0, 0) in the coordinate system), this causes issues when centering the widget within a container. Rendering dead-center would be useful for displaying figures for music theory education.

Example of the issue:

Example code:

@override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Simple Sheet Music Example')),
      body: Center(
        child: Container(
          decoration: BoxDecoration(border: Border.all()),
          width: 200.0,
          height: 200.0,
          child: Align(
            alignment: Alignment.center,
            child: SimpleSheetMusic(
              initialClef: initialClef,
              height: 100,
              width: 100,
              staffs: [staff],
            ),
          ),
        ),
      ),
    );
  }
}

[heyaphra]

Update: I was able to "fix" this problem by changing the staffLineCenterY in built_staff.dart:

final measureOnCanvas = measure.placeOnCanvas(
    staffLineCenterY + staffLineCenterY / 2),
    currentX,
);

Not sure if this would break any other intended use cases.

[tomoyu719]

Thank you for the Issue and kind example. We will address this issue as soon as possible. Incidentally, how about using the uppermost part as the origin of the Y-coordinate? (in this case, the topmost part of the G clef)

[heyaphra]

I'm concerned that if the uppermost part were used as the origin then the staff would be off-center inside of its container. Are there any benefits conferred by that approach that I'm not seeing?

Here's a picture to go along with the code example that I modified:

[tomoyu719]

I was a little mistaken. I thought it would cause problems with rendering multi-stage Stave, but your method will work. I will put out a revised version in a few more days.