Drop in replacement slider

[deakjahn]

A slider with a tape measure look:

There will be a snapping effect around the main ticks (the green ones, 45, 90, etc degrees in my sample).

The code is not very nice, I know, I needed to copy quite large a part of the original slider.dart just to be able to modify the drawing of the ticks. The original Slider simply calculates if there are too many ticks and decides not to draw at all in that case. Because we don't draw every tick now, this calculation is wrong.

You can easily use it in your existing example as:

TapeMeasureSlider(
  value: _rotation,
  min: -180,
  max: 180,
  divisions: 361,
  smallTickEvery: 5,
  bigTickEvery: 15,
  mainTickEvery: 45,
  mainSnapDistance: 3,
  tickColor: Colors.black54,
  onChanged: (angle) {
    setState(() {
      _rotation = angle.roundToDouble();
      controller.rotation = _rotation;
    });
  },
),

[deakjahn]

@xclud Changed the thumb coloring a bit, it's more visible now.

[xclud]

Thank you for whole lot of contributions. Please give me some time to review :)

[deakjahn]

Oh, I will, I will, but I probably go forth and take a look at that other, outdated PR with the rotate gesture because I need everything, including the kitchen sink. :-)