LineString.parseCoords constructor

LineString.parseCoords(String coordinates, { Pattern delimiter = ',', Coords type = Coords.xy, bool swapXY = false, bool singlePrecision = false, })

Parses a line string geometry from coordinates with coordinate values separated by delimiter.

Use the required optional type to explicitely set the coordinate type.

If swapXY is true, then swaps x and y for all positions in the result.

If singlePrecision is true, then coordinate values of positions are stored in Float32List instead of the Float64List (default).

Examples:

// a line string from 2D positions
LineString.parseCoords(
  // values for three (x, y) positions
  '10.0,20.0,12.5,22.5,15.0,25.0',
  type: Coords.xy,
);

// a line string from 3D positions
LineString.parseCoords(
  // values for three (x, y, z) positions
  '10.0,20.0,30.0,12.5,22.5,32.5,15.0,25.0,35.0',
  type: Coords.xyz,
);

// a line string from measured 2D positions
LineString.parseCoords(
  // values for three (x, y, m) positions
  '10.0,20.0,40.0,12.5,22.5,42.5,15.0,25.0,45.0',
  type: Coords.xym,
);

// a line string from measured 3D positions
LineString.parseCoords(
  // values for three (x, y, z, m) positions
  '10.0,20.0,30.0,40.0,12.5,22.5,32.5,42.5,15.0,25.0,35.0,45.0',
  type: Coords.xyzm,
);

// a line string from 2D positions using an alternative delimiter
LineString.parseCoords(
  // values for three (x, y) positions
  '10.0;20.0;12.5;22.5;15.0;25.0',
  type: Coords.xy,
  delimiter: ';',
);

// a line string from 2D positions with x before y
LineString.parseCoords(
  // values for three (x, y) positions
  '20.0,10.0,22.5,12.5,25.0,15.0',
  type: Coords.xy,
  swapXY: true,
);

// a line string from 2D positions with the internal storage using single
// precision floating point numbers (`Float32List` in this case)
LineString.parseCoords(
  // values for three (x, y) positions
  '10.0,20.0,12.5,22.5,15.0,25.0',
  type: Coords.xy,
  singlePrecision: true,
);

Implementation

factory LineString.parseCoords(
  String coordinates, {
  Pattern delimiter = ',',
  Coords type = Coords.xy,
  bool swapXY = false,
  bool singlePrecision = false,
}) {
  final str = coordinates.trim();
  if (str.isEmpty) {
    return LineString(PositionSeries.empty(type));
  }
  // NOTE: validate line string (at least two points)
  return LineString(
    parsePositionSeriesFromTextDim1(
      str,
      delimiter: delimiter,
      type: type,
      swapXY: swapXY,
      singlePrecision: singlePrecision,
    ),
  );
}