addNumbers method

void addNumbers(Canvas canvas, Size size)

Adds numbers to the graph indicating the grid steps.

Implementation

void addNumbers(Canvas canvas, Size size) {
  double xPositiveLength = size.width / 2 + graph.focusPoint.x;
  double yPositiveLength = (size.height / 2 + graph.focusPoint.y);

  var counter = 0;
  var pointsCountFromBeginning = (xPositiveLength / graph.gridStep).floor();

  // Determine how many grid steps are on the screen.
  for (double i = 0; i <= size.width; i += graph.gridStep) {
    var offset = Offset(
        (graph.gridStep * (pointsCountFromBeginning - counter)).toDouble() -
            4,
        0);
    if ((pointsCountFromBeginning - counter) != 0) {
      addObject(GraphLine(
          color: graph.gridColor,
          startOffset: Offset(
              offset.dx + 4, -(size.height / 2 + graph.focusPoint.y.abs())),
          endOffset: Offset(
              offset.dx + 4, size.height / 2 + graph.focusPoint.y.abs()),
          lineWidth: graph.gridWidth));
      addObject(GraphText(
          text: (pointsCountFromBeginning - counter).toString(),
          offset: offset));
    }
    counter++;
  }
  counter = 0;
  pointsCountFromBeginning = (yPositiveLength / graph.gridStep).floor();
  // Draw numbers on the y-axis.
  for (double i = 0; i <= size.height; i += graph.gridStep) {
    var offset = Offset(
        0,
        (graph.gridStep * (pointsCountFromBeginning - counter)).toDouble() -
            9);
    if (pointsCountFromBeginning - counter != 0) {
      addObject(GraphLine(
          color: graph.gridColor,
          startOffset: Offset(
              -(size.width / 2 + graph.focusPoint.x.abs()), offset.dy + 10),
          endOffset: Offset(
              (size.width / 2 + graph.focusPoint.x.abs()), offset.dy + 10),
          lineWidth: graph.gridWidth));
      addObject(GraphText(
        text: (-(pointsCountFromBeginning - counter)).toString(),
        offset: offset,
      ));
    }
    counter++;
  }
}