renderCandles method

void renderCandles(CanvasRenderingContext2D ctx)

Implementation

void renderCandles(CanvasRenderingContext2D ctx) {
  candlePoints.clear();
  for (var i = 0; i < candleData.length; i++) {
    final candleRow = candleData[i];
    final x = axis.style.leftMargin + axis.xStepPix * i;
    final x0 = x - axis.xStepPix / 2;
    final x1 = x + axis.xStepPix / 2;
    final y0 = height -
        axis.style.bottomMargin -
        (candleRow.open - axis.yFrom) / axis.yScaleValue;
    final y1 = height -
        axis.style.bottomMargin -
        (candleRow.close - axis.yFrom) / axis.yScaleValue;
    ctx
      ..beginPath()
      ..lineWidth = 1;
    if (candleRow.open > candleRow.close) {
      ctx
        ..fillStyle = '#dc3912'
        ..strokeStyle = '#dc3912'
        ..fillRect(x0, y1, x1 - x0, y0 - y1);
    } else {
      ctx
        ..fillStyle = '#33bb33'
        ..strokeStyle = '#33bb33'
        ..fillRect(x0, y0, x1 - x0, y1 - y0);
    }
    final midX = x + 0.5;
    var z0 = min(y0, y1);
    var z1 = max(y0, y1);
    if (candleRow.low < candleRow.open && candleRow.low < candleRow.close) {
      z0 = height -
          axis.style.bottomMargin -
          (candleRow.low - axis.yFrom) / axis.yScaleValue;
    }
    if (candleRow.high > candleRow.open && candleRow.high > candleRow.close) {
      z1 = height -
          axis.style.bottomMargin -
          (candleRow.high - axis.yFrom) / axis.yScaleValue;
    }
    ctx
      ..moveTo(midX, z0)
      ..lineTo(midX, z1)
      ..stroke();
    candlePoints.add(CandlePoint(x0, y0, x1, y1, candleRow));
  }
}