@netdata/charts/dist/es6/components/drawer/correlate/sparklineCanvas.js

Netdata frontend SDK and chart utilities

function _toConsumableArray(r) { return _arrayWithoutHoles(r) || _iterableToArray(r) || _unsupportedIterableToArray(r) || _nonIterableSpread(); }
function _nonIterableSpread() { throw new TypeError("Invalid attempt to spread non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method."); }
function _unsupportedIterableToArray(r, a) { if (r) { if ("string" == typeof r) return _arrayLikeToArray(r, a); var t = {}.toString.call(r).slice(8, -1); return "Object" === t && r.constructor && (t = r.constructor.name), "Map" === t || "Set" === t ? Array.from(r) : "Arguments" === t || /^(?:Ui|I)nt(?:8|16|32)(?:Clamped)?Array$/.test(t) ? _arrayLikeToArray(r, a) : void 0; } }
function _iterableToArray(r) { if ("undefined" != typeof Symbol && null != r[Symbol.iterator] || null != r["@@iterator"]) return Array.from(r); }
function _arrayWithoutHoles(r) { if (Array.isArray(r)) return _arrayLikeToArray(r); }
function _arrayLikeToArray(r, a) { (null == a || a > r.length) && (a = r.length); for (var e = 0, n = Array(a); e < a; e++) n[e] = r[e]; return n; }
import React, { memo, useCallback, useLayoutEffect, useRef } from "react";
import { Box } from "@netdata/netdata-ui";
import { jsx as _jsx } from "react/jsx-runtime";
var defaultWidth = 120;
var defaultHeight = 24;
var linePadding = 4;
export var getSparklinePoints = function getSparklinePoints(values, width, height) {
  var finiteValues = values.filter(Number.isFinite);
  if (!finiteValues.length) return [];
  var min = Math.min.apply(Math, _toConsumableArray(finiteValues));
  var max = Math.max.apply(Math, _toConsumableArray(finiteValues));
  var range = max - min;
  var xRange = Math.max(width - linePadding * 2, 1);
  var yRange = Math.max(height - linePadding * 2, 1);
  var divisor = Math.max(values.length - 1, 1);
  return values.map(function (value, index) {
    if (!Number.isFinite(value)) return null;
    return {
      x: linePadding + index / divisor * xRange,
      y: range ? linePadding + (max - value) / range * yRange : height / 2
    };
  });
};
export var drawSparkline = function drawSparkline(context, values, width, height, color) {
  var points = getSparklinePoints(values, width, height);
  context.clearRect(0, 0, width, height);
  if (!points.length) return;
  context.beginPath();
  var drawing = false;
  points.forEach(function (point) {
    if (!point) {
      drawing = false;
      return;
    }
    if (drawing) context.lineTo(point.x, point.y);else context.moveTo(point.x, point.y);
    drawing = true;
  });
  context.strokeStyle = color;
  context.lineWidth = 1;
  context.lineJoin = "round";
  context.lineCap = "round";
  context.stroke();
};
var SparklineCanvas = function SparklineCanvas(_ref) {
  var values = _ref.values,
    color = _ref.color,
    _ref$height = _ref.height,
    height = _ref$height === void 0 ? defaultHeight : _ref$height;
  var canvasRef = useRef(null);
  var frameRef = useRef(null);
  var draw = useCallback(function () {
    var canvas = canvasRef.current;
    if (!canvas) return;
    var width = Math.max(Math.round(canvas.getBoundingClientRect().width) || defaultWidth, 1);
    var ratio = window.devicePixelRatio || 1;
    var pixelWidth = Math.round(width * ratio);
    var pixelHeight = Math.round(height * ratio);
    if (canvas.width !== pixelWidth) canvas.width = pixelWidth;
    if (canvas.height !== pixelHeight) canvas.height = pixelHeight;
    var context = canvas.getContext("2d");
    if (!context) return;
    context.setTransform(ratio, 0, 0, ratio, 0, 0);
    drawSparkline(context, values, width, height, color);
  }, [color, height, values]);
  useLayoutEffect(function () {
    draw();
    if (typeof ResizeObserver === "undefined") return;
    var observer = new ResizeObserver(function () {
      if (frameRef.current) window.cancelAnimationFrame(frameRef.current);
      frameRef.current = window.requestAnimationFrame(draw);
    });
    observer.observe(canvasRef.current);
    return function () {
      observer.disconnect();
      if (frameRef.current) window.cancelAnimationFrame(frameRef.current);
    };
  }, [draw]);
  return /*#__PURE__*/_jsx(Box, {
    as: "canvas",
    ref: canvasRef,
    width: "100%",
    height: "".concat(height, "px"),
    role: "img",
    "aria-label": "Metric trend"
  });
};
export default /*#__PURE__*/memo(SparklineCanvas);