view weather_server/static/graph.js @ 27:99b0759386b1

index: Add meta-viewport declaration.
author Paul Fisher <paul@pfish.zone>
date Sun, 10 Nov 2019 23:48:38 -0500
parents 47987502bf4c
children f817fa785c93
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var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
    return new (P || (P = Promise))(function (resolve, reject) {
        function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
        function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
        step((generator = generator.apply(thisArg, _arguments || [])).next());
    });
};
define("math", ["require", "exports"], function (require, exports) {
    "use strict";
    Object.defineProperty(exports, "__esModule", { value: true });
    /** Converts Celsius to Fahrenheit. */
    function cToF(tempC) {
        return tempC * 9 / 5 + 32;
    }
    exports.cToF = cToF;
    const MAGNUS_B = 17.62;
    const MAGNUS_C = 243.12;
    /** The gamma function to calculate dew point. */
    function gammaFn(tempC, rhPct) {
        return Math.log(rhPct / 100) + MAGNUS_B * tempC / (MAGNUS_C + tempC);
    }
    /** Calculates the dew point. */
    function dewPointC(tempC, rhPct) {
        const gamma = gammaFn(tempC, rhPct);
        return MAGNUS_C * gamma / (MAGNUS_B - gamma);
    }
    exports.dewPointC = dewPointC;
});
define("graph", ["require", "exports", "math"], function (require, exports, math_1) {
    "use strict";
    Object.defineProperty(exports, "__esModule", { value: true });
    /** The amount of time we will draw on the graph. */
    const HISTORY_SECONDS = 60 * 60 * 4;
    /** The amount of buffer room we will request before HISTORY_SECONDS. */
    const BUFFER_SECONDS = 300;
    /**
     * Sets up everything.
     * @param tempElement The element where temperature data is.
     * @param dewPointElement The element where the dew point is.
     */
    function setUp(root, tempElement, dewPointElement) {
        return __awaiter(this, void 0, void 0, function* () {
            const nowTS = new Date().getTime() / 1000;
            const startTS = nowTS - HISTORY_SECONDS;
            const query = new URL('?', location.href);
            query.pathname = query.pathname + '/recent';
            query.searchParams.set('seconds', String(HISTORY_SECONDS + BUFFER_SECONDS));
            const results = yield fetch(query.href);
            if (!results.ok)
                return;
            const data = yield results.json();
            const readings = data.readings;
            if (readings.length === 0)
                return;
            root.classList.remove('plain');
            root.classList.add('fancy');
            const tempsF = readings.map(s => [s.sample_time, math_1.cToF(s.temp_c)]);
            const dewPointsF = readings.map(s => [s.sample_time, math_1.cToF(math_1.dewPointC(s.temp_c, s.rh_pct))]);
            setUpElement(tempElement, [startTS, nowTS], tempsF);
            setUpElement(dewPointElement, [startTS, nowTS], dewPointsF);
        });
    }
    exports.setUp = setUp;
    /**
     * Sets up charting for this element.
     * @param element The element to put a graph in.
     * @param timeRange The `[start, end]` of the time range.
     * @param data The data to chart.
     */
    function setUpElement(element, timeRange, data) {
        if (data.length === 0)
            return;
        const chart = new Chart(element, timeRange, data);
        chart.resize();
        addEventListener('resize', () => chart.resize());
    }
    /** The number of degrees that the graph shows vertically. */
    const Y_DEGREE_RANGE = 10;
    const LINE_WIDTH_PX = 2;
    const FONT_SIZE = '40px';
    class Chart {
        /**
         * Creates a new chart.
         * @param element The parent element to create `<canvas>`-based chart in.
         * @param timeRange `[start, end]` of the range to chart as Unix timestamps.
         * @param data The data to chart.
         */
        constructor(element, timeRange, data) {
            this.element = element;
            this.timeRange = timeRange;
            this.data = data;
            this.canvas = document.createElement('canvas');
            this.element.insertBefore(this.canvas, element.firstChild);
            const unit = element.getElementsByClassName('unit')[0];
            this.unit = unit && unit.textContent || '';
        }
        resize() {
            const dpr = self.devicePixelRatio || 1;
            const [w, h] = this.size();
            const pxSize = [w * dpr, h * dpr];
            this.canvas.width = pxSize[0];
            this.canvas.height = pxSize[1];
            const ctx = this.canvas.getContext('2d');
            ctx.clearRect(0, 0, pxSize[0], pxSize[1]);
            ctx.scale(dpr, dpr);
            this.redraw(ctx);
        }
        redraw(ctx) {
            const stroke = getComputedStyle(this.element).color;
            const family = getComputedStyle(this.element).fontFamily;
            ctx.strokeStyle = stroke;
            ctx.lineJoin = 'round';
            ctx.lineWidth = LINE_WIDTH_PX;
            ctx.font = `bold ${FONT_SIZE} ${family}`;
            const yRange = calculateYRange(this.data.map(d => d[1]));
            const [fullW, fullH] = this.size();
            const [xPad, yMargin] = this.measureMargin(ctx);
            const graphSize = [fullW - xPad, fullH];
            ctx.beginPath();
            for (const pt of this.data) {
                const projected = project(pt, graphSize, this.timeRange, yRange);
                ctx.lineTo(...projected);
            }
            ctx.stroke();
            ctx.beginPath();
            const lastPt = this.data[this.data.length - 1];
            const center = project(lastPt, graphSize, this.timeRange, yRange);
            ctx.ellipse(center[0], center[1], 1.5 * LINE_WIDTH_PX, 1.5 * LINE_WIDTH_PX, 0, 0, 2 * Math.PI);
            ctx.fillStyle = getComputedStyle(this.element).backgroundColor;
            ctx.fill();
            ctx.stroke();
            ctx.fillStyle = stroke;
            ctx.textAlign = 'left';
            ctx.textBaseline = 'top';
            ctx.fillText(`${niceNumber(lastPt[1])} ${this.unit}`, center[0] + 5 * LINE_WIDTH_PX, center[1] + yMargin);
        }
        measureMargin(ctx) {
            const bbox = ctx.measureText(`−99 ${this.unit}`);
            const margin = 5 * LINE_WIDTH_PX + // margin to text
                bbox.width + // max (?) width of text
                16; // Pixel margin to wall.
            return [margin, -31.5 / 2];
        }
        size() {
            const cssSize = this.element.getBoundingClientRect();
            return [cssSize.width, cssSize.height];
        }
    }
    function niceNumber(n) {
        return Math.round(n).toLocaleString('en-us').replace('-', '−');
    }
    /** The closest that the last point will be allowed to get to the edge. */
    const EDGE_FRACTION = 0.125;
    /**
     * Determines what the Y range of the chart should be.
     * @param ys The Y values of the chart.
     * @return The lowest and highest values of the range.
     */
    function calculateYRange(ys) {
        const yMax = Math.max(...ys);
        const yMin = Math.min(...ys);
        const yMid = (yMin + yMax) / 2;
        const lastY = ys[ys.length - 1];
        const yLo = yMid - Y_DEGREE_RANGE / 2;
        const yProportion = Math.max(Math.min((lastY - yLo) / Y_DEGREE_RANGE, 1 - EDGE_FRACTION), EDGE_FRACTION);
        const rangeLo = lastY - yProportion * Y_DEGREE_RANGE;
        return [rangeLo, rangeLo + Y_DEGREE_RANGE];
    }
    /**
     * Projects a Cartesian coordinate into Canvas space.
     *
     * @param coord The `[x, y]` coordinate to project.
     * @param size The `[width, height]` of the context.
     * @param xRange The range of X values in the context.
     * @param yRange The range of Y values in the context.
     * @return The `[x, y]` coordinate in Canvas space.
     */
    function project(coord, size, xRange, yRange) {
        const [x, y] = coord;
        const [xMin, xMax] = xRange;
        const xSpan = xMax - xMin;
        const [yMin, yMax] = yRange;
        const ySpan = yMax - yMin;
        const [xSize, ySize] = size;
        return [
            (x - xMin) / xSpan * xSize,
            (yMax - y) / ySpan * ySize,
        ];
    }
});
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