370 lines
11 KiB
JavaScript
370 lines
11 KiB
JavaScript
// https://observablehq.com/@d3/color-legend@808
|
||
function _1(md){return(
|
||
md`# Color Legend
|
||
|
||
A simple legend for a [color scale](/@d3/color-schemes). Supports [continuous](/@d3/continuous-scales), [sequential](/@d3/sequential-scales), [diverging](/@d3/diverging-scales), [quantize, quantile, threshold](/@d3/quantile-quantize-and-threshold-scales) and [ordinal](/@d3/d3-scaleordinal) scales. To use:
|
||
|
||
~~~js
|
||
import {Legend, Swatches} from "@d3/color-legend"
|
||
~~~
|
||
|
||
Then call the legend function as shown below. (For ordinal scales, also consider the swatches function.)`
|
||
)}
|
||
|
||
function _2(Legend,d3){return(
|
||
Legend(d3.scaleSequential([0, 100], d3.interpolateViridis), {
|
||
title: "Temperature (°F)"
|
||
})
|
||
)}
|
||
|
||
function _3(Legend,d3){return(
|
||
Legend(d3.scaleSequentialSqrt([0, 1], d3.interpolateTurbo), {
|
||
title: "Speed (kts)"
|
||
})
|
||
)}
|
||
|
||
function _4(Legend,d3){return(
|
||
Legend(d3.scaleDiverging([-0.1, 0, 0.1], d3.interpolatePiYG), {
|
||
title: "Daily change",
|
||
tickFormat: "+%"
|
||
})
|
||
)}
|
||
|
||
function _5(Legend,d3){return(
|
||
Legend(d3.scaleDivergingSqrt([-0.1, 0, 0.1], d3.interpolateRdBu), {
|
||
title: "Daily change",
|
||
tickFormat: "+%"
|
||
})
|
||
)}
|
||
|
||
function _6(Legend,d3){return(
|
||
Legend(d3.scaleSequentialLog([1, 100], d3.interpolateBlues), {
|
||
title: "Energy (joules)",
|
||
ticks: 10
|
||
})
|
||
)}
|
||
|
||
function _7(Legend,d3){return(
|
||
Legend(d3.scaleSequentialQuantile(d3.range(100).map(() => Math.random() ** 2), d3.interpolateBlues), {
|
||
title: "Quantile",
|
||
tickFormat: ".2f"
|
||
})
|
||
)}
|
||
|
||
function _8(Legend,d3){return(
|
||
Legend(d3.scaleSqrt([-100, 0, 100], ["blue", "white", "red"]), {
|
||
title: "Temperature (°C)"
|
||
})
|
||
)}
|
||
|
||
function _9(Legend,d3){return(
|
||
Legend(d3.scaleQuantize([1, 10], d3.schemePurples[9]), {
|
||
title: "Unemployment rate (%)"
|
||
})
|
||
)}
|
||
|
||
function _10(Legend,d3){return(
|
||
Legend(d3.scaleQuantile(d3.range(1000).map(d3.randomNormal(100, 20)), d3.schemeSpectral[9]), {
|
||
title: "Height (cm)",
|
||
tickFormat: ".0f"
|
||
})
|
||
)}
|
||
|
||
function _11(Legend,d3){return(
|
||
Legend(d3.scaleThreshold([2.5, 3.1, 3.5, 3.9, 6, 7, 8, 9.5], d3.schemeRdBu[9]), {
|
||
title: "Unemployment rate (%)",
|
||
tickSize: 0
|
||
})
|
||
)}
|
||
|
||
function _12(Legend,d3){return(
|
||
Legend(d3.scaleOrdinal(["<10", "10-19", "20-29", "30-39", "40-49", "50-59", "60-69", "70-79", "≥80"], d3.schemeSpectral[10]), {
|
||
title: "Age (years)",
|
||
tickSize: 0
|
||
})
|
||
)}
|
||
|
||
function _13(md){return(
|
||
md`But wait, there’s more!
|
||
|
||
How about swatches for ordinal color scales? Both variable-width swatches and [column layout](https://developer.mozilla.org/en-US/docs/Web/CSS/columns) are supported.`
|
||
)}
|
||
|
||
function _14(Swatches,d3){return(
|
||
Swatches(d3.scaleOrdinal(["blueberries", "oranges", "apples"], d3.schemeCategory10))
|
||
)}
|
||
|
||
function _15(Swatches,d3){return(
|
||
Swatches(d3.scaleOrdinal(["Wholesale and Retail Trade", "Manufacturing", "Leisure and hospitality", "Business services", "Construction", "Education and Health", "Government", "Finance", "Self-employed", "Other"], d3.schemeTableau10), {
|
||
columns: "180px"
|
||
})
|
||
)}
|
||
|
||
function _16(md){return(
|
||
md`---
|
||
|
||
## Implementation`
|
||
)}
|
||
|
||
function _Legend(d3){return(
|
||
function Legend(color, {
|
||
title,
|
||
tickSize = 6,
|
||
width = 320,
|
||
height = 44 + tickSize,
|
||
marginTop = 18,
|
||
marginRight = 0,
|
||
marginBottom = 16 + tickSize,
|
||
marginLeft = 0,
|
||
ticks = width / 64,
|
||
tickFormat,
|
||
tickValues
|
||
} = {}) {
|
||
|
||
function ramp(color, n = 256) {
|
||
const canvas = document.createElement("canvas");
|
||
canvas.width = n;
|
||
canvas.height = 1;
|
||
const context = canvas.getContext("2d");
|
||
for (let i = 0; i < n; ++i) {
|
||
context.fillStyle = color(i / (n - 1));
|
||
context.fillRect(i, 0, 1, 1);
|
||
}
|
||
return canvas;
|
||
}
|
||
|
||
const svg = d3.create("svg")
|
||
.attr("width", width)
|
||
.attr("height", height)
|
||
.attr("viewBox", [0, 0, width, height])
|
||
.style("overflow", "visible")
|
||
.style("display", "block");
|
||
|
||
let tickAdjust = g => g.selectAll(".tick line").attr("y1", marginTop + marginBottom - height);
|
||
let x;
|
||
|
||
// Continuous
|
||
if (color.interpolate) {
|
||
const n = Math.min(color.domain().length, color.range().length);
|
||
|
||
x = color.copy().rangeRound(d3.quantize(d3.interpolate(marginLeft, width - marginRight), n));
|
||
|
||
svg.append("image")
|
||
.attr("x", marginLeft)
|
||
.attr("y", marginTop)
|
||
.attr("width", width - marginLeft - marginRight)
|
||
.attr("height", height - marginTop - marginBottom)
|
||
.attr("preserveAspectRatio", "none")
|
||
.attr("xlink:href", ramp(color.copy().domain(d3.quantize(d3.interpolate(0, 1), n))).toDataURL());
|
||
}
|
||
|
||
// Sequential
|
||
else if (color.interpolator) {
|
||
x = Object.assign(color.copy()
|
||
.interpolator(d3.interpolateRound(marginLeft, width - marginRight)),
|
||
{range() { return [marginLeft, width - marginRight]; }});
|
||
|
||
svg.append("image")
|
||
.attr("x", marginLeft)
|
||
.attr("y", marginTop)
|
||
.attr("width", width - marginLeft - marginRight)
|
||
.attr("height", height - marginTop - marginBottom)
|
||
.attr("preserveAspectRatio", "none")
|
||
.attr("xlink:href", ramp(color.interpolator()).toDataURL());
|
||
|
||
// scaleSequentialQuantile doesn’t implement ticks or tickFormat.
|
||
if (!x.ticks) {
|
||
if (tickValues === undefined) {
|
||
const n = Math.round(ticks + 1);
|
||
tickValues = d3.range(n).map(i => d3.quantile(color.domain(), i / (n - 1)));
|
||
}
|
||
if (typeof tickFormat !== "function") {
|
||
tickFormat = d3.format(tickFormat === undefined ? ",f" : tickFormat);
|
||
}
|
||
}
|
||
}
|
||
|
||
// Threshold
|
||
else if (color.invertExtent) {
|
||
const thresholds
|
||
= color.thresholds ? color.thresholds() // scaleQuantize
|
||
: color.quantiles ? color.quantiles() // scaleQuantile
|
||
: color.domain(); // scaleThreshold
|
||
|
||
const thresholdFormat
|
||
= tickFormat === undefined ? d => d
|
||
: typeof tickFormat === "string" ? d3.format(tickFormat)
|
||
: tickFormat;
|
||
|
||
x = d3.scaleLinear()
|
||
.domain([-1, color.range().length - 1])
|
||
.rangeRound([marginLeft, width - marginRight]);
|
||
|
||
svg.append("g")
|
||
.selectAll("rect")
|
||
.data(color.range())
|
||
.join("rect")
|
||
.attr("x", (d, i) => x(i - 1))
|
||
.attr("y", marginTop)
|
||
.attr("width", (d, i) => x(i) - x(i - 1))
|
||
.attr("height", height - marginTop - marginBottom)
|
||
.attr("fill", d => d);
|
||
|
||
tickValues = d3.range(thresholds.length);
|
||
tickFormat = i => thresholdFormat(thresholds[i], i);
|
||
}
|
||
|
||
// Ordinal
|
||
else {
|
||
x = d3.scaleBand()
|
||
.domain(color.domain())
|
||
.rangeRound([marginLeft, width - marginRight]);
|
||
|
||
svg.append("g")
|
||
.selectAll("rect")
|
||
.data(color.domain())
|
||
.join("rect")
|
||
.attr("x", x)
|
||
.attr("y", marginTop)
|
||
.attr("width", Math.max(0, x.bandwidth() - 1))
|
||
.attr("height", height - marginTop - marginBottom)
|
||
.attr("fill", color);
|
||
|
||
tickAdjust = () => {};
|
||
}
|
||
|
||
svg.append("g")
|
||
.attr("transform", `translate(0,${height - marginBottom})`)
|
||
.call(d3.axisBottom(x)
|
||
.ticks(ticks, typeof tickFormat === "string" ? tickFormat : undefined)
|
||
.tickFormat(typeof tickFormat === "function" ? tickFormat : undefined)
|
||
.tickSize(tickSize)
|
||
.tickValues(tickValues))
|
||
.call(tickAdjust)
|
||
.call(g => g.select(".domain").remove())
|
||
.call(g => g.append("text")
|
||
.attr("x", marginLeft)
|
||
.attr("y", marginTop + marginBottom - height - 6)
|
||
.attr("fill", "currentColor")
|
||
.attr("text-anchor", "start")
|
||
.attr("font-weight", "bold")
|
||
.attr("class", "title")
|
||
.text(title));
|
||
|
||
return svg.node();
|
||
}
|
||
)}
|
||
|
||
function _legend(Legend){return(
|
||
function legend({color, ...options}) {
|
||
return Legend(color, options);
|
||
}
|
||
)}
|
||
|
||
function _Swatches(d3,htl){return(
|
||
function Swatches(color, {
|
||
columns = null,
|
||
format,
|
||
unknown: formatUnknown,
|
||
swatchSize = 15,
|
||
swatchWidth = swatchSize,
|
||
swatchHeight = swatchSize,
|
||
marginLeft = 0
|
||
} = {}) {
|
||
const id = `-swatches-${Math.random().toString(16).slice(2)}`;
|
||
const unknown = formatUnknown == null ? undefined : color.unknown();
|
||
const unknowns = unknown == null || unknown === d3.scaleImplicit ? [] : [unknown];
|
||
const domain = color.domain().concat(unknowns);
|
||
if (format === undefined) format = x => x === unknown ? formatUnknown : x;
|
||
|
||
function entity(character) {
|
||
return `&#${character.charCodeAt(0).toString()};`;
|
||
}
|
||
|
||
if (columns !== null) return htl.html`<div style="display: flex; align-items: center; margin-left: ${+marginLeft}px; min-height: 33px; font: 10px sans-serif;">
|
||
<style>
|
||
|
||
.${id}-item {
|
||
break-inside: avoid;
|
||
display: flex;
|
||
align-items: center;
|
||
padding-bottom: 1px;
|
||
}
|
||
|
||
.${id}-label {
|
||
white-space: nowrap;
|
||
overflow: hidden;
|
||
text-overflow: ellipsis;
|
||
max-width: calc(100% - ${+swatchWidth}px - 0.5em);
|
||
}
|
||
|
||
.${id}-swatch {
|
||
width: ${+swatchWidth}px;
|
||
height: ${+swatchHeight}px;
|
||
margin: 0 0.5em 0 0;
|
||
}
|
||
|
||
</style>
|
||
<div style=${{width: "100%", columns}}>${domain.map(value => {
|
||
const label = `${format(value)}`;
|
||
return htl.html`<div class=${id}-item>
|
||
<div class=${id}-swatch style=${{background: color(value)}}></div>
|
||
<div class=${id}-label title=${label}>${label}</div>
|
||
</div>`;
|
||
})}
|
||
</div>
|
||
</div>`;
|
||
|
||
return htl.html`<div style="display: flex; align-items: center; min-height: 33px; margin-left: ${+marginLeft}px; font: 10px sans-serif;">
|
||
<style>
|
||
|
||
.${id} {
|
||
display: inline-flex;
|
||
align-items: center;
|
||
margin-right: 1em;
|
||
}
|
||
|
||
.${id}::before {
|
||
content: "";
|
||
width: ${+swatchWidth}px;
|
||
height: ${+swatchHeight}px;
|
||
margin-right: 0.5em;
|
||
background: var(--color);
|
||
}
|
||
|
||
</style>
|
||
<div>${domain.map(value => htl.html`<span class="${id}" style="--color: ${color(value)}">${format(value)}</span>`)}</div>`;
|
||
}
|
||
)}
|
||
|
||
function _swatches(Swatches){return(
|
||
function swatches({color, ...options}) {
|
||
return Swatches(color, options);
|
||
}
|
||
)}
|
||
|
||
export default function define(runtime, observer) {
|
||
const main = runtime.module();
|
||
main.variable(observer()).define(["md"], _1);
|
||
main.variable(observer()).define(["Legend","d3"], _2);
|
||
main.variable(observer()).define(["Legend","d3"], _3);
|
||
main.variable(observer()).define(["Legend","d3"], _4);
|
||
main.variable(observer()).define(["Legend","d3"], _5);
|
||
main.variable(observer()).define(["Legend","d3"], _6);
|
||
main.variable(observer()).define(["Legend","d3"], _7);
|
||
main.variable(observer()).define(["Legend","d3"], _8);
|
||
main.variable(observer()).define(["Legend","d3"], _9);
|
||
main.variable(observer()).define(["Legend","d3"], _10);
|
||
main.variable(observer()).define(["Legend","d3"], _11);
|
||
main.variable(observer()).define(["Legend","d3"], _12);
|
||
main.variable(observer()).define(["md"], _13);
|
||
main.variable(observer()).define(["Swatches","d3"], _14);
|
||
main.variable(observer()).define(["Swatches","d3"], _15);
|
||
main.variable(observer()).define(["md"], _16);
|
||
main.variable(observer("Legend")).define("Legend", ["d3"], _Legend);
|
||
main.variable(observer("legend")).define("legend", ["Legend"], _legend);
|
||
main.variable(observer("Swatches")).define("Swatches", ["d3","htl"], _Swatches);
|
||
main.variable(observer("swatches")).define("swatches", ["Swatches"], _swatches);
|
||
return main;
|
||
}
|