excalidraw/src/components/ColorPicker.tsx

import React from "react";
import { Popover } from "./Popover";

import "./ColorPicker.css";
import { KEYS } from "../keys";
import { useTranslation } from "react-i18next";
import { TFunction } from "i18next";

// This is a narrow reimplementation of the awesome react-color Twitter component
// https://github.com/casesandberg/react-color/blob/master/src/components/twitter/Twitter.js

const Picker = function({
  colors,
  color,
  onChange,
  onClose,
  label,
  t,
}: {
  colors: string[];
  color: string | null;
  onChange: (color: string) => void;
  onClose: () => void;
  label: string;
  t: TFunction;
}) {
  const firstItem = React.useRef<HTMLButtonElement>();
  const colorInput = React.useRef<HTMLInputElement>();

  React.useEffect(() => {
    // After the component is first mounted
    // focus on first input
    if (firstItem.current) firstItem.current.focus();
  }, []);

  const handleKeyDown = (e: React.KeyboardEvent) => {
    if (e.key === KEYS.TAB) {
      const { activeElement } = document;
      if (e.shiftKey) {
        if (activeElement === firstItem.current) {
          colorInput.current?.focus();
          e.preventDefault();
        }
      } else {
        if (activeElement === colorInput.current) {
          firstItem.current?.focus();
          e.preventDefault();
        }
      }
    } else if (e.key === KEYS.ESCAPE) {
      onClose();
      e.nativeEvent.stopImmediatePropagation();
    }
  };

  return (
    <div
      className="color-picker"
      role="dialog"
      aria-modal="true"
      aria-label={t("labels.colorPicker")}
      onKeyDown={handleKeyDown}
    >
      <div className="color-picker-triangle-shadow"></div>
      <div className="color-picker-triangle"></div>
      <div className="color-picker-content">
        <div className="colors-gallery">
          {colors.map((color, i) => (
            <button
              className="color-picker-swatch"
              onClick={() => {
                onChange(color);
              }}
              title={color}
              aria-label={color}
              style={{ backgroundColor: color }}
              key={color}
              ref={el => {
                if (i === 0 && el) firstItem.current = el;
              }}
            >
              {color === "transparent" ? (
                <div className="color-picker-transparent"></div>
              ) : (
                undefined
              )}
            </button>
          ))}
        </div>
        <ColorInput
          color={color}
          label={label}
          onChange={color => {
            onChange(color);
          }}
          ref={colorInput}
        />
      </div>
    </div>
  );
};

const ColorInput = React.forwardRef(
  (
    {
      color,
      onChange,
      label,
    }: {
      color: string | null;
      onChange: (color: string) => void;
      label: string;
    },
    ref,
  ) => {
    const colorRegex = /^([0-9a-f]{3}|[0-9a-f]{6}|[0-9a-f]{8}|transparent)$/;
    const [innerValue, setInnerValue] = React.useState(color);
    const inputRef = React.useRef(null);

    React.useEffect(() => {
      setInnerValue(color);
    }, [color]);

    React.useImperativeHandle(ref, () => inputRef.current);

    return (
      <div className="color-input-container">
        <div className="color-picker-hash">#</div>
        <input
          spellCheck={false}
          className="color-picker-input"
          aria-label={label}
          onChange={e => {
            const value = e.target.value.toLowerCase();
            if (value.match(colorRegex)) {
              onChange(value === "transparent" ? "transparent" : "#" + value);
            }
            setInnerValue(value);
          }}
          value={(innerValue || "").replace(/^#/, "")}
          onPaste={e => onChange(e.clipboardData.getData("text"))}
          onBlur={() => setInnerValue(color)}
          ref={inputRef}
        />
      </div>
    );
  },
);

export function ColorPicker({
  type,
  color,
  onChange,
  label,
}: {
  type: "canvasBackground" | "elementBackground" | "elementStroke";
  color: string | null;
  onChange: (color: string) => void;
  label: string;
}) {
  const { t } = useTranslation();

  const [isActive, setActive] = React.useState(false);
  const pickerButton = React.useRef<HTMLButtonElement>(null);

  return (
    <div>
      <div className="color-picker-control-container">
        <button
          className="color-picker-label-swatch"
          aria-label={label}
          style={color ? { backgroundColor: color } : undefined}
          onClick={() => setActive(!isActive)}
          ref={pickerButton}
        />
        <ColorInput
          color={color}
          label={label}
          onChange={color => {
            onChange(color);
          }}
        />
      </div>
      <React.Suspense fallback="">
        {isActive ? (
          <Popover onCloseRequest={() => setActive(false)}>
            <Picker
              colors={colors[type]}
              color={color || null}
              onChange={changedColor => {
                onChange(changedColor);
              }}
              onClose={() => {
                setActive(false);
                pickerButton.current?.focus();
              }}
              label={label}
              t={t}
            />
          </Popover>
        ) : null}
      </React.Suspense>
    </div>
  );
}

// https://yeun.github.io/open-color/
const colors = {
  // Shade 0
  canvasBackground: [
    "#ffffff",
    "#f8f9fa",
    "#f1f3f5",
    "#fff5f5",
    "#fff0f6",
    "#f8f0fc",
    "#f3f0ff",
    "#edf2ff",
    "#e7f5ff",
    "#e3fafc",
    "#e6fcf5",
    "#ebfbee",
    "#f4fce3",
    "#fff9db",
    "#fff4e6",
  ],
  // Shade 6
  elementBackground: [
    "transparent",
    "#ced4da",
    "#868e96",
    "#fa5252",
    "#e64980",
    "#be4bdb",
    "#7950f2",
    "#4c6ef5",
    "#228be6",
    "#15aabf",
    "#12b886",
    "#40c057",
    "#82c91e",
    "#fab005",
    "#fd7e14",
  ],
  // Shade 9
  elementStroke: [
    "#000000",
    "#343a40",
    "#495057",
    "#c92a2a",
    "#a61e4d",
    "#862e9c",
    "#5f3dc4",
    "#364fc7",
    "#1864ab",
    "#0b7285",
    "#087f5b",
    "#2b8a3e",
    "#5c940d",
    "#e67700",
    "#d9480f",
  ],
};