Wcag color a11y tool

packages/building-blocks/package.json

@@ -9,6 +9,7 @@
   "module": "esm/index.js",
   "private": false,
   "dependencies": {
+    "color-contrast": "^1.0.0",
     "mapbox-gl": "npm:[email protected]",
     "maplibre-gl": "^2.1.9",
     "react-map-gl": "^7.0.15",

packages/building-blocks/src/stories/color-stories/ColorPalette.story.tsx

@@ -0,0 +1,231 @@
+import React, { useEffect, useState } from "react";
+
+import styled, { css } from "styled-components";
+import { getMostReadableTextColor } from "@opentripplanner/core-utils/lib/route";
+import WcagChecker from "./WCAGChecker.story";
+import ColorPickerInput from "./ColorPickerInput.story";
+import blue from "../../colors/blue";
+import grey from "../../colors/grey";
+import SelectedColorOptions from "./SelectedColorOptions.story";
+import { Hue } from "../../types/hue";
+
+interface Props {
+  color: Hue;
+  label: string;
+}
+
+export const borderStyles = css`
+  border: 1px solid ${grey[100]};
+  border-radius: 7px;
+`;
+
+const Info = styled.div`
+  background-color: ${blue[50]};
+  line-height: 1.5;
+  padding: 10px;
+  border-radius: 5px;
+  margin-bottom: 15px;
+  text-align: center;
+
+  p {
+    margin: 0;
+  }
+
+  a {
+    color: ${blue[700]};
+    font-weight: 700;
+    text-decoration: none;
+
+    &:hover {
+      color: ${blue[900]};
+    }
+  }
+`;
+
+const ColorContainer = styled.div`
+  display: flex;
+  gap: 15px;
+  font-family: Arial, Helvetica, sans-serif;
+  margin: 0 auto;
+`;
+
+const ColorPaletteContainer = styled.div``;
+
+const ColorBlock = styled.div<{ hex: string }>`
+  align-items: center;
+  background-color: ${props => props.hex};
+  color: ${props => getMostReadableTextColor(props.hex, "#ffffff")};
+  text-shadow: ${props =>
+    getMostReadableTextColor(props.hex, "#ffffff") === "#ffffff"
+      ? "1px 1px 2px black"
+      : ""};
+  display: flex;
+  height: 40px;
+  justify-content: space-between;
+  margin: 0;
+  padding: 10px;
+  transition: all 0.2s ease-in;
+  width: 300px;
+
+  &:first-of-type {
+    border-radius: 8px 8px 0 0;
+  }
+  &:last-of-type {
+    border-radius: 0 0 8px 8px;
+  }
+
+  &:hover {
+    transform: scale(1.012);
+    transition: all 0.2s ease-in;
+    cursor: pointer;
+  }
+`;
+
+const ColorPickForm = styled.form`
+  display: flex;
+  gap: 15px;
+  margin-bottom: 15px;
+`;
+
+const WCAGContainer = styled.div`
+  max-width: 425px;
+`;
+
+const ColorPalette = ({ color, label }: Props): JSX.Element => {
+  const colorArray: Array<Hue> = Object.entries(color);
+  const [selectedColor, setSelectedColor] = useState(colorArray[0]);
+  const [foregroundColor, setForegroundColor] = useState(colorArray[0][1]);
+  const [foregroundColorInput, setForegroundColorInput] = useState(
+    colorArray[0][1]
+  );
+  const [backgroundColorInput, setBackgroundColorInput] = useState("#FFFFFF");
+  const [backgroundColor, setBackgroundColor] = useState("#FFFFFF");
+  const [foregroundError, setForegroundError] = useState(false);
+  const [backgroundError, setBackgroundError] = useState(false);
+
+  const REX_EXP = /(^#[0-9A-F]{6}$)/i;
+
+  const isValidHexCode = code => {
+    let hexcode = code;
+    if (!code.startsWith("#")) hexcode = `#${code}`;
+    return REX_EXP.test(hexcode);
+  };
+
+  const backgroundHandleChange = event => {
+    const value = event.target.value;
+    setBackgroundColorInput(value);
+  };
+
+  const foregroundHandleChange = event => {
+    const value = event.target.value;
+    setForegroundColorInput(value);
+  };
+  const hexArray = colorArray.map(x => x[1]);
+  const foregroundColorIsInPalette = () => {
+    if (foregroundColorInput && hexArray.includes(foregroundColorInput)) {
+      return `${label} ${
+        colorArray[hexArray.indexOf(foregroundColorInput)][0]
+      }`;
+    }
+    return null;
+  };
+  const backgroundColorIsInPalette = () => {
+    if (backgroundColorInput && hexArray.includes(backgroundColorInput)) {
+      return `${label} ${
+        colorArray[hexArray.indexOf(backgroundColorInput)][0]
+      }`;
+    }
+    return null;
+  };
+  const selectedColorReset =
+    selectedColor &&
+    foregroundColorInput !== selectedColor[1] &&
+    backgroundColorInput !== selectedColor[1];
+
+  useEffect(() => {
+    if (selectedColorReset) {
+      setSelectedColor(undefined);
+    }
+    if (!isValidHexCode(foregroundColorInput)) {
+      setForegroundError(true);
+    } else {
+      setForegroundError(false);
+      setForegroundColor(foregroundColorInput);
+    }
+  }, [foregroundColorInput]);
+
+  useEffect(() => {
+    if (selectedColorReset) {
+      setSelectedColor(undefined);
+    }
+    if (!isValidHexCode(backgroundColorInput)) {
+      setBackgroundError(true);
+    } else {
+      setBackgroundError(false);
+      setBackgroundColor(backgroundColorInput);
+    }
+  }, [backgroundColorInput]);
+
+  return (
+    <ColorContainer>
+      <ColorPaletteContainer>
+        {colorArray.map(
+          (hue: Hue): JSX.Element => {
+            return (
+              <ColorBlock
+                key={hue[0]}
+                hex={hue[1]}
+                onClick={() => setSelectedColor(hue)}
+              >
+                <p>{hue[0]}</p>
+                <p>{hue[1]}</p>
+              </ColorBlock>
+            );
+          }
+        )}
+      </ColorPaletteContainer>
+
+      <WCAGContainer>
+        <Info>
+          <p>
+            Select a color variable from the palette to check it against WCAG
+            contrast requirements.{" "}
+            <a
+              target="_blank"
+              rel="noopener noreferrer"
+              href="https://webaim.org/articles/contrast/"
+            >
+              See more
+            </a>{" "}
+          </p>
+        </Info>
+        <SelectedColorOptions
+          selectedColor={selectedColor}
+          selectedColorLabel={label}
+          setBackgroundColor={setBackgroundColor}
+          setForegroundColor={setForegroundColor}
+          setBackgroundColorInput={setBackgroundColorInput}
+          setForegroundColorInput={setForegroundColorInput}
+        />
+        <ColorPickForm>
+          <ColorPickerInput
+            colorInPalette={foregroundColorIsInPalette()}
+            handleChange={foregroundHandleChange}
+            inputLabel="Foreground color"
+            colorInput={foregroundColorInput}
+            error={foregroundError}
+          />
+          <ColorPickerInput
+            colorInPalette={backgroundColorIsInPalette()}
+            handleChange={backgroundHandleChange}
+            inputLabel="Background color"
+            colorInput={backgroundColorInput}
+            error={backgroundError}
+          />
+        </ColorPickForm>
+        <WcagChecker background={backgroundColor} hue={foregroundColor} />
+      </WCAGContainer>
+    </ColorContainer>
+  );
+};
+export default ColorPalette;

packages/building-blocks/src/stories/color-stories/ColorPickerInput.story.tsx

@@ -0,0 +1,81 @@
+import React, { ChangeEventHandler, ReactElement } from "react";
+import styled from "styled-components";
+import grey from "../../colors/grey";
+import red from "../../colors/red";
+
+interface Props {
+  handleChange: ChangeEventHandler<HTMLInputElement>;
+  colorInPalette: string | null;
+  inputLabel: string;
+  colorInput: string;
+  error: boolean;
+}
+
+const ColorPicker = styled.div`
+  position: relative;
+  width: 50%;
+  label span {
+    color: ${grey[700]};
+    font-size: 12px;
+    background-color: white;
+    z-index: 10;
+    margin-left: 8px;
+    padding: 0 7px;
+  }
+`;
+
+const InputError = styled.div`
+  margin: 5px 0 0 8px;
+  color: ${red[800]};
+  font-size: 12px;
+`;
+
+const InputContainer = styled.div`
+  border: 1px solid ${grey[100]};
+  border-radius: 7px;
+  display: flex;
+  align-items: center;
+  padding: 5px;
+  margin-top: -8px;
+
+  input {
+    border: none;
+    background: transparent;
+  }
+
+  input[type="text"] {
+    height: 27px;
+    padding: 0 5px;
+    min-width: 70px;
+    width: 80%;
+  }
+`;
+
+const ColorPickerInput = ({
+  colorInPalette,
+  handleChange,
+  colorInput,
+  error,
+  inputLabel
+}: Props): ReactElement => {
+  return (
+    <ColorPicker>
+      <label htmlFor={inputLabel}>
+        <span>{inputLabel}</span>
+        <InputContainer>
+          <input
+            id={inputLabel}
+            type="text"
+            onChange={handleChange}
+            value={colorInput}
+          />
+          <span>{colorInPalette}</span>
+          <input type="color" onChange={handleChange} value={colorInput} />
+        </InputContainer>
+      </label>
+      <InputError>{error ? "Please enter a valid hex code" : ""}</InputError>
+    </ColorPicker>
+  );
+};
+
+export default ColorPickerInput;