Code walkthrough

import {Fill, Easing, interpolate, useBrand, useFrame, useDesignScale} from "odori";

export type WalkthroughStep = {
  /** Inclusive line range to focus, one-based. */
  from: number;
  to: number;
  note?: string;
};

export type CodeWalkthroughProps = {
  code: string;
  steps: WalkthroughStep[];
  title?: string;
  /** Frames each step holds before the next takes focus. */
  hold?: number;
};

/**
 * Source read in authored order. Every line stays on screen the whole time, so
 * the reader keeps their place; focus moves by dimming everything the current
 * step is not about.
 */
export const CodeWalkthrough = ({code, steps, title = "videos/launch/video.tsx", hold = 60}: CodeWalkthroughProps) => {
  const frame = useFrame();
  const brand = useBrand();
  const scale = useDesignScale();
  const lines = code.split("\n");
  const index = Math.min(steps.length - 1, Math.floor(Math.max(0, frame - 12) / hold));
  const step = steps[index];
  const stepStart = 12 + index * hold;
  const focus = interpolate(frame, [stepStart, stepStart + 16], [0, 1], {easing: Easing.standard});

  return (
    <Fill style={{alignItems: "center", justifyContent: "center", padding: 90 * scale}}>
      <div
        style={{
          background: brand.colors.surface,
          border: `1px solid ${brand.colors.border}`,
          borderRadius: 26 * scale,
          minWidth: 1180 * scale,
          overflow: "hidden",
        }}
      >
        <div
          style={{
            borderBottom: `1px solid ${brand.colors.border}`,
            color: brand.colors.muted,
            fontFamily: brand.typography.mono,
            fontSize: 24 * scale,
            padding: `${20 * scale}px ${28 * scale}px`,
          }}
        >
          {title}
        </div>
        <div style={{padding: `${20 * scale}px 0`}}>
          {lines.map((line, lineIndex) => {
            const number = lineIndex + 1;
            const inFocus = step && number >= step.from && number <= step.to;
            const dim = inFocus ? 1 : 1 - 0.68 * focus;
            return (
              <div
                key={`${line}-${lineIndex}`}
                style={{
                  alignItems: "center",
                  background: inFocus
                    ? `color-mix(in srgb, ${brand.colors.accent} ${focus * 10}%, transparent)`
                    : "transparent",
                  display: "flex",
                  gap: 24 * scale,
                  opacity: dim,
                  padding: `${6 * scale}px ${28 * scale}px`,
                }}
              >
                <span style={{color: brand.colors.muted, fontFamily: brand.typography.mono, fontSize: 24 * scale, width: 44 * scale}}>
                  {number}
                </span>
                <span style={{fontFamily: brand.typography.mono, fontSize: 30 * scale, whiteSpace: "pre"}}>{line}</span>
              </div>
            );
          })}
        </div>
        {step?.note ? (
          <div
            style={{
              borderTop: `1px solid ${brand.colors.border}`,
              color: brand.colors.muted,
              fontSize: 30 * scale,
              opacity: focus,
              padding: `${22 * scale}px ${28 * scale}px`,
            }}
          >
            {step.note}
          </div>
        ) : null}
      </div>
    </Fill>
  );
};

import {defineComponentPreview} from "odori/preview";
import {CodeWalkthrough} from "./code-walkthrough";

export default defineComponentPreview({
  title: "Code walkthrough",
  category: "Developer proof/Code",
  description: "Progressive code reveal with authored focal regions.",
  component: CodeWalkthrough,
  canvas: {width: 1920, height: 1080, duration: "8s"},
  controls: {
    title: {type: "text", defaultValue: "videos/launch/video.tsx"},
    hold: {type: "number", defaultValue: 60, min: 24, max: 120},
  },
  examples: [
    {
      name: "Metadata to timeline",
      props: {
        code: `export const metadata = defineVideoMetadata({
  id: "launch",
  duration: "8s",
});

export default function LaunchVideo() {
  return (
    <Video>
      <Scene duration="5s">
        <TitleReveal title="Ship the story." />
      </Scene>
    </Video>
  );
}`,
        steps: [
          {from: 1, to: 4, note: "Static metadata, so discovery never runs your component."},
          {from: 6, to: 13, note: "Ordinary JSX for the timeline."},
          {from: 8, to: 10, note: "Scenes are ordered, not numbered."},
        ],
      },
    },
  ],
});

import {Scene, Video} from "odori";
import {CodeWalkthrough} from "../components/code-walkthrough/code-walkthrough";

<Video>
  <Scene id="code-walkthrough" duration="8s">
    <CodeWalkthrough
      code={`export const metadata = defineVideoMetadata({
  id: "launch",
  duration: "8s",
});

export default function LaunchVideo() {
  return (
    <Video>
      <Scene duration="5s">
        <TitleReveal title="Ship the story." />
      </Scene>
    </Video>
  );
}`}
      steps={[
        {
          from: 1,
          to: 4,
          note: "Static metadata, so discovery never runs your component."
        },
        {
          from: 6,
          to: 13,
          note: "Ordinary JSX for the timeline."
        },
        {
          from: 8,
          to: 10,
          note: "Scenes are ordered, not numbered."
        }
      ]}
      title="videos/launch/video.tsx"
      hold={60}
    />
  </Scene>
</Video>