before-after

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

export type BeforeAfterProps = {
  before: ReactNode;
  after: ReactNode;
  beforeLabel?: string;
  afterLabel?: string;
  /** Where the divider ends up, 0 to 1. */
  settleAt?: number;
};

/**
 * One frame, two states, a divider that travels across it. Both sides are
 * always rendered at full size, so nothing reflows as the divider moves.
 */
export const BeforeAfter = ({before, after, beforeLabel = "Before", afterLabel = "After", settleAt = 0.5}: BeforeAfterProps) => {
  const frame = useFrame();
  const brand = useBrand();
  const scale = useDesignScale();
  const position = interpolate(frame, [12, 60], [1, settleAt], {
    easing: Easing.standard,
    extrapolateLeft: "clamp",
    extrapolateRight: "clamp",
  });

  const label = (text: string, side: "left" | "right") => (
    <span
      style={{
        background: brand.colors.surface,
        border: `1px solid ${brand.colors.border}`,
        borderRadius: 999,
        bottom: 44 * scale,
        color: brand.colors.muted,
        fontFamily: brand.typography.mono,
        fontSize: 24 * scale,
        left: side === "left" ? 44 * scale : undefined,
        padding: `${10 * scale}px ${20 * scale}px`,
        position: "absolute",
        right: side === "right" ? 44 * scale : undefined,
      }}
    >
      {text}
    </span>
  );

  return (
    <Fill>
      <Fill>{after}</Fill>
      <Fill style={{clipPath: `inset(0 ${(1 - position) * 100}% 0 0)`}}>{before}</Fill>
      <Fill style={{pointerEvents: "none"}}>
        <div
          style={{
            background: brand.colors.accent,
            bottom: 0,
            left: `${position * 100}%`,
            position: "absolute",
            top: 0,
            width: 3 * scale,
          }}
        />
        {label(beforeLabel, "left")}
        {label(afterLabel, "right")}
      </Fill>
    </Fill>
  );
};

import {defineComponentPreview} from "odori/preview";
import {BeforeAfter} from "./before-after";

export default defineComponentPreview({
  title: "Before and after",
  category: "Narrative",
  description: "Direct visual comparison with a controlled divider.",
  component: BeforeAfter,
  canvas: {width: 1920, height: 1080, duration: "4s"},
  controls: {
    beforeLabel: {type: "text", defaultValue: "Before"},
    afterLabel: {type: "text", defaultValue: "After"},
    settleAt: {type: "number", defaultValue: 0.5, min: 0.1, max: 0.9, step: 0.05},
  },
  examples: [
    {
      name: "Timeline",
      props: {
        before: "Hand-numbered frames",
        after: "Ordered scenes",
      },
    },
  ],
});

import {Scene, Video} from "odori";
import {BeforeAfter} from "../components/before-after/before-after";

<Video>
  <Scene id="before-after" duration="4s">
    <BeforeAfter
      beforeLabel="Before"
      afterLabel="After"
      settleAt={0.5}
    />
  </Scene>
</Video>