motion-react（motion React 前端）

Motion for React

Package: motion (formerly framer-motion). Import from "motion/react".

Installation

pnpm add motion

Imports

// Standard React (Vite, CRA, Pages Router)
import { motion, AnimatePresence } from "motion/react"

// Next.js App Router — use "motion/react-client" for RSC tree-shaking
"use client"
import * as motion from "motion/react-client"

// Minimal bundle (2.3 KB) — imperative API only
import { useAnimate } from "motion/react-mini"

// Reduced bundle (4.6 KB) — LazyMotion + m component
import { LazyMotion, domAnimation, m } from "motion/react"

Motion Component

Every HTML/SVG element has a motion counterpart:

<motion.div />
<motion.button />
<motion.svg />
<motion.circle />

Custom components: wrap with motion.create():

const MotionBox = motion.create(Box)
// forwardRef required — the ref must reach a DOM node

Core Animation Props

<motion.div
  initial={{ opacity: 0, y: 20 }}     // mount state (or false to skip)
  animate={{ opacity: 1, y: 0 }}      // target state
  exit={{ opacity: 0, y: -20 }}       // unmount state (needs AnimatePresence)
  transition={{ type: "spring", bounce: 0.25 }}
  whileHover={{ scale: 1.05 }}
  whileTap={{ scale: 0.95 }}
  whileFocus={{ borderColor: "#00f" }}
  whileDrag={{ scale: 1.1 }}
  whileInView={{ opacity: 1 }}
  viewport={{ once: true, margin: "-100px" }}
/>

Animatable Values

Motion animates any CSS value: opacity, filter, background-image, mask-image.

Independent transforms (not possible in CSS alone):

• Translate: x, y, z
• Scale: scale, scaleX, scaleY
• Rotate: rotate, rotateX, rotateY, rotateZ
• Skew: skewX, skewY
• Origin: originX, originY, originZ

Value types: numbers, strings with units ("100px"), colors (hex/rgba/hsla), "auto" for width/height.

Hardware acceleration: set transform directly for GPU compositing:

<motion.li
  initial={{ transform: "translateX(-100px)" }}
  animate={{ transform: "translateX(0px)" }}
  transition={{ type: "spring" }}
/>

Keyframes

Pass arrays to animate through a sequence:

<motion.div animate={{ x: [0, 100, 0] }} />

// null = "use current value"
<motion.div animate={{ x: [null, 100, 0] }} />

Variants

Named animation states for orchestrated animations:

const list = {
  visible: {
    transition: { staggerChildren: 0.1 }
  },
  hidden: {}
}

const item = {
  visible: { opacity: 1, y: 0 },
  hidden: { opacity: 0, y: 20 }
}

<motion.ul initial="hidden" animate="visible" variants={list}>
  <motion.li variants={item} />
  <motion.li variants={item} />
</motion.ul>

Variants propagate through the tree. Children inherit animate/initial/exit from parent.

AnimatePresence — Exit Animations

import { AnimatePresence } from "motion/react"

<AnimatePresence>
  {isVisible && (
    <motion.div
      key="modal"           // REQUIRED: unique key
      initial={{ opacity: 0 }}
      animate={{ opacity: 1 }}
      exit={{ opacity: 0 }}
    />
  )}
</AnimatePresence>

Critical rules:

1. AnimatePresence must stay mounted — never wrap it in a conditional
2. Direct children must have unique key props
3. exit prop only works on motion components inside AnimatePresence

// WRONG — AnimatePresence unmounts with condition
{show && <AnimatePresence><motion.div /></AnimatePresence>}

// CORRECT — condition inside AnimatePresence
<AnimatePresence>{show && <motion.div key="k" />}</AnimatePresence>

Modes: "sync" (default), "wait" (sequential enter/exit), "popLayout" (pop exiting element out of flow).

Slideshow pattern — change key to trigger exit+enter:

<AnimatePresence mode="wait">
  <motion.img
    key={image.src}
    initial={{ x: 300, opacity: 0 }}
    animate={{ x: 0, opacity: 1 }}
    exit={{ x: -300, opacity: 0 }}
  />
</AnimatePresence>

Dynamic exit data — pass via custom prop + usePresenceData:

<AnimatePresence custom={direction}>
  <Slide key={id} />
</AnimatePresence>

// Inside Slide:
const direction = usePresenceData()

Transitions

For full transition API details, see references/transitions-api.md.

Quick reference:

// Spring (default for physical props: x, y, scale)
transition={{ type: "spring", bounce: 0.25 }}
transition={{ type: "spring", stiffness: 300, damping: 20 }}
transition={{ type: "spring", visualDuration: 0.5, bounce: 0.25 }}

// Tween (default for opacity, color)
transition={{ duration: 0.3, ease: "easeInOut" }}

// Per-value transitions
transition={{
  default: { type: "spring" },
  opacity: { duration: 0.2, ease: "linear" }
}}

// Orchestration
transition={{ delay: 0.5, repeat: Infinity, repeatType: "reverse" }}

// Global default
<MotionConfig transition={{ duration: 0.3 }}>

Layout Animations

For full layout animation details, see references/layout-animations.md.

// Auto-animate any layout change
<motion.div layout />

// Shared element transitions
<motion.div layoutId="underline" />

// Customize layout transition
<motion.div layout transition={{ layout: { duration: 0.3 } }} />

Gestures & Drag

For full gesture/drag API, see references/gestures-and-drag.md.

<motion.div
  whileHover={{ scale: 1.1 }}
  whileTap={{ scale: 0.9 }}
  drag                           // enable both axes
  drag="x"                       // constrain to x-axis
  dragConstraints={{ left: -100, right: 100 }}
  dragElastic={0.2}
/>

Scroll Animations

For full scroll API, see references/scroll-animations.md.

// Viewport-triggered
<motion.div
  initial={{ opacity: 0, y: 50 }}
  whileInView={{ opacity: 1, y: 0 }}
  viewport={{ once: true }}
/>

// Scroll-linked progress bar
const { scrollYProgress } = useScroll()
<motion.div style={{ scaleX: scrollYProgress }} />

// Element scroll progress
const ref = useRef(null)
const { scrollYProgress } = useScroll({
  target: ref,
  offset: ["start end", "end start"]
})

Hooks & Motion Values

For full hooks API, see references/hooks-and-motion-values.md.

// Manual motion values (no re-renders)
const x = useMotionValue(0)
const opacity = useTransform(x, [-200, 0, 200], [0, 1, 0])
<motion.div drag="x" style={{ x, opacity }} />

// Smooth spring following
const springX = useSpring(x, { stiffness: 100, damping: 30 })

// Imperative animation control
const [scope, animate] = useAnimate()
animate("li", { opacity: 1 }, { stagger: 0.1 })

// Event listener (no re-render)
useMotionValueEvent(scrollY, "change", (v) => console.log(v))

Bundle Optimization

// LazyMotion pattern
import { LazyMotion, domAnimation, m } from "motion/react"

<LazyMotion features={domAnimation}>
  <m.div animate={{ opacity: 1 }} />
</LazyMotion>

Accessibility

<MotionConfig reducedMotion="user">
  <App />
</MotionConfig>

Options: "user" (respect OS setting), "always" (force instant), "never" (ignore).

Hook: useReducedMotion() returns true when user prefers reduced motion.

Tailwind Integration

Let each library handle its strength. **Remove Tailwind transition-* classes** — they conflict.

// WRONG — Tailwind transition conflicts with Motion
<motion.div className="transition-all duration-300" animate={{ x: 100 }} />

// CORRECT — Tailwind for styling, Motion for animation
<motion.div className="rounded-lg bg-blue-600 p-4" whileHover={{ scale: 1.05 }} />

Next.js App Router

Motion components require client-side rendering. Use "motion/react-client" for optimal tree-shaking:

// components/motion-client.tsx
"use client"
import * as motion from "motion/react-client"
export { motion }

// app/page.tsx (Server Component)
import { motion } from "@/components/motion-client"
<motion.div animate={{ opacity: 1 }} />

Common Pitfalls

1. Exit animations not firing — AnimatePresence must stay mounted; children need unique key
2. Tailwind transition conflict — Remove transition-* classes from motion elements
3. height: "auto" + display: "none" — Use visibility: "hidden" instead
4. Layout animations in scrollable containers — Add layoutScroll prop to scroll parent
5. Layout animations in fixed elements — Add layoutRoot prop to fixed parent
6. Percentage transforms + layout — Convert to pixels; percentage values break FLIP calculation
7. popLayout mode — Custom components must use forwardRef to forward ref to DOM node
8. AnimatePresence propagate — Set to true on nested AnimatePresence to fire child exits

References

• Animation API details: references/animation-api.md
• Transition types & spring config: references/transitions-api.md
• Gestures & drag: references/gestures-and-drag.md
• Layout animations: references/layout-animations.md
• Scroll animations: references/scroll-animations.md
• Hooks & motion values: references/hooks-and-motion-values.md