soroban-abacus-flashcards/apps/web/src/components/InteractiveFlashcards.tsx

345 lines
12 KiB
TypeScript

'use client'
import { AbacusReact } from '@soroban/abacus-react'
import { useEffect, useRef, useState } from 'react'
import { css } from '../../styled-system/css'
interface Flashcard {
id: number
number: number
initialX: number
initialY: number
initialRotation: number
zIndex: number
}
/**
* InteractiveFlashcards - A fun flashcard display where you can drag cards around
* Cards stay where you drop them - simple and intuitive
*/
export function InteractiveFlashcards() {
const containerRef = useRef<HTMLDivElement>(null)
const [cards, setCards] = useState<Flashcard[]>([])
useEffect(() => {
if (!containerRef.current) return
// Double rAF pattern - ensures layout is fully complete
const frameId1 = requestAnimationFrame(() => {
const frameId2 = requestAnimationFrame(() => {
if (!containerRef.current) return
const containerWidth = containerRef.current.offsetWidth
const containerHeight = containerRef.current.offsetHeight
// Only generate cards once we have proper dimensions
if (containerWidth < 100 || containerHeight < 100) {
return
}
const count = Math.floor(Math.random() * 8) + 8 // 8-15 cards
const generated: Flashcard[] = []
// Position cards within the actual container bounds
const cardWidth = 120 // approximate card width
const cardHeight = 200 // approximate card height
for (let i = 0; i < count; i++) {
const card = {
id: i,
number: Math.floor(Math.random() * 900) + 100, // 100-999
initialX: Math.random() * (containerWidth - cardWidth - 40) + 20,
initialY: Math.random() * (containerHeight - cardHeight - 40) + 20,
initialRotation: Math.random() * 40 - 20, // -20 to 20 degrees
zIndex: i,
}
generated.push(card)
}
setCards(generated)
})
})
return () => {
// Note: can't cancel nested rAF properly, but component cleanup will prevent state updates
}
}, [])
return (
<div
ref={containerRef}
className={css({
position: 'relative',
width: '100%',
maxW: '1200px',
mx: 'auto',
height: { base: '400px', md: '500px' },
overflow: 'visible',
bg: 'rgba(0, 0, 0, 0.3)',
rounded: 'xl',
border: '1px solid rgba(255, 255, 255, 0.1)',
})}
>
{cards.map((card) => (
<DraggableCard key={card.id} card={card} />
))}
</div>
)
}
interface DraggableCardProps {
card: Flashcard
}
function DraggableCard({ card }: DraggableCardProps) {
// Track position - starts at initial, updates when dragged
const [position, setPosition] = useState({ x: card.initialX, y: card.initialY })
const [rotation, setRotation] = useState(card.initialRotation) // Now dynamic!
const [zIndex, setZIndex] = useState(card.zIndex)
const [isDragging, setIsDragging] = useState(false)
const [dragSpeed, setDragSpeed] = useState(0) // Speed for dynamic shadow
// Track drag state
const dragStartRef = useRef<{ x: number; y: number; cardX: number; cardY: number } | null>(null)
const grabOffsetRef = useRef<{ x: number; y: number }>({ x: 0, y: 0 }) // Offset from card center where grabbed
const baseRotationRef = useRef(card.initialRotation) // Starting rotation
const lastMoveTimeRef = useRef<number>(0)
const lastMovePositionRef = useRef<{ x: number; y: number }>({ x: 0, y: 0 })
const lastLogTimeRef = useRef<number>(0) // Separate throttling for logging
const cardRef = useRef<HTMLDivElement>(null) // Reference to card element
const handlePointerDown = (e: React.PointerEvent) => {
setIsDragging(true)
setZIndex(1000) // Bring to front
setDragSpeed(0)
// Capture the pointer
e.currentTarget.setPointerCapture(e.pointerId)
// Record where the drag started (pointer position and card position)
dragStartRef.current = {
x: e.clientX,
y: e.clientY,
cardX: position.x,
cardY: position.y,
}
// Calculate grab offset from card center
if (cardRef.current) {
const rect = cardRef.current.getBoundingClientRect()
const cardCenterX = rect.left + rect.width / 2
const cardCenterY = rect.top + rect.height / 2
grabOffsetRef.current = {
x: e.clientX - cardCenterX,
y: e.clientY - cardCenterY,
}
console.log(
`[GrabPoint] Grabbed at offset: (${grabOffsetRef.current.x.toFixed(0)}, ${grabOffsetRef.current.y.toFixed(0)})px from center`
)
}
// Store the current rotation as the base for this drag
baseRotationRef.current = rotation
// Initialize velocity tracking
const now = Date.now()
lastMoveTimeRef.current = now
lastMovePositionRef.current = { x: e.clientX, y: e.clientY }
lastLogTimeRef.current = now
console.log('[Shadow] Drag started, speed reset to 0')
}
const handlePointerMove = (e: React.PointerEvent) => {
if (!isDragging || !dragStartRef.current) return
// Calculate how far the pointer has moved since drag started
const deltaX = e.clientX - dragStartRef.current.x
const deltaY = e.clientY - dragStartRef.current.y
// Calculate velocity for dynamic shadow
const now = Date.now()
const timeDelta = now - lastMoveTimeRef.current
if (timeDelta > 0) {
// Distance moved since last frame
const distX = e.clientX - lastMovePositionRef.current.x
const distY = e.clientY - lastMovePositionRef.current.y
const distance = Math.sqrt(distX * distX + distY * distY)
// Speed in pixels per millisecond, then convert to reasonable scale
const speed = distance / timeDelta
const scaledSpeed = Math.min(speed * 100, 100) // Cap at 100 for reasonable shadow size
setDragSpeed(scaledSpeed)
// Log occasionally (every ~200ms) to avoid console spam
const timeSinceLastLog = now - lastLogTimeRef.current
if (timeSinceLastLog > 200) {
console.log(
`[Shadow] Speed: ${scaledSpeed.toFixed(1)}, distance: ${distance.toFixed(0)}px, timeDelta: ${timeDelta}ms`
)
lastLogTimeRef.current = now
}
lastMoveTimeRef.current = now
lastMovePositionRef.current = { x: e.clientX, y: e.clientY }
}
// Calculate rotation based on grab point physics
// Cross product of grab offset and drag direction determines rotation
// If grabbed on left and dragged right → clockwise rotation
// If grabbed on right and dragged left → counter-clockwise rotation
const crossProduct = grabOffsetRef.current.x * deltaY - grabOffsetRef.current.y * deltaX
const rotationInfluence = crossProduct / 500 // Reduced scale factor for more visible rotation
const newRotation = baseRotationRef.current + rotationInfluence
// Clamp rotation to prevent excessive spinning
const clampedRotation = Math.max(-45, Math.min(45, newRotation))
setRotation(clampedRotation)
// Log rotation changes occasionally (same throttle as shadow logging)
const timeSinceLastLog = now - lastLogTimeRef.current
if (timeSinceLastLog > 200) {
console.log(
`[GrabPoint] Rotation: ${clampedRotation.toFixed(1)}° (influence: ${rotationInfluence.toFixed(1)}°, cross: ${crossProduct.toFixed(0)})`
)
}
// Update card position - keep the grab point "stuck" to the cursor
// As the card rotates, the grab point rotates with it, so we need to account for rotation
const rotationRad = (clampedRotation * Math.PI) / 180
const cosRot = Math.cos(rotationRad)
const sinRot = Math.sin(rotationRad)
// Rotate the grab offset by the current rotation angle
const rotatedGrabX = grabOffsetRef.current.x * cosRot - grabOffsetRef.current.y * sinRot
const rotatedGrabY = grabOffsetRef.current.x * sinRot + grabOffsetRef.current.y * cosRot
// Current cursor position
const cursorX = e.clientX
const cursorY = e.clientY
// Card center should be at: cursor position - rotated grab offset
// But we need to position the card element (top-left), not the center
// Get card dimensions to calculate offset from center to top-left
if (cardRef.current) {
const rect = cardRef.current.getBoundingClientRect()
const cardWidth = rect.width
const cardHeight = rect.height
// Card center position in screen space
const cardCenterX = cursorX - rotatedGrabX
const cardCenterY = cursorY - rotatedGrabY
// Convert center position to top-left position (what we store in position state)
// Note: position.x/y is used in translate(), which positions the element
setPosition({
x: cardCenterX - cardWidth / 2,
y: cardCenterY - cardHeight / 2,
})
} else {
// Fallback to simple delta if we don't have card dimensions yet
setPosition({
x: dragStartRef.current.cardX + deltaX,
y: dragStartRef.current.cardY + deltaY,
})
}
}
const handlePointerUp = (e: React.PointerEvent) => {
setIsDragging(false)
dragStartRef.current = null
console.log('[Shadow] Drag released, speed decaying to 0')
console.log(
`[GrabPoint] Final rotation: ${rotation.toFixed(1)}° (base was ${baseRotationRef.current.toFixed(1)}°)`
)
// Gradually decay speed back to 0 for smooth shadow transition
const decayInterval = setInterval(() => {
setDragSpeed((prev) => {
const newSpeed = prev * 0.8 // Decay by 20% each frame
if (newSpeed < 1) {
clearInterval(decayInterval)
return 0
}
return newSpeed
})
}, 50) // Update every 50ms
// Release the pointer capture
e.currentTarget.releasePointerCapture(e.pointerId)
}
// Calculate dynamic shadow based on drag speed
// Base shadow: 0 8px 24px rgba(0, 0, 0, 0.3)
// Fast drag: 0 32px 64px rgba(0, 0, 0, 0.6)
const shadowY = 8 + (dragSpeed / 100) * 24 // 8px to 32px
const shadowBlur = 24 + (dragSpeed / 100) * 40 // 24px to 64px
const shadowOpacity = 0.3 + (dragSpeed / 100) * 0.3 // 0.3 to 0.6
const boxShadow = `0 ${shadowY}px ${shadowBlur}px rgba(0, 0, 0, ${shadowOpacity})`
return (
<div
ref={cardRef}
onPointerDown={handlePointerDown}
onPointerMove={handlePointerMove}
onPointerUp={handlePointerUp}
style={{
position: 'absolute',
left: 0,
top: 0,
transform: `translate(${position.x}px, ${position.y}px) rotate(${rotation}deg) scale(${isDragging ? 1.05 : 1})`,
zIndex,
touchAction: 'none',
cursor: isDragging ? 'grabbing' : 'grab',
transition: isDragging ? 'none' : 'transform 0.2s ease-out',
}}
className={css({
userSelect: 'none',
})}
>
<div
style={{
boxShadow, // Dynamic shadow based on drag speed
}}
className={css({
bg: 'white',
rounded: 'lg',
p: '4',
display: 'flex',
flexDirection: 'column',
alignItems: 'center',
gap: '2',
minW: '120px',
border: '2px solid rgba(0, 0, 0, 0.1)',
transition: 'box-shadow 0.1s', // Quick transition for responsive feel
})}
>
{/* Abacus visualization */}
<div
className={css({
transform: 'scale(0.6)',
transformOrigin: 'center',
})}
>
<AbacusReact value={card.number} columns={3} beadShape="circle" />
</div>
{/* Number display */}
<div
className={css({
fontSize: 'xl',
fontWeight: 'bold',
color: 'gray.800',
fontFamily: 'mono',
})}
>
{card.number}
</div>
</div>
</div>
)
}