Press n or j to go to the next uncovered block, b, p or k for the previous block.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 | import { useEffect, useRef, useCallback } from 'react' import type { NumberLineState } from './types' import { screenXToNumber } from './numberLineTicks' interface UseNumberLineTouchOptions { stateRef: React.MutableRefObject<NumberLineState> canvasRef: React.RefObject<HTMLCanvasElement | null> onStateChange: () => void /** Called with instantaneous zoom velocity and focal point (0-1 fraction of canvas width). */ onZoomVelocity?: (velocity: number, focalX: number) => void /** Called when a tap (short press, no movement) is detected. Coordinates are CSS px relative to canvas. */ onTap?: (screenX: number, screenY: number) => void /** Called on mousemove (when not dragging) with CSS px coordinates. (-1, -1) signals mouse left. */ onHover?: (screenX: number, screenY: number) => void /** Called when a long-press (≥500ms hold, <10px movement) is detected. Coordinates are CSS px relative to canvas. */ onLongPress?: (screenX: number, screenY: number) => void } const TAP_MAX_DURATION_MS = 300 const TAP_MAX_DISTANCE_PX = 10 const LONG_PRESS_MS = 500 // Zoom limits — 1e14 allows viewing down to ~femto-scale (power -15) // while staying well within float64's ~15 significant digits const MIN_PIXELS_PER_UNIT = 0.001 const MAX_PIXELS_PER_UNIT = 1e14 function clampPixelsPerUnit(ppu: number): number { return Math.max(MIN_PIXELS_PER_UNIT, Math.min(MAX_PIXELS_PER_UNIT, ppu)) } /** * Hook that attaches touch, mouse, and wheel handlers to a canvas element * for panning and zooming a number line. * * All math uses absolute anchor-based computations (not deltas) to prevent drift. */ export function useNumberLineTouch({ stateRef, canvasRef, onStateChange, onZoomVelocity, onTap, onHover, onLongPress, }: UseNumberLineTouchOptions) { // Anchor state for single-finger drag / mouse drag const dragAnchorRef = useRef<number | null>(null) // Anchor state for two-finger pinch const pinchAnchorsRef = useRef<{ n1: number; n2: number; id1: number; id2: number } | null>(null) // Tap detection state const tapStartRef = useRef<{ time: number; x: number; y: number; cancelled: boolean } | null>( null ) // Long-press timer const longPressTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null) const getCanvasWidth = useCallback(() => { return canvasRef.current?.getBoundingClientRect().width ?? 0 }, [canvasRef]) const getCanvasRect = useCallback(() => { return canvasRef.current?.getBoundingClientRect() }, [canvasRef]) useEffect(() => { const canvas = canvasRef.current if (!canvas) return // --- Touch handlers --- function handleTouchStart(e: TouchEvent) { e.preventDefault() const rect = getCanvasRect() if (!rect) return const canvasWidth = rect.width const state = stateRef.current if (e.touches.length === 1) { // Single finger: anchor the number under the touch const x = e.touches[0].clientX - rect.left const y = e.touches[0].clientY - rect.top const anchorNumber = screenXToNumber(x, state.center, state.pixelsPerUnit, canvasWidth) dragAnchorRef.current = anchorNumber pinchAnchorsRef.current = null // Start tap detection tapStartRef.current = { time: performance.now(), x, y, cancelled: false } // Start long-press timer if (longPressTimerRef.current) clearTimeout(longPressTimerRef.current) longPressTimerRef.current = setTimeout(() => { const tap = tapStartRef.current if (tap && !tap.cancelled) { tap.cancelled = true // prevent tap from also firing onLongPress?.(tap.x, tap.y) } longPressTimerRef.current = null }, LONG_PRESS_MS) } else if (e.touches.length === 2) { // Two fingers: anchor both numbers const x1 = e.touches[0].clientX - rect.left const x2 = e.touches[1].clientX - rect.left const n1 = screenXToNumber(x1, state.center, state.pixelsPerUnit, canvasWidth) const n2 = screenXToNumber(x2, state.center, state.pixelsPerUnit, canvasWidth) pinchAnchorsRef.current = { n1, n2, id1: e.touches[0].identifier, id2: e.touches[1].identifier, } dragAnchorRef.current = null // Cancel tap and long-press on second finger if (tapStartRef.current) tapStartRef.current.cancelled = true if (longPressTimerRef.current) { clearTimeout(longPressTimerRef.current) longPressTimerRef.current = null } } } function handleTouchMove(e: TouchEvent) { e.preventDefault() const rect = getCanvasRect() if (!rect) return const canvasWidth = rect.width const state = stateRef.current // Cancel tap and long-press if finger moved too far if (tapStartRef.current && !tapStartRef.current.cancelled && e.touches.length === 1) { const tx = e.touches[0].clientX - rect.left const ty = e.touches[0].clientY - rect.top const dx = tx - tapStartRef.current.x const dy = ty - tapStartRef.current.y if (Math.sqrt(dx * dx + dy * dy) > TAP_MAX_DISTANCE_PX) { tapStartRef.current.cancelled = true if (longPressTimerRef.current) { clearTimeout(longPressTimerRef.current) longPressTimerRef.current = null } } } if (e.touches.length === 2 && pinchAnchorsRef.current) { // Two-finger pinch + drag const { n1, n2, id1, id2 } = pinchAnchorsRef.current // Find touches by identifier let touch1: Touch | null = null let touch2: Touch | null = null for (let i = 0; i < e.touches.length; i++) { if (e.touches[i].identifier === id1) touch1 = e.touches[i] if (e.touches[i].identifier === id2) touch2 = e.touches[i] } if (!touch1 || !touch2) return const screen1 = touch1.clientX - rect.left const screen2 = touch2.clientX - rect.left const oldPPU = state.pixelsPerUnit // Edge case: anchors too close together if (Math.abs(n1 - n2) < 1e-12) { // Treat as single-finger drag using midpoint const midScreen = (screen1 + screen2) / 2 const midAnchor = (n1 + n2) / 2 state.center = midAnchor - (midScreen - canvasWidth / 2) / state.pixelsPerUnit } else { // Solve two equations for pixelsPerUnit and center const newPPU = clampPixelsPerUnit((screen1 - screen2) / (n1 - n2)) state.pixelsPerUnit = newPPU state.center = n1 - (screen1 - canvasWidth / 2) / newPPU } stateRef.current = state onStateChange() // Report zoom velocity for pinch (focal point = midpoint of two fingers) if (state.pixelsPerUnit !== oldPPU) { const midX = (screen1 + screen2) / 2 onZoomVelocity?.(Math.log(state.pixelsPerUnit / oldPPU), midX / canvasWidth) } } else if (e.touches.length === 1 && dragAnchorRef.current !== null) { // Single finger drag const x = e.touches[0].clientX - rect.left const anchor = dragAnchorRef.current state.center = anchor - (x - canvasWidth / 2) / state.pixelsPerUnit stateRef.current = state onStateChange() } } function handleTouchEnd(e: TouchEvent) { e.preventDefault() const rect = getCanvasRect() if (!rect) return const canvasWidth = rect.width const state = stateRef.current if (e.touches.length === 1 && pinchAnchorsRef.current) { // Transition 2 -> 1 finger: re-anchor remaining finger const remainingTouch = e.touches[0] const x = remainingTouch.clientX - rect.left const anchorNumber = screenXToNumber(x, state.center, state.pixelsPerUnit, canvasWidth) dragAnchorRef.current = anchorNumber pinchAnchorsRef.current = null } else if (e.touches.length === 0) { // Clear long-press timer if (longPressTimerRef.current) { clearTimeout(longPressTimerRef.current) longPressTimerRef.current = null } // Fire tap if conditions met const tap = tapStartRef.current if (tap && !tap.cancelled) { const elapsed = performance.now() - tap.time if (elapsed < TAP_MAX_DURATION_MS) { onTap?.(tap.x, tap.y) } } tapStartRef.current = null dragAnchorRef.current = null pinchAnchorsRef.current = null } } // --- Mouse handlers --- let mouseAnchor: number | null = null let mouseDownInfo: { time: number; x: number; y: number; cancelled: boolean } | null = null let mouseLongPressTimer: ReturnType<typeof setTimeout> | null = null function handleMouseDown(e: MouseEvent) { if (e.button !== 0) return // left button only const rect = getCanvasRect() if (!rect) return const canvasWidth = rect.width const x = e.clientX - rect.left const y = e.clientY - rect.top const state = stateRef.current mouseAnchor = screenXToNumber(x, state.center, state.pixelsPerUnit, canvasWidth) mouseDownInfo = { time: performance.now(), x, y, cancelled: false } canvas!.style.cursor = 'grabbing' // Start long-press timer for mouse if (mouseLongPressTimer) clearTimeout(mouseLongPressTimer) mouseLongPressTimer = setTimeout(() => { if (mouseDownInfo && !mouseDownInfo.cancelled) { mouseDownInfo.cancelled = true onLongPress?.(mouseDownInfo.x, mouseDownInfo.y) } mouseLongPressTimer = null }, LONG_PRESS_MS) } function handleMouseMove(e: MouseEvent) { if (mouseAnchor === null) return const rect = getCanvasRect() if (!rect) return const canvasWidth = rect.width const x = e.clientX - rect.left const y = e.clientY - rect.top const state = stateRef.current state.center = mouseAnchor - (x - canvasWidth / 2) / state.pixelsPerUnit stateRef.current = state onStateChange() // Cancel mouse tap and long-press if moved too far if (mouseDownInfo && !mouseDownInfo.cancelled) { const dx = x - mouseDownInfo.x const dy = y - mouseDownInfo.y if (Math.sqrt(dx * dx + dy * dy) > TAP_MAX_DISTANCE_PX) { mouseDownInfo.cancelled = true if (mouseLongPressTimer) { clearTimeout(mouseLongPressTimer) mouseLongPressTimer = null } } } } function handleMouseUp(e: MouseEvent) { // Clear long-press timer if (mouseLongPressTimer) { clearTimeout(mouseLongPressTimer) mouseLongPressTimer = null } // Fire tap if conditions met if (mouseDownInfo && !mouseDownInfo.cancelled) { const elapsed = performance.now() - mouseDownInfo.time if (elapsed < TAP_MAX_DURATION_MS) { const rect = getCanvasRect() if (rect) { const x = e.clientX - rect.left const y = e.clientY - rect.top onTap?.(x, y) } } } mouseDownInfo = null mouseAnchor = null if (canvas) canvas.style.cursor = 'grab' } // --- Wheel handler --- function handleWheel(e: WheelEvent) { e.preventDefault() const rect = getCanvasRect() if (!rect) return const canvasWidth = rect.width const x = e.clientX - rect.left const state = stateRef.current // Anchor the number under the cursor const anchorNumber = screenXToNumber(x, state.center, state.pixelsPerUnit, canvasWidth) // Zoom factor: positive deltaY = scroll down = zoom out const oldPPU = state.pixelsPerUnit const zoomFactor = 1.001 ** -e.deltaY const newPPU = clampPixelsPerUnit(oldPPU * zoomFactor) state.pixelsPerUnit = newPPU // Re-center so anchorNumber stays under the cursor state.center = anchorNumber - (x - canvasWidth / 2) / newPPU stateRef.current = state onStateChange() // Report zoom velocity and focal point onZoomVelocity?.(Math.log(newPPU / oldPPU), x / canvasWidth) } // --- Hover handler (independent of drag) --- function handleCanvasMouseMove(e: MouseEvent) { // Only fire hover when not dragging if (mouseAnchor !== null) return const rect = getCanvasRect() if (!rect) return const x = e.clientX - rect.left const y = e.clientY - rect.top onHover?.(x, y) } function handleCanvasMouseLeave() { onHover?.(-1, -1) } // Attach listeners canvas.addEventListener('touchstart', handleTouchStart, { passive: false }) canvas.addEventListener('touchmove', handleTouchMove, { passive: false }) canvas.addEventListener('touchend', handleTouchEnd, { passive: false }) canvas.addEventListener('touchcancel', handleTouchEnd, { passive: false }) canvas.addEventListener('mousedown', handleMouseDown) window.addEventListener('mousemove', handleMouseMove) window.addEventListener('mouseup', handleMouseUp) canvas.addEventListener('wheel', handleWheel, { passive: false }) canvas.addEventListener('mousemove', handleCanvasMouseMove) canvas.addEventListener('mouseleave', handleCanvasMouseLeave) // Set initial cursor canvas.style.cursor = 'grab' return () => { canvas.removeEventListener('touchstart', handleTouchStart) canvas.removeEventListener('touchmove', handleTouchMove) canvas.removeEventListener('touchend', handleTouchEnd) canvas.removeEventListener('touchcancel', handleTouchEnd) canvas.removeEventListener('mousedown', handleMouseDown) window.removeEventListener('mousemove', handleMouseMove) window.removeEventListener('mouseup', handleMouseUp) canvas.removeEventListener('wheel', handleWheel) canvas.removeEventListener('mousemove', handleCanvasMouseMove) canvas.removeEventListener('mouseleave', handleCanvasMouseLeave) if (longPressTimerRef.current) clearTimeout(longPressTimerRef.current) if (mouseLongPressTimer) clearTimeout(mouseLongPressTimer) } }, [ canvasRef, stateRef, onStateChange, onZoomVelocity, onTap, onHover, onLongPress, getCanvasWidth, getCanvasRect, ]) } |