Skip to content

On-canvas confirm affordance, re-editable signature realism, pinch/drag exclusion #157

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
JamesmarkeyUK merged 2 commits into from
Aug 7, 2026
Merged

On-canvas confirm affordance, re-editable signature realism, pinch/drag exclusion #157

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
fc1b341
Add a confirm affordance beside Delete on a freshly placed object
claude Aug 7, 2026
e63699a
Signature realism after placement, pinch/drag exclusion, placement si…
claude Aug 7, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
158 changes: 17 additions & 141 deletions src/components/Signature/SignaturePad.tsx
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -4,7 +4,8 @@ import type Konva from 'konva'
import { useUniversal } from '@unisim/sdk'
import { useSignatureStore, type SignatureExtras } from '../../stores/signatureStore'
import { useAnnotationStore } from '../../stores/annotationStore'
import { SIGNATURE_INK, formatSigningDate } from '../../lib/signature'
import { formatSigningDate } from '../../lib/signature'
import { inkColorFor, renderInkSignature } from '../../lib/renderInk'
import { composeSignatureWithLabels } from '../../lib/composeSignature'
import type { SignatureData } from '../../types/annotations'
import { brandedQrPngDataUrl } from '../../lib/brandedQr'
Expand All @@ -20,141 +21,6 @@ import {
const PAD_W = 600
const PAD_H = 240

// Small seeded PRNG (mulberry32) so the ink jitter/speckles are deterministic
// for a given drawing — no flicker, stable output.
function mulberry32(seed: number) {
let s = seed >>> 0
return () => {
s = (s + 0x6d2b79f5) >>> 0
let t = Math.imul(s ^ (s >>> 15), 1 | s)
t = (t + Math.imul(t ^ (t >>> 7), 61 | t)) ^ t
return ((t ^ (t >>> 14)) >>> 0) / 4294967296
}
}

// Stroke a smooth path through points using midpoint quadratics (matches the
// clean, tension-smoothed look of the on-screen preview).
function strokeSmooth(ctx: CanvasRenderingContext2D, pts: { x: number; y: number }[]) {
if (pts.length < 2) return
ctx.beginPath()
ctx.moveTo(pts[0].x, pts[0].y)
for (let i = 1; i < pts.length - 1; i++) {
const mx = (pts[i].x + pts[i + 1].x) / 2
const my = (pts[i].y + pts[i + 1].y) / 2
ctx.quadraticCurveTo(pts[i].x, pts[i].y, mx, my)
}
ctx.lineTo(pts[pts.length - 1].x, pts[pts.length - 1].y)
ctx.stroke()
}

// Render the captured pen strokes. With `realistic` on, lays down deep-blue ink
// with a faint bleed, a shaky-hand wobble, per-segment width variation (thinner
// when moving fast) and a couple of speckles — subtle cues that read as a real
// signature. With it off, draws a clean uniform smoothed line. Returns a
// cropped PNG + its logical (CSS-px) size.
function renderInkSignature(
lines: number[][],
color: string,
realistic: boolean
): { dataUrl: string; width: number; height: number } | null {
let minX = Infinity, minY = Infinity, maxX = -Infinity, maxY = -Infinity
for (const ln of lines) {
for (let i = 0; i < ln.length; i += 2) {
const x = ln[i], y = ln[i + 1]
if (x < minX) minX = x
if (y < minY) minY = y
if (x > maxX) maxX = x
if (y > maxY) maxY = y
}
}
if (!isFinite(minX)) return null

const pad = 6
minX -= pad; minY -= pad; maxX += pad; maxY += pad
const w = Math.max(1, maxX - minX)
const h = Math.max(1, maxY - minY)
const RS = 2

const canvas = document.createElement('canvas')
canvas.width = Math.ceil(w * RS)
canvas.height = Math.ceil(h * RS)
const ctx = canvas.getContext('2d')!
ctx.scale(RS, RS)
ctx.translate(-minX, -minY)
ctx.lineCap = 'round'
ctx.lineJoin = 'round'
ctx.strokeStyle = color
ctx.fillStyle = color

const rnd = mulberry32(0x5eed)
const JITTER = realistic ? 0.6 : 0
const BASE_W = 2.4

for (const ln of lines) {
const pts: { x: number; y: number }[] = []
for (let i = 0; i < ln.length; i += 2) {
pts.push({
x: ln[i] + (rnd() * 2 - 1) * JITTER,
y: ln[i + 1] + (rnd() * 2 - 1) * JITTER
})
}
if (pts.length === 0) continue
if (pts.length === 1) {
ctx.globalAlpha = 0.9
ctx.beginPath()
ctx.arc(pts[0].x, pts[0].y, BASE_W * 0.6, 0, Math.PI * 2)
ctx.fill()
continue
}

// Clean mode: one uniform smoothed stroke, no bleed/variation/speckles.
if (!realistic) {
ctx.globalAlpha = 1
ctx.lineWidth = 2.5
strokeSmooth(ctx, pts)
continue
}

// Faint, slightly-wider blurred underlay → ink bleed.
ctx.save()
ctx.globalAlpha = 0.16
ctx.lineWidth = BASE_W * 1.9
try { ctx.filter = 'blur(0.6px)' } catch { /* filter unsupported — plain wide line */ }
ctx.beginPath()
ctx.moveTo(pts[0].x, pts[0].y)
for (let i = 1; i < pts.length; i++) ctx.lineTo(pts[i].x, pts[i].y)
ctx.stroke()
ctx.restore()

// Main pass: per-segment width + subtle alpha/width noise.
for (let i = 1; i < pts.length; i++) {
const a = pts[i - 1], b = pts[i]
const d = Math.hypot(b.x - a.x, b.y - a.y)
let segW = BASE_W * (1 - Math.min(0.45, d / 45))
segW *= 0.85 + rnd() * 0.3
ctx.globalAlpha = 0.82 + rnd() * 0.18
ctx.lineWidth = Math.max(0.8, segW)
ctx.beginPath()
ctx.moveTo(a.x, a.y)
ctx.lineTo(b.x, b.y)
ctx.stroke()
}

// A couple of tiny ink speckles near the stroke.
const speckles = 1 + Math.floor(rnd() * 2)
for (let k = 0; k < speckles; k++) {
const p = pts[Math.floor(rnd() * pts.length)]
ctx.globalAlpha = 0.35 + rnd() * 0.3
ctx.beginPath()
ctx.arc(p.x + (rnd() * 2 - 1) * 2, p.y + (rnd() * 2 - 1) * 2, 0.4 + rnd() * 0.7, 0, Math.PI * 2)
ctx.fill()
}
}

ctx.globalAlpha = 1
return { dataUrl: canvas.toDataURL('image/png'), width: w, height: h }
}

// iOS-style toggle used by the advanced options.
function OptionToggle({
checked,
Expand Down Expand Up @@ -312,7 +178,7 @@ export default function SignaturePad() {
// Whether there's anything to place separately (gates the placement control).
const hasExtras = (includeName && !!name.trim()) || includeDate
// Ink colour follows the realism toggle (deep blue vs plain near-black).
const inkColor = realistic ? SIGNATURE_INK : '#0f172a'
const inkColor = inkColorFor(realistic)

if (!open) return null

Expand Down Expand Up @@ -363,10 +229,14 @@ export default function SignaturePad() {
// Bake the ink (plus the field's requested name/date labels) into a single
// PNG and drop it into the signature-request box the user clicked, then
// return to the editor. Used when the pad was opened by clicking a field.
// `strokes` is the raw pen path behind `sig` when it came from this pad. It
// rides along so the placed signature's realism can still be toggled later;
// a phone/imported image arrives already rasterised and passes nothing.
async function fillField(
fieldId: string,
sig: { dataUrl: string; width: number; height: number },
trimmedName: string
trimmedName: string,
strokes?: number[][]
) {
const ann = useAnnotationStore.getState().annotations.find((a) => a.id === fieldId)
if (!ann || ann.type !== 'sigfield') {
Expand Down Expand Up @@ -402,7 +272,9 @@ export default function SignaturePad() {
showDate: wantDate,
align: 'center',
labelScale: 1,
color: inkColor
color: inkColor,
strokes: strokes && strokes.length > 0 ? strokes : undefined,
realistic
}
useAnnotationStore.getState().update(fieldId, { signed: { src, width: w, height: h, data } })
resetForm()
Expand All @@ -421,7 +293,7 @@ export default function SignaturePad() {
// instead of adding a reusable library signature.
const fieldId = useSignatureStore.getState().signingFieldId
if (fieldId) {
await fillField(fieldId, ink, trimmed)
await fillField(fieldId, ink, trimmed, lines)
return
}

Expand Down Expand Up @@ -462,7 +334,11 @@ export default function SignaturePad() {
showDate: wantDate && !separatePlacement,
align: 'center',
labelScale: 1,
color: inkColor
color: inkColor,
// Keep the pen path so realism stays a toggle after placement, not a
// decision frozen at draw time.
strokes: lines,
realistic
}

add({ name: sigName, dataUrl: finalUrl, width: finalW, height: finalH, extras, sig })
Expand Down
Loading