figcraft/docs/interaction-measurements.md

Interaction measurements

Last reviewed: 2026-11-08 · Last updated: 2026-11-08 · Change: minor (first record of the interactions measured against Figma, case by case) · Target: Figma Design web app, measured 2026-11-08

On 2026-11-08 a set of interactions was measured in Figma's web app and compared with FigCraft's: modifier keys on move, resize and rotate, arrow keys, zoom steps, auto layout Fill and Hug, instances, components, number field scrubbing, sidebar widths, auto-pan at the viewport edge, copy and paste in vector edit mode, duplicate and paste placement, and text-editing keys. Every measurement used synthetic files, driving the UI and reading the Design and Layers panels (field values, dropdown labels, bounding boxes), or counting pixels on screen where a panel could not show the number. No incumbent screenshots are committed. This complements ui-parity.md and works on gap 4 in gaps.md, "Interaction fidelity not compared tool by tool". It is not a full pass: each section lists what was covered, and the open questions at the end list what could not be measured.

Status values: matches (FigCraft already behaved as measured), fixed in #NNNN (open) (a mismatch found, with the pull request that fixes it, open when this was written; the pull request carries its tests and CI), partly fixed in #NNNN (open) (the same, with what is still missing named), not measured (with the reason), inconclusive. Error margins are given where the measurement had one. Trust the shapes of the rules more than the last digit of a number.

Move, resize and rotate modifiers

Synthetic pointer sequences on the canvas with modifier flags set. Resize handles were pressed 4 px inside the edge, so absolute resize numbers are about 8 px short per side; the cases were read relatively.

Behaviour	Figma (measured)	FigCraft	Status
Shift while moving	locks to the dominant axis (drags of +100,+30 and +100,+90 both gave dy 0); no 45 degree snap	the smaller of dx and dy is zeroed	matches
Alt while moving	a copy stays at the original place and the selection moves (layers 1 to 2)	duplicates on drag, re-synced with the Alt key	matches
Ctrl while moving	inconclusive: with Ctrl from the start the layer did not move, with Ctrl late in the drag it still snapped; a synthetic Ctrl does not seem to reach Figma as the modifier	Ctrl or Cmd turns snapping off	not measured (synthetic Ctrl is not delivered as a modifier)
Shift while resizing	corner (+50,+10) on a 100 by 50 layer keeps the ratio; right edge (+50,0) scales the height too, about the vertical centre	corner by the dominant factor about the opposite corner; edge about the opposite edge's middle	matches
Alt while resizing	a right edge grows symmetrically, the centre kept	resizes from the centre	matches
Shift and Alt on a corner	proportional, centre kept	both	matches
Modifier changed mid-drag	Shift on the second half locks; Shift on then off unlocks again; read fresh on every move	modifiers read on each move	matches
Shift while rotating	snaps the absolute angle to multiples of 15	snapped the change in angle	fixed in #2096 (open)
Space while drawing or marquee	not measurable through the browser	not compared	not measured (the browser does not deliver it)

Nudge and arrow pan

Real keys; pan distances read from screenshots, plus or minus 3 px.

Behaviour	Figma (measured)	FigCraft	Status
Arrow keys on a selection	nudge 1 document px, 10 with Shift, at any zoom	same	matches
Arrow keys with nothing selected	pan the view: Right about 62 to 64 px (two trials), Shift+Right about 320 px (5 times)	20 and 200 px (PAN_STEP_PX, 10 times)	fixed in #2106 (open)

Zoom steps and fit

Real keys. The canvas was 1389 by 903 CSS px with the floating bottom toolbar over it.

Behaviour	Figma (measured)	FigCraft	Status
Zoom in from 100%	200, 400, 800, 1600, 3200, 6400, 12800, 25600 (maximum)	same steps (STEPS in cmd/view.rs)	matches
Zoom out from 100%	50, 25, 13, 6, 3, 2 (minimum)	same	matches
Zoom from a typed 150%	in gives 200, out gives 100 (snaps to the list)	same	matches
Zoom to fit (Shift+1)	a 100 by 100 layer at 793% (vertical margin about 55 px); a 1000 by 200 layer at 134% (horizontal margin about 24 px each side); not a fixed 64 px margin, and not separated from the toolbar overlay	not changed	inconclusive (the toolbar overlay mixes into the margins)
Zoom to selection (Shift+2)	a 10 by 10 layer at 7630%, about 39 px above and about 100 px below (toolbar)	not changed	inconclusive (same overlay)

Snapping and menus

Measured earlier the same day; recorded here by pull request only.

Behaviour	Figma (measured)	FigCraft	Status
Snap threshold	a layer snaps about 4.5 screen px from a guide, at 100% and 200%	snapped at 5 screen px	fixed in #2086 (open)
Submenu opening	a submenu opens about 11 ms after its row is hovered; no safe triangle seen	opened after 0.15 s, with a safe triangle	delay fixed in #2093 (open); the safe triangle FigCraft keeps is unresolved (none seen in Figma; asked in #2093)

Auto layout: Fill and Hug

Values read from the zoomed Design panel's fields and dropdowns, in horizontal rows hugging height unless noted.

Behaviour	Figma (measured)	FigCraft	Status
Cross axis: a child set to Fill in a hugging parent	the child stretches to the tallest sibling; the parent stays Hug (child 40 Fill, parent 40 Hug; sibling typed to 60 gives 60 Fill and 60 Hug); no notice	turned the hugging parent Fixed	fixed in #2099 (open)
Cross axis: every child set to Fill	when the last non-Fill child is set, toast "Height set to Fixed for Frame 1" and the parent turns Fixed at its current size; typing 80 on the parent gives 80 Fixed with both children 80 Fill	the parent turned Fixed and the child kept its own size	fixed in #2099 (open)
Vertical stack hugging width	C (20 by 10) set to W Fill gives C 100 and the parent 100 Hug; D typed to 150 gives C 150, parent 150 Hug; no toast	the parent turned Fixed and the child kept its own size	fixed in #2099 (open)
Padding with a stretched child	padding 10 top and bottom, parent H 60 Hug; child H Fill gives 40 (the content box), parent stays 60 Hug	the parent turned Fixed and the child kept its own size	fixed in #2099 (open)
Min height on a stretched child	min height 50 gives child 50 Fill and parent 50 Hug (the stretched child's minimum counts toward the hug size)	the parent turned Fixed and the child kept its own size	fixed in #2099 (open)
Text sibling	rect H Fill beside two lines of text (Inter 24, line height 32): text 64 Hug, rect 64 Fill, parent 64 Hug; a third line gives 96, 96, 96 Hug	the parent turned Fixed and the child kept its own size	fixed in #2099 (open)
Main axis: a Fill child in a hugging parent	the parent turns Fixed (toast "Width set to Fixed for Frame 1", parent 197 Fixed)	the parent becomes fixed	matches
Wrap on, Fill height on a child	"Fill container" for height is greyed out on a child of a wrapping row (checked only with the parent hugging height)	not compared	not measured (only the hugging case was checked)
Setting a parent to Hug while a child fills along it	the child turns Fixed with the toast Width set to Fixed for Rectangle 1 (the child's name)	demoted the child silently	fixed in #2099 (open)

Instances

Behaviour	Figma (measured)	FigCraft	Status
Main component width and height follow its content	main: horizontal auto layout, W Hug, H Hug (135 by 49); a pasted instance reads the same	instance root sizing did not follow its main	fixed in #2099 (open)
A child set to Fill along the main axis	toast "Width set to Fixed for Frame 1"; main W Fixed 135, H Hug; the plain instance turns W Fixed 135 too, H Hug	the instance's own resizing never followed its main	fixed in #2099 (open)
Instance with its width overridden to 200	stays W 200 Fixed through the main's change, H keeps following (Hug)	the instance's own resizing never followed its main	fixed in #2099 (open)
Main set back to Hug contents	toast "Width set to Fixed for Rectangle 1"; main 135 Hug; the plain instance back to 135 Hug; the overridden one stays 200 Fixed	the instance's own resizing never followed its main	fixed in #2099 (open)
Undo after the Fill change	unreliable in the web app (reverted the child, left the main Fixed)	not compared	inconclusive (not used as evidence)

Components

Third entry of the sidebar header's component dropdown, several layers selected.

Behaviour	Figma (measured)	FigCraft	Status
Create component set on frames named "Primary", "Secondary", "Ghost"	one set named "Component 1"; variants show their bare names; one property "Property 1" with the names as values, in canvas order left to right	no Create component set	fixed in #2095 (open)
Frames named "Size=Small", "Size=Large", "Size=Medium"	set "Component 1"; property "Size", values parsed from the names (Layers shows "Small", "Large", "Medium")	no Create component set	fixed in #2095 (open)
Three frames all named "Card"	set named "Card"; property "Property 1", every variant "Default"; the panel warns that some variants share property values, with "Select conflicting variants"	no Create component set	partly fixed in #2095 (open): the set and its names; the duplicate-value warning and Select conflicting variants are not added
Layout of the new set	no auto layout; the frames stay where they were; the set (purple dashed frame, stroke #8A38F5 inside 1 px, corner radius 5) wraps them with 20 px on every side; the set is selected afterwards; one undo reverts everything	no Create component set	fixed in #2095 (open)
Wrap style, caret in one paragraph	Balance re-wraps only that paragraph; with the layer selected the control shows "Mixed"	a wrap style per layer only	fixed in #2094 (open)
Wrap style set on the whole layer	Pretty overwrites the paragraph's Balance; editing again, both paragraphs show Pretty	a wrap style per layer only	fixed in #2094 (open)
Text style carrying the wrap style	not checked	not compared	not measured (not checked)

Number field scrubbing

Real drags on the field's label; values read from the input.

Behaviour	Figma (measured)	FigCraft	Status
X from 100	a 12.2 CSS px drag right gives 106; a 61.2 CSS px drag gives 131; about 0.5 per CSS px, whole numbers	1 per point, with a speed factor by height	fixed in #2102 (open)
Rotation	a 12.2 CSS px drag right on its icon gave -6 degrees (one clean run; direction to confirm)	1 per point	fixed in #2102 (open)
Opacity from 100%	12.2 CSS px left gives 95% (about 0.4 per px); clamped at 100 going right	1 per point	fixed in #2102 (open)
Shift and Alt rates	synthetic events did not reach the label's handlers	ten times with Shift, a tenth with Alt	not measured (not deliverable through the browser)
Pointer lock	not measured	not compared	not measured

Sidebars

Read with getBoundingClientRect at a 1920 CSS px viewport, device pixel ratio 1.

Behaviour	Figma (measured)	FigCraft	Status
Left sidebar	default 240, minimum 240, maximum about 450 (451 with the border)	200 to 480	fixed in #2103 (open)
Right sidebar	default 240 (241 with the border), minimum 240, maximum 500	240 to 480	fixed in #2103 (open)
Edge	a double-click resets to the default; the hit zone is a couple of px wide	double-click resets	matches

Auto-pan at the viewport edge

Synthetic held drags at 100% zoom, pan speeds read from timed holds (0.5, 1.0, 1.5 and 3.0 s, linear in time).

Behaviour	Figma (measured)	FigCraft	Status
Moving a layer with the pointer near an edge	40, 25 and 15 px inside: no pan; 12 px inside about 120 px/s; 8 px about 275 px/s; 2 px 520 to 530 px/s; 30 px outside about 600 px/s	no auto-pan for any drag	fixed in #2104 (open)
Fit of the speed	speed = clamp(40 x (15 - d), 0, 600) screen px per second, d = distance inside the edge (negative outside); zone about 14 to 15 px; cap about 600 px/s; no acceleration	n/a	fixed in #2104 (open)
Marquee, drawing a rectangle, dragging a prototype connection	the same pan (bottom, left and right edges tested)	none	fixed in #2104 (open)
Resize, rotate and other gestures	not measured	not compared	not measured
Speed at other zooms	not measured (taken as screen px per second)	not compared	not measured

Vector edit clipboard

Real keys and clicks, an open pen path A-B-C-D (three segments), vector edit mode entered on it.

Behaviour	Figma (measured)	FigCraft	Status
Copy a segment, leave edit mode, paste	a new layer holding only that segment, in place, sized to it	copied the whole layer	fixed in #2105 (open)
Copy one point, paste	a new layer holding the segments touching the point, in place	copied the whole layer	fixed in #2105 (open)
Cut a segment	removed from the network; the path splits into two subpaths in the same layer; edit mode stays; pasting outside gives a new layer with the cut segment, in place	deleted the segment without copying it	fixed in #2105 (open)
Paste while editing the same vector	no new layer; a duplicate of the segment is added to the network in place; the pasted points are selected	did nothing	fixed in #2105 (open)
Paste a copied rectangle while editing a vector	the rectangle's outline joins the network in place (four corners selected); no new layer; the bounds grow to include it	did nothing	fixed in #2105 (open)

A click on a segment's middle can add a point there in Figma's edit mode (seen once); it did not change the rules above.

Duplicate and paste

Behaviour	Figma (measured)	FigCraft	Status
Ctrl+D	a copy in place, selected, just above	same	matches
Move the copy +100, Ctrl+D	repeats +100 (smart duplicate); a reselect forgets the step	same	matches
Alt-drag +100, Ctrl+D	repeats (+200 in total)	same	matches
Paste with the original in view	in place on it, selected, just above	same	matches
Paste with the original off screen	at the view's centre	same	matches
Paste with a frame selected (far away)	inside the frame, at its centre	same	matches
Tests for the three paste placement rules	the three rules above	already as measured; no test pinned them	matches (pinned by tests in #2108, open)
Ctrl+Shift+V (paste over)	not measured (chord blocked or slow)	paste over at the selection's top-left	not measured (chord blocked or slow)

Selection keys

Behaviour	Figma (measured)	FigCraft	Status
Escape with a nested layer selected	one Escape selects nothing, whether the layer was selected on the canvas, from the Layers panel or by Tab	selected the parent first	fixed in #2107 (open)

Text-editing keys

Defaults for a new text: Inter Regular 12, line height Auto, letter spacing 0%.

Behaviour	Figma (measured)	FigCraft	Status
Ctrl+Shift+> and <	font size +1 and -1 (12 to 18 stepped)	step 1	matches
Alt+Shift+> and <	line height +1 and -1 px; from Auto at 12 it starts about 15 (not exact)	from the resolved height, 1 px	matches
Alt+> and <	letter spacing +1% and -1%	1%	matches
Ctrl+B, I, U on a selected layer	toggles bold, italic, underline	same	matches
Double-click a word while editing	selects the word	same	matches
Triple-click	selects the line (paragraph)	same	matches
Escape while editing	leaves editing, the layer stays selected	same	matches
Ctrl+A while editing	selects all the text	same	matches

Open questions

Behaviour	Figma (measured)	FigCraft	Status
Add auto layout (Shift+A) defaults	two 40 by 40 layers side by side: horizontal, gap "Auto", padding 0, W Fixed (140), H Hug (40); the same with a Y offset of 30 drops the offset; stacked: vertical, gap 60 (numeric), W Fixed (40), H Hug (140); a single 40 by 40 layer: new frame, W and H Hug (60), padding 10, gap 10; an existing 300 by 200 frame with two layers: W stays Fixed (300), H becomes Hug (149), gap "Auto", padding 49	Hug on both axes for a wrapped selection and an inferred gap	inconclusive (inconsistent between cases in Figma itself: the gap is "Auto" in one case and numeric in another, the cross axis Fixed in the vertical case; the inference has more inputs than measured)

Also open, as listed in their sections: the zoom-to-fit margins (zoom section, inconclusive because of the toolbar overlay), Space while drawing or dragging a selection box and Ctrl while moving (modifiers section, not measurable from the browser), and the Shift and Alt scrub rates (number field section, not measurable).

Revision history

Date	Change	Summary
2026-11-08	minor	Created from the 2026-11-08 black-box comparison of FigCraft's interactions with Figma's, with synthetic files and no committed incumbent screenshots