mirror of
https://github.com/DayuanJiang/next-ai-draw-io.git
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db9db1ff4e
The expressiveness gap between engine output and hand-written XML came down to two missing capabilities, both generic: - Block layout inside a box: nested containers already existed, but there was no way to split space by weight, pin a child to an edge, or tighten padding. Added grow (flex-grow over the parent's leftover flow-axis space, TeX's glue), align (start/center/end/stretch on the cross axis) and pad (per-group interior padding). All three round-trip via dai_grow/dai_align/ dai_pad markers. - Inline rich text: labels already render HTML (html=1 on every style, esc() entities decode back), but the measure pass counted markup as text. The visibleText() strip makes autoBoxSize measure what draw.io draws: <br> is a line, other inline tags are invisible. Graphviz (HTML-like table labels), D2 (grid containers + markdown-in-shape) and TeX (box+glue) converged on exactly this design: nested boxes for block structure, proportional glue, a small inline set for text — never full HTML. Prompts teach the composition with a comparison-card recipe; verified by rebuilding the CoT poster end to end in the real editor.
910 lines
33 KiB
TypeScript
910 lines
33 KiB
TypeScript
/**
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* Layout: tree → coordinates.
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*
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* Two passes, the same shape as a flexbox implementation:
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*
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* measure — bottom-up. A leaf reports its intrinsic size; a container sums its
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* children along the flow axis, takes the maximum across it, and adds
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* padding and its title strip. A container therefore always ends up big
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* enough to hold what is inside it, which is why "child spills out of its
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* frame" cannot happen by construction.
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*
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* place — top-down. Each container distributes its now-known interior among its
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* children.
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*
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* The model never supplies a coordinate. It declares nesting, direction and gap; every
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* x/y/width/height comes from here.
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*
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* Five container kinds share those two passes, because they differ only in how a parent
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* distributes its interior:
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*
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* group — children stacked along one axis. Cloud architecture, nested frames.
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* grid — children packed into a fixed number of columns.
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* pool — a sparse (lane × column) grid. Swimlane and BPMN diagrams.
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* sequence — participants across the top, lifelines below. Sequence diagrams.
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* radial — a centre with branches fanning out, or hanging below. Mind maps, org charts.
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*
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* Ported from drawio-ai-kit (MIT) — see NOTICE. The pool geometry follows that project's
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* `pool()` primitive; sequence and radial are original to this repository.
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*/
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import { type Role, roleMetrics } from "./theme"
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import type {
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ContainerNode,
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DiagramNode,
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PoolNode,
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RadialNode,
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Rect,
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SequenceNode,
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} from "./types"
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import { isContainer } from "./types"
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/** Default glyph size for a catalog icon. */
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export const ICON_SIZE = 48
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/** Interior padding of a container. */
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const PAD = 24
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/** A group's interior padding: its own `pad` when declared, the default otherwise. */
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function padOf(n: ContainerNode): number {
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return n.kind === "group" && n.pad != null ? Math.max(0, n.pad) : PAD
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}
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/** The flex-grow weight a node declared, 0 when none. */
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function growOf(n: DiagramNode): number {
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const g = (n.kind === "box" || n.kind === "group") && n.grow
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return typeof g === "number" && g > 0 ? g : 0
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}
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/** The cross-axis alignment a node declared. */
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function alignOf(n: DiagramNode): "start" | "center" | "end" | "stretch" {
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const a = (n.kind === "box" || n.kind === "group") && n.align
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return a === "start" || a === "end" || a === "stretch" ? a : "center"
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}
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/** Height of a container's title strip. Zero when it has no label — an empty strip
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* reads as a dead band at the top of the frame. */
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const HEADER = 36
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/** Approximate width of one label character at the engine's font size. */
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const CHAR_W = 6.6
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// ---- pool geometry, shared with render.ts so the bands land under the nodes ----
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/** Interior padding of a pool. Tighter than a group's: lane bands sit flush. */
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export const POOL_PAD = 16
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/** Width of the lane-name column (height, when the pool is vertical). */
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export const LANE_LABEL = 110
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/** Height of the milestone band (width, when the pool is vertical). */
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const PHASE_LABEL = 26
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/** A pool's own title strip. */
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const POOL_HEADER = 34
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/** Vertical padding inside a lane band, so nodes do not touch the band's edges. */
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const LANE_PAD = 14
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// ---- sequence geometry ----
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/** Height of a participant head. */
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const HEAD_H = 44
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/** Vertical distance from the participant heads to the first message. */
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const LIFELINE_TOP = 28
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/** How far the lifeline runs past the last message. */
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const LIFELINE_TAIL = 36
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/**
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* The geometry a pool needs, derived once and used by both layout and rendering.
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*
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* Rendering has to paint the lane bands and label columns at exactly the positions layout
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* used, or the nodes sit off their bands. Computing it in one place is what keeps the two
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* from drifting.
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*/
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export interface PoolMetrics {
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horizontal: boolean
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lanes: number
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cols: number
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/** Cell size along the flow axis. */
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cellW: number
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/** Cell size across the lane axis. */
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cellH: number
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header: number
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phaseLabel: number
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/** Where cell (0,0) starts. */
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contentX: number
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contentY: number
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/** Total extent of the cell area. */
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contentW: number
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contentH: number
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}
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export function poolMetrics(
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n: PoolNode,
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rect: Rect,
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kids: { rect: Rect }[],
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): PoolMetrics {
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const horizontal = n.orientation !== "vertical"
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const lanes = Math.max(1, n.lanes.length)
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const cols = Math.max(1, ...n.children.map((c) => poolCellOf(c).col + 1))
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const cellW = Math.max(80, ...kids.map((k) => k.rect.w))
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const cellH = Math.max(40, ...kids.map((k) => k.rect.h)) + LANE_PAD
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const header = n.label ? POOL_HEADER : 0
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const phaseLabel = n.phases.length ? PHASE_LABEL : 0
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const contentW = horizontal
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? cols * cellW + n.gap * (cols - 1)
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: lanes * cellW
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const contentH = horizontal
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? lanes * cellH
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: cols * cellH + n.gap * (cols - 1)
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return {
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horizontal,
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lanes,
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cols,
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cellW,
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cellH,
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header,
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phaseLabel,
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contentX: horizontal
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? rect.x + POOL_PAD + LANE_LABEL
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: rect.x + POOL_PAD,
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contentY: horizontal
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? rect.y + header + phaseLabel + POOL_PAD
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: rect.y + header + POOL_PAD + LANE_LABEL,
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contentW,
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contentH,
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}
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}
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/** How far a sequence diagram's lifelines run, and where each message sits. */
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export interface SequenceMetrics {
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/** Bottom of the lifeline. */
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bottom: number
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/** Vertical position of message N, for N starting at 1. */
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messageY: (step: number) => number
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}
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export function sequenceMetrics(
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n: SequenceNode,
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rect: Rect,
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messages: number,
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): SequenceMetrics {
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const head = n.label ? HEADER : 0
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// The first message hangs a fixed distance below the participant heads.
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const first = rect.y + head + PAD + HEAD_H + LIFELINE_TOP
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return {
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bottom: first + Math.max(0, messages - 1) * n.step + LIFELINE_TAIL,
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messageY: (step) => first + Math.max(0, step - 1) * n.step,
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}
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}
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/** A node with its computed box. Layout works on this, leaving the tree untouched. */
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export interface Placed {
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node: DiagramNode
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rect: Rect
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children: Placed[]
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}
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/**
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* The arrows layout needs, which the node tree alone does not carry.
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*
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* Three of the five container kinds are laid out from the diagram's arrows, not from
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* nesting: a sequence diagram's messages set how tall the lifelines have to be, and a mind
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* map's hierarchy IS its arrows. Links live on the tree, not on the node, so they are
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* passed down rather than read from a parent pointer.
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*/
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export type LayoutLinks = { source: string; target: string; step?: number }[]
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/**
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* Reduce a label to the text draw.io will actually lay out.
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*
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* Labels may carry inline HTML (every style has `html=1`): a <br> is a line break, any
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* other tag is invisible markup around visible text. Measuring the raw string counted
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* `<font color="#B85450">` as thirty characters of text, making rich boxes twice as
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* wide as their content.
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*/
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function visibleText(label: string): string {
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return String(label ?? "")
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.replace(/<br\s*\/?>/gi, "\n")
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.replace(/<\/?(?:b|i|u|s|sub|sup|font|span|div)(?:\s[^<>]*)?>/gi, "")
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}
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/**
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* Intrinsic size of a text box: widest wrapped line by line count.
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*
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* The role scales the estimate: a banner sets 20px type and a footnote 9px, and layout has
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* to reserve what render will draw or the text overflows its cell.
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*/
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export function autoBoxSize(
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label: string,
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role?: Role,
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): { w: number; h: number } {
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const r = roleMetrics(role)
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const maxW = Math.round(260 * Math.max(1, r.charScale))
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const explicit = visibleText(label).split("\n")
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const longest = Math.max(1, ...explicit.map((l) => l.length))
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const w = Math.min(
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maxW,
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Math.max(120, Math.round(longest * CHAR_W * r.charScale + 28)),
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)
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// Count the lines the text ACTUALLY occupies: draw.io wraps at the box width, so a
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// long line becomes several. Estimating by explicit newlines alone left the box one
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// line tall while the text wrapped to six — and overflowed straight out of it.
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const charsPerLine = Math.max(
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8,
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Math.floor((w - 28) / (CHAR_W * r.charScale)),
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)
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const lines = explicit.reduce(
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(sum, l) => sum + Math.max(1, Math.ceil(l.length / charsPerLine)),
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0,
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)
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const lineH = Math.round(r.fontSize * 1.6)
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return { w, h: Math.max(r.minH, lines * lineH + 26) }
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}
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/**
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* Intrinsic size of an icon cell: the glyph, plus room for the label underneath, and
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* wide enough that a long label does not overflow the cell it is centred in.
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*/
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function iconSize(label: string, glyph: number): { w: number; h: number } {
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return {
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w: Math.max(96, glyph + 20, Math.min(200, label.length * 7 + 24)),
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h: glyph + 34,
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}
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}
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/** A container is never narrower than its own title. */
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function titleFloor(label: string, pad: number): number {
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return label ? Math.ceil(label.length * CHAR_W) + pad * 2 : 0
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}
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function headerFor(n: ContainerNode): number {
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if (n.kind === "pool") return n.label ? POOL_HEADER : 0
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return n.label ? HEADER : 0
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}
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/**
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* The cell a node occupies inside a pool. Absent means (0,0).
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*
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* No clamping needed: `add_icon`/`add_box` clamp at the boundary where the model's numbers
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* arrive, and the only other way a cell gets set is the parser, whose `dai_cell` pattern
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* matches digits only. So by here it is already non-negative.
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*/
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export function poolCellOf(n: DiagramNode): { lane: number; col: number } {
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if ((n.kind === "icon" || n.kind === "box") && n.cell) return n.cell
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return { lane: 0, col: 0 }
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}
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/**
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* How many messages a sequence container has: the highest step number among the links
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* between its participants, or the link count when the model numbered nothing.
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*
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* Steps are what order the messages vertically, so a diagram whose links carry no step
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* still needs one row per message — otherwise every arrow lands on the same y.
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*/
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export function messageCount(n: SequenceNode, links: LayoutLinks): number {
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const own = new Set(n.children.map((c) => c.id))
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const mine = links.filter((l) => own.has(l.source) && own.has(l.target))
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const steps = mine
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.map((l) => l.step)
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.filter((s): s is number => s != null && s > 0)
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return Math.max(mine.length, ...(steps.length ? steps : [0]))
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}
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/**
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* One node of a radial tree: a placed box plus the branches hanging off it.
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*
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* Separate from `Placed` because the tree is derived from the LINKS, not from nesting, so it
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* exists only during a radial container's layout.
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*/
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interface RadialTree {
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p: Placed
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kids: RadialTree[]
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/** How much room this whole subtree needs across the branching axis. */
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extent: number
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}
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/**
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* Build the branch hierarchy of a radial container from the diagram's arrows.
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*
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* The root is the node nothing points at. Every other node hangs off whichever node points
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* at it — the FIRST one, if several do, since a mind map is a tree and a second parent has
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* to be drawn as a plain cross-link instead.
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*
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* A node no arrow reaches at all becomes a branch of the root, so it is still drawn. Dropping
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* it would silently lose a box the model asked for.
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*/
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function radialHierarchy(
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kids: Placed[],
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links: LayoutLinks,
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across: "w" | "h",
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gap: number,
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): { root: RadialTree; branches: RadialTree[] } | null {
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if (kids.length === 0) return null
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const own = new Map(kids.map((k) => [k.node.id, k]))
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const parent = new Map<string, string>()
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for (const l of links) {
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if (!own.has(l.source) || !own.has(l.target)) continue
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if (l.source === l.target) continue
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if (!parent.has(l.target)) parent.set(l.target, l.source)
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}
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// Guard against a cycle in the arrows: walking up must terminate.
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const rootOf = (id: string): string => {
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const seen = new Set<string>([id])
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let cur = id
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for (;;) {
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const up = parent.get(cur)
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if (up === undefined || seen.has(up)) return cur
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seen.add(up)
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cur = up
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}
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}
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// The first declared node that is nobody's child is the centre. Falling back to the first
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// child keeps a cycle-only graph drawable.
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const rootId =
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kids.find((k) => !parent.has(k.node.id))?.node.id ??
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rootOf(kids[0].node.id)
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const childrenOf = new Map<string, Placed[]>()
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for (const k of kids) {
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if (k.node.id === rootId) continue
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const up = parent.get(k.node.id)
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// An orphan, or a node whose parent chain loops back on itself, attaches to the root.
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// `up === k.node.id` cannot happen: self-links are skipped when `parent` is built.
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const attach =
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up !== undefined && rootOf(k.node.id) === rootId ? up : rootId
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const list = childrenOf.get(attach)
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if (list) list.push(k)
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else childrenOf.set(attach, [k])
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}
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// No visited-set needed: `parent` records at most one parent per node, so `childrenOf`
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// is a forest by construction, and `rootOf` above already reattached anything whose
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// parent chain looped. The recursion cannot revisit a node.
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const build = (p: Placed): RadialTree => {
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const kidTrees = (childrenOf.get(p.node.id) ?? []).map(build)
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const total =
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kidTrees.reduce((s, t) => s + t.extent, 0) +
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gap * Math.max(0, kidTrees.length - 1)
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return {
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p,
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kids: kidTrees,
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extent: Math.max(p.rect[across], total),
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}
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}
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const root = build(own.get(rootId) as Placed)
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return { root, branches: root.kids }
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}
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/** Widest node at each generation, for laying a radial tree out in even rings. */
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function widestPerLevel(trees: RadialTree[], along: "w" | "h"): number[] {
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const out: number[] = []
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const visit = (t: RadialTree, level: number) => {
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out[level] = Math.max(out[level] ?? 0, t.p.rect[along])
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for (const k of t.kids) visit(k, level + 1)
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}
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for (const t of trees) visit(t, 0)
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return out
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}
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/**
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* How far one side of a radial map reaches from the centre.
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*
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* Each generation contributes one gap plus the width of the widest node in it. This has to be
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* computed per SIDE, not once for the whole map: a mind map whose left branches go three
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* generations deep and whose right branches go one needs an asymmetric frame, and reserving
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* the same room on both sides would push the deeper side off the page.
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*/
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function radialReach(
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side: RadialTree[],
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along: "w" | "h",
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gap: number,
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): number {
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// widestPerLevel writes one entry per generation that exists, so its length IS the depth
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// of the deepest branch on this side. An empty side yields an empty list, and reducing
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// that from 0 already gives 0.
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return widestPerLevel(side, along).reduce((s, v) => s + v + gap, 0)
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}
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/**
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* Split a radial map's branches into the two sides they will be drawn on.
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*
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* The same split has to be used by measure and by place, or the frame is sized for one
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* arrangement and the branches are drawn in another.
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*/
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function radialSides(branches: RadialTree[]): {
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right: RadialTree[]
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left: RadialTree[]
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} {
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const half = Math.ceil(branches.length / 2)
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return { right: branches.slice(0, half), left: branches.slice(half) }
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}
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/**
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* measure: give every node a size, bottom-up.
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*
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* Siblings are equalised across the cross axis — frames in a row share a bottom edge,
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* frames in a column share left and right edges. Only containers stretch; a leaf keeps
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* its natural size, because stretching an icon would distort the glyph.
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*/
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function measure(
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n: DiagramNode,
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defaultGlyph: number,
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links: LayoutLinks,
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): Placed {
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if (n.kind === "icon") {
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const glyph = n.size ?? defaultGlyph
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const s = iconSize(n.label, glyph)
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return { node: n, rect: { x: 0, y: 0, ...s }, children: [] }
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}
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if (n.kind === "box") {
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const auto = autoBoxSize(n.label, n.role)
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return {
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node: n,
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rect: { x: 0, y: 0, w: n.w ?? auto.w, h: n.h ?? auto.h },
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children: [],
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}
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}
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if (n.kind === "title") {
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return { node: n, rect: { x: 0, y: 0, w: 0, h: 30 }, children: [] }
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}
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const kids = n.children.map((c) => measure(c, defaultGlyph, links))
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const head = headerFor(n)
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const gap = n.gap
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if (n.kind === "pool") {
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const m = poolMetrics(n, { x: 0, y: 0, w: 0, h: 0 }, kids)
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const w = m.horizontal
|
||
? POOL_PAD * 2 + LANE_LABEL + m.contentW
|
||
: POOL_PAD * 2 + m.contentW + m.phaseLabel
|
||
const h = m.horizontal
|
||
? m.header + m.phaseLabel + POOL_PAD * 2 + m.contentH
|
||
: m.header + POOL_PAD * 2 + LANE_LABEL + m.contentH
|
||
return {
|
||
node: n,
|
||
rect: {
|
||
x: 0,
|
||
y: 0,
|
||
w: Math.max(w, titleFloor(n.label, POOL_PAD)),
|
||
h,
|
||
},
|
||
children: kids,
|
||
}
|
||
}
|
||
|
||
if (n.kind === "sequence") {
|
||
// Participants sit side by side; the lifelines below them set the height.
|
||
const w =
|
||
PAD * 2 +
|
||
kids.reduce((s, k) => s + k.rect.w, 0) +
|
||
gap * Math.max(0, kids.length - 1)
|
||
const m = sequenceMetrics(
|
||
n,
|
||
{ x: 0, y: 0, w: 0, h: 0 },
|
||
messageCount(n, links),
|
||
)
|
||
return {
|
||
node: n,
|
||
rect: {
|
||
x: 0,
|
||
y: 0,
|
||
w: Math.max(w, titleFloor(n.label, PAD)),
|
||
h: m.bottom + PAD,
|
||
},
|
||
children: kids,
|
||
}
|
||
}
|
||
|
||
if (n.kind === "radial") {
|
||
const down = n.spread === "down"
|
||
const across = down ? "w" : "h"
|
||
const tree = radialHierarchy(kids, links, across, n.gap)
|
||
if (!tree)
|
||
return {
|
||
node: n,
|
||
rect: { x: 0, y: 0, w: PAD * 2, h: head + PAD * 2 },
|
||
children: kids,
|
||
}
|
||
const { root, branches } = tree
|
||
const spanOf = (bs: RadialTree[]) =>
|
||
bs.length === 0
|
||
? 0
|
||
: bs.reduce((s, b) => s + b.extent, 0) + n.gap * (bs.length - 1)
|
||
|
||
if (down) {
|
||
// Everything hangs below the centre: one direction, so one reach.
|
||
const h = root.p.rect.h + radialReach(branches, "h", n.gap)
|
||
const w = Math.max(root.p.rect.w, spanOf(branches))
|
||
return {
|
||
node: n,
|
||
rect: {
|
||
x: 0,
|
||
y: 0,
|
||
w: Math.max(PAD * 2 + w, titleFloor(n.label, PAD)),
|
||
h: head + PAD * 2 + h,
|
||
},
|
||
children: kids,
|
||
}
|
||
}
|
||
|
||
// Radial: the two sides reach different distances, so each is measured on its own.
|
||
// Using one figure for both would leave the deeper side hanging outside the frame.
|
||
const { right, left } = radialSides(branches)
|
||
const w =
|
||
radialReach(left, "w", n.gap) +
|
||
root.p.rect.w +
|
||
radialReach(right, "w", n.gap)
|
||
const h = Math.max(root.p.rect.h, spanOf(right), spanOf(left))
|
||
return {
|
||
node: n,
|
||
rect: {
|
||
x: 0,
|
||
y: 0,
|
||
w: Math.max(PAD * 2 + w, titleFloor(n.label, PAD)),
|
||
h: head + PAD * 2 + h,
|
||
},
|
||
children: kids,
|
||
}
|
||
}
|
||
|
||
if (n.kind === "grid") {
|
||
const cols = Math.max(1, n.cols)
|
||
const rows = Math.ceil(kids.length / cols) || 1
|
||
const cellW = Math.max(0, ...kids.map((k) => k.rect.w))
|
||
const cellH = Math.max(0, ...kids.map((k) => k.rect.h))
|
||
const w = PAD * 2 + cols * cellW + gap * (cols - 1)
|
||
const h = head + PAD * 2 + rows * cellH + gap * (rows - 1)
|
||
return {
|
||
node: n,
|
||
rect: {
|
||
x: 0,
|
||
y: 0,
|
||
w: Math.max(w, titleFloor(n.label, PAD)),
|
||
h,
|
||
},
|
||
children: kids,
|
||
}
|
||
}
|
||
|
||
// group: row or col
|
||
const pad = padOf(n)
|
||
if (n.dir === "row") {
|
||
const tallest = Math.max(0, ...kids.map((k) => k.rect.h))
|
||
// Only a group stretches to match its siblings. A leaf keeps its natural size,
|
||
// because stretching an icon distorts the glyph; and a grid, pool, sequence or
|
||
// radial computes its interior from its own rule, so forcing one bigger leaves dead
|
||
// space inside rather than filling anything — and for a pool it would detach the
|
||
// lane bands from the nodes sitting on them.
|
||
for (const k of kids)
|
||
if (k.node.kind === "group") k.rect.h = Math.max(k.rect.h, tallest)
|
||
const w =
|
||
pad * 2 +
|
||
kids.reduce((s, k) => s + k.rect.w, 0) +
|
||
gap * Math.max(0, kids.length - 1)
|
||
const h = head + pad * 2 + Math.max(0, ...kids.map((k) => k.rect.h))
|
||
return {
|
||
node: n,
|
||
rect: { x: 0, y: 0, w: Math.max(w, titleFloor(n.label, pad)), h },
|
||
children: kids,
|
||
}
|
||
}
|
||
|
||
const widest = Math.max(0, ...kids.map((k) => k.rect.w))
|
||
// Only a group stretches — same reasoning as the row branch above.
|
||
for (const k of kids)
|
||
if (k.node.kind === "group") k.rect.w = Math.max(k.rect.w, widest)
|
||
const w = pad * 2 + Math.max(0, ...kids.map((k) => k.rect.w))
|
||
const h =
|
||
head +
|
||
pad * 2 +
|
||
kids.reduce((s, k) => s + k.rect.h, 0) +
|
||
gap * Math.max(0, kids.length - 1)
|
||
return {
|
||
node: n,
|
||
rect: { x: 0, y: 0, w: Math.max(w, titleFloor(n.label, pad)), h },
|
||
children: kids,
|
||
}
|
||
}
|
||
|
||
/**
|
||
* place: assign absolute positions, top-down.
|
||
*
|
||
* When a container ended up larger than its content — because a sibling forced it
|
||
* wider, or its own title did — the slack is shared between the children rather than
|
||
* left as dead margin on one side. The extra spacing is capped at one base gap so a
|
||
* stretched frame reads as deliberately spaced instead of sparse, and the resulting
|
||
* cluster is centred.
|
||
*/
|
||
function place(p: Placed, x: number, y: number, links: LayoutLinks): void {
|
||
p.rect.x = Math.round(x)
|
||
p.rect.y = Math.round(y)
|
||
const n = p.node
|
||
if (!isContainer(n)) return
|
||
|
||
const head = headerFor(n)
|
||
const pad = n.kind === "group" ? padOf(n) : PAD
|
||
const innerX = p.rect.x + pad
|
||
const innerTop = p.rect.y + head + pad
|
||
const innerW = p.rect.w - pad * 2
|
||
const innerH = p.rect.h - head - pad * 2
|
||
const kids = p.children
|
||
|
||
if (n.kind === "grid") {
|
||
const cols = Math.max(1, n.cols)
|
||
const cellW = Math.max(0, ...kids.map((k) => k.rect.w))
|
||
const cellH = Math.max(0, ...kids.map((k) => k.rect.h))
|
||
kids.forEach((k, i) => {
|
||
const r = Math.floor(i / cols)
|
||
const c = i % cols
|
||
const cx = innerX + c * (cellW + n.gap)
|
||
const cy = innerTop + r * (cellH + n.gap)
|
||
// centre each child in its cell so a short label does not sit off-axis
|
||
place(
|
||
k,
|
||
cx + (cellW - k.rect.w) / 2,
|
||
cy + (cellH - k.rect.h) / 2,
|
||
links,
|
||
)
|
||
})
|
||
return
|
||
}
|
||
|
||
if (n.kind === "pool") {
|
||
// Each child goes to the (lane, column) cell it declared. Empty cells stay empty:
|
||
// in a swimlane diagram, "this role does nothing at this step" is information.
|
||
const m = poolMetrics(n, p.rect, kids)
|
||
for (const k of kids) {
|
||
const { lane, col } = poolCellOf(k.node)
|
||
const cx = m.horizontal
|
||
? m.contentX + col * (m.cellW + n.gap)
|
||
: m.contentX + Math.min(lane, m.lanes - 1) * m.cellW
|
||
const cy = m.horizontal
|
||
? m.contentY + Math.min(lane, m.lanes - 1) * m.cellH
|
||
: m.contentY + col * (m.cellH + n.gap)
|
||
place(
|
||
k,
|
||
cx + (m.cellW - k.rect.w) / 2,
|
||
cy + (m.cellH - k.rect.h) / 2,
|
||
links,
|
||
)
|
||
}
|
||
return
|
||
}
|
||
|
||
if (n.kind === "sequence") {
|
||
// Participants in a row across the top. Their lifelines hang below, emitted by the
|
||
// renderer, so nothing else has to be placed here.
|
||
let cur = innerX
|
||
for (const k of kids) {
|
||
place(k, cur, innerTop, links)
|
||
cur += k.rect.w + n.gap
|
||
}
|
||
return
|
||
}
|
||
|
||
if (n.kind === "radial") {
|
||
placeRadial(p, n, innerX, innerTop, innerW, innerH, links)
|
||
return
|
||
}
|
||
|
||
const alongRow = n.dir === "row"
|
||
const sizes = kids.map((k) => (alongRow ? k.rect.w : k.rect.h))
|
||
const content = sizes.reduce((s, v) => s + v, 0)
|
||
const extent = alongRow ? innerW : innerH
|
||
const k = kids.length
|
||
let slack = Math.max(0, extent - content - n.gap * (k - 1))
|
||
|
||
// flex-grow: children with a weight split the leftover space between them, TeX's
|
||
// glue. This runs before the gap stretch below — declared weights are a statement
|
||
// about where the slack should go, and padding it into the gaps instead would
|
||
// silently override that statement.
|
||
const weights = kids.map((kid) => growOf(kid.node))
|
||
const totalWeight = weights.reduce((s, v) => s + v, 0)
|
||
if (totalWeight > 0 && slack > 0) {
|
||
kids.forEach((kid, i) => {
|
||
const extra = (slack * weights[i]) / totalWeight
|
||
if (alongRow) kid.rect.w += extra
|
||
else kid.rect.h += extra
|
||
})
|
||
slack = 0
|
||
}
|
||
|
||
const gap = k > 1 ? n.gap + Math.min(n.gap, slack / (k - 1)) : n.gap
|
||
const span =
|
||
kids.reduce((s, kid) => s + (alongRow ? kid.rect.w : kid.rect.h), 0) +
|
||
gap * Math.max(0, k - 1)
|
||
let cur = (alongRow ? innerX : innerTop) + Math.max(0, (extent - span) / 2)
|
||
|
||
for (const kid of kids) {
|
||
// A stretching role fills the cross axis: a masthead spans its page, a section
|
||
// heading spans its column. Measured at its text width, then widened here — the
|
||
// container's size still comes from the widest ordinary child.
|
||
const kn = kid.node
|
||
const a = alignOf(kn)
|
||
const stretches =
|
||
a === "stretch" ||
|
||
(kn.kind === "box" && kn.role && roleMetrics(kn.role).stretch)
|
||
// Cross-axis position: centred unless the child asked for an edge.
|
||
const cross = (room: number, size: number): number => {
|
||
if (a === "start") return 0
|
||
if (a === "end") return Math.max(0, room - size)
|
||
return (room - size) / 2
|
||
}
|
||
if (alongRow) {
|
||
if (stretches) kid.rect.h = innerH
|
||
place(kid, cur, innerTop + cross(innerH, kid.rect.h), links)
|
||
cur += kid.rect.w + gap
|
||
} else {
|
||
if (stretches) kid.rect.w = innerW
|
||
place(kid, innerX + cross(innerW, kid.rect.w), cur, links)
|
||
cur += kid.rect.h + gap
|
||
}
|
||
}
|
||
}
|
||
|
||
/**
|
||
* Place a radial container: a centre with its branches fanning out.
|
||
*
|
||
* Two shapes, because a mind map and an org chart want opposite things. A mind map reads
|
||
* best with branches on both sides of the centre, which keeps it compact and balanced. An
|
||
* org chart must hang everything downwards — a reporting line drawn upwards or sideways
|
||
* reads as the wrong relationship, no matter how much space it saves.
|
||
*
|
||
* Each generation sits in its own ring, the ring's depth set by the widest node in it, so
|
||
* siblings line up instead of stepping raggedly outwards.
|
||
*/
|
||
function placeRadial(
|
||
p: Placed,
|
||
n: RadialNode,
|
||
innerX: number,
|
||
innerTop: number,
|
||
innerW: number,
|
||
innerH: number,
|
||
links: LayoutLinks,
|
||
): void {
|
||
const down = n.spread === "down"
|
||
const along = down ? "h" : "w"
|
||
const across = down ? "w" : "h"
|
||
const tree = radialHierarchy(p.children, links, across, n.gap)
|
||
if (!tree) return
|
||
const { root, branches } = tree
|
||
const centre = root.p
|
||
|
||
/**
|
||
* Lay one generation out along the cross axis, then recurse.
|
||
*
|
||
* `start` is the middle of the band this generation has to fill; each branch gets a slice
|
||
* of it as wide as its own subtree needs, and is centred in that slice. Sizing slices by
|
||
* subtree extent — not by branch count — is what keeps a bushy branch from being drawn
|
||
* over a bare sibling.
|
||
*/
|
||
const spread = (
|
||
items: RadialTree[],
|
||
start: number,
|
||
alongPos: number,
|
||
sign: 1 | -1,
|
||
) => {
|
||
const total =
|
||
items.reduce((s, b) => s + b.extent, 0) +
|
||
n.gap * Math.max(0, items.length - 1)
|
||
let cur = start - total / 2
|
||
for (const b of items) {
|
||
const mid = cur + b.extent / 2
|
||
// On the left side the ring position is the branch's FAR edge, so its own size has
|
||
// to come off to get its origin.
|
||
const a = sign > 0 ? alongPos : alongPos - b.p.rect[along]
|
||
if (down) place(b.p, mid - b.p.rect.w / 2, a, links)
|
||
else place(b.p, a, mid - b.p.rect.h / 2, links)
|
||
|
||
if (b.kids.length) {
|
||
// `alongPos` means the NEAR edge going outwards and the FAR edge coming back,
|
||
// which is why the two directions are not symmetric here: on the left the
|
||
// recursion subtracts the child's own width, so subtracting the ring width as
|
||
// well would place it a full ring too far out — off the frame.
|
||
const next = sign > 0 ? a + b.p.rect[along] + n.gap : a - n.gap
|
||
spread(b.kids, mid, next, sign)
|
||
}
|
||
cur += b.extent + n.gap
|
||
}
|
||
}
|
||
|
||
if (down) {
|
||
place(centre, innerX + (innerW - centre.rect.w) / 2, innerTop, links)
|
||
spread(
|
||
branches,
|
||
centre.rect.x + centre.rect.w / 2,
|
||
centre.rect.y + centre.rect.h + n.gap,
|
||
1,
|
||
)
|
||
return
|
||
}
|
||
|
||
// Radial: split the branches between the two sides, keeping declaration order within each
|
||
// side so the model can predict where a branch lands.
|
||
//
|
||
// The centre goes at the LEFT side's reach, not at the frame's middle. Those are the same
|
||
// only when both sides are equally deep; centring a lopsided map would push the deeper
|
||
// side out past the frame's edge and off the page.
|
||
const { right, left } = radialSides(branches)
|
||
place(
|
||
centre,
|
||
innerX + radialReach(left, "w", n.gap),
|
||
innerTop + (innerH - centre.rect.h) / 2,
|
||
links,
|
||
)
|
||
const midY = centre.rect.y + centre.rect.h / 2
|
||
spread(right, midY, centre.rect.x + centre.rect.w + n.gap, 1)
|
||
spread(left, midY, centre.rect.x - n.gap, -1)
|
||
}
|
||
|
||
export interface LayoutResult {
|
||
/** Placed roots, in the order given. */
|
||
roots: Placed[]
|
||
/** Page size that fits everything, with a margin. */
|
||
page: { w: number; h: number }
|
||
}
|
||
|
||
/** Where the tree starts on the page. Leaves room for a title above it. */
|
||
const ORIGIN = { x: 40, y: 90 }
|
||
const MARGIN = { right: 40, bottom: 50 }
|
||
|
||
/**
|
||
* Lay out a forest of roots side by side and report the page size that fits them.
|
||
*
|
||
* A pinned node keeps the position it already had: the user moved it deliberately, and
|
||
* the whole point of the pin is that a re-layout does not undo that.
|
||
*/
|
||
export function layoutForest(
|
||
roots: DiagramNode[],
|
||
opts: {
|
||
iconSize?: number
|
||
gap?: number
|
||
/** The diagram's links. Needed by sequence containers, which size themselves from
|
||
* the number of messages between their participants. */
|
||
links?: LayoutLinks
|
||
} = {},
|
||
): LayoutResult {
|
||
const glyph = opts.iconSize ?? ICON_SIZE
|
||
const gap = opts.gap ?? 70
|
||
const links: LayoutLinks = opts.links ?? []
|
||
const placed = roots.map((r) => measure(r, glyph, links))
|
||
|
||
let cur = ORIGIN.x
|
||
for (const p of placed) {
|
||
const n = p.node
|
||
const held =
|
||
n.kind === "title" ? null : n.pinned ? (n.rect ?? null) : null
|
||
if (held) {
|
||
place(p, held.x, held.y, links)
|
||
} else {
|
||
place(p, cur, ORIGIN.y, links)
|
||
cur += p.rect.w + gap
|
||
}
|
||
}
|
||
|
||
let maxX = 0
|
||
let maxY = 0
|
||
const visit = (p: Placed) => {
|
||
maxX = Math.max(maxX, p.rect.x + p.rect.w)
|
||
maxY = Math.max(maxY, p.rect.y + p.rect.h)
|
||
p.children.forEach(visit)
|
||
}
|
||
placed.forEach(visit)
|
||
|
||
return {
|
||
roots: placed,
|
||
page: {
|
||
w: Math.round(maxX + MARGIN.right),
|
||
h: Math.round(maxY + MARGIN.bottom),
|
||
},
|
||
}
|
||
}
|
||
|
||
/** Flatten a placed forest into (node, rect, parentId) triples in document order. */
|
||
export function flatten(
|
||
roots: Placed[],
|
||
): { node: DiagramNode; rect: Rect; parent: string }[] {
|
||
const out: { node: DiagramNode; rect: Rect; parent: string }[] = []
|
||
const walk = (p: Placed, parent: string) => {
|
||
out.push({ node: p.node, rect: p.rect, parent })
|
||
for (const c of p.children) walk(c, p.node.id)
|
||
}
|
||
for (const r of roots) walk(r, "1")
|
||
return out
|
||
}
|