Clyune Component GalleryTree View · How it works & code
Tree Navigation: Folders can be expanded or collapsed, and child items are displayed with hierarchical indentation.
Runtime logic
Visiting `/ui/tree`, DemoHost lazy-loads `demos/kits/kit-ui.js` (registry `mod: 'kit-ui'`) and calls `mount(host, { variant: 'tree' })`. mount resolves the variant to family `tree`; `withControls` builds the control panel (4 presets + sliders). `createCanvasStage` creates the `<canvas>` (HiDPI ≤ 2×, ResizeObserver) and the info panel. The family’s `build(S)` initialises state and returns the per-frame callback. Every `requestAnimationFrame`: read controls, advance a speed-scaled clock (dt ≤ 50 ms), run the frame callback; returned readouts go to the info panel. Changing parameters: colour/speed/size apply live; structural ones remount; leaving the page cancels rAF, removes listeners and frees resources.
Environment
Canvas 2D: 2D canvas drawing; requestAnimationFrame: Display-synced animation loop; ResizeObserver: Canvas follows container size; Pointer Events: Unified mouse/touch/pen events; devicePixelRatio: Crisp HiDPI rendering (capped at 2×) · react 18.3.1, react-router-dom 6.30.6, vite 5.4.21
Dependencies
react 18.3.1
Imported APIs
withControls — Wraps the demo in the shared control panel (presets, sliders, reset); hot-updates or remounts on change; paramsFromSpec — Turns the spec (colour/speed/size/count/extras) into control-panel parameter definitions; createCanvasStage — Shared Canvas 2D stage: canvas + info panel, HiDPI, one rAF loop, pointer state, idle auto-pointer; hueOf — Hue of a colour (0–360°); clamp — Clamps a value to a range; F — Formula block HTML; S.clear — Clears with the background colour (translucent = trails); S.isAutoDemo — Whether auto demo is on; S.onFrame — Registers a per-frame callback; its return value feeds the info panel; ctx.fillRect() — Fills a rectangle; ctx.fillText() — Draws filled text; ctx.beginPath() — Starts a new path; ctx.moveTo() — Moves the pen without drawing; ctx.arcTo() — Adds an arc using tangent lines; ctx.closePath() — Closes the current sub-path; ctx.fill() — Fills the current path; ctx.stroke() — Strokes the current path; ctx.lineTo() — Adds a straight line to a point
Source code
frontend/src/demos/kits/kit-ui.js: FAM.tree (L396-L408)
Code walkthrough
L396-408: Calls the factory `uiFam()` to produce the full definition (spec + doc + build) from the options below. L396-396: Title shown in the info and control panels: “Tree”. L396-396: Range/default of the size slider: Indent Width. L396-396: Range/default of the count slider: Expansion Level. L397-397: List of extra controls: Level Connections. L397-397: Preset buttons: name → parameter overrides (4). L398-398: Body of the “Notes” section. L398-398: Main formula of the “Formula” section. L398-398: Second formula line. L399-408: Per-frame draw function: draws with Canvas 2D `fillRect`; math via `Math.min`, `Math.floor`; returns readouts `mode`, `n`, `cell` to the info panel.
Principles
x = Left margin + Depth × Retreat into Visible Rows = Depth ≤ Expansion Level Tree control: Node can be scaled up, subnode indent is shown, and parent-child relationships are indicated on the line; currently selected rows are highlighted.