Clyune Component GalleryBouncy Checkbox · How it works & code
When clicking a checkbox, the box first shrinks slightly, then bounces back beyond its original size (spring effect), and the checkmark draws along the stroke from left to right, with text adding strikethrough...
Runtime logic
Visiting `/micro/check`, DemoHost lazy-loads `demos/kits/kit-micro.js` (registry `mod: 'kit-micro'`) and calls `mount(host, { variant: 'check' })`. mount resolves the variant to family `check`; `withControls` builds the control panel (6 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. Pointer down/drag/move updates the interaction (drag handles, hover readouts); when untouched and auto-demo is on, the pointer follows a Lissajous path. 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; fmt — Number formatting (fixed decimals); F — Formula block HTML; S.onDown — Pointer down; S.onUp — Pointer up; 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.save() — Saves the drawing state (transform, styles, clip); ctx.translate() — Translates the coordinate system; ctx.scale() — Scales the coordinate system; ctx.fill() — Fills the current path; ctx.stroke() — Strokes the current path; ctx.restore() — Restores the saved drawing state; ctx.fillRect() — Fills a rectangle; ctx.measureText() — Measures text width; 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
Source code
frontend/src/demos/kits/kit-micro.js: FAM.check (L251-L265)
Code walkthrough
L251-265: Calls the factory `mFam()` to produce the full definition (spec + doc + build) from the options below. L251-251: Title shown in the info and control panels: “Bouncy Checkbox”. L251-251: Range/default of the count slider. L251-251: Extra demo-specific slider/toggle: Bounce Amplitude. L251-251: Range/default of the size slider. L251-251: Default main colour. L251-251: Animation period (s). L252-252: Help text of the count parameter. L252-252: Help text of the extra parameter. L252-252: Help text of the size parameter. L253-253: Preset buttons: name → parameter overrides (5). L254-254: Body of the “Notes” section. L255-255: Main formula of the “Formula” section. L255-255: Second formula line. L256-265: Per-frame draw function: draws with Canvas 2D `save`, `translate`, `scale`, `fill`, `stroke`, `restore` …; math via `Math.ceil`, `Math.min`, `Math.floor`, `Math.max`, `Math.abs`; returns readouts `mode`, `cell` to the info panel.
Principles
Box Zoom = 1 + range · Reverse echo Transnational (spring(e)−1) length of a tick = total brush · S Facilities Extraordinary Drawing Enhancement Tick Bounce: When clicking the check box, narrow the box first, It goes beyond its original size and comes back (springs), while ticking the brush from left to right "painting" with text and strike-line ash. Multiple boxes are ticked sequentially to create a sense of completion of the to-do list. There's no real use here DOM 控件：每个微交互都在画布上逐帧画出来。动画按固定周期自动循环播放，并用一个「演示指针」模拟用户的点击、按住或拖动；你在画布上点一下，动画就会从头重新播放一遍。右侧滑条改动后立刻生效，下方信息面板实时显示当前状态。