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@ue-too/board / ZoomByHandlerFunction

Type Alias: ZoomByHandlerFunction() ​

ZoomByHandlerFunction = (delta, camera, config) => number

Defined in: packages/board/src/camera/camera-rig/zoom-handler.ts:161

Handler function type for relative "zoom by" camera operations.

Parameters ​

delta ​

number

Zoom level change (added to current zoom)

camera ​

BoardCamera

Current camera instance

config ​

ZoomHandlerConfig

Zoom behavior configuration

Returns ​

number

Transformed zoom delta (after applying restrictions and clamping)

Remarks ​

Zoom-by handlers process relative zoom change requests. They form a pipeline that can apply restrictions, clamping, and other transformations to the delta.

Handler pipeline pattern:

  • Each handler receives the zoom delta, camera state, and config
  • Returns a potentially modified delta
  • Handlers can be chained using createHandlerChain

Common transformations:

  • Boundary clamping (prevent exceeding min/max zoom)
  • Zoom locking (return zero delta)
  • Delta dampening or acceleration

Example ​

typescript
const myZoomByHandler: ZoomByHandlerFunction = (delta, camera, config) => {
  // Custom logic: dampen large zoom changes
  if (Math.abs(delta) > 1.0) {
    return delta * 0.5;  // 50% dampening
  }
  return delta;
};

See ​