@ue-too/board / index / 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

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

• createHandlerChain for composing handler pipelines
• createDefaultZoomByOnlyHandler for the default implementation