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@ue-too/board / zoomLevelBoundariesShouldUpdate

Function: zoomLevelBoundariesShouldUpdate() ​

zoomLevelBoundariesShouldUpdate(zoomLevelBoundaries, targetMinZoomLevel): targetMinZoomLevel is number

Defined in: packages/board/src/utils/zoomlevel-adjustment.ts:144

Determines if zoom level boundaries should be updated.

Parameters ​

zoomLevelBoundaries ​

Current zoom level limits

ZoomLevelLimits | undefined

targetMinZoomLevel ​

Proposed new minimum zoom level

number | undefined

Returns ​

targetMinZoomLevel is number

True if boundaries should be updated (type guard for targetMinZoomLevel)

Remarks ​

Zoom level boundary updates only tighten (increase minimum zoom), never relax. This prevents the camera from zooming out too far when boundaries shrink.

Returns true (update needed) when:

  • No current boundaries exist (first-time setup)
  • Target minimum is higher than current minimum (tightening)

Returns false (no update) when:

  • Target is undefined (invalid/incomplete)
  • Target is Infinity (invalid state)
  • Target is lower than current minimum (would relax, not allowed)

This function is a type guard: when it returns true, TypeScript knows targetMinZoomLevel is a number (not undefined).

Example ​

typescript
const currentLimits = { min: 0.5, max: 10 };
const newMin = 0.8;

if (zoomLevelBoundariesShouldUpdate(currentLimits, newMin)) {
  // Safe to use newMin as number here
  currentLimits.min = newMin;  // Tighten the limit
}

// No update for lower values
zoomLevelBoundariesShouldUpdate(currentLimits, 0.3);  // false