@ue-too/board / index / zoomLevelBoundariesShouldUpdate

関数: zoomLevelBoundariesShouldUpdate()

zoomLevelBoundariesShouldUpdate(zoomLevelBoundaries, targetMinZoomLevel): targetMinZoomLevel is number

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

Determines if zoom level boundaries should be updated.

パラメータ

zoomLevelBoundaries

Current zoom level limits

ZoomLevelLimits | undefined

targetMinZoomLevel

Proposed new minimum zoom level

number | undefined

戻り値

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).

例

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