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Segment Locking

You can lock specific segments in a segmentation to prevent them from being modified by any tools.

For example, consider the following image with an overlaid labelmap:

  • Left image: shows segment index 1
  • Middle image: shows the result when segment index 2 is drawn on top of segment index 1
  • Right image: shows the result when segment index 1 is locked and segment index 2 is drawn on top of segment index 1

As shown in the locked scenario (right image), when segment index 1 is locked, it cannot be modified by new drawings.

![segment-locking-example]

API​

The locking API has been updated in version 2.x to provide clearer method names and functionality:

import { segmentation } from '@cornerstonejs/tools';

// Lock/unlock a segment index in a segmentation
segmentation.locking.setSegmentIndexLocked(
  segmentationId,
  segmentIndex,
  locked
);

// Get all locked segment indices for a segmentation
const lockedIndices = segmentation.locking.getLockedSegmentIndices(segmentationId);

// Check if a segment index is locked
const isLocked = segmentation.locking.isSegmentIndexLocked(
  segmentationId,
  segmentIndex
);

Example Usage​

// Lock segment 1 in a segmentation
segmentation.locking.setSegmentIndexLocked('segmentation1', 1, true);

// Check if segment 1 is locked
const isLocked = segmentation.locking.isSegmentIndexLocked('segmentation1', 1);
console.log(`Segment 1 is ${isLocked ? 'locked' : 'unlocked'}`);

// Get all locked segments
const lockedIndices = segmentation.locking.getLockedSegmentIndices('segmentation1');
console.log('Locked segment indices:', lockedIndices);

// Unlock segment 1
segmentation.locking.setSegmentIndexLocked('segmentation1', 1, false);

Key Changes in Version 2.x​

  1. Renamed getLockedSegments to getLockedSegmentIndices for clarity
  2. The locked state is now stored in the segment data structure:
{
  segments: {
    [segmentIndex]: {
      locked: boolean,
      // other segment properties...
    }
  }
}

Note that the locking state applies to the segmentation as a whole, not to specific representations or viewports. If a segment is locked, it will be locked across all viewports and representations.