export function layerIndexResolver()

in modules/core/src/passes/layers-pass.js [218:255]

• 29 lines of code
• 10 McCabe index (conditional complexity)

export function layerIndexResolver(startIndex = 0, layerIndices = {}) {
  const resolvers = {};

  const resolveLayerIndex = (layer, isDrawn) => {
    const indexOverride = layer.props._offset;
    const layerId = layer.id;
    const parentId = layer.parent && layer.parent.id;

    let index;

    if (parentId && !(parentId in layerIndices)) {
      // Populate layerIndices with the parent layer's index
      resolveLayerIndex(layer.parent, false);
    }

    if (parentId in resolvers) {
      const resolver = (resolvers[parentId] =
        resolvers[parentId] || layerIndexResolver(layerIndices[parentId], layerIndices));
      index = resolver(layer, isDrawn);
      resolvers[layerId] = resolver;
    } else if (Number.isFinite(indexOverride)) {
      index = indexOverride + (layerIndices[parentId] || 0);
      // Mark layer as needing its own resolver
      // We don't actually create it until it's used for the first time
      resolvers[layerId] = null;
    } else {
      index = startIndex;
    }

    if (isDrawn && index >= startIndex) {
      startIndex = index + 1;
    }

    layerIndices[layerId] = index;
    return index;
  };
  return resolveLayerIndex;
}