jsketcher/web/app/cad/scene/entityContextPlugin.js

import {state} from 'lstream';

import {addToListInMap} from 'gems/iterables';
import {EMPTY_ARRAY} from '../../../../modules/gems/iterables';
import {DATUM, FACE, SHELL, SKETCH_OBJECT, EDGE} from './entites';

export const SELECTABLE_ENTITIES = [FACE, EDGE, SKETCH_OBJECT, DATUM, SHELL];

export function defineStreams(ctx) {
  ctx.streams.selection = {};
  SELECTABLE_ENTITIES.forEach(entity => {
    ctx.streams.selection[entity] = state([]);
  });
}

export function activate(ctx) {
  ctx.services.selection = {};
  SELECTABLE_ENTITIES.forEach(entity => {
    let entitySelectApi = {
      objects: [],
      single: undefined
    };
    ctx.services.selection[entity] = entitySelectApi;
    let selectionState = ctx.streams.selection[entity];
    
    selectionState.attach(selection => {
      entitySelectApi.objects = selection.map(id => ctx.services.cadRegistry.findEntity(entity, id));
      entitySelectApi.single = entitySelectApi.objects[0];
    });
    
    entitySelectApi.select = ids => ctx.services.marker.markArrayExclusively(entity, ids);
  });

  ctx.services.marker.$markedEntities.attach(marked => {
    let byType = new Map();
    marked.forEach((obj) => {
      addToListInMap(byType, obj.TYPE, obj);
    });
    SELECTABLE_ENTITIES.forEach(entityType => {
      let entities = byType.get(entityType);
      if (entities) {
        ctx.streams.selection[entityType].next(entities.map(obj => obj.id));
      } else {
        ctx.streams.selection[entityType].next(EMPTY_ARRAY);
      }
    });
  })
}