vscroll/dist/esm5/processes/adapter/insert.js

Virtual scroll engine

import { __extends, __read, __spreadArray } from "tslib";
import Update from './update';
import { BaseAdapterProcessFactory, AdapterProcess, ProcessStatus } from '../misc/index';
import { Item } from '../../classes/item';
import { Direction } from '../../inputs/index';
var Insert = /** @class */ (function (_super) {
  __extends(Insert, _super);
  function Insert() {
    return _super !== null && _super.apply(this, arguments) || this;
  }
  Insert.run = function (scroller, options) {
    var params = Insert.parseInput(scroller, options).params;
    if (!params) {
      return;
    }
    var shouldInsert = Insert.doInsert(scroller, params);
    scroller.workflow.call({
      process: Insert.process,
      status: shouldInsert ? ProcessStatus.next : ProcessStatus.done
    });
  };
  Insert.doInsert = function (scroller, params) {
    if (!Insert.insertEmpty(scroller, params)) {
      if (!Insert.insertInBuffer(scroller, params)) {
        if (!Insert.insertVirtually(scroller, params)) {
          return false;
        }
      }
    }
    return true;
  };
  Insert.insertEmpty = function (scroller, params) {
    var buffer = scroller.buffer, routines = scroller.routines, fetch = scroller.state.fetch;
    if (buffer.size) {
      return false;
    }
    var beforeIndex = params.beforeIndex, afterIndex = params.afterIndex, items = params.items, decrease = params.decrease;
    if (!buffer.fillEmpty(items, beforeIndex, afterIndex, !!decrease, function (index, data) { return new Item(index, data, routines); })) {
      return false;
    }
    fetch.fill(buffer.items, buffer.startIndex);
    return true;
  };
  Insert.insertInBuffer = function (scroller, params) {
    var before = params.before, after = params.after, beforeIndex = params.beforeIndex, afterIndex = params.afterIndex, items = params.items, decrease = params.decrease;
    var indexToInsert = scroller.buffer.getIndexToInsert(before || after, beforeIndex, afterIndex);
    if (params.virtualize || isNaN(indexToInsert)) {
      return false;
    }
    var isBackward = Number.isInteger(beforeIndex) || before;
    var updateOptions = {
      predicate: function (_a) {
        var $index = _a.$index, data = _a.data;
        if (indexToInsert === $index) {
          return isBackward ? __spreadArray(__spreadArray([], __read(items), false), [data], false) : __spreadArray([data], __read(items), false);
        }
        return true;
      },
      fixRight: decrease
    };
    return Update.doUpdate(scroller, updateOptions);
  };
  Insert.insertVirtually = function (scroller, params) {
    var beforeIndex = params.beforeIndex, afterIndex = params.afterIndex, items = params.items, decrease = params.decrease;
    var buffer = scroller.buffer, fetch = scroller.state.fetch, viewport = scroller.viewport;
    var direction = Number.isInteger(beforeIndex) ? Direction.backward : Direction.forward;
    var indexToInsert = (direction === Direction.backward ? beforeIndex : afterIndex);
    if (!buffer.insertVirtually(items, indexToInsert, direction, !!decrease)) {
      return false;
    }
    var _a = viewport.getEdgeVisibleItem(buffer.items, Direction.backward), index = _a.index, diff = _a.diff;
    fetch.firstVisible.index = index;
    if (!isNaN(index)) {
      fetch.simulate = true;
      fetch.firstVisible.delta = -buffer.getSizeByIndex(index) + diff;
    }
    return true;
  };
  return Insert;
}(BaseAdapterProcessFactory(AdapterProcess.insert)));
export default Insert;
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