vaadin-grid-active-item-mixin.html

<!--
@license
Copyright (c) 2017 Vaadin Ltd.
This program is available under Apache License Version 2.0, available at https://vaadin.com/license/
-->

<script>
  window.Vaadin = window.Vaadin || {};
  window.Vaadin.Grid = window.Vaadin.Grid || {};

  /**
   * @polymerMixin
   */
  Vaadin.Grid.ActiveItemMixin = superClass => class ActiveItemMixin extends superClass {

    static get properties() {
      return {
        /*
         * The item user has last interacted with. Turns to `null` after user deactivates
         * the item by re-interacting with the currently active item.
         */
        activeItem: {
          type: Object,
          notify: true,
          value: null
        }
      };
    }

    static get observers() {
      return [
        '_activeItemChanged(activeItem)'
      ];
    }

    ready() {
      super.ready();
      this.addEventListener('cell-activate', this._activateItem.bind(this));
    }

    _activateItem(e) {
      const model = e.detail.model;
      const clickedItem = model ? model.item : null;

      if (clickedItem) {
        this.activeItem = !this._itemsEqual(this.activeItem, clickedItem) ? clickedItem : null;
      }
    }

    _activeItemChanged() {
      if (this.$.scroller._physicalItems) {
        this.$.scroller._physicalItems.forEach(row => this._updateItem(row, row.item));
      }
    }
  };
</script>