Ember SelectionMixin

gistfile1.js

var SelectionMixin = Ember.Mixin.create({
    init: function() {
      this.get(this.get('itemClassName')).reopen({
        classNameBindings: ['isSelected:selected'],
        isSelected: false,
        click: function(ev) {
            ev.stopImmediatePropagation();
            this.get('parentView').handleSelection(ev, this);
        }
      });
      this.set('selected', Ember.A([]));
      return this._super();
    },

    itemClassName: 'itemViewClass',
    addSelected: function(itemView) {
      if (this.get('selected').indexOf(itemView) === -1) {
        itemView.set('isSelected', true);
        this.get('selected').pushObject(itemView);
      }
    },
    clearSelection: function() {
      var item;
      while (this.get('selected.length') !== 0) {
        item = this.get('selected').popObject();
        item.set('isSelected', false);
      }
    },
    handleSelection: function(ev, itemView) {
        // if non of the ctrl, meta, and shift keys
        // are pressed, clear the selection
      if (!ev.ctrlKey && !ev.metaKey && !ev.shiftKey) {
        this.clearSelection();
      }

        // if selection is performed with shift key
        // the selected items should be between the last
        // and currently clicked items
      if (ev.shiftKey) {
        var lastSelected = this.get('selected.lastObject'),
            lastSelectedIndex = this.get('content').indexOf(lastSelected.get('content')),
            itemViewIndex = this.get('content').indexOf(itemView.get('content')),
            minIndex = Math.min(lastSelectedIndex, itemViewIndex),
            maxIndex = Math.max(lastSelectedIndex, itemViewIndex),
            childViews = this.get('childViews');
          this.clearSelection();
          for (var i = minIndex; i <= maxIndex; i += 1) {
            this.addSelected(childViews[i]);
          }
      }

      this.addSelected(itemView);
    },
    click: function() {
      this.clearSelection();
    },
    keyPress: function(ev) {
      if (ev.keyCode === 65 && ev.shiftKey) {
        this.get('childViews').forEach(function(itemView) {
          this.addSelected(itemView);
        }, this);
      }
    }

  });

gistfile2.js

Ember.CollectionView.extend(SelectionMixin, {
  tagName: 'ul',
  attributeBindings: ['tabIndex'],
  tabIndex: -1
});