gistfile1.js

Flame.DisclosureView = Flame.LabelView.extend({
    classNames: ['flame-disclosure-view'],
    buttonExpanded: Flame.image('disclosure_triangle_down.png'),
    buttonCollapsed: Flame.image('disclosure_triangle_left.png'),
    button: function () {
      this.get('visibilityTarget') ? this.get('buttonExpanded') : this.get('buttonCollapsed');
    }.property('visibilityTarget', 'buttonExpanded', 'buttonCollapsed'),
    handlebars: '<img {{bindAttr src="button"}}> {{value}}',
    action: function() {
        var value = this.getPath('visibilityTarget');
        this.setPath('visibilityTarget', !value);
        return true;
    }
});