ionic-framework/ionic/components/tabs/tabs.js

import {Ancestor, Parent} from 'angular2/src/core/annotations_impl/visibility';
import {Optional} from 'angular2/src/di/annotations_impl'
import {Directive, Component} from 'angular2/src/core/annotations_impl/annotations';
import {View} from 'angular2/src/core/annotations_impl/view';
import {ElementRef} from 'angular2/src/core/compiler/element_ref';
import {Compiler} from 'angular2/angular2';
import {DynamicComponentLoader} from 'angular2/src/core/compiler/dynamic_component_loader';
import {Injector} from 'angular2/di';
import {NgFor} from 'angular2/angular2';
import {ViewContainerRef} from 'angular2/src/core/compiler/view_container_ref';

import {ViewController} from '../view/view-controller';
import {ViewItem} from '../view/view-item';
import {TabButton} from './tab-button';
import {Icon} from '../icon/icon';
import {IonicComponent} from '../../config/component';
import {ModeComponent} from '../../config/component';


@ModeComponent({
  selector: 'ion-tabs',
  properties: [
    'tabBarPlacement',
    'tabBarIcons'
  ],
  classId: 'tabs'
})
@View({
  template: `
    <nav class="navbar-container tab-bar-container">
      <div class="tab-bar" role="tablist">
        <button *ng-for="#t of tabs" [tab]="t" class="tab-button" role="tab">
          <icon [name]="t.tabIcon" class="tab-button-icon"></icon>
          <span class="tab-button-text">{{t.tabTitle}}</span>
        </button>
      </div>
    </nav>
    <section class="content-container">
      <content></content>
    </section>
  `,
  directives: [NgFor, TabButton, Icon]
})
export class Tabs extends ViewController {

  constructor(
    @Optional() viewController: ViewController,
    @Optional() item: ViewItem,
    compiler: Compiler,
    elementRef: ElementRef,
    loader: DynamicComponentLoader,
    injector: Injector
  ) {
    super(viewController, compiler, elementRef, loader, injector);
    this.item = item;
  }

  addTab(tabItem) {
    this.add(tabItem);

    if (this.length() === 1) {
      this.item && this.item.waitForResolve();
      tabItem._initial = true;
    }
  }

  select(tab) {
    let enteringItem = null;
    if (typeof tab === 'number') {
      enteringItem = this.getByIndex(tab);
    } else {
      enteringItem = this.getByInstance(tab)
    }

    if (!enteringItem || !enteringItem.instance || this.isTransitioning()) {
      return;
    }

    enteringItem.instance.loadInitial(() => {
      let opts = {
        animate: false
      };

      let leavingItem = this.getActive() || new ViewItem();
      leavingItem.shouldDestroy = false;
      leavingItem.shouldCache = true;
      leavingItem.willCache();

      // set the Tab navbarView from the active view in the tab
      enteringItem.navbarView = (enteringItem.instance.getActive() || {}).navbarView;
      if (leavingItem.instance) {
        leavingItem.navbarView = (leavingItem.instance.getActive() || {}).navbarView;
      }

      this.transition(enteringItem, leavingItem, opts, () => {
        this.item && this.item.resolve();
      });
    });
  }

  get tabs() {
    return this.instances();
  }

}
// new IonicComponent(Tabs, {
//   properties: {
//     tabBarPlacement: {
//       defaults: {
//         ios: 'bottom',
//         android: 'top',
//         core: 'bottom'
//       }
//     },
//     tabBarIcons: {
//       defaults: {
//         ios: 'top',
//         android: 'top',
//         core: 'top'
//       }
//     }
//   }
// });