onsenui/esm/elements/ons-segment.js

/*
Copyright 2013-2015 ASIAL CORPORATION

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

*/

import onsElements from '../ons/elements.js';
import util from '../ons/util.js';
import autoStyle from '../ons/autostyle.js';
import ModifierUtil from '../ons/internal/modifier-util.js';
import BaseElement from './base/base-element.js';
import contentReady from '../ons/content-ready.js';

const defaultClassName = 'segment';
const scheme = {
  '': 'segment--*',
  '.segment__item': 'segment--*__item',
  '.segment__input': 'segment--*__input',
  '.segment__button': 'segment--*__button'
};

const generateId = (() => {
  let i = 0;
  return () => 'ons-segment-gen-' + (i++);
})();

/**
 * @element ons-segment
 * @category control
 * @modifier material
 *   [en]Material Design segment[/en]
 *   [ja][/ja]
 * @description
 *   [en]
 *     Segment component. Use this component to have a button bar with automatic styles that switch on click of another button.
 *
 *     Will automatically display as a Material Design segment on Android.
 *   [/en]
 *   [ja][/ja]
 * @codepen hLayx
 * @tutorial vanilla/Reference/segment
 * @guide theming.html#modifiers [en]More details about the `modifier` attribute[/en][ja]modifier属性の使い方[/ja]
 * @guide theming.html#cross-platform-styling-autostyling [en]Information about cross platform styling[/en][ja]Information about cross platform styling[/ja]
 * @example
 * <ons-segment>
 *   <ons-button>Label 1</ons-button>
 *   <ons-button>Label 2</ons-button>
 *   <ons-button>Label 3</ons-button>
 * </ons-segment>
 */

export default class SegmentElement extends BaseElement {

  /**
   * @event postchange
   * @description
   *   [en]Fires after the active button is changed.[/en]
   *   [ja][/ja]
   * @param {Object} event
   *   [en]Event object.[/en]
   *   [ja][/ja]
   * @param {Number} event.index
   *   [en]Tapped button index.[/en]
   *   [ja][/ja]
   * @param {Object} event.segmentItem
   *   [en]Segment item object.[/en]
   *   [ja][/ja]
   */

  /**
   * @attribute modifier
   * @type {String}
   * @description
   *  [en]The appearance of the segment.[/en]
   *  [ja][/ja]
   */

  /**
   * @attribute tabbar-id
   * @initonly
   * @type {String}
   * @description
   *  [en]ID of the tabbar element to "connect" to the segment. Must be inside the same page.[/en]
   *  [ja][/ja]
   */

  /**
   * @attribute active-index
   * @default 0
   * @type {Number}
   * @description
   *  [en]Index of the active button. If a tabbar is connected, this will be set to the tabbar's active index.[/en]
   *  [ja][/ja]
   */

  /**
   * @property activeIndex
   * @default 0
   * @type {Number}
   * @description
   *  [en]Index of the active button. If a tabbar is connected, this will be set to the tabbar's active index.[/en]
   *  [ja][/ja]
   */

  /**
   * @attribute disabled
   * @description
   *   [en]Specify if segment should be disabled.[/en]
   *   [ja]ボタンを無効化する場合は指定します。[/ja]
   */


  constructor() {
    super();

    this._segmentId = generateId();
    this._tabbar = null;
    this._onChange = this._onChange.bind(this);
    this._onTabbarPreChange = this._onTabbarPreChange.bind(this);

    contentReady(this, () => {
      this._compile();
      setImmediate(() => this._lastActiveIndex = this._tabbar ? this._tabbar.getActiveTabIndex() : this.getActiveButtonIndex());
    });
  }

  _compile() {
    autoStyle.prepare(this);
    this.classList.add(defaultClassName);

    for (let index = this.children.length - 1; index >= 0; index--) {
      const item = this.children[index];
      item.classList.add('segment__item');

      const input = util.findChild(item, '.segment__input') || util.create('input.segment__input');
      input.type = 'radio';
      input.value = index;
      input.name = input.name || this._segmentId;
      input.checked = !this.hasAttribute('tabbar-id') && index === (this.activeIndex || 0);

      const button = util.findChild(item, '.segment__button') || util.create('.segment__button');
      if (button.parentElement !== item) {
        while (item.firstChild) {
          button.appendChild(item.firstChild);
        }
      }

      item.appendChild(input);
      item.appendChild(button);
    }

    ModifierUtil.initModifier(this, scheme);
  }

  connectedCallback() {
    contentReady(this, () => {
      if (this.hasAttribute('tabbar-id')) {
        const page = util.findParent(this, 'ons-page');
        this._tabbar = page && page.querySelector('#' + this.getAttribute('tabbar-id'));
        if (!this._tabbar || this._tabbar.tagName !== 'ONS-TABBAR') {
          util.throw(`No tabbar with id ${this.getAttribute('tabbar-id')} was found.`);
        }

        this._tabbar.setAttribute('hide-tabs', '');
        setImmediate(() => {
          const index = this._tabbar.getActiveTabIndex();
          this._setChecked(index);
          this.activeIndex = index;
        });

        this._tabbar.addEventListener('prechange', this._onTabbarPreChange);
      }
    });

    this.addEventListener('change', this._onChange);
  }

  disconnectedCallback() {
    contentReady(this, () => {
      if (this._tabbar) {
        this._tabbar.removeEventListener('prechange', this._onTabbarPreChange);
        this._tabbar = null;
      }
    });
    this.removeEventListener('change', this._onChange);
  }

  _setChecked(index) {
    this.children[index].firstElementChild.checked = true;
  }

  /**
   * @method setActiveButton
   * @signature setActiveButton(index, [options])
   * @param {Number} index
   *   [en]Button index.[/en]
   *   [ja][/ja]
   * @param {Object} [options]
   *   [en]Parameter object, works only if there is a connected tabbar. Supports the same options as `ons-tabbar`'s `setActiveTab` method.[/en]
   *   [ja][/ja]
   * @description
   *   [en]Make button with the specified index active. If there is a connected tabbar it shows the corresponding tab page. In this case animations and their options can be specified by the second parameter.[/en]
   *   [ja][/ja]
   * @return {Promise}
   *   [en]Resolves to the selected index or to the new page element if there is a connected tabbar.[/en]
   *   [ja][/ja]
   */
  setActiveButton(index, options) {
    if (this._tabbar) {
      return this._tabbar.setActiveTab(index, options);
    }

    this._setChecked(index);
    this._postChange(index);
    return Promise.resolve(index);
  }

  /**
   * @method getActiveButtonIndex
   * @signature getActiveButtonIndex()
   * @return {Number}
   *   [en]The index of the currently active button.[/en]
   *   [ja][/ja]
   * @description
   *   [en]Returns button index of current active button. If active button is not found, returns -1.[/en]
   *   [ja][/ja]
   */
  getActiveButtonIndex() {
    for (let i = this.children.length - 1; i >= 0; i--) { // Array.findIndex
      if (this.children[i].firstElementChild.checked) {
        return i;
      }
    }
    return -1;
  }

  _onChange(event) {
    event.stopPropagation();
    this._tabbar
      ? this._tabbar.setActiveTab(this.getActiveButtonIndex(), { reject: false })
      : this._postChange(this.getActiveButtonIndex());
  }

  _onTabbarPreChange(event) {
    setImmediate(() => {
      if (!event.detail.canceled) {
        this._setChecked(event.index);
        this._postChange(event.index);
      }
    });
  }

  _postChange(index) {
    util.triggerElementEvent(this, 'postchange', {
      index,
      activeIndex: index,
      lastActiveIndex: this._lastActiveIndex,
      segmentItem: this.children[index]
    });
    this._lastActiveIndex = index;
    this.activeIndex = index;
  }

  /**
   * @property disabled
   * @type {Boolean}
   * @description
   *   [en]Whether the segment is disabled or not.[/en]
   *   [ja]無効化されている場合に`true`。[/ja]
   */

  get activeIndex() {
    return parseInt(this.getAttribute('active-index'));
  }

  set activeIndex(value) {
    if (value !== null && value !== undefined) {
      this.setAttribute('active-index', value);
    }
  }

  static get observedAttributes() {
    return ['class', 'modifier', 'active-index'];
  }

  attributeChangedCallback(name, last, current) {
    switch (name) {
      case 'class':
        util.restoreClass(this, defaultClassName, scheme);
        break;
      case 'modifier':
        ModifierUtil.onModifierChanged(last, current, this, scheme);
        break;
      case 'active-index':
        contentReady(this, () => {
          if (this.getActiveButtonIndex() !== this.activeIndex) {
            this.setActiveButton(this.activeIndex);
          }
        });
        break;
    }
  }

  static get events() {
    return ['postchange'];
  }
}

util.defineBooleanProperties(SegmentElement, ['disabled']);

onsElements.Segment = SegmentElement;
customElements.define('ons-segment', SegmentElement);