onsenui/esm/elements/ons-page.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 internal from '../ons/internal/index.js';
import autoStyle from '../ons/autostyle.js';
import ModifierUtil from '../ons/internal/modifier-util.js';
import BaseElement from './base/base-element.js';
import deviceBackButtonDispatcher from '../ons/internal/device-back-button-dispatcher.js';
import contentReady from '../ons/content-ready.js';

import './ons-toolbar.js'; // ensures that 'ons-toolbar' element is registered

const defaultClassName = 'page';
const scheme = {
  '': 'page--*',
  '.page__content': 'page--*__content',
  '.page__background': 'page--*__background'
};

/**
 * @element ons-page
 * @category page
 * @modifier material
 *   [en]Material Design style[/en]
 *   [ja][/ja]
 * @description
 *   [en]
 *     This component defines the root of each page. If the content is large it will become scrollable.
 *
 *     A navigation bar can be added to the top of the page using the `<ons-toolbar>` element.
 *   [/en]
 *   [ja]ページ定義のためのコンポーネントです。このコンポーネントの内容はスクロールが許可されます。[/ja]
 * @tutorial vanilla/Reference/page
 * @guide lifecycle.html#events
 *   [en]Overview of page events[/en]
 *   [ja]Overview of page events[/ja]
 * @guide fundamentals.html#managing-pages
 *   [en]Managing multiple pages[/en]
 *   [ja]複数のページを管理する[/ja]
 * @guide theming.html#modifiers [en]More details about the `modifier` attribute[/en][ja]modifier属性の使い方[/ja]
 * @seealso ons-toolbar
 *   [en]Use the `<ons-toolbar>` element to add a navigation bar to the top of the page.[/en]
 *   [ja][/ja]
 * @example
 * <ons-page>
 *   <ons-toolbar>
 *     <div class="left">
 *       <ons-back-button>Back</ons-back-button>
 *     </div>
 *     <div class="center">Title</div>
 *     <div class="right">
 *       <ons-toolbar-button>
 *         <ons-icon icon="md-menu"></ons-icon>
 *       </ons-toolbar-button>
 *     </div>
 *   </ons-toolbar>
 *
 *   <p>Page content</p>
 * </ons-page>
 *
 * @example
 * <script>
 *   myApp.handler = function(done) {
 *     loadMore().then(done);
 *   }
 * </script>
 *
 * <ons-page on-infinite-scroll="myApp.handler">
 *   <ons-toolbar>
 *     <div class="center">List</div>
 *   </ons-toolbar>
 *
 *   <ons-list>
 *     <ons-list-item>#1</ons-list-item>
 *     <ons-list-item>#2</ons-list-item>
 *     <ons-list-item>#3</ons-list-item>
 *     ...
 *   </ons-list>
 * </ons-page>
 */
export default class PageElement extends BaseElement {

  /**
   * @event init
   * @description
   *   [en]Fired right after the page is attached.[/en]
   *   [ja]ページがアタッチされた後に発火します。[/ja]
   * @param {Object} event [en]Event object.[/en]
   */

  /**
   * @event show
   * @description
   *   [en]Fired right after the page is shown.[/en]
   *   [ja]ページが表示された後に発火します。[/ja]
   * @param {Object} event [en]Event object.[/en]
   */

  /**
   * @event hide
   * @description
   *   [en]Fired right after the page is hidden.[/en]
   *   [ja]ページが隠れた後に発火します。[/ja]
   * @param {Object} event [en]Event object.[/en]
   */

  /**
   * @event destroy
   * @description
   *   [en]Fired right before the page is destroyed.[/en]
   *   [ja]ページが破棄される前に発火します。[/ja]
   * @param {Object} event [en]Event object.[/en]
   */

  /**
   * @attribute modifier
   * @type {String}
   * @description
   *   [en]Specify modifier name to specify custom styles.[/en]
   *   [ja]スタイル定義をカスタマイズするための名前を指定します。[/ja]
   */

  /**
   * @attribute on-infinite-scroll
   * @type {String}
   * @description
   *   [en]Path of the function to be executed on infinite scrolling. Example: `app.loadData`. The function receives a done callback that must be called when it's finished.[/en]
   *   [ja][/ja]
   */

  constructor() {
    super();

    this._deriveHooks();

    this._defaultClassName = defaultClassName;
    this.classList.add(defaultClassName);

    this._initialized = false;

    contentReady(this, () => {
      this._compile();

      this._isShown = false;
      this._contentElement = this._getContentElement();
      this._backgroundElement = this._getBackgroundElement();
    });
  }

  _compile() {
    autoStyle.prepare(this);

    const toolbar = util.findChild(this, 'ons-toolbar');

    const background = util.findChild(this, '.page__background') || util.findChild(this, '.background') || document.createElement('div');
    background.classList.add('page__background');
    this.insertBefore(background, !toolbar && this.firstChild || toolbar && toolbar.nextSibling);

    const content = util.findChild(this, '.page__content') || util.findChild(this, '.content') || document.createElement('div');
    content.classList.add('page__content');
    if (!content.parentElement) {
      util.arrayFrom(this.childNodes).forEach(node => {
        if (node.nodeType !== 1 || this._elementShouldBeMoved(node)) {
          content.appendChild(node); // Can trigger detached connectedCallbacks
        }
      });
    }

    this._tryToFillStatusBar(content); // Must run before child pages try to fill status bar.
    this.insertBefore(content, background.nextSibling); // Can trigger attached connectedCallbacks

    if ((!toolbar || !util.hasModifier(toolbar, 'transparent'))
      && content.children.length === 1
      && util.isPageControl(content.children[0])
    ) {
      this._defaultClassName += ' page--wrapper';
      this.attributeChangedCallback('class');
    }

    const bottomToolbar = util.findChild(this, 'ons-bottom-toolbar');
    if (bottomToolbar) {
      this._defaultClassName += ' page-with-bottom-toolbar';
      this.attributeChangedCallback('class');
    }

    ModifierUtil.initModifier(this, scheme);
  }

  _elementShouldBeMoved(el) {
    if (el.classList.contains('page__background')) {
      return false;
    }
    const tagName = el.tagName.toLowerCase();
    if (tagName === 'ons-fab') {
      return !el.hasAttribute('position');
    }
    const fixedElements = ['script', 'ons-toolbar', 'ons-bottom-toolbar', 'ons-modal', 'ons-speed-dial', 'ons-dialog', 'ons-alert-dialog', 'ons-popover', 'ons-action-sheet'];
    return el.hasAttribute('inline') || fixedElements.indexOf(tagName) === -1;
  }

  _tryToFillStatusBar(content = this._contentElement) {
    internal.autoStatusBarFill(() => {
      util.toggleAttribute(this, 'status-bar-fill',
        !util.findParent(this, e => e.hasAttribute('status-bar-fill')) // Not already filled
        && (this._canAnimateToolbar(content) || !util.findChild(content, util.isPageControl)) // Has toolbar or cannot delegate
      );
    });
  }

  _canAnimateToolbar(content = this._contentElement) {
    if (util.findChild(this, 'ons-toolbar')) {
      return true;
    }

    return !!util.findChild(content, el => {
      return util.match(el, 'ons-toolbar') && !el.hasAttribute('inline');
    });
  }

  connectedCallback() {
    if (!util.isAttached(this)) { // Avoid detached calls
      return;
    }

    contentReady(this, () => {
      this._tryToFillStatusBar(); // Ensure status bar when the element was compiled before connected

      if (this.hasAttribute('on-infinite-scroll')) {
        this.attributeChangedCallback('on-infinite-scroll', null, this.getAttribute('on-infinite-scroll'));
      }

      if (!this._initialized) {
        this._initialized = true;

        setImmediate(() => {
          this.onInit && this.onInit();
          util.triggerElementEvent(this, 'init');
        });

        if (!util.hasAnyComponentAsParent(this)) {
          setImmediate(() => this._show());
        }
      }
    });
  }

  updateBackButton(show) {
    if (this.backButton) {
      show ? this.backButton.show() : this.backButton.hide();
    }
  }

  set name(str) {
    this.setAttribute('name', str);
  }

  get name() {
    return this.getAttribute('name');
  }

  get backButton() {
    return this.querySelector('ons-back-button');
  }

  /**
   * @property onInfiniteScroll
   * @description
   *  [en]Function to be executed when scrolling to the bottom of the page. The function receives a done callback as an argument that must be called when it's finished.[/en]
   *  [ja][/ja]
   */
  set onInfiniteScroll(value) {
    if (value && !(value instanceof Function)) {
      util.throw('"onInfiniteScroll" must be function or null');
    }

    contentReady(this, () => {
      if (!value) {
        this._contentElement.removeEventListener('scroll', this._boundOnScroll);
      } else if (!this._onInfiniteScroll) {
        this._infiniteScrollLimit = 0.9;
        this._boundOnScroll = this._onScroll.bind(this);
        setImmediate(() => this._contentElement.addEventListener('scroll', this._boundOnScroll));
      }
      this._onInfiniteScroll = value;
    });
  }

  get onInfiniteScroll() {
    return this._onInfiniteScroll;
  }

  _onScroll() {
    const c = this._contentElement,
      overLimit = (c.scrollTop + c.clientHeight) / c.scrollHeight >= this._infiniteScrollLimit;

    if (this._onInfiniteScroll && !this._loadingContent && overLimit) {
      this._loadingContent = true;
      this._onInfiniteScroll(() => this._loadingContent = false);
    }
  }

  /**
   * @property onDeviceBackButton
   * @type {Object}
   * @description
   *   [en]Back-button handler.[/en]
   *   [ja]バックボタンハンドラ。[/ja]
   */
  get onDeviceBackButton() {
    return this._backButtonHandler;
  }

  set onDeviceBackButton(callback) {
    if (this._backButtonHandler) {
      this._backButtonHandler.destroy();
    }

    this._backButtonHandler = deviceBackButtonDispatcher.createHandler(this, callback);
  }

  get scrollTop() {
    return this._contentElement.scrollTop;
  }

  set scrollTop(newValue) {
    this._contentElement.scrollTop = newValue;
  }

  _getContentElement() {
    const result = util.findChild(this, '.page__content');
    if (result) {
      return result;
    }
    util.throw('Fail to get ".page__content" element');
  }

  _getBackgroundElement() {
    const result = util.findChild(this, '.page__background');
    if (result) {
      return result;
    }
    util.throw('Fail to get ".page__background" element');
  }

  _getBottomToolbarElement() {
    return util.findChild(this, 'ons-bottom-toolbar') || internal.nullElement;
  }

  _getToolbarElement() {
    return util.findChild(this, 'ons-toolbar') || document.createElement('ons-toolbar');
  }

  static get observedAttributes() {
    return ['modifier', 'on-infinite-scroll', 'class'];
  }

  attributeChangedCallback(name, last, current) {
    switch (name) {
      case 'class':
        util.restoreClass(this, this._defaultClassName, scheme);
        break;
      case 'modifier':
        ModifierUtil.onModifierChanged(last, current, this, scheme);
        break;
      case 'on-infinite-scroll':
        if (current === null) {
          this.onInfiniteScroll = null;
        } else {
          this.onInfiniteScroll = (done) => {
            const f = util.findFromPath(current);
            this.onInfiniteScroll = f;
            f(done);
          };
        }
        break;
    }
  }

  _show() {
    if (!this._isShown && util.isAttached(this)) {
      this._isShown = true;
      this.setAttribute('shown', '');
      this.onShow && this.onShow();
      util.triggerElementEvent(this, 'show');
      util.propagateAction(this, '_show');
    }
  }

  _hide() {
    if (this._isShown) {
      this._isShown = false;
      this.removeAttribute('shown');
      this.onHide && this.onHide();
      util.triggerElementEvent(this, 'hide');
      util.propagateAction(this, '_hide');
    }
  }

  _destroy() {
    this._hide();

    this.onDestroy && this.onDestroy();
    util.triggerElementEvent(this, 'destroy');

    if (this.onDeviceBackButton) {
      this.onDeviceBackButton.destroy();
    }

    util.propagateAction(this, '_destroy');

    this.remove();
  }

  _deriveHooks() {
    this.constructor.events.forEach(event => {
      const key = 'on' + event.charAt(0).toUpperCase() + event.slice(1);
      Object.defineProperty(this, key, {
        configurable: true,
        enumerable: true,
        get: () => this[`_${key}`],
        set: value => {
          if (!(value instanceof Function)) {
            util.throw(`"${key}" hook must be a function`);
          }
          this[`_${key}`] = value.bind(this);
        }
      });
    });
  }

  static get events() {
    return ['init', 'show', 'hide', 'destroy'];
  }

  /**
   * @property data
   * @type {*}
   * @description
   *   [en]User's custom data passed to `pushPage()`-like methods.[/en]
   *   [ja][/ja]
   */
}

onsElements.Page = PageElement;
customElements.define('ons-page', PageElement);