onsenui/esm/ons/internal/modifier-util.js

HTML5 Mobile Framework & UI Components

/*
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 util from '../util.js';
import autoStyle from '../autostyle.js';

export default class ModifierUtil {
  /**
   * @param {String} last
   * @param {String} current
   */
  static diff(last, current) {
    last = makeDict(('' + last).trim());
    current = makeDict(('' + current).trim());

    const removed = Object.keys(last).reduce((result, token) => {
      if (!current[token]) {
        result.push(token);
      }
      return result;
    }, []);

    const added = Object.keys(current).reduce((result, token) => {
      if (!last[token]) {
        result.push(token);
      }
      return result;
    }, []);

    return {added, removed};

    function makeDict(modifier) {
      const dict = {};
      ModifierUtil.split(modifier).forEach(token => dict[token] = token);
      return dict;
    }
  }

  /**
   * @param {Object} diff
   * @param {Array} diff.removed
   * @param {Array} diff.added
   * @param {Object} classList
   * @param {String} template
   */
  static applyDiffToClassList(diff, classList, template) {
    diff.added
      .map(modifier => template.replace(/\*/g, modifier))
      .forEach(klass => klass.split(/\s+/).forEach(k => classList.add(k)));

    diff.removed
      .map(modifier => template.replace(/\*/g, modifier))
      .forEach(klass => klass.split(/\s+/).forEach(k => classList.remove(k)));
  }

  /**
   * @param {Object} diff
   * @param {Array} diff.removed
   * @param {Array} diff.added
   * @param {HTMLElement} element
   * @param {Object} scheme
   */
  static applyDiffToElement(diff, element, scheme) {
    Object.keys(scheme).forEach(selector => {
      const targetElements = !selector || util.match(element, selector)
        ? [element]
        : Array.prototype.filter.call(
            element.querySelectorAll(selector),
            targetElement => !util.findParent(targetElement, element.tagName, parent => parent === element)
          );

      for (let i = 0; i < targetElements.length; i++) {
        ModifierUtil.applyDiffToClassList(diff, targetElements[i].classList, scheme[selector]);
      }
    });
  }

  /**
   * @param {String} last
   * @param {String} current
   * @param {HTMLElement} element
   * @param {Object} scheme
   */
  static onModifierChanged(last, current, element, scheme) {
    ModifierUtil.applyDiffToElement(ModifierUtil.diff(last, current), element, scheme);
    autoStyle.restoreModifier(element);
  }

  static refresh(element, scheme) {
    ModifierUtil.applyDiffToElement(ModifierUtil.diff('', element.getAttribute('modifier') || ''), element, scheme);
  }

  /**
   * @param {HTMLElement} element
   * @param {Object} scheme
   */
  static initModifier(element, scheme) {
    const modifier = element.getAttribute('modifier');
    if (typeof modifier !== 'string') {
      return;
    }

    ModifierUtil.applyDiffToElement({
      removed: [],
      added: ModifierUtil.split(modifier)
    }, element, scheme);
  }

  static split(modifier) {
    if (typeof modifier !== 'string') {
      return [];
    }

    return modifier.trim().split(/ +/).filter(token => token !== '');
  }

  /**
   * Add modifier token to an element.
   */
  static addModifier(element, modifierToken) {
    if (!element.hasAttribute('modifier')) {
      element.setAttribute('modifier', modifierToken);
    } else {
      const tokens = ModifierUtil.split(element.getAttribute('modifier'));
      if (tokens.indexOf(modifierToken) == -1) {
        tokens.push(modifierToken);
        element.setAttribute('modifier', tokens.join(' '));
      }
    }
  }

  /**
   * Remove modifier token from an element.
   */
  static removeModifier(element, modifierToken) {
    if (element.hasAttribute('modifier')) {
      const tokens = ModifierUtil.split(element.getAttribute('modifier'));
      const index = tokens.indexOf(modifierToken);
      if (index !== -1) {
        tokens.splice(index, 1);
        element.setAttribute('modifier', tokens.join(' '));
      }
    }
  }
}