wekan/client/lib/utils.js

Utils = {
  // XXX We should remove these two methods
  goBoardId(_id) {
    const board = Boards.findOne(_id);
    return board && FlowRouter.go('board', {
      id: board._id,
      slug: board.slug,
    });
  },

  goCardId(_id) {
    const card = Cards.findOne(_id);
    const board = Boards.findOne(card.boardId);
    return board && FlowRouter.go('card', {
      cardId: card._id,
      boardId: board._id,
      slug: board.slug,
    });
  },

  capitalize(string) {
    return string.charAt(0).toUpperCase() + string.slice(1);
  },

  windowResizeDep: new Tracker.Dependency(),

  // in fact, what we really care is screen size
  // large mobile device like iPad or android Pad has a big screen, it should also behave like a desktop
  // in a small window (even on desktop), Wekan run in compact mode.
  // we can easily debug with a small window of desktop browser. :-)
  isMiniScreen() {
    this.windowResizeDep.depend();
    return $(window).width() <= 800;
  },

  calculateIndexData(prevData, nextData, nItems = 1) {
    let base, increment;
    // If we drop the card to an empty column
    if (!prevData && !nextData) {
      base = 0;
      increment = 1;
    // If we drop the card in the first position
    } else if (!prevData) {
      base = nextData.sort - 1;
      increment = -1;
    // If we drop the card in the last position
    } else if (!nextData) {
      base = prevData.sort + 1;
      increment = 1;
    }
    // In the general case take the average of the previous and next element
    // sort indexes.
    else {
      const prevSortIndex = prevData.sort;
      const nextSortIndex = nextData.sort;
      increment = (nextSortIndex - prevSortIndex) / (nItems + 1);
      base = prevSortIndex + increment;
    }
    // XXX Return a generator that yield values instead of a base with a
    // increment number.
    return {
      base,
      increment,
    };
  },

  // Determine the new sort index
  calculateIndex(prevCardDomElement, nextCardDomElement, nCards = 1) {
    let base, increment;
    // If we drop the card to an empty column
    if (!prevCardDomElement && !nextCardDomElement) {
      base = 0;
      increment = 1;
    // If we drop the card in the first position
    } else if (!prevCardDomElement) {
      base = Blaze.getData(nextCardDomElement).sort - 1;
      increment = -1;
    // If we drop the card in the last position
    } else if (!nextCardDomElement) {
      base = Blaze.getData(prevCardDomElement).sort + 1;
      increment = 1;
    }
    // In the general case take the average of the previous and next element
    // sort indexes.
    else {
      const prevSortIndex = Blaze.getData(prevCardDomElement).sort;
      const nextSortIndex = Blaze.getData(nextCardDomElement).sort;
      increment = (nextSortIndex - prevSortIndex) / (nCards + 1);
      base = prevSortIndex + increment;
    }
    // XXX Return a generator that yield values instead of a base with a
    // increment number.
    return {
      base,
      increment,
    };
  },

  // Detect touch device
  isTouchDevice() {
    const isTouchable = (() => {
      const prefixes = ' -webkit- -moz- -o- -ms- '.split(' ');
      const mq = function(query) {
        return window.matchMedia(query).matches;
      };

      if (('ontouchstart' in window) || window.DocumentTouch && document instanceof window.DocumentTouch) {
        return true;
      }

      // include the 'heartz' as a way to have a non matching MQ to help terminate the join
      // https://git.io/vznFH
      const query = ['(', prefixes.join('touch-enabled),('), 'heartz', ')'].join('');
      return mq(query);
    })();
    Utils.isTouchDevice = () => isTouchable;
    return isTouchable;
  },

  calculateTouchDistance(touchA, touchB) {
    return Math.sqrt(
      Math.pow(touchA.screenX - touchB.screenX, 2) +
      Math.pow(touchA.screenY - touchB.screenY, 2)
    );
  },

  enableClickOnTouch(selector) {
    let touchStart = null;
    let lastTouch = null;

    $(document).on('touchstart', selector, function(e) {
      touchStart = e.originalEvent.touches[0];
    });
    $(document).on('touchmove', selector, function(e) {
      const touches = e.originalEvent.touches;
      lastTouch = touches[touches.length - 1];
    });
    $(document).on('touchend', selector, function(e) {
      if (touchStart && lastTouch && Utils.calculateTouchDistance(touchStart, lastTouch) <= 20) {
        e.preventDefault();
        const clickEvent = document.createEvent('MouseEvents');
        clickEvent.initEvent('click', true, true);
        e.target.dispatchEvent(clickEvent);
      }
    });
  },
};

// A simple tracker dependency that we invalidate every time the window is
// resized. This is used to reactively re-calculate the popup position in case
// of a window resize. This is the equivalent of a "Signal" in some other
// programming environments (eg, elm).
$(window).on('resize', () => Utils.windowResizeDep.changed());