gitlab-org--gitlab-foss/app/assets/javascripts/commit/image_file.js

/* eslint-disable func-names, consistent-return, one-var, no-return-assign */

import $ from 'jquery';
import 'jquery.waitforimages';

// Width where images must fits in, for 2-up this gets divided by 2
const availWidth = 900;
const viewModes = ['two-up', 'swipe'];

export default class ImageFile {
  constructor(file) {
    this.file = file;
    this.requestImageInfo($('.two-up.view .frame.deleted img', this.file), () =>
      this.requestImageInfo($('.two-up.view .frame.added img', this.file), () => {
        this.initViewModes();

        // Load two-up view after images are loaded
        // so that we can display the correct width and height information
        const $images = $('.two-up.view img', this.file);

        $images.waitForImages(() => {
          this.initView('two-up');
        });
      }),
    );
  }

  initViewModes() {
    const viewMode = viewModes[0];
    $('.view-modes', this.file).removeClass('hide');
    $('.view-modes-menu', this.file).on('click', 'li', event => {
      if (!$(event.currentTarget).hasClass('active')) {
        return this.activateViewMode(event.currentTarget.className);
      }
    });
    return this.activateViewMode(viewMode);
  }

  activateViewMode(viewMode) {
    $('.view-modes-menu li', this.file)
      .removeClass('active')
      .filter(`.${viewMode}`)
      .addClass('active');

    // eslint-disable-next-line no-jquery/no-fade
    return $(`.view:visible:not(.${viewMode})`, this.file).fadeOut(200, () => {
      // eslint-disable-next-line no-jquery/no-fade
      $(`.view.${viewMode}`, this.file).fadeIn(200);
      return this.initView(viewMode);
    });
  }

  initView(viewMode) {
    return this.views[viewMode].call(this);
  }
  // eslint-disable-next-line class-methods-use-this
  initDraggable($el, padding, callback) {
    let dragging = false;
    const $body = $('body');
    const $offsetEl = $el.parent();
    const dragStart = function() {
      dragging = true;
      $body.css('user-select', 'none');
    };
    const dragStop = function() {
      dragging = false;
      $body.css('user-select', '');
    };
    const dragMove = function(e) {
      const moveX = e.pageX || e.touches[0].pageX;
      const left = moveX - ($offsetEl.offset().left + padding);
      if (!dragging) return;

      callback(e, left);
    };

    $el
      .off('mousedown')
      .off('touchstart')
      .on('mousedown', dragStart)
      .on('touchstart', dragStart);

    $body
      .off('mouseup')
      .off('mousemove')
      .off('touchend')
      .off('touchmove')
      .on('mouseup', dragStop)
      .on('touchend', dragStop)
      .on('mousemove', dragMove)
      .on('touchmove', dragMove);
  }

  static prepareFrames(view) {
    let maxWidth = 0;
    let maxHeight = 0;
    $('.frame', view)
      .each((index, frame) => {
        const width = $(frame).width();
        const height = $(frame).height();
        maxWidth = width > maxWidth ? width : maxWidth;
        return (maxHeight = height > maxHeight ? height : maxHeight);
      })
      .css({
        width: maxWidth,
        height: maxHeight,
      });
    return [maxWidth, maxHeight];
  }

  views = {
    'two-up': function() {
      return $('.two-up.view .wrap', this.file).each((index, wrap) => {
        $('img', wrap).each(function() {
          const currentWidth = $(this).width();
          if (currentWidth > availWidth / 2) {
            return $(this).width(availWidth / 2);
          }
        });
        return this.requestImageInfo($('img', wrap), (width, height) => {
          $('.image-info .meta-width', wrap).text(`${width}px`);
          $('.image-info .meta-height', wrap).text(`${height}px`);
          return $('.image-info', wrap).removeClass('hide');
        });
      });
    },
    swipe() {
      let maxWidth = 0;
      let maxHeight = 0;
      return $('.swipe.view', this.file).each((index, view) => {
        const ref = ImageFile.prepareFrames(view);
        [maxWidth, maxHeight] = ref;
        const $swipeFrame = $('.swipe-frame', view);
        const $swipeWrap = $('.swipe-wrap', view);
        const $swipeBar = $('.swipe-bar', view);

        $swipeFrame.css({
          width: maxWidth + 16,
          height: maxHeight + 28,
        });
        $swipeWrap.css({
          width: maxWidth + 1,
          height: maxHeight + 2,
        });
        // Set swipeBar left position to match image frame
        $swipeBar.css({
          left: 1,
        });

        const wrapPadding = parseInt($swipeWrap.css('right').replace('px', ''), 10);

        this.initDraggable($swipeBar, wrapPadding, (e, left) => {
          if (left > 0 && left < $swipeFrame.width() - wrapPadding * 2) {
            $swipeWrap.width(maxWidth + 1 - left);
            $swipeBar.css('left', left);
          }
        });
      });
    },
    'onion-skin': function() {
      let maxHeight, maxWidth;
      maxWidth = 0;
      maxHeight = 0;
      const dragTrackWidth = $('.drag-track', this.file).width() - $('.dragger', this.file).width();
      return $('.onion-skin.view', this.file).each((index, view) => {
        const ref = ImageFile.prepareFrames(view);
        [maxWidth, maxHeight] = ref;
        const $frame = $('.onion-skin-frame', view);
        const $frameAdded = $('.frame.added', view);
        const $track = $('.drag-track', view);
        const $dragger = $('.dragger', $track);

        $frame.css({
          width: maxWidth + 16,
          height: maxHeight + 28,
        });
        $('.swipe-wrap', view).css({
          width: maxWidth + 1,
          height: maxHeight + 2,
        });
        $dragger.css({
          left: dragTrackWidth,
        });

        $frameAdded.css('opacity', 1);
        const framePadding = parseInt($frameAdded.css('right').replace('px', ''), 10);

        this.initDraggable($dragger, framePadding, (e, left) => {
          const opacity = left / dragTrackWidth;

          if (opacity >= 0 && opacity <= 1) {
            $dragger.css('left', left);
            $frameAdded.css('opacity', opacity);
          }
        });
      });
    },
  };

  requestImageInfo(img, callback) {
    const domImg = img.get(0);
    if (domImg) {
      if (domImg.complete) {
        return callback.call(this, domImg.naturalWidth, domImg.naturalHeight);
      }
      return img.on('load', () => callback.call(this, domImg.naturalWidth, domImg.naturalHeight));
    }
  }
}