From 45c44989c8fb6e24badd18bb83ac5f68de0aceaf Mon Sep 17 00:00:00 2001
From: kibigo! <marrus-sh@users.noreply.github.com>
Date: Fri, 17 Nov 2017 19:11:18 -0800
Subject: Forking glitch theme

---
 .../themes/glitch/components/scrollable_list.js    | 198 +++++++++++++++++++++
 1 file changed, 198 insertions(+)
 create mode 100644 app/javascript/themes/glitch/components/scrollable_list.js

(limited to 'app/javascript/themes/glitch/components/scrollable_list.js')

diff --git a/app/javascript/themes/glitch/components/scrollable_list.js b/app/javascript/themes/glitch/components/scrollable_list.js
new file mode 100644
index 000000000..ccdcd7c85
--- /dev/null
+++ b/app/javascript/themes/glitch/components/scrollable_list.js
@@ -0,0 +1,198 @@
+import React, { PureComponent } from 'react';
+import { ScrollContainer } from 'react-router-scroll-4';
+import PropTypes from 'prop-types';
+import IntersectionObserverArticleContainer from 'themes/glitch/containers/intersection_observer_article_container';
+import LoadMore from './load_more';
+import IntersectionObserverWrapper from 'themes/glitch/util/intersection_observer_wrapper';
+import { throttle } from 'lodash';
+import { List as ImmutableList } from 'immutable';
+import classNames from 'classnames';
+import { attachFullscreenListener, detachFullscreenListener, isFullscreen } from 'themes/glitch/util/fullscreen';
+
+export default class ScrollableList extends PureComponent {
+
+  static contextTypes = {
+    router: PropTypes.object,
+  };
+
+  static propTypes = {
+    scrollKey: PropTypes.string.isRequired,
+    onScrollToBottom: PropTypes.func,
+    onScrollToTop: PropTypes.func,
+    onScroll: PropTypes.func,
+    trackScroll: PropTypes.bool,
+    shouldUpdateScroll: PropTypes.func,
+    isLoading: PropTypes.bool,
+    hasMore: PropTypes.bool,
+    prepend: PropTypes.node,
+    emptyMessage: PropTypes.node,
+    children: PropTypes.node,
+  };
+
+  static defaultProps = {
+    trackScroll: true,
+  };
+
+  state = {
+    lastMouseMove: null,
+  };
+
+  intersectionObserverWrapper = new IntersectionObserverWrapper();
+
+  handleScroll = throttle(() => {
+    if (this.node) {
+      const { scrollTop, scrollHeight, clientHeight } = this.node;
+      const offset = scrollHeight - scrollTop - clientHeight;
+      this._oldScrollPosition = scrollHeight - scrollTop;
+
+      if (400 > offset && this.props.onScrollToBottom && !this.props.isLoading) {
+        this.props.onScrollToBottom();
+      } else if (scrollTop < 100 && this.props.onScrollToTop) {
+        this.props.onScrollToTop();
+      } else if (this.props.onScroll) {
+        this.props.onScroll();
+      }
+    }
+  }, 150, {
+    trailing: true,
+  });
+
+  handleMouseMove = throttle(() => {
+    this._lastMouseMove = new Date();
+  }, 300);
+
+  handleMouseLeave = () => {
+    this._lastMouseMove = null;
+  }
+
+  componentDidMount () {
+    this.attachScrollListener();
+    this.attachIntersectionObserver();
+    attachFullscreenListener(this.onFullScreenChange);
+
+    // Handle initial scroll posiiton
+    this.handleScroll();
+  }
+
+  componentDidUpdate (prevProps) {
+    const someItemInserted = React.Children.count(prevProps.children) > 0 &&
+      React.Children.count(prevProps.children) < React.Children.count(this.props.children) &&
+      this.getFirstChildKey(prevProps) !== this.getFirstChildKey(this.props);
+
+    // Reset the scroll position when a new child comes in in order not to
+    // jerk the scrollbar around if you're already scrolled down the page.
+    if (someItemInserted && this._oldScrollPosition && this.node.scrollTop > 0) {
+      const newScrollTop = this.node.scrollHeight - this._oldScrollPosition;
+
+      if (this.node.scrollTop !== newScrollTop) {
+        this.node.scrollTop = newScrollTop;
+      }
+    } else {
+      this._oldScrollPosition = this.node.scrollHeight - this.node.scrollTop;
+    }
+  }
+
+  componentWillUnmount () {
+    this.detachScrollListener();
+    this.detachIntersectionObserver();
+    detachFullscreenListener(this.onFullScreenChange);
+  }
+
+  onFullScreenChange = () => {
+    this.setState({ fullscreen: isFullscreen() });
+  }
+
+  attachIntersectionObserver () {
+    this.intersectionObserverWrapper.connect({
+      root: this.node,
+      rootMargin: '300% 0px',
+    });
+  }
+
+  detachIntersectionObserver () {
+    this.intersectionObserverWrapper.disconnect();
+  }
+
+  attachScrollListener () {
+    this.node.addEventListener('scroll', this.handleScroll);
+  }
+
+  detachScrollListener () {
+    this.node.removeEventListener('scroll', this.handleScroll);
+  }
+
+  getFirstChildKey (props) {
+    const { children } = props;
+    let firstChild = children;
+    if (children instanceof ImmutableList) {
+      firstChild = children.get(0);
+    } else if (Array.isArray(children)) {
+      firstChild = children[0];
+    }
+    return firstChild && firstChild.key;
+  }
+
+  setRef = (c) => {
+    this.node = c;
+  }
+
+  handleLoadMore = (e) => {
+    e.preventDefault();
+    this.props.onScrollToBottom();
+  }
+
+  _recentlyMoved () {
+    return this._lastMouseMove !== null && ((new Date()) - this._lastMouseMove < 600);
+  }
+
+  render () {
+    const { children, scrollKey, trackScroll, shouldUpdateScroll, isLoading, hasMore, prepend, emptyMessage } = this.props;
+    const { fullscreen } = this.state;
+    const childrenCount = React.Children.count(children);
+
+    const loadMore     = (hasMore && childrenCount > 0) ? <LoadMore visible={!isLoading} onClick={this.handleLoadMore} /> : null;
+    let scrollableArea = null;
+
+    if (isLoading || childrenCount > 0 || !emptyMessage) {
+      scrollableArea = (
+        <div className={classNames('scrollable', { fullscreen })} ref={this.setRef} onMouseMove={this.handleMouseMove} onMouseLeave={this.handleMouseLeave}>
+          <div role='feed' className='item-list'>
+            {prepend}
+
+            {React.Children.map(this.props.children, (child, index) => (
+              <IntersectionObserverArticleContainer
+                key={child.key}
+                id={child.key}
+                index={index}
+                listLength={childrenCount}
+                intersectionObserverWrapper={this.intersectionObserverWrapper}
+                saveHeightKey={trackScroll ? `${this.context.router.route.location.key}:${scrollKey}` : null}
+              >
+                {child}
+              </IntersectionObserverArticleContainer>
+            ))}
+
+            {loadMore}
+          </div>
+        </div>
+      );
+    } else {
+      scrollableArea = (
+        <div className='empty-column-indicator' ref={this.setRef}>
+          {emptyMessage}
+        </div>
+      );
+    }
+
+    if (trackScroll) {
+      return (
+        <ScrollContainer scrollKey={scrollKey} shouldUpdateScroll={shouldUpdateScroll}>
+          {scrollableArea}
+        </ScrollContainer>
+      );
+    } else {
+      return scrollableArea;
+    }
+  }
+
+}
-- 
cgit