[Glitch] Improved media modal

Port 4e929b2d173fa22b722c58c0e9f8223eb4f44b0e to glitch-soc

4 files changed, 238 insertions, 31 deletions

diff --git a/app/javascript/flavours/glitch/features/ui/components/image_loader.js b/app/javascript/flavours/glitch/features/ui/components/image_loader.js
index e3e7197c5..c7360a726 100644
--- a/app/javascript/flavours/glitch/features/ui/components/image_loader.js
+++ b/app/javascript/flavours/glitch/features/ui/components/image_loader.js
@@ -1,6 +1,7 @@
 import React from 'react';
 import PropTypes from 'prop-types';
 import classNames from 'classnames';
+import ZoomableImage from './zoomable_image';
 
 export default class ImageLoader extends React.PureComponent {
 
@@ -10,6 +11,7 @@ export default class ImageLoader extends React.PureComponent {
     previewSrc: PropTypes.string,
     width: PropTypes.number,
     height: PropTypes.number,
+    onClick: PropTypes.func,
   }
 
   static defaultProps = {
@@ -24,6 +26,7 @@ export default class ImageLoader extends React.PureComponent {
   }
 
   removers = [];
+  canvas = null;
 
   get canvasContext() {
     if (!this.canvas) {
@@ -43,6 +46,10 @@ export default class ImageLoader extends React.PureComponent {
     }
   }
 
+  componentWillUnmount () {
+    this.removeEventListeners();
+  }
+
   loadImage (props) {
     this.removeEventListeners();
     this.setState({ loading: true, error: false });
@@ -118,7 +125,7 @@ export default class ImageLoader extends React.PureComponent {
   }
 
   render () {
-    const { alt, src, width, height } = this.props;
+    const { alt, src, width, height, onClick } = this.props;
     const { loading } = this.state;
 
     const className = classNames('image-loader', {
@@ -128,22 +135,19 @@ export default class ImageLoader extends React.PureComponent {
 
     return (
       <div className={className}>
-        <canvas
-          className='image-loader__preview-canvas'
-          width={width}
-          height={height}
-          ref={this.setCanvasRef}
-          style={{ opacity: loading ? 1 : 0 }}
-        />
-
-        {!loading && (
-          <img
-            alt={alt}
-            className='image-loader__img'
-            src={src}
+        {loading ? (
+          <canvas
+            className='image-loader__preview-canvas'
+            ref={this.setCanvasRef}
             width={width}
             height={height}
           />
+        ) : (
+          <ZoomableImage
+            alt={alt}
+            src={src}
+            onClick={onClick}
+          />
         )}
       </div>
     );
diff --git a/app/javascript/flavours/glitch/features/ui/components/media_modal.js b/app/javascript/flavours/glitch/features/ui/components/media_modal.js
index 26c7e9ebc..5353b62db 100644
--- a/app/javascript/flavours/glitch/features/ui/components/media_modal.js
+++ b/app/javascript/flavours/glitch/features/ui/components/media_modal.js
@@ -3,6 +3,7 @@ import ReactSwipeableViews from 'react-swipeable-views';
 import ImmutablePropTypes from 'react-immutable-proptypes';
 import PropTypes from 'prop-types';
 import ExtendedVideoPlayer from 'flavours/glitch/components/extended_video_player';
+import classNames from 'classnames';
 import { defineMessages, injectIntl } from 'react-intl';
 import IconButton from 'flavours/glitch/components/icon_button';
 import ImmutablePureComponent from 'react-immutable-pure-component';
@@ -26,6 +27,7 @@ export default class MediaModal extends ImmutablePureComponent {
 
   state = {
     index: null,
+    navigationHidden: false,
   };
 
   handleSwipe = (index) => {
@@ -68,14 +70,21 @@ export default class MediaModal extends ImmutablePureComponent {
     return this.state.index !== null ? this.state.index : this.props.index;
   }
 
+  toggleNavigation = () => {
+    this.setState(prevState => ({
+      navigationHidden: !prevState.navigationHidden,
+    }));
+  };
+
   render () {
     const { media, intl, onClose } = this.props;
+    const { navigationHidden } = this.state;
 
     const index = this.getIndex();
     let pagination = [];
 
-    const leftNav  = media.size > 1 && <button tabIndex='0' className='modal-container__nav modal-container__nav--left' onClick={this.handlePrevClick} aria-label={intl.formatMessage(messages.previous)}><i className='fa fa-fw fa-chevron-left' /></button>;
-    const rightNav = media.size > 1 && <button tabIndex='0' className='modal-container__nav  modal-container__nav--right' onClick={this.handleNextClick} aria-label={intl.formatMessage(messages.next)}><i className='fa fa-fw fa-chevron-right' /></button>;
+    const leftNav  = media.size > 1 && <button tabIndex='0' className='media-modal__nav media-modal__nav--left' onClick={this.handlePrevClick} aria-label={intl.formatMessage(messages.previous)}><i className='fa fa-fw fa-chevron-left' /></button>;
+    const rightNav = media.size > 1 && <button tabIndex='0' className='media-modal__nav  media-modal__nav--right' onClick={this.handleNextClick} aria-label={intl.formatMessage(messages.next)}><i className='fa fa-fw fa-chevron-right' /></button>;
 
     if (media.size > 1) {
       pagination = media.map((item, i) => {
@@ -92,9 +101,30 @@ export default class MediaModal extends ImmutablePureComponent {
       const height = image.getIn(['meta', 'original', 'height']) || null;
 
       if (image.get('type') === 'image') {
-        return <ImageLoader previewSrc={image.get('preview_url')} src={image.get('url')} width={width} height={height} alt={image.get('description')} key={image.get('url')} />;
+        return (
+          <ImageLoader
+            previewSrc={image.get('preview_url')}
+            src={image.get('url')}
+            width={width}
+            height={height}
+            alt={image.get('description')}
+            key={image.get('url')}
+            onClick={this.toggleNavigation}
+          />
+        );
       } else if (image.get('type') === 'gifv') {
-        return <ExtendedVideoPlayer src={image.get('url')} muted controls={false} width={width} height={height} key={image.get('preview_url')} alt={image.get('description')} />;
+        return (
+          <ExtendedVideoPlayer
+            src={image.get('url')}
+            muted
+            controls={false}
+            width={width}
+            height={height}
+            key={image.get('preview_url')}
+            alt={image.get('description')}
+            onClick={this.toggleNavigation}
+          />
+        );
       }
 
       return null;
@@ -104,21 +134,43 @@ export default class MediaModal extends ImmutablePureComponent {
       alignItems: 'center', // center vertically
     };
 
+    const navigationClassName = classNames('media-modal__navigation', {
+      'media-modal__navigation--hidden': navigationHidden,
+    });
+
     return (
       <div className='modal-root__modal media-modal'>
-        {leftNav}
-
-        <div className='media-modal__content'>
-          <IconButton className='media-modal__close' title={intl.formatMessage(messages.close)} icon='times' onClick={onClose} size={16} />
-          <ReactSwipeableViews containerStyle={containerStyle} onChangeIndex={this.handleSwipe} index={index}>
-            {content}
-          </ReactSwipeableViews>
+        <div
+          className='media-modal__closer'
+          role='presentation'
+          onClick={onClose}
+        >
+          <div className='media-modal__content'>
+            <ReactSwipeableViews
+              style={{
+                // you can't use 100vh, because the viewport height is taller
+                // than the visible part of the document in some mobile
+                // browsers when it's address bar is visible.
+                // https://developers.google.com/web/updates/2016/12/url-bar-resizing
+                height: `${document.body.clientHeight}px`,
+              }}
+              containerStyle={containerStyle}
+              onChangeIndex={this.handleSwipe}
+              onSwitching={this.handleSwitching}
+              index={index}
+            >
+              {content}
+            </ReactSwipeableViews>
+          </div>
+        </div>
+        <div className={navigationClassName}>
+          <IconButton className='media-modal__close' title={intl.formatMessage(messages.close)} icon='times' onClick={onClose} size={40} />
+          {leftNav}
+          {rightNav}
+          <ul className='media-modal__pagination'>
+            {pagination}
+          </ul>
         </div>
-        <ul className='media-modal__pagination'>
-          {pagination}
-        </ul>
-
-        {rightNav}
       </div>
     );
   }
diff --git a/app/javascript/flavours/glitch/features/ui/components/video_modal.js b/app/javascript/flavours/glitch/features/ui/components/video_modal.js
index 4412fd0f7..e0cb7fc09 100644
--- a/app/javascript/flavours/glitch/features/ui/components/video_modal.js
+++ b/app/javascript/flavours/glitch/features/ui/components/video_modal.js
@@ -16,7 +16,7 @@ export default class VideoModal extends ImmutablePureComponent {
     const { media, time, onClose } = this.props;
 
     return (
-      <div className='modal-root__modal media-modal'>
+      <div className='modal-root__modal video-modal'>
         <div>
           <Video
             preview={media.get('preview_url')}
diff --git a/app/javascript/flavours/glitch/features/ui/components/zoomable_image.js b/app/javascript/flavours/glitch/features/ui/components/zoomable_image.js
new file mode 100644
index 000000000..0a0a4d41a
--- /dev/null
+++ b/app/javascript/flavours/glitch/features/ui/components/zoomable_image.js
@@ -0,0 +1,151 @@
+import React from 'react';
+import PropTypes from 'prop-types';
+
+const MIN_SCALE = 1;
+const MAX_SCALE = 4;
+
+const getMidpoint = (p1, p2) => ({
+  x: (p1.clientX + p2.clientX) / 2,
+  y: (p1.clientY + p2.clientY) / 2,
+});
+
+const getDistance = (p1, p2) =>
+  Math.sqrt(Math.pow(p1.clientX - p2.clientX, 2) + Math.pow(p1.clientY - p2.clientY, 2));
+
+const clamp = (min, max, value) => Math.min(max, Math.max(min, value));
+
+export default class ZoomableImage extends React.PureComponent {
+
+  static propTypes = {
+    alt: PropTypes.string,
+    src: PropTypes.string.isRequired,
+    width: PropTypes.number,
+    height: PropTypes.number,
+    onClick: PropTypes.func,
+  }
+
+  static defaultProps = {
+    alt: '',
+    width: null,
+    height: null,
+  };
+
+  state = {
+    scale: MIN_SCALE,
+  }
+
+  removers = [];
+  container = null;
+  image = null;
+  lastTouchEndTime = 0;
+  lastDistance = 0;
+
+  componentDidMount () {
+    let handler = this.handleTouchStart;
+    this.container.addEventListener('touchstart', handler);
+    this.removers.push(() => this.container.removeEventListener('touchstart', handler));
+    handler = this.handleTouchMove;
+    // on Chrome 56+, touch event listeners will default to passive
+    // https://www.chromestatus.com/features/5093566007214080
+    this.container.addEventListener('touchmove', handler, { passive: false });
+    this.removers.push(() => this.container.removeEventListener('touchend', handler));
+  }
+
+  componentWillUnmount () {
+    this.removeEventListeners();
+  }
+
+  removeEventListeners () {
+    this.removers.forEach(listeners => listeners());
+    this.removers = [];
+  }
+
+  handleTouchStart = e => {
+    if (e.touches.length !== 2) return;
+
+    this.lastDistance = getDistance(...e.touches);
+  }
+
+  handleTouchMove = e => {
+    const { scrollTop, scrollHeight, clientHeight } = this.container;
+    if (e.touches.length === 1 && scrollTop !== scrollHeight - clientHeight) {
+      // prevent propagating event to MediaModal
+      e.stopPropagation();
+      return;
+    }
+    if (e.touches.length !== 2) return;
+
+    e.preventDefault();
+    e.stopPropagation();
+
+    const distance = getDistance(...e.touches);
+    const midpoint = getMidpoint(...e.touches);
+    const scale = clamp(MIN_SCALE, MAX_SCALE, this.state.scale * distance / this.lastDistance);
+
+    this.zoom(scale, midpoint);
+
+    this.lastMidpoint = midpoint;
+    this.lastDistance = distance;
+  }
+
+  zoom(nextScale, midpoint) {
+    const { scale } = this.state;
+    const { scrollLeft, scrollTop } = this.container;
+
+    // math memo:
+    // x = (scrollLeft + midpoint.x) / scrollWidth
+    // x' = (nextScrollLeft + midpoint.x) / nextScrollWidth
+    // scrollWidth = clientWidth * scale
+    // scrollWidth' = clientWidth * nextScale
+    // Solve x = x' for nextScrollLeft
+    const nextScrollLeft = (scrollLeft + midpoint.x) * nextScale / scale - midpoint.x;
+    const nextScrollTop = (scrollTop + midpoint.y) * nextScale / scale - midpoint.y;
+
+    this.setState({ scale: nextScale }, () => {
+      this.container.scrollLeft = nextScrollLeft;
+      this.container.scrollTop = nextScrollTop;
+    });
+  }
+
+  handleClick = e => {
+    // don't propagate event to MediaModal
+    e.stopPropagation();
+    const handler = this.props.onClick;
+    if (handler) handler();
+  }
+
+  setContainerRef = c => {
+    this.container = c;
+  }
+
+  setImageRef = c => {
+    this.image = c;
+  }
+
+  render () {
+    const { alt, src } = this.props;
+    const { scale } = this.state;
+    const overflow = scale === 1 ? 'hidden' : 'scroll';
+
+    return (
+      <div
+        className='zoomable-image'
+        ref={this.setContainerRef}
+        style={{ overflow }}
+      >
+        <img
+          role='presentation'
+          ref={this.setImageRef}
+          alt={alt}
+          src={src}
+          style={{
+            transform: `scale(${scale})`,
+            transformOrigin: '0 0',
+          }}
+          onClick={this.handleClick}
+        />
+      </div>
+    );
+  }
+
+}