Add custom scrollbar to sidepanel and torrent list

client/source/scripts/components/ui/CustomScrollbars.js

@@ -0,0 +1,43 @@
+import classnames from 'classnames';
+import React from 'react';
+import {Scrollbars} from 'react-custom-scrollbars';
+
+export default class CustomScrollbar extends React.Component {
+  getHorizontalThumb(props) {
+    return (
+      <div {...props}
+        className="scrollbars__thumb scrollbars__thumb--horizontal"/>
+    );
+  }
+
+  getVerticalThumb(props) {
+    return (
+      <div {...props}
+        className="scrollbars__thumb scrollbars__thumb--vertical"/>
+    );
+  }
+
+  render() {
+    let classes = classnames('scrollbars', {
+      [this.props.className]: this.props.className,
+      'is-inverted': this.props.inverted
+    });
+
+    return (
+      <Scrollbars
+        className={classes}
+        ref="scrollbar"
+        renderThumbHorizontal={this.getHorizontalThumb}
+        renderThumbVertical={this.getVerticalThumb}
+        onScroll={this.props.scrollHandler}>
+        {this.props.children}
+      </Scrollbars>
+    );
+  }
+}
+
+CustomScrollbar.defaultProps = {
+  className: '',
+  inverted: false,
+  scrollHandler: null
+};