Moving splitPane over to the components folder

Just to reduce the number of changes needed to review on the UI overhaul #4122 PR

client/components/splitPane/splitPane.jsx

@@ -0,0 +1,110 @@
+require('./splitPane.less');
+const React = require('react');
+const { useState, useEffect } = React;
+
+const storageKey = 'naturalcrit-pane-split';
+
+const SplitPane = (props)=>{
+	const {
+		onDragFinish = ()=>{},
+		showDividerButtons = true
+	} = props;
+
+	const [isDragging, setIsDragging] = useState(false);
+	const [dividerPos, setDividerPos] = useState(null);
+	const [moveSource, setMoveSource] = useState(false);
+	const [moveBrew, setMoveBrew] = useState(false);
+	const [showMoveArrows, setShowMoveArrows] = useState(true);
+	const [liveScroll, setLiveScroll] = useState(false);
+
+	useEffect(()=>{
+		const savedPos = window.localStorage.getItem(storageKey);
+		setDividerPos(savedPos ? limitPosition(savedPos, 0.1 * (window.innerWidth - 13), 0.9 * (window.innerWidth - 13)) : window.innerWidth / 2);
+		setLiveScroll(window.localStorage.getItem('liveScroll') === 'true');
+
+		window.addEventListener('resize', handleResize);
+		return ()=>window.removeEventListener('resize', handleResize);
+	}, []);
+
+	const limitPosition = (x, min = 1, max = window.innerWidth - 13)=>Math.round(Math.min(max, Math.max(min, x)));
+
+	//when resizing, the divider should grow smaller if less space is given, then grow back if the space is restored, to the original position
+	const handleResize = ()=>setDividerPos(limitPosition(window.localStorage.getItem(storageKey), 0.1 * (window.innerWidth - 13), 0.9 * (window.innerWidth - 13)));
+
+	const handleUp =(e)=>{
+		e.preventDefault();
+		if(isDragging) {
+			onDragFinish(dividerPos);
+			window.localStorage.setItem(storageKey, dividerPos);
+		}
+		setIsDragging(false);
+	};
+
+	const handleDown = (e)=>{
+		e.preventDefault();
+		setIsDragging(true);
+	};
+
+	const handleMove = (e)=>{
+		if(!isDragging) return;
+		e.preventDefault();
+		setDividerPos(limitPosition(e.pageX));
+	};
+
+	const liveScrollToggle = ()=>{
+		window.localStorage.setItem('liveScroll', String(!liveScroll));
+		setLiveScroll(!liveScroll);
+	};
+
+	const  renderMoveArrows = (showMoveArrows &&
+		<>
+			<div className='arrow left'
+				onClick={()=>setMoveSource(!moveSource)} >
+				<i className='fas fa-arrow-left' />
+			</div>
+			<div className='arrow right'
+				onClick={()=>setMoveBrew(!moveBrew)} >
+				<i className='fas fa-arrow-right' />
+			</div>
+			<div id='scrollToggleDiv' className={liveScroll ? 'arrow lock' : 'arrow unlock'}
+				onClick={liveScrollToggle} >
+				<i id='scrollToggle' className={liveScroll ? 'fas fa-lock' : 'fas fa-unlock'} />
+			</div>
+		</>
+	);
+
+	const renderDivider = (
+		<div className={`divider ${isDragging && 'dragging'}`} onPointerDown={handleDown}>
+			{showDividerButtons && renderMoveArrows}
+			<div className='dots'>
+				<i className='fas fa-circle' />
+				<i className='fas fa-circle' />
+				<i className='fas fa-circle' />
+			</div>
+		</div>
+	);
+
+	return (
+		<div className='splitPane' onPointerMove={handleMove} onPointerUp={handleUp}>
+			<Pane width={dividerPos} moveBrew={moveBrew} moveSource={moveSource} liveScroll={liveScroll} setMoveArrows={setShowMoveArrows}>
+				{props.children[0]}
+			</Pane>
+			{renderDivider}
+			<Pane isDragging={isDragging}>{props.children[1]}</Pane>
+		</div>
+	);
+};
+
+const Pane = ({ width, children, isDragging, moveBrew, moveSource, liveScroll, setMoveArrows })=>{
+	const styles = width
+		? { flex: 'none', width: `${width}px` }
+		: { pointerEvents: isDragging ? 'none' : 'auto' }; //Disable mouse capture in the right pane; else dragging into the iframe drops the divider
+
+	return (
+		<div className='pane' style={styles}>
+			{React.cloneElement(children, { moveBrew, moveSource, liveScroll, setMoveArrows })}
+		</div>
+	);
+};
+
+module.exports = SplitPane;