Add View Mode Options

Adds a new AnchoredBox component that is functionally a clone of the "saving error" notifications, but drops a lot of the JS in favor of the new (chrome-only!) CSS Anchor Positioning API.  In subsequent commits, either alternate styling or a polyfill will be added non-supported browsers.

The box contains a few inputs that modify the CSS applied to `.pages`, most critically a "start on right" toggle for the Facing Pages mode.

client/homebrew/brewRenderer/brewRenderer.jsx

@@ -67,7 +67,8 @@ const BrewRenderer = (props)=>{
 		height     : PAGE_HEIGHT,
 		isMounted  : false,
 		visibility : 'hidden',
-		zoom       : 100
+		zoom       : 100,
+		pagesStyle : null
 	});
 
 	const mainRef  = useRef(null);
@@ -187,6 +188,13 @@ const BrewRenderer = (props)=>{
 		}));
 	};
 
+	const handleStyle = (newStyle)=>{
+		setState((prevState)=>({
+			...prevState,
+			pagesStyle : { ...prevState.pagesStyle, ...newStyle }, 
+		}));
+	};
+
 	return (
 		<>
 			{/*render dummy page while iFrame is mounting.*/}
@@ -204,7 +212,7 @@ const BrewRenderer = (props)=>{
 				<NotificationPopup />
 			</div>
 
-			<ToolBar onZoomChange={handleZoom} currentPage={props.currentBrewRendererPageNum}  totalPages={rawPages.length}/>
+			<ToolBar onZoomChange={handleZoom} currentPage={props.currentBrewRendererPageNum}  totalPages={rawPages.length} onStyleChange={handleStyle} />
 
 			{/*render in iFrame so broken code doesn't crash the site.*/}
 			<Frame id='BrewRenderer' initialContent={INITIAL_CONTENT}
@@ -223,7 +231,7 @@ const BrewRenderer = (props)=>{
 						&&
 						<>
 							{renderStyle()}
-							<div className='pages' lang={`${props.lang || 'en'}`} style={{ zoom: `${state.zoom}%` }}>
+							<div className='pages' lang={`${props.lang || 'en'}`} style={{ zoom: `${state.zoom}%`, ...state.pagesStyle }}>
 								{renderPages()}
 							</div>
 						</>

client/homebrew/brewRenderer/toolBar/toolBar.jsx

@@ -3,16 +3,19 @@ const React = require('react');
 const { useState, useEffect } = React;
 const _ = require('lodash');
 
+import AnchoredBox from '../../../components/anchoredBox.jsx';
+// import * as ZoomIcons from '../../../icons/icon-components/zoomIcons.jsx';
 
 const MAX_ZOOM = 300;
 const MIN_ZOOM = 10;
 
-const ToolBar = ({ onZoomChange, currentPage, onPageChange, totalPages })=>{
+const ToolBar = ({ onZoomChange, currentPage, onPageChange, totalPages, onStyleChange })=>{
 
 	const [zoomLevel, setZoomLevel] = useState(100);
 	const [pageNum, setPageNum] = useState(currentPage);
 	const [arrangement, setArrangement] = useState('single');
 	const [startOnRight, setStartOnRight] = useState(true);
+	const [pagesStyle, setPagesStyle] = useState({});
 	const [toolsVisible, setToolsVisible] = useState(true);
 	const modes = ['single', 'facing', 'flow'];
 
@@ -25,6 +28,7 @@ const ToolBar = ({ onZoomChange, currentPage, onPageChange, totalPages })=>{
 	}, [currentPage]);;
 
 	// update display arrangement when arrangement state is changed.
+	// todo: do this the 'react' way, without querying the dom.
 	useEffect(()=>{
 		const iframe = document.getElementById('BrewRenderer');
 		const pagesContainer = iframe?.contentWindow?.document.querySelector('.pages');
@@ -35,7 +39,6 @@ const ToolBar = ({ onZoomChange, currentPage, onPageChange, totalPages })=>{
 			['recto', 'verso'].forEach((leaf)=>pagesContainer.classList.remove(leaf));
 			pagesContainer.classList.add(startOnRight ? 'recto' : 'verso');
 		}
-	}, [arrangement]);
 	}, [arrangement, startOnRight]);
 
 
@@ -152,6 +155,19 @@ const ToolBar = ({ onZoomChange, currentPage, onPageChange, totalPages })=>{
 				>
 					{arrangement}
 				</button>
+				<AnchoredBox id='view-mode-options' className='tool' title='Options'>
+					<label title='Modify the horizontal space between pages.'>Column gap<input type='range' min={0} max={200} className='range-input' onChange={(evt)=>onStyleChange({ columnGap: `${evt.target.value}px` })} /></label>
+					<label title='Modify the vertical space between rows of pages.'>Row gap<input type='range' min={0} max={200} className='range-input' onChange={(evt)=>onStyleChange({ rowGap: `${evt.target.value}px` })} /></label>
+
+					<h2>Facing</h2>
+					<label title='Start 1st page on the right side, such as if you have cover page.'>Start on right
+						<input type='checkbox'
+							onChange={()=>setStartOnRight(!startOnRight)}
+							checked={startOnRight}
+							disabled={arrangement !== 'facing' ? true : false}
+							title={arrangement !== 'facing' ? 'Switch to Facing to enable toggle.' : null} />
+					</label>
+				</AnchoredBox>
 			</div>
 
 			<div className='group'>

client/homebrew/brewRenderer/toolBar/toolBar.less

@@ -34,6 +34,13 @@
 		align-items : center;
 	}
 
+	.anchored-box {
+		color: #CCCCCC;
+		input[type='number']{
+			width: 4ch;
+		}
+	}
+
 	input {
 		position       : relative;
 		height         : 1.5em;