moonfire-nvr/ui/src/Live/Multiview.tsx

259 lines
7.3 KiB
TypeScript
Raw Normal View History

// This file is part of Moonfire NVR, a security camera network video recorder.
// Copyright (C) 2021 The Moonfire NVR Authors; see AUTHORS and LICENSE.txt.
// SPDX-License-Identifier: GPL-v3.0-or-later WITH GPL-3.0-linking-exception
import Select from "@material-ui/core/Select";
import MenuItem from "@material-ui/core/MenuItem";
import React, { useReducer, useState } from "react";
import { Camera } from "../types";
import { makeStyles } from "@material-ui/core/styles";
import useResizeObserver from "@react-hook/resize-observer";
import Box from "@material-ui/core/Box";
export interface Layout {
className: string;
cameras: number;
}
// These class names must match useStyles rules (below).
const LAYOUTS: Layout[] = [
{ className: "solo", cameras: 1 },
{ className: "main-plus-five", cameras: 6 },
{ className: "two-by-two", cameras: 4 },
{ className: "three-by-three", cameras: 9 },
];
const MAX_CAMERAS = 9;
const useStyles = makeStyles((theme) => ({
root: {
flex: "1 0 0",
overflow: "hidden",
color: "white",
marginTop: theme.spacing(2),
},
mid: {
display: "none",
position: "relative",
padding: 0,
margin: 0,
"&.wider, &.wider img": {
height: "100%",
display: "inline-block",
},
"&.taller, &.taller img": {
width: "100%",
display: "inline-block",
},
"& img": {
objectFit: "contain",
},
},
inner: {
// match parent's size without influencing it.
overflow: "hidden",
position: "absolute",
top: 0,
bottom: 0,
left: 0,
right: 0,
display: "grid",
gridGap: "0px",
// These class names must match LAYOUTS (above).
"&.solo": {
gridTemplateColumns: "100%",
gridTemplateRows: "100%",
},
"&.two-by-two": {
gridTemplateColumns: "repeat(2, calc(100% / 2))",
gridTemplateRows: "repeat(2, calc(100% / 2))",
},
"&.main-plus-five, &.three-by-three": {
gridTemplateColumns: "repeat(3, calc(100% / 3))",
gridTemplateRows: "repeat(3, calc(100% / 3))",
},
"&.main-plus-five > div:nth-child(1)": {
gridColumn: "span 2",
gridRow: "span 2",
},
},
}));
export interface MultiviewProps {
cameras: Camera[];
layoutIndex: number;
renderCamera: (camera: Camera) => JSX.Element;
}
export interface MultiviewChooserProps {
/// An index into <tt>LAYOUTS</tt>.
layoutIndex: number;
onChoice: (selectedIndex: number) => void;
}
/**
* Chooses the layout for a Multiview.
* Styled for placement in the app menu bar.
*/
export const MultiviewChooser = (props: MultiviewChooserProps) => {
return (
<Select
id="layout"
value={props.layoutIndex}
onChange={(e) => props.onChoice(e.target.value)}
size="small"
sx={{
// Hacky attempt to style for the app menu.
color: "inherit",
"& svg": {
color: "inherit",
},
}}
>
{LAYOUTS.map((e, i) => (
<MenuItem key={e.className} value={i}>
{e.className}
</MenuItem>
))}
</Select>
);
};
/**
* The cameras selected for the multiview.
* This is always an array of length <tt>MAX_CAMERAS</tt>; only the first
* LAYOUTS[layoutIndex].cameras are currently visible. There are no duplicates;
* setting one element to a given camera unsets any others pointing to the same
* camera.
*/
type SelectedCameras = Array<number | null>;
interface SelectOp {
selectedIndex: number;
cameraIndex: number | null;
}
function selectedReducer(old: SelectedCameras, op: SelectOp): SelectedCameras {
let selected = [...old]; // shallow clone.
if (op.cameraIndex !== null) {
// de-dupe.
for (let i = 0; i < selected.length; i++) {
if (selected[i] === op.cameraIndex) {
selected[i] = null;
}
}
}
selected[op.selectedIndex] = op.cameraIndex ?? null;
return selected;
}
/**
* Presents one or more camera views in one of several layouts.
*
* The parent should arrange for the multiview's outer div to be as large
* as possible. Internally, multiview uses the largest possible aspect
* ratio-constrained section of it. It uses a ResizeObserver to determine if
* the outer div is wider or taller than 16x9, and then sets an appropriate CSS
* class to constrain the width or height respectively using a technique like
* <https://stackoverflow.com/a/14911949/23584>. The goal is to have the
* smoothest resizing by changing the DOM/CSS as little as possible.
*/
const Multiview = (props: MultiviewProps) => {
const [selected, updateSelected] = useReducer(
selectedReducer,
Array(MAX_CAMERAS).fill(null)
);
const [widerOrTaller, setWiderOrTaller] = useState("wider");
const outerRef = React.useRef<HTMLDivElement>(null);
useResizeObserver(outerRef, (entry: ResizeObserverEntry) => {
const w = entry.contentRect.width;
const h = entry.contentRect.height;
setWiderOrTaller((w * 9) / 16 > h ? "wider" : "taller");
});
const classes = useStyles();
const layout = LAYOUTS[props.layoutIndex];
const monoviews = selected.slice(0, layout.cameras).map((e, i) => {
// When a camera is selected, use the camera's index as the key.
// This allows swapping cameras' positions without tearing down their
// WebSocket connections and buffers.
//
// When no camera is selected, use the index within selected. (Actually,
// its negation, to disambiguate between the two cases.)
const key = e ?? -i;
return (
<Monoview
key={key}
cameras={props.cameras}
cameraIndex={e}
renderCamera={props.renderCamera}
onSelect={(cameraIndex) =>
updateSelected({ selectedIndex: i, cameraIndex })
}
/>
);
});
return (
<div className={classes.root} ref={outerRef}>
<div className={`${classes.mid} ${widerOrTaller}`}>
{/* a 16x9 black png from png-pixel.com */}
<img
src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAJCAQAAACRI2S5AAAAEklEQVR42mNk+M+AFzCOKgADALyGCQGyq8YeAAAAAElFTkSuQmCC"
alt=""
/>
<div className={`${classes.inner} ${layout.className}`}>
{monoviews}
</div>
</div>
</div>
);
};
interface MonoviewProps {
cameras: Camera[];
cameraIndex: number | null;
onSelect: (cameraIndex: number | null) => void;
renderCamera: (camera: Camera) => JSX.Element;
}
/** A single pane of a Multiview, including its camera chooser. */
const Monoview = (props: MonoviewProps) => {
return (
<Box>
<Box
sx={{
zIndex: 1,
position: "absolute",
height: "100%",
width: "100%",
}}
>
<Select
value={props.cameraIndex == null ? undefined : props.cameraIndex}
onChange={(e) => props.onSelect(e.target.value ?? null)}
displayEmpty
size="small"
sx={{
// Restyle to fit over the video (or black).
backgroundColor: "rgba(255, 255, 255, 0.5)",
"& svg": {
color: "inherit",
},
}}
>
<MenuItem value={undefined}>(none)</MenuItem>
{props.cameras.map((e, i) => (
<MenuItem key={i} value={i}>
{e.shortName}
</MenuItem>
))}
</Select>
</Box>
{props.cameraIndex !== null &&
props.renderCamera(props.cameras[props.cameraIndex])}
</Box>
);
};
export default Multiview;