Files
papercrate/frontend/src/detail/PreviewZoomOverlay.tsx
T
2025-11-22 14:43:05 +01:00

374 lines
10 KiB
TypeScript

import React, { CSSProperties, useEffect, useMemo, useRef, useState } from 'react';
import { createPortal } from 'react-dom';
import { clamp } from '../utils/math';
import PdfViewer from '../preview/PdfViewer';
type DocumentLike = {
id?: string | number;
title?: string;
mime_type?: string | null;
[key: string]: unknown;
};
interface PreviewZoomOverlayProps {
open?: boolean;
onClose?: () => void;
document?: DocumentLike | null;
}
type NaturalSize = { width: number | null; height: number | null };
type FocusPoint = { xRatio: number; yRatio: number } | null;
type DisplayKind = 'image' | 'pdf';
type DocumentLink = {
url: string;
alt?: string;
mimeType?: string | null;
};
type DocumentLikeWithPreview = DocumentLike & { documentLink?: DocumentLink };
const determineDisplayKind = (entry?: DocumentLink | null): DisplayKind => {
const type = entry?.mimeType?.toLowerCase?.() || '';
if (type.includes('pdf')) {
return 'pdf';
}
if (type.startsWith('image/')) {
return 'image';
}
const url = entry?.url?.toLowerCase?.() || '';
if (url.endsWith('.pdf')) {
return 'pdf';
}
return 'image';
};
const noop = () => {};
const PreviewZoomOverlay: React.FC<PreviewZoomOverlayProps> = ({
open = false,
onClose = noop,
document: overlayDocument = null,
}) => {
const portalTarget = document.body;
const [isNativeScale, setIsNativeScale] = useState(false);
const [naturalSize, setNaturalSize] = useState<NaturalSize>({ width: null, height: null });
const [renderBackdrop, setRenderBackdrop] = useState(false);
const [isBackdropVisible, setBackdropVisible] = useState(false);
const [documentSnapshot, setDocumentSnapshot] = useState<DocumentLikeWithPreview | null>(null);
const scrollRef = useRef<HTMLDivElement | null>(null);
const mediaRef = useRef<HTMLImageElement | null>(null);
const focusRef = useRef<FocusPoint>(null);
const previouslyFocusedRef = useRef<HTMLElement | null>(null);
const visibilityTimerRef = useRef<number | null>(null);
const displayTimerRef = useRef<number | null>(null);
const currentDocument = overlayDocument as DocumentLikeWithPreview | null;
useEffect(() => {
if (currentDocument?.documentLink?.url) {
setDocumentSnapshot(currentDocument);
}
}, [currentDocument]);
const activeDocument = open && currentDocument?.documentLink?.url ? currentDocument : documentSnapshot;
const documentLink = activeDocument?.documentLink || null;
const displayKind = useMemo(() => determineDisplayKind(documentLink), [documentLink]);
const isPdfDisplay = displayKind === 'pdf';
const documentTitle = activeDocument?.title || undefined;
const effectiveAlt = documentLink?.alt || documentTitle || 'Document preview';
useEffect(() => {
if (visibilityTimerRef.current) {
clearTimeout(visibilityTimerRef.current);
visibilityTimerRef.current = null;
}
if (displayTimerRef.current) {
cancelAnimationFrame(displayTimerRef.current);
displayTimerRef.current = null;
}
if (open && documentLink?.url) {
setRenderBackdrop(true);
displayTimerRef.current = requestAnimationFrame(() => {
displayTimerRef.current = requestAnimationFrame(() => {
setBackdropVisible(true);
});
});
return () => {
if (displayTimerRef.current) {
cancelAnimationFrame(displayTimerRef.current);
displayTimerRef.current = null;
}
};
}
setBackdropVisible(false);
visibilityTimerRef.current = window.setTimeout(() => {
setRenderBackdrop(false);
}, 260);
return () => {
if (visibilityTimerRef.current) {
clearTimeout(visibilityTimerRef.current);
visibilityTimerRef.current = null;
}
};
}, [open, documentLink?.url]);
useEffect(() => () => {
if (visibilityTimerRef.current) {
clearTimeout(visibilityTimerRef.current);
}
if (displayTimerRef.current) {
cancelAnimationFrame(displayTimerRef.current);
}
}, []);
useEffect(() => {
}, [isPdfDisplay, open, documentLink?.url]);
useEffect(() => {
setIsNativeScale(false);
setNaturalSize({ width: null, height: null });
focusRef.current = null;
const scrollEl = scrollRef.current;
if (scrollEl) {
scrollEl.scrollLeft = 0;
scrollEl.scrollTop = 0;
}
}, [open, documentLink?.url, displayKind]);
useEffect(() => {
if (!open || !isNativeScale) {
return;
}
const scrollEl = scrollRef.current;
const mediaEl = mediaRef.current;
if (!scrollEl || !mediaEl) {
return;
}
const imageWidth = naturalSize.width || mediaEl.clientWidth;
const imageHeight = naturalSize.height || mediaEl.clientHeight;
if (!(imageWidth > 0 && imageHeight > 0)) {
return;
}
const target = focusRef.current || { xRatio: 0.5, yRatio: 0.5 };
const maxScrollLeft = Math.max(0, imageWidth - scrollEl.clientWidth);
const maxScrollTop = Math.max(0, imageHeight - scrollEl.clientHeight);
const desiredLeft = target.xRatio * imageWidth - scrollEl.clientWidth / 2;
const desiredTop = target.yRatio * imageHeight - scrollEl.clientHeight / 2;
scrollEl.scrollLeft = clamp(desiredLeft, 0, maxScrollLeft);
scrollEl.scrollTop = clamp(desiredTop, 0, maxScrollTop);
}, [open, isNativeScale, naturalSize.width, naturalSize.height]);
useEffect(() => {
if (!open) {
previouslyFocusedRef.current?.focus?.();
previouslyFocusedRef.current = null;
return;
}
const active = document.activeElement;
previouslyFocusedRef.current = active instanceof HTMLElement ? active : null;
}, [open]);
useEffect(() => {
if (!documentLink?.url) {
return;
}
const scrollEl = scrollRef.current;
if (scrollEl) {
scrollEl.scrollLeft = 0;
scrollEl.scrollTop = 0;
}
focusRef.current = null;
}, [documentLink?.url]);
useEffect(() => {
if (!renderBackdrop || !documentLink?.url) {
return undefined;
}
const frame = requestAnimationFrame(() => {
scrollRef.current?.focus?.({ preventScroll: true });
});
return () => cancelAnimationFrame(frame);
}, [renderBackdrop, documentLink?.url]);
const handleKeyDown = (event: React.KeyboardEvent<HTMLDivElement>) => {
event.stopPropagation();
if (!open) {
return;
}
const key = event.key;
if (key === ' ' || key === 'Space' || key === 'Spacebar') {
const target = event.target;
if (target instanceof HTMLElement) {
const tag = target.tagName ? target.tagName.toLowerCase() : '';
if (
target.isContentEditable
|| tag === 'input'
|| tag === 'textarea'
|| tag === 'select'
) {
return;
}
}
event.preventDefault();
onClose();
return;
}
if (key === 'Escape') {
event.preventDefault();
onClose();
return;
}
};
const toggleZoomAtPoint = (clientX: number, clientY: number) => {
if (isPdfDisplay) {
return;
}
const media = mediaRef.current;
setIsNativeScale((current) => {
if (!current && media) {
const rect = media.getBoundingClientRect();
const xRatio = rect.width > 0 ? (clientX - rect.left) / rect.width : 0.5;
const yRatio = rect.height > 0 ? (clientY - rect.top) / rect.height : 0.5;
focusRef.current = {
xRatio: clamp(xRatio, 0, 1),
yRatio: clamp(yRatio, 0, 1),
};
} else {
focusRef.current = null;
}
return !current;
});
};
const handleContentClick = (event: React.MouseEvent<HTMLElement>) => {
if (isPdfDisplay) {
return;
}
event.stopPropagation();
toggleZoomAtPoint(event.clientX ?? 0, event.clientY ?? 0);
};
const shouldRender = renderBackdrop && Boolean(documentLink?.url);
const stageClassName = isPdfDisplay
? 'preview-zoom__stage preview-zoom__stage--pdf'
: 'preview-zoom__stage';
const containerClassName = [
'preview-zoom__scroll',
isNativeScale ? 'preview-zoom__scroll--native' : null,
isPdfDisplay ? 'preview-zoom__scroll--pdf' : null,
]
.filter(Boolean)
.join(' ');
const backdropClassName = [
'preview-zoom-backdrop',
isBackdropVisible ? 'preview-zoom-backdrop--visible' : '',
]
.filter(Boolean)
.join(' ');
const contentStyle: CSSProperties = isNativeScale
? {
cursor: 'zoom-out',
width: naturalSize.width ? `${naturalSize.width}px` : 'auto',
height: naturalSize.height ? `${naturalSize.height}px` : 'auto',
maxWidth: 'none',
maxHeight: 'none',
touchAction: 'manipulation',
}
: {
cursor: 'zoom-in',
maxWidth: '95vw',
maxHeight: '95vh',
touchAction: 'manipulation',
};
if (!shouldRender) {
return null;
}
const effectiveDisplay = documentLink;
return createPortal(
(
<div
className={backdropClassName}
role="dialog"
aria-modal="true"
aria-label="Enlarged document preview"
onClick={onClose}
onKeyDown={handleKeyDown}
>
<div
className={stageClassName}
onClick={(event) => {
if (event.target === event.currentTarget) {
onClose();
}
}}
>
<div
className={containerClassName}
ref={scrollRef}
tabIndex={-1}
>
{isPdfDisplay ? (
<div className="preview-zoom__pdf">
<PdfViewer
src={effectiveDisplay.url}
title={effectiveAlt}
className="preview-zoom__pdf-viewer"
viewportRef={scrollRef}
/>
</div>
) : (
<img
src={effectiveDisplay.url}
alt={effectiveAlt}
className="preview-zoom__image"
ref={(node) => {
mediaRef.current = node;
}}
draggable={false}
onLoad={(event) => {
setNaturalSize({
width: event.currentTarget.naturalWidth || null,
height: event.currentTarget.naturalHeight || null,
});
}}
onClick={handleContentClick}
style={contentStyle}
/>
)}
</div>
</div>
</div>
),
portalTarget,
);
};
export default PreviewZoomOverlay;