Files
papercrate/frontend/src/detail/PreviewZoomOverlay.jsx
T
2025-11-02 15:44:09 +01:00

368 lines
9.9 KiB
React

import React, { useEffect, useRef, useState } from 'react';
import { createPortal } from 'react-dom';
import { ArrowLeftIcon, ArrowRightIcon } from '../ui/icons';
import usePointerTap from '../ui/usePointerTap';
const noop = () => {};
const clamp = (value, min, max) => {
if (value < min) return min;
if (value > max) return max;
return value;
};
const ensureDocumentRoot = () => {
if (typeof document === 'undefined') {
return null;
}
return document.body;
};
const CLICK_DELAY_MS = 240;
const PreviewZoomOverlay = ({
open = false,
display = null,
onClose = noop,
}) => {
const portalTarget = ensureDocumentRoot();
const [isNativeScale, setIsNativeScale] = useState(false);
const [naturalSize, setNaturalSize] = useState({ width: null, height: null });
const [renderBackdrop, setRenderBackdrop] = useState(false);
const [isBackdropVisible, setBackdropVisible] = useState(false);
const [displaySnapshot, setDisplaySnapshot] = useState(null);
const scrollRef = useRef(null);
const imageRef = useRef(null);
const focusRef = useRef(null);
const previouslyFocusedRef = useRef(null);
const visibilityTimerRef = useRef(null);
const displayTimerRef = useRef(null);
useEffect(() => {
if (display?.url) {
setDisplaySnapshot(display);
}
}, [display]);
useEffect(() => {
if (visibilityTimerRef.current) {
clearTimeout(visibilityTimerRef.current);
visibilityTimerRef.current = null;
}
if (displayTimerRef.current) {
cancelAnimationFrame(displayTimerRef.current);
displayTimerRef.current = null;
}
if (open && display?.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 = setTimeout(() => {
setRenderBackdrop(false);
}, 260);
return () => {
if (visibilityTimerRef.current) {
clearTimeout(visibilityTimerRef.current);
visibilityTimerRef.current = null;
}
};
}, [open, display?.url]);
useEffect(() => () => {
if (visibilityTimerRef.current) {
clearTimeout(visibilityTimerRef.current);
}
if (displayTimerRef.current) {
cancelAnimationFrame(displayTimerRef.current);
}
}, []);
useEffect(() => {
setIsNativeScale(false);
setNaturalSize({ width: null, height: null });
focusRef.current = null;
const scrollEl = scrollRef.current;
if (scrollEl) {
scrollEl.scrollLeft = 0;
scrollEl.scrollTop = 0;
}
}, [open]);
useEffect(() => {
if (!open || !isNativeScale) {
return;
}
const scrollEl = scrollRef.current;
const imageEl = imageRef.current;
if (!scrollEl || !imageEl) {
return;
}
const imageWidth = imageEl.naturalWidth || imageEl.clientWidth;
const imageHeight = imageEl.naturalHeight || imageEl.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) {
if (previouslyFocusedRef.current && typeof previouslyFocusedRef.current.focus === 'function') {
previouslyFocusedRef.current.focus();
}
previouslyFocusedRef.current = null;
return;
}
if (typeof document !== 'undefined') {
const active = document.activeElement;
if (active && typeof active.focus === 'function') {
previouslyFocusedRef.current = active;
} else {
previouslyFocusedRef.current = null;
}
}
}, [open]);
const activeDisplay = open && display?.url ? display : displaySnapshot;
useEffect(() => {
if (!renderBackdrop || !activeDisplay?.url) {
return undefined;
}
const frame = requestAnimationFrame(() => {
const scrollEl = scrollRef.current;
if (scrollEl && typeof scrollEl.focus === 'function') {
scrollEl.focus({ preventScroll: true });
}
});
return () => cancelAnimationFrame(frame);
}, [renderBackdrop, activeDisplay?.url]);
const handleKeyDown = (event) => {
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;
}
if (key === 'ArrowLeft') {
if (activeDisplay?.canGoPrev && activeDisplay?.goPrev) {
event.preventDefault();
activeDisplay.goPrev();
}
return;
}
if (key === 'ArrowRight') {
if (activeDisplay?.canGoNext && activeDisplay?.goNext) {
event.preventDefault();
activeDisplay.goNext();
}
}
};
const toggleZoomAtPoint = (clientX, clientY) => {
const img = imageRef.current;
setIsNativeScale((current) => {
if (!current && img) {
const rect = img.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 pointerTapHandler = usePointerTap({
delay: CLICK_DELAY_MS,
onSingle: () => {
onClose();
},
onDouble: ({ clientX, clientY }) => {
toggleZoomAtPoint(clientX, clientY);
},
});
const handleImagePointerDown = (event) => {
event.stopPropagation();
pointerTapHandler(event);
};
if (!renderBackdrop || !activeDisplay?.url || !portalTarget) {
return null;
}
const effectiveDisplay = activeDisplay;
const navVisible = Boolean(effectiveDisplay?.canGoPrev || effectiveDisplay?.canGoNext);
const stageClassName = [
'preview-zoom__stage',
]
.filter(Boolean)
.join(' ');
const containerClassName = [
'preview-zoom__scroll',
isNativeScale ? 'preview-zoom__scroll--native' : '',
]
.filter(Boolean)
.join(' ');
const backdropClassName = [
'preview-zoom-backdrop',
isBackdropVisible ? 'preview-zoom-backdrop--visible' : '',
]
.filter(Boolean)
.join(' ');
const imageStyle = 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',
};
return createPortal(
(
<div
className={backdropClassName}
role="dialog"
aria-modal="true"
aria-label="Enlarged document preview"
onClick={onClose}
>
<div
className={stageClassName}
onClick={(event) => event.stopPropagation()}
onKeyDown={handleKeyDown}
>
<div
className={containerClassName}
ref={scrollRef}
tabIndex={-1}
>
<img
src={effectiveDisplay.url}
alt={effectiveDisplay.alt || 'Document preview'}
className="preview-zoom__image"
ref={imageRef}
draggable={false}
onLoad={(event) => {
setNaturalSize({
width: event.currentTarget.naturalWidth || null,
height: event.currentTarget.naturalHeight || null,
});
}}
onPointerDown={handleImagePointerDown}
style={imageStyle}
/>
</div>
{navVisible ? (
<div className="preview-zoom__nav">
<button
type="button"
className="preview-zoom__nav-button"
onClick={(event) => {
event.stopPropagation();
if (effectiveDisplay?.canGoPrev && effectiveDisplay?.goPrev) {
effectiveDisplay.goPrev();
}
}}
aria-label="Previous preview"
disabled={!effectiveDisplay?.canGoPrev}
>
<ArrowLeftIcon />
</button>
<button
type="button"
className="preview-zoom__nav-button"
onClick={(event) => {
event.stopPropagation();
if (effectiveDisplay?.canGoNext && effectiveDisplay?.goNext) {
effectiveDisplay.goNext();
}
}}
aria-label="Next preview"
disabled={!effectiveDisplay?.canGoNext}
>
<ArrowRightIcon />
</button>
</div>
) : null}
</div>
</div>
),
portalTarget,
);
};
export default PreviewZoomOverlay;