File size: 2,122 Bytes
f56a29b | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 | import type { PPTElement } from '@/lib/types/slides';
/**
* Extract the semantic payload for each element type.
* Used by elementFingerprint to detect content-only changes
* (same id/position but different text, chart data, media src, etc.).
*/
function semanticPart(e: PPTElement): unknown {
switch (e.type) {
case 'text':
return { content: e.content };
case 'image':
return { src: e.src };
case 'shape':
return {
path: e.path,
fill: e.fill,
text: e.text?.content ?? '',
gradient: e.gradient ?? null,
pattern: e.pattern ?? null,
};
case 'line':
return {
start: e.start,
end: e.end,
color: e.color,
style: e.style,
points: e.points,
};
case 'chart':
return {
chartType: e.chartType,
data: e.data,
themeColors: e.themeColors,
};
case 'table':
return {
data: e.data.map((row) => row.map((c) => c.text)),
colWidths: e.colWidths,
theme: e.theme ?? null,
};
case 'latex':
return { latex: e.latex };
case 'video':
return { src: e.src, poster: e.poster ?? '' };
case 'audio':
return { src: e.src };
case 'code':
return { language: e.language, lines: e.lines, fileName: e.fileName ?? '' };
default: {
const exhaustiveCheck: never = e;
return exhaustiveCheck;
}
}
}
/**
* Generate a fingerprint string for a list of whiteboard elements.
* Used for change detection and deduplication in history snapshots.
*
* Covers both geometry (id, position, size) AND semantic content
* via structured JSON.stringify — avoids delimiter-collision issues
* that hand-concatenated strings would have with rich-text HTML content.
*/
export function elementFingerprint(els: PPTElement[]): string {
return JSON.stringify(
els.map((e) => ({
id: e.id,
left: e.left ?? 0,
top: e.top ?? 0,
width: 'width' in e ? e.width : 0,
height: 'height' in e && e.height != null ? e.height : 0,
sem: semanticPart(e),
})),
);
}
|