Files
fx-test/fluxer_app/src/lib/PlaceholderSpecs.ts
Hampus Kraft 2f557eda8c initial commit
2026-01-01 21:05:54 +00:00

108 lines
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TypeScript

/*
* Copyright (C) 2026 Fluxer Contributors
*
* This file is part of Fluxer.
*
* Fluxer is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Fluxer is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with Fluxer. If not, see <https://www.gnu.org/licenses/>.
*/
import {useMemo} from 'react';
export function generatePlaceholderSpecs(options: {
compact: boolean;
messageGroups: number;
groupRange: number;
attachments: number;
fontSize: number;
groupSpacing: number;
}): {
messages: Array<number>;
attachmentSpecs: Array<[number, {width: number; height: number}] | undefined>;
totalHeight: number;
groupSpacing: number;
} {
const {compact, messageGroups, groupRange, attachments, fontSize, groupSpacing} = options;
if (attachments > messageGroups) {
throw new Error(
`generatePlaceholderSpecs: too many attachments relative to messageGroups: ${messageGroups}, ${attachments}`,
);
}
const DEFAULT_FONT_SIZE = 16;
const scale = fontSize / DEFAULT_FONT_SIZE;
const MESSAGE_HEIGHT_COZY = 22;
const MESSAGE_HEIGHT_COMPACT = 16;
const ATTACHMENT_MARGIN = 8;
const messageHeight = compact ? MESSAGE_HEIGHT_COMPACT : MESSAGE_HEIGHT_COZY;
let totalHeight = 0;
const messageCounts: Array<number> = [];
for (let i = 0; i < messageGroups; i++) {
const count = Math.floor(Math.random() * groupRange) + 1;
messageCounts.push(count);
totalHeight += groupSpacing * scale;
totalHeight += messageHeight * scale;
totalHeight += (count - 1) * messageHeight * scale;
}
const availableGroupIndices = messageCounts.map((_, i) => i);
const attachmentSpecs: Array<[number, {width: number; height: number}] | undefined> =
Array(messageGroups).fill(undefined);
for (let i = 0; i < attachments; i++) {
const randomIndex = Math.floor(Math.random() * availableGroupIndices.length);
const groupIndex = availableGroupIndices.splice(randomIndex, 1)[0];
const width = Math.floor(Math.random() * (400 - 140 + 1)) + 140;
const height = Math.floor(Math.random() * (320 - 100 + 1)) + 100;
attachmentSpecs[groupIndex] = [groupIndex, {width, height}];
totalHeight += height + ATTACHMENT_MARGIN * scale;
}
return {
messages: messageCounts,
attachmentSpecs,
totalHeight,
groupSpacing,
};
}
export function usePlaceholderSpecs(compact: boolean, groupSpacing: number, fontSize: number) {
return useMemo(() => {
return compact
? generatePlaceholderSpecs({
compact: true,
messageGroups: 30,
groupRange: 4,
attachments: 8,
fontSize,
groupSpacing,
})
: generatePlaceholderSpecs({
compact: false,
messageGroups: 26,
groupRange: 4,
attachments: 8,
fontSize,
groupSpacing,
});
}, [compact, fontSize, groupSpacing]);
}