Jamie Wong
608006232f
While it was kind of nice having everything at the top level, the number of files is now getting a bit unwieldy and hard to understand, so I took a stab at organizing the directories without introducing too much nesting. Test Plan: - Ran `npm run serve` to ensure that local builds still work - Ran `npm run prepack` then `open dist/release/index.html` to ensure that release builds still work - Ran `scripts/deploy.sh` to ensure that the deployed version of the site will still work when I eventually redeploy - Ran `npm run jest` to ensure that tests still work correctly
40 lines
1.2 KiB
TypeScript
40 lines
1.2 KiB
TypeScript
import {binarySearch} from './utils'
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export const ELLIPSIS = '\u2026'
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// NOTE: This blindly assumes the same result across contexts.
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const measureTextCache = new Map<string, number>()
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let lastDevicePixelRatio = -1
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export function cachedMeasureTextWidth(ctx: CanvasRenderingContext2D, text: string): number {
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if (window.devicePixelRatio !== lastDevicePixelRatio) {
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// This cache is no longer valid!
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measureTextCache.clear()
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lastDevicePixelRatio = window.devicePixelRatio
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}
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if (!measureTextCache.has(text)) {
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measureTextCache.set(text, ctx.measureText(text).width)
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}
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return measureTextCache.get(text)!
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}
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function buildTrimmedText(text: string, length: number) {
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const prefixLength = Math.floor(length / 2)
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const prefix = text.substr(0, prefixLength)
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const suffix = text.substr(text.length - prefixLength, prefixLength)
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return prefix + ELLIPSIS + suffix
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}
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export function trimTextMid(ctx: CanvasRenderingContext2D, text: string, maxWidth: number) {
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if (cachedMeasureTextWidth(ctx, text) <= maxWidth) return text
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const [lo] = binarySearch(
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0,
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text.length,
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n => {
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return cachedMeasureTextWidth(ctx, buildTrimmedText(text, n))
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},
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maxWidth,
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)
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return buildTrimmedText(text, lo)
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}
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