monaco-editor-core
Version:
A browser based code editor
204 lines (203 loc) • 10.3 kB
JavaScript
/*---------------------------------------------------------------------------------------------
* Copyright (c) Microsoft Corporation. All rights reserved.
* Licensed under the MIT License. See License.txt in the project root for license information.
*--------------------------------------------------------------------------------------------*/
import { getWindowId } from '../../../base/browser/dom.js';
import { PixelRatio } from '../../../base/browser/pixelRatio.js';
import { Emitter } from '../../../base/common/event.js';
import { Disposable } from '../../../base/common/lifecycle.js';
import { CharWidthRequest, readCharWidths } from './charWidthReader.js';
import { EditorFontLigatures } from '../../common/config/editorOptions.js';
import { FontInfo } from '../../common/config/fontInfo.js';
export class FontMeasurementsImpl extends Disposable {
constructor() {
super(...arguments);
this._cache = new Map();
this._evictUntrustedReadingsTimeout = -1;
this._onDidChange = this._register(new Emitter());
this.onDidChange = this._onDidChange.event;
}
dispose() {
if (this._evictUntrustedReadingsTimeout !== -1) {
clearTimeout(this._evictUntrustedReadingsTimeout);
this._evictUntrustedReadingsTimeout = -1;
}
super.dispose();
}
/**
* Clear all cached font information and trigger a change event.
*/
clearAllFontInfos() {
this._cache.clear();
this._onDidChange.fire();
}
_ensureCache(targetWindow) {
const windowId = getWindowId(targetWindow);
let cache = this._cache.get(windowId);
if (!cache) {
cache = new FontMeasurementsCache();
this._cache.set(windowId, cache);
}
return cache;
}
_writeToCache(targetWindow, item, value) {
const cache = this._ensureCache(targetWindow);
cache.put(item, value);
if (!value.isTrusted && this._evictUntrustedReadingsTimeout === -1) {
// Try reading again after some time
this._evictUntrustedReadingsTimeout = targetWindow.setTimeout(() => {
this._evictUntrustedReadingsTimeout = -1;
this._evictUntrustedReadings(targetWindow);
}, 5000);
}
}
_evictUntrustedReadings(targetWindow) {
const cache = this._ensureCache(targetWindow);
const values = cache.getValues();
let somethingRemoved = false;
for (const item of values) {
if (!item.isTrusted) {
somethingRemoved = true;
cache.remove(item);
}
}
if (somethingRemoved) {
this._onDidChange.fire();
}
}
/**
* Read font information.
*/
readFontInfo(targetWindow, bareFontInfo) {
const cache = this._ensureCache(targetWindow);
if (!cache.has(bareFontInfo)) {
let readConfig = this._actualReadFontInfo(targetWindow, bareFontInfo);
if (readConfig.typicalHalfwidthCharacterWidth <= 2 || readConfig.typicalFullwidthCharacterWidth <= 2 || readConfig.spaceWidth <= 2 || readConfig.maxDigitWidth <= 2) {
// Hey, it's Bug 14341 ... we couldn't read
readConfig = new FontInfo({
pixelRatio: PixelRatio.getInstance(targetWindow).value,
fontFamily: readConfig.fontFamily,
fontWeight: readConfig.fontWeight,
fontSize: readConfig.fontSize,
fontFeatureSettings: readConfig.fontFeatureSettings,
fontVariationSettings: readConfig.fontVariationSettings,
lineHeight: readConfig.lineHeight,
letterSpacing: readConfig.letterSpacing,
isMonospace: readConfig.isMonospace,
typicalHalfwidthCharacterWidth: Math.max(readConfig.typicalHalfwidthCharacterWidth, 5),
typicalFullwidthCharacterWidth: Math.max(readConfig.typicalFullwidthCharacterWidth, 5),
canUseHalfwidthRightwardsArrow: readConfig.canUseHalfwidthRightwardsArrow,
spaceWidth: Math.max(readConfig.spaceWidth, 5),
middotWidth: Math.max(readConfig.middotWidth, 5),
wsmiddotWidth: Math.max(readConfig.wsmiddotWidth, 5),
maxDigitWidth: Math.max(readConfig.maxDigitWidth, 5),
}, false);
}
this._writeToCache(targetWindow, bareFontInfo, readConfig);
}
return cache.get(bareFontInfo);
}
_createRequest(chr, type, all, monospace) {
const result = new CharWidthRequest(chr, type);
all.push(result);
monospace?.push(result);
return result;
}
_actualReadFontInfo(targetWindow, bareFontInfo) {
const all = [];
const monospace = [];
const typicalHalfwidthCharacter = this._createRequest('n', 0 /* CharWidthRequestType.Regular */, all, monospace);
const typicalFullwidthCharacter = this._createRequest('\uff4d', 0 /* CharWidthRequestType.Regular */, all, null);
const space = this._createRequest(' ', 0 /* CharWidthRequestType.Regular */, all, monospace);
const digit0 = this._createRequest('0', 0 /* CharWidthRequestType.Regular */, all, monospace);
const digit1 = this._createRequest('1', 0 /* CharWidthRequestType.Regular */, all, monospace);
const digit2 = this._createRequest('2', 0 /* CharWidthRequestType.Regular */, all, monospace);
const digit3 = this._createRequest('3', 0 /* CharWidthRequestType.Regular */, all, monospace);
const digit4 = this._createRequest('4', 0 /* CharWidthRequestType.Regular */, all, monospace);
const digit5 = this._createRequest('5', 0 /* CharWidthRequestType.Regular */, all, monospace);
const digit6 = this._createRequest('6', 0 /* CharWidthRequestType.Regular */, all, monospace);
const digit7 = this._createRequest('7', 0 /* CharWidthRequestType.Regular */, all, monospace);
const digit8 = this._createRequest('8', 0 /* CharWidthRequestType.Regular */, all, monospace);
const digit9 = this._createRequest('9', 0 /* CharWidthRequestType.Regular */, all, monospace);
// monospace test: used for whitespace rendering
const rightwardsArrow = this._createRequest('→', 0 /* CharWidthRequestType.Regular */, all, monospace);
const halfwidthRightwardsArrow = this._createRequest('￫', 0 /* CharWidthRequestType.Regular */, all, null);
// U+00B7 - MIDDLE DOT
const middot = this._createRequest('·', 0 /* CharWidthRequestType.Regular */, all, monospace);
// U+2E31 - WORD SEPARATOR MIDDLE DOT
const wsmiddotWidth = this._createRequest(String.fromCharCode(0x2E31), 0 /* CharWidthRequestType.Regular */, all, null);
// monospace test: some characters
const monospaceTestChars = '|/-_ilm%';
for (let i = 0, len = monospaceTestChars.length; i < len; i++) {
this._createRequest(monospaceTestChars.charAt(i), 0 /* CharWidthRequestType.Regular */, all, monospace);
this._createRequest(monospaceTestChars.charAt(i), 1 /* CharWidthRequestType.Italic */, all, monospace);
this._createRequest(monospaceTestChars.charAt(i), 2 /* CharWidthRequestType.Bold */, all, monospace);
}
readCharWidths(targetWindow, bareFontInfo, all);
const maxDigitWidth = Math.max(digit0.width, digit1.width, digit2.width, digit3.width, digit4.width, digit5.width, digit6.width, digit7.width, digit8.width, digit9.width);
let isMonospace = (bareFontInfo.fontFeatureSettings === EditorFontLigatures.OFF);
const referenceWidth = monospace[0].width;
for (let i = 1, len = monospace.length; isMonospace && i < len; i++) {
const diff = referenceWidth - monospace[i].width;
if (diff < -0.001 || diff > 0.001) {
isMonospace = false;
break;
}
}
let canUseHalfwidthRightwardsArrow = true;
if (isMonospace && halfwidthRightwardsArrow.width !== referenceWidth) {
// using a halfwidth rightwards arrow would break monospace...
canUseHalfwidthRightwardsArrow = false;
}
if (halfwidthRightwardsArrow.width > rightwardsArrow.width) {
// using a halfwidth rightwards arrow would paint a larger arrow than a regular rightwards arrow
canUseHalfwidthRightwardsArrow = false;
}
return new FontInfo({
pixelRatio: PixelRatio.getInstance(targetWindow).value,
fontFamily: bareFontInfo.fontFamily,
fontWeight: bareFontInfo.fontWeight,
fontSize: bareFontInfo.fontSize,
fontFeatureSettings: bareFontInfo.fontFeatureSettings,
fontVariationSettings: bareFontInfo.fontVariationSettings,
lineHeight: bareFontInfo.lineHeight,
letterSpacing: bareFontInfo.letterSpacing,
isMonospace: isMonospace,
typicalHalfwidthCharacterWidth: typicalHalfwidthCharacter.width,
typicalFullwidthCharacterWidth: typicalFullwidthCharacter.width,
canUseHalfwidthRightwardsArrow: canUseHalfwidthRightwardsArrow,
spaceWidth: space.width,
middotWidth: middot.width,
wsmiddotWidth: wsmiddotWidth.width,
maxDigitWidth: maxDigitWidth
}, true);
}
}
class FontMeasurementsCache {
constructor() {
this._keys = Object.create(null);
this._values = Object.create(null);
}
has(item) {
const itemId = item.getId();
return !!this._values[itemId];
}
get(item) {
const itemId = item.getId();
return this._values[itemId];
}
put(item, value) {
const itemId = item.getId();
this._keys[itemId] = item;
this._values[itemId] = value;
}
remove(item) {
const itemId = item.getId();
delete this._keys[itemId];
delete this._values[itemId];
}
getValues() {
return Object.keys(this._keys).map(id => this._values[id]);
}
}
export const FontMeasurements = new FontMeasurementsImpl();