code-server/lib/vscode/extensions/markdown-language-features/src/tableOfContentsProvider.ts

119 lines
3.3 KiB
TypeScript

/*---------------------------------------------------------------------------------------------
* Copyright (c) Microsoft Corporation. All rights reserved.
* Licensed under the MIT License. See License.txt in the project root for license information.
*--------------------------------------------------------------------------------------------*/
import * as vscode from 'vscode';
import { MarkdownEngine } from './markdownEngine';
import { Slug, githubSlugifier } from './slugify';
export interface TocEntry {
readonly slug: Slug;
readonly text: string;
readonly level: number;
readonly line: number;
readonly location: vscode.Location;
}
export interface SkinnyTextLine {
text: string;
}
export interface SkinnyTextDocument {
readonly uri: vscode.Uri;
readonly version: number;
readonly lineCount: number;
lineAt(line: number): SkinnyTextLine;
getText(): string;
}
export class TableOfContentsProvider {
private toc?: TocEntry[];
public constructor(
private engine: MarkdownEngine,
private document: SkinnyTextDocument
) { }
public async getToc(): Promise<TocEntry[]> {
if (!this.toc) {
try {
this.toc = await this.buildToc(this.document);
} catch (e) {
this.toc = [];
}
}
return this.toc;
}
public async lookup(fragment: string): Promise<TocEntry | undefined> {
const toc = await this.getToc();
const slug = githubSlugifier.fromHeading(fragment);
return toc.find(entry => entry.slug.equals(slug));
}
private async buildToc(document: SkinnyTextDocument): Promise<TocEntry[]> {
const toc: TocEntry[] = [];
const tokens = await this.engine.parse(document);
const existingSlugEntries = new Map<string, { count: number }>();
for (const heading of tokens.filter(token => token.type === 'heading_open')) {
const lineNumber = heading.map[0];
const line = document.lineAt(lineNumber);
let slug = githubSlugifier.fromHeading(line.text);
const existingSlugEntry = existingSlugEntries.get(slug.value);
if (existingSlugEntry) {
++existingSlugEntry.count;
slug = githubSlugifier.fromHeading(slug.value + '-' + existingSlugEntry.count);
} else {
existingSlugEntries.set(slug.value, { count: 0 });
}
toc.push({
slug,
text: TableOfContentsProvider.getHeaderText(line.text),
level: TableOfContentsProvider.getHeaderLevel(heading.markup),
line: lineNumber,
location: new vscode.Location(document.uri,
new vscode.Range(lineNumber, 0, lineNumber, line.text.length))
});
}
// Get full range of section
return toc.map((entry, startIndex): TocEntry => {
let end: number | undefined = undefined;
for (let i = startIndex + 1; i < toc.length; ++i) {
if (toc[i].level <= entry.level) {
end = toc[i].line - 1;
break;
}
}
const endLine = end ?? document.lineCount - 1;
return {
...entry,
location: new vscode.Location(document.uri,
new vscode.Range(
entry.location.range.start,
new vscode.Position(endLine, document.lineAt(endLine).text.length)))
};
});
}
private static getHeaderLevel(markup: string): number {
if (markup === '=') {
return 1;
} else if (markup === '-') {
return 2;
} else { // '#', '##', ...
return markup.length;
}
}
private static getHeaderText(header: string): string {
return header.replace(/^\s*#+\s*(.*?)\s*#*$/, (_, word) => word.trim());
}
}