vscode-extension-samples/contentprovider-sample/src/provider.ts

/*---------------------------------------------------------
 * Copyright (C) Microsoft Corporation. All rights reserved.
 *--------------------------------------------------------*/
'use strict';

import * as vscode from 'vscode';
import ReferencesDocument from './referencesDocument';

export default class Provider implements vscode.TextDocumentContentProvider, vscode.DocumentLinkProvider {

    static scheme = 'references';

    private _onDidChange = new vscode.EventEmitter<vscode.Uri>();
    private _documents = new Map<string, ReferencesDocument>();
    private _editorDecoration = vscode.window.createTextEditorDecorationType({ textDecoration: 'underline' });
    private _subscriptions: vscode.Disposable;

    constructor() {

        // Listen to the following events:
        // * closeTextDocument - which means we must clear the corresponding model object - `ReferencesDocument`
        this._subscriptions = vscode.workspace.onDidCloseTextDocument(doc => this._documents.delete(doc.uri.toString()));
    }

    dispose() {
        this._subscriptions.dispose();
        this._documents.clear();
        this._editorDecoration.dispose();
        this._onDidChange.dispose();
    }

    /**
     * Expose an event to signal changes of _virtual_ documents
     * to the editor
     */
    get onDidChange() {
        return this._onDidChange.event;
    }

    /**
     * Provider method that takes an uri of the `references`-scheme and
     * resolves its content by (1) running the reference search command
     * and (2) formatting the results
     */
    provideTextDocumentContent(uri: vscode.Uri): string | Thenable<string> {

        // already loaded?
        let document = this._documents.get(uri.toString());
        if (document) {
            return document.value;
        }

        // Decode target-uri and target-position from the provided uri and execute the
        // `reference provider` command (http://code.visualstudio.com/docs/extensionAPI/vscode-api-commands).
        // From the result create a references document which is in charge of loading,
        // printing, and formatting references
        const [target, pos] = decodeLocation(uri);
        return vscode.commands.executeCommand<vscode.Location[]>('vscode.executeReferenceProvider', target, pos).then(locations => {

            // sort by locations and shuffle to begin from target resource
            let idx = 0;
            locations.sort(Provider._compareLocations).find((loc, i) => loc.uri.toString() === target.toString() && (idx = i) && true);
            locations.push(...locations.splice(0, idx));

            // create document and return its early state
            let document = new ReferencesDocument(uri, locations, this._onDidChange);
            this._documents.set(uri.toString(), document);
            return document.value;
        });
    }

    private static _compareLocations(a: vscode.Location, b: vscode.Location): number {
        if (a.uri.toString() < b.uri.toString()) {
            return -1;
        } else if (a.uri.toString() > b.uri.toString()) {
            return 1;
        } else {
            return a.range.start.compareTo(b.range.start)
        }
    }

    provideDocumentLinks(document: vscode.TextDocument, token: vscode.CancellationToken): vscode.DocumentLink[] {
        // While building the virtual document we have already created the links.
        // Those are composed from the range inside the document and a target uri
        // to which they point
        const doc = this._documents.get(document.uri.toString());
        if (doc) {
            return doc.links;
        }
    }
}

let seq = 0;

export function encodeLocation(uri: vscode.Uri, pos: vscode.Position): vscode.Uri {
    const query = JSON.stringify([uri.toString(), pos.line, pos.character]);
    return vscode.Uri.parse(`${Provider.scheme}:References.locations?${query}#${seq++}`);
}

export function decodeLocation(uri: vscode.Uri): [vscode.Uri, vscode.Position] {
    let [target, line, character] = <[string, number, number]>JSON.parse(uri.query);
    return [vscode.Uri.parse(target), new vscode.Position(line, character)];
}