Revert 1d0a9f9e63 (#169578)

Resubmits the original PR with test fixes for windows

extensions/markdown-language-features/src/languageFeatures/copyFiles/dropIntoEditor.ts

@@ -0,0 +1,139 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import * as path from 'path';
+import * as vscode from 'vscode';
+import * as URI from 'vscode-uri';
+import { Schemes } from '../../util/schemes';
+
+export const imageFileExtensions = new Set<string>([
+	'bmp',
+	'gif',
+	'ico',
+	'jpe',
+	'jpeg',
+	'jpg',
+	'png',
+	'psd',
+	'svg',
+	'tga',
+	'tif',
+	'tiff',
+	'webp',
+]);
+
+export function registerDropIntoEditorSupport(selector: vscode.DocumentSelector) {
+	return vscode.languages.registerDocumentDropEditProvider(selector, new class implements vscode.DocumentDropEditProvider {
+		async provideDocumentDropEdits(document: vscode.TextDocument, _position: vscode.Position, dataTransfer: vscode.DataTransfer, token: vscode.CancellationToken): Promise<vscode.DocumentDropEdit | undefined> {
+			const enabled = vscode.workspace.getConfiguration('markdown', document).get('editor.drop.enabled', true);
+			if (!enabled) {
+				return undefined;
+			}
+
+			const snippet = await tryGetUriListSnippet(document, dataTransfer, token);
+			return snippet ? new vscode.DocumentDropEdit(snippet) : undefined;
+		}
+	});
+}
+
+export async function tryGetUriListSnippet(document: vscode.TextDocument, dataTransfer: vscode.DataTransfer, token: vscode.CancellationToken): Promise<vscode.SnippetString | undefined> {
+	const urlList = await dataTransfer.get('text/uri-list')?.asString();
+	if (!urlList || token.isCancellationRequested) {
+		return undefined;
+	}
+
+	const uris: vscode.Uri[] = [];
+	for (const resource of urlList.split('\n')) {
+		try {
+			uris.push(vscode.Uri.parse(resource));
+		} catch {
+			// noop
+		}
+	}
+
+	return createUriListSnippet(document, uris);
+}
+
+interface UriListSnippetOptions {
+	readonly placeholderText?: string;
+
+	readonly placeholderStartIndex?: number;
+
+	/**
+	 * Should the snippet be for an image?
+	 *
+	 * If `undefined`, tries to infer this from the uri.
+	 */
+	readonly insertAsImage?: boolean;
+
+	readonly separator?: string;
+}
+
+export function createUriListSnippet(document: vscode.TextDocument, uris: readonly vscode.Uri[], options?: UriListSnippetOptions): vscode.SnippetString | undefined {
+	if (!uris.length) {
+		return undefined;
+	}
+
+	const dir = getDocumentDir(document);
+
+	const snippet = new vscode.SnippetString();
+	uris.forEach((uri, i) => {
+		const mdPath = getMdPath(dir, uri);
+
+		const ext = URI.Utils.extname(uri).toLowerCase().replace('.', '');
+		const insertAsImage = typeof options?.insertAsImage === 'undefined' ? imageFileExtensions.has(ext) : !!options.insertAsImage;
+
+		snippet.appendText(insertAsImage ? '![' : '[');
+
+		const placeholderText = options?.placeholderText ?? (insertAsImage ? 'Alt text' : 'label');
+		const placeholderIndex = typeof options?.placeholderStartIndex !== 'undefined' ? options?.placeholderStartIndex + i : undefined;
+		snippet.appendPlaceholder(placeholderText, placeholderIndex);
+
+		snippet.appendText(`](${mdPath})`);
+
+		if (i < uris.length - 1 && uris.length > 1) {
+			snippet.appendText(options?.separator ?? ' ');
+		}
+	});
+	return snippet;
+}
+
+function getMdPath(dir: vscode.Uri | undefined, file: vscode.Uri) {
+	if (dir && dir.scheme === file.scheme && dir.authority === file.authority) {
+		if (file.scheme === Schemes.file) {
+			// On windows, we must use the native `path.relative` to generate the relative path
+			// so that drive-letters are resolved cast insensitively. However we then want to
+			// convert back to a posix path to insert in to the document.
+			const relativePath = path.relative(dir.fsPath, file.fsPath);
+			return encodeURI(path.posix.normalize(relativePath.split(path.sep).join(path.posix.sep)));
+		}
+
+		return encodeURI(path.posix.relative(dir.path, file.path));
+	}
+
+	return file.toString(false);
+}
+
+function getDocumentDir(document: vscode.TextDocument): vscode.Uri | undefined {
+	const docUri = getParentDocumentUri(document);
+	if (docUri.scheme === Schemes.untitled) {
+		return vscode.workspace.workspaceFolders?.[0]?.uri;
+	}
+	return URI.Utils.dirname(docUri);
+}
+
+export function getParentDocumentUri(document: vscode.TextDocument): vscode.Uri {
+	if (document.uri.scheme === Schemes.notebookCell) {
+		for (const notebook of vscode.workspace.notebookDocuments) {
+			for (const cell of notebook.getCells()) {
+				if (cell.document === document) {
+					return notebook.uri;
+				}
+			}
+		}
+	}
+
+	return document.uri;
+}