Improve rendering of no file system provider when remote connection isn't available (fix microsoft#198764) (microsoft#199553)

* Improve rendering of no file system provider when remote connection isn't available (fix microsoft#198764)

* .

Author: bpasero

src/vs/base/common/strings.ts

@@ -92,6 +92,17 @@ export function truncate(value: string, maxLength: number, suffix = '…'): stri
 	return `${value.substr(0, maxLength)}${suffix}`;
 }
 
+export function truncateMiddle(value: string, maxLength: number, suffix = '…'): string {
+	if (value.length <= maxLength) {
+		return value;
+	}
+
+	const prefixLength = Math.ceil(maxLength / 2) - suffix.length / 2;
+	const suffixLength = Math.floor(maxLength / 2) - suffix.length / 2;
+
+	return `${value.substr(0, prefixLength)}${suffix}${value.substr(value.length - suffixLength)}`;
+}
+
 /**
  * Removes all occurrences of needle from the beginning and end of haystack.
  * @param haystack string to trim

src/vs/base/test/common/strings.test.ts

@@ -371,6 +371,11 @@ suite('Strings', () => {
 		assert.strictEqual('hello…', strings.truncate('hello world', 5));
 	});
 
+	test('truncateMiddle', () => {
+		assert.strictEqual('hello world', strings.truncateMiddle('hello world', 100));
+		assert.strictEqual('he…ld', strings.truncateMiddle('hello world', 5));
+	});
+
 	test('replaceAsync', async () => {
 		let i = 0;
 		assert.strictEqual(await strings.replaceAsync('abcabcabcabc', /b(.)/g, async (match, after) => {

src/vs/workbench/browser/parts/editor/editorPlaceholder.ts

@@ -5,6 +5,7 @@
 
 import 'vs/css!./media/editorplaceholder';
 import { localize } from 'vs/nls';
+import { truncate, truncateMiddle } from 'vs/base/common/strings';
 import Severity from 'vs/base/common/severity';
 import { IEditorOpenContext, isEditorOpenError } from 'vs/workbench/common/editor';
 import { EditorInput } from 'vs/workbench/common/editor/editorInput';
@@ -28,7 +29,6 @@ import { SimpleIconLabel } from 'vs/base/browser/ui/iconLabel/simpleIconLabel';
 import { FileChangeType, FileOperationError, FileOperationResult, IFileService } from 'vs/platform/files/common/files';
 import { toErrorMessage } from 'vs/base/common/errorMessage';
 import { IDialogService } from 'vs/platform/dialogs/common/dialogs';
-import { truncate } from 'vs/base/common/strings';
 
 export interface IEditorPlaceholderContents {
 	icon: string;
@@ -47,7 +47,7 @@ export interface IErrorEditorPlaceholderOptions extends IEditorOptions {
 
 export abstract class EditorPlaceholder extends EditorPane {
 
-	private static readonly PLACEHOLDER_LABEL_MAX_LENGTH = 1024;
+	protected static readonly PLACEHOLDER_LABEL_MAX_LENGTH = 1024;
 
 	private container: HTMLElement | undefined;
 	private scrollbar: DomScrollableElement | undefined;
@@ -245,7 +245,7 @@ export class ErrorPlaceholderEditor extends EditorPlaceholder {
 		} else if (isEditorOpenError(error) && error.forceMessage) {
 			label = error.message;
 		} else if (error) {
-			label = localize('unknownErrorEditorTextWithError', "The editor could not be opened due to an unexpected error: {0}", toErrorMessage(error));
+			label = localize('unknownErrorEditorTextWithError', "The editor could not be opened due to an unexpected error: {0}", truncateMiddle(toErrorMessage(error), EditorPlaceholder.PLACEHOLDER_LABEL_MAX_LENGTH / 2));
 		} else {
 			label = localize('unknownErrorEditorTextWithoutError', "The editor could not be opened due to an unexpected error.");
 		}