terminalInstance.ts

/*---------------------------------------------------------------------------------------------
 *  Copyright (c) Microsoft Corporation. All rights reserved.
 *  Licensed under the MIT License. See License.txt in the project root for license information.
 *--------------------------------------------------------------------------------------------*/

import * as lifecycle from 'vs/base/common/lifecycle';
import * as nls from 'vs/nls';
import * as platform from 'vs/base/common/platform';
import * as dom from 'vs/base/browser/dom';
import * as paths from 'vs/base/common/paths';
import * as os from 'os';
import { Event, Emitter } from 'vs/base/common/event';
import { WindowsShellHelper } from 'vs/workbench/parts/terminal/node/windowsShellHelper';
import { Terminal as XTermTerminal, ISearchOptions } from 'vscode-xterm';
import { IContextKeyService, IContextKey } from 'vs/platform/contextkey/common/contextkey';
import { IKeybindingService } from 'vs/platform/keybinding/common/keybinding';
import { IPanelService } from 'vs/workbench/services/panel/common/panelService';
import { ITerminalInstance, KEYBINDING_CONTEXT_TERMINAL_TEXT_SELECTED, TERMINAL_PANEL_ID, IShellLaunchConfig, ITerminalProcessManager, ProcessState, NEVER_MEASURE_RENDER_TIME_STORAGE_KEY, ITerminalDimensions } from 'vs/workbench/parts/terminal/common/terminal';
import { IInstantiationService } from 'vs/platform/instantiation/common/instantiation';
import { StandardKeyboardEvent } from 'vs/base/browser/keyboardEvent';
import { TabFocus } from 'vs/editor/common/config/commonEditorConfig';
import { TerminalConfigHelper } from 'vs/workbench/parts/terminal/electron-browser/terminalConfigHelper';
import { TerminalLinkHandler } from 'vs/workbench/parts/terminal/electron-browser/terminalLinkHandler';
import { TerminalWidgetManager } from 'vs/workbench/parts/terminal/browser/terminalWidgetManager';
import { registerThemingParticipant, ITheme, ICssStyleCollector, IThemeService } from 'vs/platform/theme/common/themeService';
import { scrollbarSliderBackground, scrollbarSliderHoverBackground, scrollbarSliderActiveBackground, activeContrastBorder } from 'vs/platform/theme/common/colorRegistry';
import { IClipboardService } from 'vs/platform/clipboard/common/clipboardService';
import { ansiColorIdentifiers, TERMINAL_BACKGROUND_COLOR, TERMINAL_FOREGROUND_COLOR, TERMINAL_CURSOR_FOREGROUND_COLOR, TERMINAL_CURSOR_BACKGROUND_COLOR, TERMINAL_SELECTION_BACKGROUND_COLOR } from 'vs/workbench/parts/terminal/common/terminalColorRegistry';
import { PANEL_BACKGROUND } from 'vs/workbench/common/theme';
import { IConfigurationService, ConfigurationTarget } from 'vs/platform/configuration/common/configuration';
import { IEditorOptions } from 'vs/editor/common/config/editorOptions';
import { INotificationService, Severity, IPromptChoice } from 'vs/platform/notification/common/notification';
import { ILogService } from 'vs/platform/log/common/log';
import { TerminalCommandTracker } from 'vs/workbench/parts/terminal/node/terminalCommandTracker';
import { TerminalProcessManager } from './terminalProcessManager';
import { IStorageService, StorageScope } from 'vs/platform/storage/common/storage';
import { execFile } from 'child_process';

// How long in milliseconds should an average frame take to render for a notification to appear
// which suggests the fallback DOM-based renderer
const SLOW_CANVAS_RENDER_THRESHOLD = 50;
const NUMBER_OF_FRAMES_TO_MEASURE = 20;

let Terminal: typeof XTermTerminal;

export class TerminalInstance implements ITerminalInstance {
	private static readonly EOL_REGEX = /\r?\n/g;

	private static _lastKnownDimensions: dom.Dimension = null;
	private static _idCounter = 1;

	private _processManager: ITerminalProcessManager | undefined;

	private _id: number;
	private _isExiting: boolean;
	private _hadFocusOnExit: boolean;
	private _isVisible: boolean;
	private _isDisposed: boolean;
	private _skipTerminalCommands: string[];
	private _title: string;
	private _wrapperElement: HTMLDivElement;
	private _xterm: XTermTerminal;
	private _xtermElement: HTMLDivElement;
	private _terminalHasTextContextKey: IContextKey<boolean>;
	private _cols: number;
	private _rows: number;
	private _dimensionsOverride: ITerminalDimensions;
	private _windowsShellHelper: WindowsShellHelper;
	private _xtermReadyPromise: Promise<void>;
	private _titleReadyPromise: Promise<string>;
	private _titleReadyComplete: (title: string) => any;

	private _disposables: lifecycle.IDisposable[];
	private _messageTitleDisposable: lifecycle.IDisposable;

	private _widgetManager: TerminalWidgetManager;
	private _linkHandler: TerminalLinkHandler;
	private _commandTracker: TerminalCommandTracker;

	public disableLayout: boolean;
	public get id(): number { return this._id; }
	public get cols(): number { return this._cols; }
	public get rows(): number { return this._rows; }
	// TODO: Ideally processId would be merged into processReady
	public get processId(): number | undefined { return this._processManager ? this._processManager.shellProcessId : undefined; }
	// TODO: How does this work with detached processes?
	// TODO: Should this be an event as it can fire twice?
	public get processReady(): Promise<void> { return this._processManager ? this._processManager.ptyProcessReady : Promise.resolve(void 0); }
	public get title(): string { return this._title; }
	public get hadFocusOnExit(): boolean { return this._hadFocusOnExit; }
	public get isTitleSetByProcess(): boolean { return !!this._messageTitleDisposable; }
	public get shellLaunchConfig(): IShellLaunchConfig { return this._shellLaunchConfig; }
	public get commandTracker(): TerminalCommandTracker { return this._commandTracker; }

	private readonly _onExit: Emitter<number> = new Emitter<number>();
	public get onExit(): Event<number> { return this._onExit.event; }
	private readonly _onDisposed: Emitter<ITerminalInstance> = new Emitter<ITerminalInstance>();
	public get onDisposed(): Event<ITerminalInstance> { return this._onDisposed.event; }
	private readonly _onFocused: Emitter<ITerminalInstance> = new Emitter<ITerminalInstance>();
	public get onFocused(): Event<ITerminalInstance> { return this._onFocused.event; }
	private readonly _onProcessIdReady: Emitter<ITerminalInstance> = new Emitter<ITerminalInstance>();
	public get onProcessIdReady(): Event<ITerminalInstance> { return this._onProcessIdReady.event; }
	private readonly _onTitleChanged: Emitter<ITerminalInstance> = new Emitter<ITerminalInstance>();
	public get onTitleChanged(): Event<ITerminalInstance> { return this._onTitleChanged.event; }
	private readonly _onProcessLaunching: Emitter<ITerminalInstance> = new Emitter<ITerminalInstance>();
	public get onProcessLaunching(): Event<ITerminalInstance> { return this._onProcessLaunching.event; }
	private readonly _onData: Emitter<string> = new Emitter<string>();
	public get onData(): Event<string> { return this._onData.event; }
	private readonly _onLineData: Emitter<string> = new Emitter<string>();
	public get onLineData(): Event<string> { return this._onLineData.event; }
	private readonly _onRendererInput: Emitter<string> = new Emitter<string>();
	public get onRendererInput(): Event<string> { return this._onRendererInput.event; }
	private readonly _onRequestExtHostProcess: Emitter<ITerminalInstance> = new Emitter<ITerminalInstance>();
	public get onRequestExtHostProcess(): Event<ITerminalInstance> { return this._onRequestExtHostProcess.event; }
	private readonly _onDimensionsChanged: Emitter<void> = new Emitter<void>();
	public get onDimensionsChanged(): Event<void> { return this._onDimensionsChanged.event; }
	private readonly _onFocus: Emitter<ITerminalInstance> = new Emitter<ITerminalInstance>();
	public get onFocus(): Event<ITerminalInstance> { return this._onFocus.event; }

	public constructor(
		private readonly _terminalFocusContextKey: IContextKey<boolean>,
		private readonly _configHelper: TerminalConfigHelper,
		private _container: HTMLElement,
		private _shellLaunchConfig: IShellLaunchConfig,
		@IContextKeyService private readonly _contextKeyService: IContextKeyService,
		@IKeybindingService private readonly _keybindingService: IKeybindingService,
		@INotificationService private readonly _notificationService: INotificationService,
		@IPanelService private readonly _panelService: IPanelService,
		@IInstantiationService private readonly _instantiationService: IInstantiationService,
		@IClipboardService private readonly _clipboardService: IClipboardService,
		@IThemeService private readonly _themeService: IThemeService,
		@IConfigurationService private readonly _configurationService: IConfigurationService,
		@ILogService private _logService: ILogService,
		@IStorageService private readonly _storageService: IStorageService
	) {
		this._disposables = [];
		this._skipTerminalCommands = [];
		this._isExiting = false;
		this._hadFocusOnExit = false;
		this._isVisible = false;
		this._isDisposed = false;
		this._id = TerminalInstance._idCounter++;

		this._titleReadyPromise = new Promise<string>(c => {
			this._titleReadyComplete = c;
		});

		this._terminalHasTextContextKey = KEYBINDING_CONTEXT_TERMINAL_TEXT_SELECTED.bindTo(this._contextKeyService);
		this.disableLayout = false;

		this._logService.trace(`terminalInstance#ctor (id: ${this.id})`, this._shellLaunchConfig);

		this._initDimensions();
		if (!this.shellLaunchConfig.isRendererOnly) {
			this._createProcess();
		} else {
			this.setTitle(this._shellLaunchConfig.name, false);
		}

		this._xtermReadyPromise = this._createXterm();
		this._xtermReadyPromise.then(() => {
			// Only attach xterm.js to the DOM if the terminal panel has been opened before.
			if (_container) {
				this._attachToElement(_container);
			}
		});

		this.addDisposable(this._configurationService.onDidChangeConfiguration(e => {
			if (e.affectsConfiguration('terminal.integrated')) {
				this.updateConfig();
			}
			if (e.affectsConfiguration('editor.accessibilitySupport')) {
				this.updateAccessibilitySupport();
			}
		}));
	}

	public addDisposable(disposable: lifecycle.IDisposable): void {
		this._disposables.push(disposable);
	}

	private _initDimensions(): void {
		// The terminal panel needs to have been created
		if (!this._container) {
			return;
		}

		const computedStyle = window.getComputedStyle(this._container.parentElement);
		const width = parseInt(computedStyle.getPropertyValue('width').replace('px', ''), 10);
		const height = parseInt(computedStyle.getPropertyValue('height').replace('px', ''), 10);
		this._evaluateColsAndRows(width, height);
	}

	/**
	 * Evaluates and sets the cols and rows of the terminal if possible.
	 * @param width The width of the container.
	 * @param height The height of the container.
	 * @return The terminal's width if it requires a layout.
	 */
	private _evaluateColsAndRows(width: number, height: number): number {
		// Ignore if dimensions are undefined or 0
		if (!width || !height) {
			return null;
		}

		const dimension = this._getDimension(width, height);
		if (!dimension) {
			return null;
		}

		const font = this._configHelper.getFont(this._xterm);

		// Because xterm.js converts from CSS pixels to actual pixels through
		// the use of canvas, window.devicePixelRatio needs to be used here in
		// order to be precise. font.charWidth/charHeight alone as insufficient
		// when window.devicePixelRatio changes.
		const scaledWidthAvailable = dimension.width * window.devicePixelRatio;

		let scaledCharWidth: number;
		if (this._configHelper.config.rendererType === 'dom') {
			scaledCharWidth = font.charWidth * window.devicePixelRatio;
		} else {
			scaledCharWidth = Math.floor(font.charWidth * window.devicePixelRatio) + font.letterSpacing;
		}
		this._cols = Math.max(Math.floor(scaledWidthAvailable / scaledCharWidth), 1);

		const scaledHeightAvailable = dimension.height * window.devicePixelRatio;
		const scaledCharHeight = Math.ceil(font.charHeight * window.devicePixelRatio);
		const scaledLineHeight = Math.floor(scaledCharHeight * font.lineHeight);
		this._rows = Math.max(Math.floor(scaledHeightAvailable / scaledLineHeight), 1);

		return dimension.width;
	}

	private _getDimension(width: number, height: number): dom.Dimension {
		// The font needs to have been initialized
		const font = this._configHelper.getFont(this._xterm);
		if (!font || !font.charWidth || !font.charHeight) {
			return null;
		}

		// The panel is minimized
		if (!this._isVisible) {
			return TerminalInstance._lastKnownDimensions;
		} else {
			// Trigger scroll event manually so that the viewport's scroll area is synced. This
			// needs to happen otherwise its scrollTop value is invalid when the panel is toggled as
			// it gets removed and then added back to the DOM (resetting scrollTop to 0).
			// Upstream issue: https://github.com/sourcelair/xterm.js/issues/291
			if (this._xterm) {
				this._xterm.emit('scroll', this._xterm._core.buffer.ydisp);
			}
		}

		if (!this._wrapperElement) {
			return null;
		}

		const wrapperElementStyle = getComputedStyle(this._wrapperElement);
		const marginLeft = parseInt(wrapperElementStyle.marginLeft.split('px')[0], 10);
		const marginRight = parseInt(wrapperElementStyle.marginRight.split('px')[0], 10);
		const bottom = parseInt(wrapperElementStyle.bottom.split('px')[0], 10);

		const innerWidth = width - marginLeft - marginRight;
		const innerHeight = height - bottom;

		TerminalInstance._lastKnownDimensions = new dom.Dimension(innerWidth, innerHeight);
		return TerminalInstance._lastKnownDimensions;
	}

	/**
	 * Create xterm.js instance and attach data listeners.
	 */
	protected async _createXterm(): Promise<void> {
		if (!Terminal) {
			Terminal = (await import('vscode-xterm')).Terminal;
			// Enable xterm.js addons
			Terminal.applyAddon(require.__$__nodeRequire('vscode-xterm/lib/addons/search/search'));
			Terminal.applyAddon(require.__$__nodeRequire('vscode-xterm/lib/addons/webLinks/webLinks'));
			Terminal.applyAddon(require.__$__nodeRequire('vscode-xterm/lib/addons/winptyCompat/winptyCompat'));
			// Localize strings
			Terminal.strings.blankLine = nls.localize('terminal.integrated.a11yBlankLine', 'Blank line');
			Terminal.strings.promptLabel = nls.localize('terminal.integrated.a11yPromptLabel', 'Terminal input');
			Terminal.strings.tooMuchOutput = nls.localize('terminal.integrated.a11yTooMuchOutput', 'Too much output to announce, navigate to rows manually to read');
		}
		const accessibilitySupport = this._configurationService.getValue<IEditorOptions>('editor').accessibilitySupport;
		const font = this._configHelper.getFont(undefined, true);
		const config = this._configHelper.config;
		this._xterm = new Terminal({
			scrollback: config.scrollback,
			theme: this._getXtermTheme(),
			drawBoldTextInBrightColors: config.drawBoldTextInBrightColors,
			fontFamily: font.fontFamily,
			fontWeight: config.fontWeight,
			fontWeightBold: config.fontWeightBold,
			fontSize: font.fontSize,
			letterSpacing: font.letterSpacing,
			lineHeight: font.lineHeight,
			bellStyle: config.enableBell ? 'sound' : 'none',
			screenReaderMode: accessibilitySupport === 'on',
			macOptionIsMeta: config.macOptionIsMeta,
			macOptionClickForcesSelection: config.macOptionClickForcesSelection,
			rightClickSelectsWord: config.rightClickBehavior === 'selectWord',
			// TODO: Guess whether to use canvas or dom better
			rendererType: config.rendererType === 'auto' ? 'canvas' : config.rendererType,
			// TODO: Remove this once the setting is removed upstream
			experimentalCharAtlas: 'dynamic'
		});
		if (this._shellLaunchConfig.initialText) {
			this._xterm.writeln(this._shellLaunchConfig.initialText);
		}
		this._xterm.winptyCompatInit();
		this._xterm.on('linefeed', () => this._onLineFeed());
		if (this._processManager) {
			this._processManager.onProcessData(data => this._onProcessData(data));
			this._xterm.on('data', data => this._processManager.write(data));
			// TODO: How does the cwd work on detached processes?
			this._linkHandler = this._instantiationService.createInstance(TerminalLinkHandler, this._xterm, platform.platform);
			this.processReady.then(() => {
				this._linkHandler.initialCwd = this._processManager.initialCwd;
			});
		}
		this._xterm.on('focus', () => this._onFocus.fire(this));

		// Register listener to trigger the onInput ext API if the terminal is a renderer only
		if (this._shellLaunchConfig.isRendererOnly) {
			this._xterm.on('data', (data) => this._sendRendererInput(data));
		}

		this._commandTracker = new TerminalCommandTracker(this._xterm);
		this._disposables.push(this._themeService.onThemeChange(theme => this._updateTheme(theme)));
	}

	public reattachToElement(container: HTMLElement): void {
		if (!this._wrapperElement) {
			throw new Error('The terminal instance has not been attached to a container yet');
		}

		if (this._wrapperElement.parentNode) {
			this._wrapperElement.parentNode.removeChild(this._wrapperElement);
		}
		this._container = container;
		this._container.appendChild(this._wrapperElement);
	}

	public attachToElement(container: HTMLElement): void {
		// The container did not change, do nothing
		if (this._container === container) {
			return;
		}

		// Attach has not occured yet
		if (!this._wrapperElement) {
			this._attachToElement(container);
			return;
		}

		// The container changed, reattach
		this._container.removeChild(this._wrapperElement);
		this._container = container;
		this._container.appendChild(this._wrapperElement);
	}

	public _attachToElement(container: HTMLElement): void {
		this._xtermReadyPromise.then(() => {
			if (this._wrapperElement) {
				throw new Error('The terminal instance has already been attached to a container');
			}

			this._container = container;
			this._wrapperElement = document.createElement('div');
			dom.addClass(this._wrapperElement, 'terminal-wrapper');
			this._xtermElement = document.createElement('div');

			// Attach the xterm object to the DOM, exposing it to the smoke tests
			(<any>this._wrapperElement).xterm = this._xterm;

			this._xterm.open(this._xtermElement);
			this._xterm.attachCustomKeyEventHandler((event: KeyboardEvent) => {
				// Disable all input if the terminal is exiting
				if (this._isExiting) {
					return false;
				}

				// Skip processing by xterm.js of keyboard events that resolve to commands described
				// within commandsToSkipShell
				const standardKeyboardEvent = new StandardKeyboardEvent(event);
				const resolveResult = this._keybindingService.softDispatch(standardKeyboardEvent, standardKeyboardEvent.target);
				if (resolveResult && this._skipTerminalCommands.some(k => k === resolveResult.commandId)) {
					event.preventDefault();
					return false;
				}

				// If tab focus mode is on, tab is not passed to the terminal
				if (TabFocus.getTabFocusMode() && event.keyCode === 9) {
					return false;
				}
				// Always have alt+F4 skip the terminal on Windows and allow it to be handled by the
				// system
				if (platform.isWindows && event.altKey && event.key === 'F4' && !event.ctrlKey) {
					return false;
				}

				return undefined;
			});
			this._disposables.push(dom.addDisposableListener(this._xterm.element, 'mousedown', (event: KeyboardEvent) => {
				// We need to listen to the mouseup event on the document since the user may release
				// the mouse button anywhere outside of _xterm.element.
				const listener = dom.addDisposableListener(document, 'mouseup', (event: KeyboardEvent) => {
					// Delay with a setTimeout to allow the mouseup to propagate through the DOM
					// before evaluating the new selection state.
					setTimeout(() => this._refreshSelectionContextKey(), 0);
					listener.dispose();
				});
			}));

			// xterm.js currently drops selection on keyup as we need to handle this case.
			this._disposables.push(dom.addDisposableListener(this._xterm.element, 'keyup', (event: KeyboardEvent) => {
				// Wait until keyup has propagated through the DOM before evaluating
				// the new selection state.
				setTimeout(() => this._refreshSelectionContextKey(), 0);
			}));

			const xtermHelper: HTMLElement = <HTMLElement>this._xterm.element.querySelector('.xterm-helpers');
			const focusTrap: HTMLElement = document.createElement('div');
			focusTrap.setAttribute('tabindex', '0');
			dom.addClass(focusTrap, 'focus-trap');
			this._disposables.push(dom.addDisposableListener(focusTrap, 'focus', (event: FocusEvent) => {
				let currentElement = focusTrap;
				while (!dom.hasClass(currentElement, 'part')) {
					currentElement = currentElement.parentElement;
				}
				const hidePanelElement = <HTMLElement>currentElement.querySelector('.hide-panel-action');
				hidePanelElement.focus();
			}));
			xtermHelper.insertBefore(focusTrap, this._xterm.textarea);

			this._disposables.push(dom.addDisposableListener(this._xterm.textarea, 'focus', (event: KeyboardEvent) => {
				this._terminalFocusContextKey.set(true);
				this._onFocused.fire(this);
			}));
			this._disposables.push(dom.addDisposableListener(this._xterm.textarea, 'blur', (event: KeyboardEvent) => {
				this._terminalFocusContextKey.reset();
				this._refreshSelectionContextKey();
			}));
			this._disposables.push(dom.addDisposableListener(this._xterm.element, 'focus', (event: KeyboardEvent) => {
				this._terminalFocusContextKey.set(true);
			}));
			this._disposables.push(dom.addDisposableListener(this._xterm.element, 'blur', (event: KeyboardEvent) => {
				this._terminalFocusContextKey.reset();
				this._refreshSelectionContextKey();
			}));

			this._wrapperElement.appendChild(this._xtermElement);
			this._container.appendChild(this._wrapperElement);

			if (this._processManager) {
				this._widgetManager = new TerminalWidgetManager(this._wrapperElement);
				this._linkHandler.setWidgetManager(this._widgetManager);
			}

			const computedStyle = window.getComputedStyle(this._container);
			const width = parseInt(computedStyle.getPropertyValue('width').replace('px', ''), 10);
			const height = parseInt(computedStyle.getPropertyValue('height').replace('px', ''), 10);
			this.layout(new dom.Dimension(width, height));
			this.setVisible(this._isVisible);
			this.updateConfig();

			// If IShellLaunchConfig.waitOnExit was true and the process finished before the terminal
			// panel was initialized.
			if (this._xterm.getOption('disableStdin')) {
				this._attachPressAnyKeyToCloseListener();
			}

			const neverMeasureRenderTime = this._storageService.getBoolean(NEVER_MEASURE_RENDER_TIME_STORAGE_KEY, StorageScope.GLOBAL, false);
			if (!neverMeasureRenderTime && this._configHelper.config.rendererType === 'auto') {
				this._measureRenderTime();
			}
		});
	}

	private _measureRenderTime(): void {
		const frameTimes: number[] = [];
		const textRenderLayer = this._xterm._core.renderer._renderLayers[0];
		const originalOnGridChanged = textRenderLayer.onGridChanged;

		const evaluateCanvasRenderer = () => {
			// Discard first frame time as it's normal to take longer
			frameTimes.shift();

			const averageTime = frameTimes.reduce((p, c) => p + c) / frameTimes.length;
			if (averageTime > SLOW_CANVAS_RENDER_THRESHOLD) {
				const promptChoices: IPromptChoice[] = [
					{
						label: nls.localize('yes', "Yes"),
						run: () => {
							this._configurationService.updateValue('terminal.integrated.rendererType', 'dom', ConfigurationTarget.USER).then(() => {
								this._notificationService.info(nls.localize('terminal.rendererInAllNewTerminals', "The terminal is now using the fallback renderer."));
							});
						}
					} as IPromptChoice,
					{
						label: nls.localize('no', "No"),
						run: () => { }
					} as IPromptChoice,
					{
						label: nls.localize('dontShowAgain', "Don't Show Again"),
						isSecondary: true,
						run: () => this._storageService.store(NEVER_MEASURE_RENDER_TIME_STORAGE_KEY, true)
					} as IPromptChoice
				];
				this._notificationService.prompt(
					Severity.Warning,
					nls.localize('terminal.slowRendering', 'The standard renderer for the integrated terminal appears to be slow on your computer. Would you like to switch to the alternative DOM-based renderer which may improve performance? [Read more about terminal settings](https://code.visualstudio.com/docs/editor/integrated-terminal#_changing-how-the-terminal-is-rendered).'),
					promptChoices
				);
			}
		};

		textRenderLayer.onGridChanged = (terminal: XTermTerminal, firstRow: number, lastRow: number) => {
			const startTime = performance.now();
			originalOnGridChanged.call(textRenderLayer, terminal, firstRow, lastRow);
			frameTimes.push(performance.now() - startTime);
			if (frameTimes.length === NUMBER_OF_FRAMES_TO_MEASURE) {
				evaluateCanvasRenderer();
				// Restore original function
				textRenderLayer.onGridChanged = originalOnGridChanged;
			}
		};
	}

	public registerLinkMatcher(regex: RegExp, handler: (url: string) => void, matchIndex?: number, validationCallback?: (uri: string, callback: (isValid: boolean) => void) => void): number {
		return this._linkHandler.registerCustomLinkHandler(regex, handler, matchIndex, validationCallback);
	}

	public deregisterLinkMatcher(linkMatcherId: number): void {
		this._xterm.deregisterLinkMatcher(linkMatcherId);
	}

	public hasSelection(): boolean {
		return this._xterm && this._xterm.hasSelection();
	}

	public copySelection(): void {
		if (this.hasSelection()) {
			this._clipboardService.writeText(this._xterm.getSelection());
		} else {
			this._notificationService.warn(nls.localize('terminal.integrated.copySelection.noSelection', 'The terminal has no selection to copy'));
		}
	}

	public get selection(): string | undefined {
		return this.hasSelection() ? this._xterm.getSelection() : undefined;
	}

	public clearSelection(): void {
		this._xterm.clearSelection();
	}

	public selectAll(): void {
		// Focus here to ensure the terminal context key is set
		this._xterm.focus();
		this._xterm.selectAll();
	}

	public findNext(term: string, searchOptions: ISearchOptions): boolean {
		return this._xterm.findNext(term, searchOptions);
	}

	public findPrevious(term: string, searchOptions: ISearchOptions): boolean {
		return this._xterm.findPrevious(term, searchOptions);
	}

	public notifyFindWidgetFocusChanged(isFocused: boolean): void {
		const terminalFocused = !isFocused && (document.activeElement === this._xterm.textarea || document.activeElement === this._xterm.element);
		this._terminalFocusContextKey.set(terminalFocused);
	}

	public dispose(isShuttingDown?: boolean): void {
		this._logService.trace(`terminalInstance#dispose (id: ${this.id})`);

		this._windowsShellHelper = lifecycle.dispose(this._windowsShellHelper);
		this._linkHandler = lifecycle.dispose(this._linkHandler);
		this._commandTracker = lifecycle.dispose(this._commandTracker);
		this._widgetManager = lifecycle.dispose(this._widgetManager);

		if (this._xterm && this._xterm.element) {
			this._hadFocusOnExit = dom.hasClass(this._xterm.element, 'focus');
		}
		if (this._wrapperElement) {
			if ((<any>this._wrapperElement).xterm) {
				(<any>this._wrapperElement).xterm = null;
			}
			this._container.removeChild(this._wrapperElement);
			this._wrapperElement = null;
			this._xtermElement = null;
		}
		if (this._xterm) {
			const buffer = (<any>this._xterm._core.buffer);
			this._sendLineData(buffer, buffer.ybase + buffer.y);
			this._xterm.dispose();
			this._xterm = null;
		}
		if (this._processManager) {
			this._processManager.dispose(isShuttingDown);
		}
		if (!this._isDisposed) {
			this._isDisposed = true;
			this._onDisposed.fire(this);
		}
		this._disposables = lifecycle.dispose(this._disposables);
	}

	public focus(force?: boolean): void {
		if (!this._xterm) {
			return;
		}
		const text = window.getSelection().toString();
		if (!text || force) {
			this._xterm.focus();
		}
	}

	public focusWhenReady(force?: boolean): Promise<void> {
		return this._xtermReadyPromise.then(() => this.focus(force));
	}

	public paste(): void {
		this.focus();
		document.execCommand('paste');
	}

	public write(text: string): void {
		this._xtermReadyPromise.then(() => {
			if (!this._xterm) {
				return;
			}
			this._xterm.write(text);
			if (this._shellLaunchConfig.isRendererOnly) {
				// Fire onData API in the extension host
				this._onData.fire(text);
			}
		});
	}

	public sendText(text: string, addNewLine: boolean): void {
		// Normalize line endings to 'enter' press.
		text = text.replace(TerminalInstance.EOL_REGEX, '\r');
		if (addNewLine && text.substr(text.length - 1) !== '\r') {
			text += '\r';
		}

		if (this._shellLaunchConfig.isRendererOnly) {
			// If the terminal is a renderer only, fire the onInput ext API
			this._sendRendererInput(text);
		} else {
			// If the terminal has a process, send it to the process
			if (this._processManager) {
				this._processManager.ptyProcessReady.then(() => {
					this._processManager.write(text);
				});
			}
		}
	}

	public preparePathForTerminalAsync(path: string): Promise<string> {
		return new Promise<string>(c => {
			const hasSpace = path.indexOf(' ') !== -1;
			if (platform.isWindows) {
				const exe = this.shellLaunchConfig.executable;
				// 17063 is the build number where wsl path was introduced.
				// Update Windows uriPath to be executed in WSL.
				if (((exe.indexOf('wsl') !== -1) || ((exe.indexOf('bash.exe') !== -1) && (exe.indexOf('git') === -1))) && (TerminalInstance.getWindowsBuildNumber() >= 17063)) {
					execFile('bash.exe', ['-c', 'echo $(wslpath ' + this._escapeNonWindowsPath(path) + ')'], {}, (error, stdout, stderr) => {
						c(this._escapeNonWindowsPath(stdout.trim()));
					});
				} else if (hasSpace) {
					c('"' + path + '"');
				}
			} else if (!platform.isWindows) {
				c(this._escapeNonWindowsPath(path));
			}
		});
	}

	private _escapeNonWindowsPath(path: string): string {
		let newPath = path;
		if (newPath.indexOf('\\') !== 0) {
			newPath = newPath.replace(/\\/g, '\\\\');
		}
		if (!newPath && (newPath.indexOf('"') !== -1)) {
			newPath = '\'' + newPath + '\'';
		} else if (newPath.indexOf(' ') !== -1) {
			newPath = newPath.replace(/ /g, '\\ ');
		}
		return newPath;
	}

	public static getWindowsBuildNumber(): number {
		const osVersion = (/(\d+)\.(\d+)\.(\d+)/g).exec(os.release());
		let buildNumber: number = 0;
		if (osVersion && osVersion.length === 4) {
			buildNumber = parseInt(osVersion[3]);
		}
		return buildNumber;
	}

	public setVisible(visible: boolean): void {
		this._isVisible = visible;
		if (this._wrapperElement) {
			dom.toggleClass(this._wrapperElement, 'active', visible);
		}
		if (visible && this._xterm) {
			// Trigger a manual scroll event which will sync the viewport and scroll bar. This is
			// necessary if the number of rows in the terminal has decreased while it was in the
			// background since scrollTop changes take no effect but the terminal's position does
			// change since the number of visible rows decreases.
			this._xterm.emit('scroll', this._xterm._core.buffer.ydisp);
			if (this._container && this._container.parentElement) {
				// Force a layout when the instance becomes invisible. This is particularly important
				// for ensuring that terminals that are created in the background by an extension will
				// correctly get correct character measurements in order to render to the screen (see
				// #34554).
				const computedStyle = window.getComputedStyle(this._container.parentElement);
				const width = parseInt(computedStyle.getPropertyValue('width').replace('px', ''), 10);
				const height = parseInt(computedStyle.getPropertyValue('height').replace('px', ''), 10);
				this.layout(new dom.Dimension(width, height));
				// HACK: Trigger another async layout to ensure xterm's CharMeasure is ready to use,
				// this hack can be removed when https://github.com/xtermjs/xterm.js/issues/702 is
				// supported.
				setTimeout(() => this.layout(new dom.Dimension(width, height)), 0);
			}
		}
	}

	public scrollDownLine(): void {
		this._xterm.scrollLines(1);
	}

	public scrollDownPage(): void {
		this._xterm.scrollPages(1);
	}

	public scrollToBottom(): void {
		this._xterm.scrollToBottom();
	}

	public scrollUpLine(): void {
		this._xterm.scrollLines(-1);
	}

	public scrollUpPage(): void {
		this._xterm.scrollPages(-1);
	}

	public scrollToTop(): void {
		this._xterm.scrollToTop();
	}

	public clear(): void {
		this._xterm.clear();
	}

	private _refreshSelectionContextKey() {
		const activePanel = this._panelService.getActivePanel();
		const isActive = activePanel && activePanel.getId() === TERMINAL_PANEL_ID;

		this._terminalHasTextContextKey.set(isActive && this.hasSelection());
	}

	protected _createProcess(): void {
		this._processManager = this._instantiationService.createInstance(TerminalProcessManager, this._id, this._configHelper);
		this._processManager.onProcessReady(() => this._onProcessIdReady.fire(this));
		this._processManager.onProcessExit(exitCode => this._onProcessExit(exitCode));
		this._processManager.onProcessData(data => this._onData.fire(data));

		this._onProcessLaunching.fire(this);

		if (this._shellLaunchConfig.name) {
			this.setTitle(this._shellLaunchConfig.name, false);
		} else {
			// Only listen for process title changes when a name is not provided
			this.setTitle(this._shellLaunchConfig.executable, true);
			this._messageTitleDisposable = this._processManager.onProcessTitle(title => this.setTitle(title ? title : '', true));
		}

		if (platform.isWindows) {
			this._processManager.ptyProcessReady.then(() => {
				this._xtermReadyPromise.then(() => {
					if (!this._isDisposed) {
						this._windowsShellHelper = new WindowsShellHelper(this._processManager.shellProcessId, this, this._xterm);
					}
				});
			});
		}

		// Create the process asynchronously to allow the terminal's container
		// to be created so dimensions are accurate
		setTimeout(() => {
			this._processManager.createProcess(this._shellLaunchConfig, this._cols, this._rows);
		}, 0);
	}

	private _onProcessData(data: string): void {
		if (this._widgetManager) {
			this._widgetManager.closeMessage();
		}
		if (this._xterm) {
			this._xterm.write(data);
		}
	}

	private _onProcessExit(exitCode: number): void {
		this._logService.debug(`Terminal process exit (id: ${this.id}) with code ${exitCode}`);

		// Prevent dispose functions being triggered multiple times
		if (this._isExiting) {
			return;
		}

		this._isExiting = true;
		let exitCodeMessage: string;

		if (exitCode) {
			exitCodeMessage = nls.localize('terminal.integrated.exitedWithCode', 'The terminal process terminated with exit code: {0}', exitCode);
		}

		this._logService.debug(`Terminal process exit (id: ${this.id}) state ${this._processManager.processState}`);

		// Only trigger wait on exit when the exit was *not* triggered by the
		// user (via the `workbench.action.terminal.kill` command).
		if (this._shellLaunchConfig.waitOnExit && this._processManager.processState !== ProcessState.KILLED_BY_USER) {
			if (exitCode) {
				this._xterm.writeln(exitCodeMessage);
			}
			let message = typeof this._shellLaunchConfig.waitOnExit === 'string'
				? this._shellLaunchConfig.waitOnExit
				: nls.localize('terminal.integrated.waitOnExit', 'Press any key to close the terminal');
			// Bold the message and add an extra new line to make it stand out from the rest of the output
			message = `\n\x1b[1m${message}\x1b[0m`;
			this._xterm.writeln(message);
			// Disable all input if the terminal is exiting and listen for next keypress
			this._xterm.setOption('disableStdin', true);
			if (this._xterm.textarea) {
				this._attachPressAnyKeyToCloseListener();
			}
		} else {
			this.dispose();
			if (exitCode) {
				if (this._processManager.processState === ProcessState.KILLED_DURING_LAUNCH) {
					let args = '';
					if (typeof this._shellLaunchConfig.args === 'string') {
						args = this._shellLaunchConfig.args;
					} else if (this._shellLaunchConfig.args && this._shellLaunchConfig.args.length) {
						args = ' ' + this._shellLaunchConfig.args.map(a => {
							if (typeof a === 'string' && a.indexOf(' ') !== -1) {
								return `'${a}'`;
							}
							return a;
						}).join(' ');
					}
					if (this._shellLaunchConfig.executable) {
						this._notificationService.error(nls.localize('terminal.integrated.launchFailed', 'The terminal process command \'{0}{1}\' failed to launch (exit code: {2})', this._shellLaunchConfig.executable, args, exitCode));
					} else {
						this._notificationService.error(nls.localize('terminal.integrated.launchFailedExtHost', 'The terminal process failed to launch (exit code: {0})', exitCode));
					}
				} else {
					if (this._configHelper.config.showExitAlert) {
						this._notificationService.error(exitCodeMessage);
					} else {
						console.warn(exitCodeMessage);
					}
				}
			}
		}

		this._onExit.fire(exitCode);
	}

	private _attachPressAnyKeyToCloseListener() {
		this._processManager.addDisposable(dom.addDisposableListener(this._xterm.textarea, 'keypress', (event: KeyboardEvent) => {
			this.dispose();
			event.preventDefault();
		}));
	}

	public reuseTerminal(shell?: IShellLaunchConfig): void {
		// Kill and clear up the process, making the process manager ready for a new process
		this._processManager.dispose();

		// Ensure new processes' output starts at start of new line
		this._xterm.write('\n\x1b[G');

		// Print initialText if specified
		if (shell.initialText) {
			this._xterm.writeln(shell.initialText);
		}

		// Initialize new process
		const oldTitle = this._title;
		this._shellLaunchConfig = shell;
		this._createProcess();
		if (oldTitle !== this._title) {
			this.setTitle(this._title, true);
		}
		this._processManager.onProcessData(data => this._onProcessData(data));

		// Clean up waitOnExit state
		if (this._isExiting && this._shellLaunchConfig.waitOnExit) {
			this._xterm.setOption('disableStdin', false);
			this._isExiting = false;
		}

		// Set the new shell launch config
		this._shellLaunchConfig = shell;
	}

	private _sendRendererInput(input: string): void {
		if (this._processManager) {
			throw new Error('onRendererInput attempted to be used on a regular terminal');
		}

		// For terminal renderers onData fires on keystrokes and when sendText is called.
		this._onRendererInput.fire(input);
	}

	private _onLineFeed(): void {
		const buffer = (<any>this._xterm._core.buffer);
		const newLine = buffer.lines.get(buffer.ybase + buffer.y);
		if (!newLine.isWrapped) {
			this._sendLineData(buffer, buffer.ybase + buffer.y - 1);
		}
	}

	private _sendLineData(buffer: any, lineIndex: number): void {
		let lineData = buffer.translateBufferLineToString(lineIndex, true);
		while (lineIndex >= 0 && buffer.lines.get(lineIndex--).isWrapped) {
			lineData = buffer.translateBufferLineToString(lineIndex, false) + lineData;
		}
		this._onLineData.fire(lineData);
	}

	public updateConfig(): void {
		const config = this._configHelper.config;
		this._setCursorBlink(config.cursorBlinking);
		this._setCursorStyle(config.cursorStyle);
		this._setCommandsToSkipShell(config.commandsToSkipShell);
		this._setEnableBell(config.enableBell);
		this._safeSetOption('scrollback', config.scrollback);
		this._safeSetOption('macOptionIsMeta', config.macOptionIsMeta);
		this._safeSetOption('macOptionClickForcesSelection', config.macOptionClickForcesSelection);
		this._safeSetOption('rightClickSelectsWord', config.rightClickBehavior === 'selectWord');
		this._safeSetOption('rendererType', config.rendererType === 'auto' ? 'canvas' : config.rendererType);
	}

	public updateAccessibilitySupport(): void {
		const value = this._configurationService.getValue('editor.accessibilitySupport');
		this._xterm.setOption('screenReaderMode', value === 'on');
	}

	private _setCursorBlink(blink: boolean): void {
		if (this._xterm && this._xterm.getOption('cursorBlink') !== blink) {
			this._xterm.setOption('cursorBlink', blink);
			this._xterm.refresh(0, this._xterm.rows - 1);
		}
	}

	private _setCursorStyle(style: string): void {
		if (this._xterm && this._xterm.getOption('cursorStyle') !== style) {
			// 'line' is used instead of bar in VS Code to be consistent with editor.cursorStyle
			const xtermOption = style === 'line' ? 'bar' : style;
			this._xterm.setOption('cursorStyle', xtermOption);
		}
	}

	private _setCommandsToSkipShell(commands: string[]): void {
		this._skipTerminalCommands = commands;
	}

	private _setEnableBell(isEnabled: boolean): void {
		if (this._xterm) {
			if (this._xterm.getOption('bellStyle') === 'sound') {
				if (!this._configHelper.config.enableBell) {
					this._xterm.setOption('bellStyle', 'none');
				}
			} else {
				if (this._configHelper.config.enableBell) {
					this._xterm.setOption('bellStyle', 'sound');
				}
			}
		}
	}

	private _safeSetOption(key: string, value: any): void {
		if (!this._xterm) {
			return;
		}

		if (this._xterm.getOption(key) !== value) {
			this._xterm.setOption(key, value);
		}
	}

	public layout(dimension: dom.Dimension): void {
		if (this.disableLayout) {
			return;
		}

		const terminalWidth = this._evaluateColsAndRows(dimension.width, dimension.height);
		if (!terminalWidth) {
			return;
		}

		if (this._xterm) {
			this._xterm.element.style.width = terminalWidth + 'px';
		}

		this._resize();
	}

	private _resize(): void {
		let cols = this._cols;
		let rows = this._rows;
		if (this._dimensionsOverride && this._dimensionsOverride.cols && this._dimensionsOverride.rows) {
			cols = Math.min(Math.max(this._dimensionsOverride.cols, 2), this._cols);
			rows = Math.min(Math.max(this._dimensionsOverride.rows, 2), this._rows);
		}

		if (this._xterm) {
			const font = this._configHelper.getFont(this._xterm);

			// Only apply these settings when the terminal is visible so that
			// the characters are measured correctly.
			if (this._isVisible) {
				const config = this._configHelper.config;
				this._safeSetOption('letterSpacing', font.letterSpacing);
				this._safeSetOption('lineHeight', font.lineHeight);
				this._safeSetOption('fontSize', font.fontSize);
				this._safeSetOption('fontFamily', font.fontFamily);
				this._safeSetOption('fontWeight', config.fontWeight);
				this._safeSetOption('fontWeightBold', config.fontWeightBold);
				this._safeSetOption('drawBoldTextInBrightColors', config.drawBoldTextInBrightColors);
			}

			if (cols !== this._xterm.cols || rows !== this._xterm.rows) {
				this._onDimensionsChanged.fire();
			}

			this._xterm.resize(cols, rows);
			if (this._isVisible) {
				// HACK: Force the renderer to unpause by simulating an IntersectionObserver event.
				// This is to fix an issue where dragging the window to the top of the screen to
				// maximize on Windows/Linux would fire an event saying that the terminal was not
				// visible.
				if (this._xterm.getOption('rendererType') === 'canvas') {
					this._xterm._core.renderer.onIntersectionChange({ intersectionRatio: 1 });
					// HACK: Force a refresh of the screen to ensure links are refresh corrected.
					// This can probably be removed when the above hack is fixed in Chromium.
					this._xterm.refresh(0, this._xterm.rows - 1);
				}
			}
		}

		if (this._processManager) {
			this._processManager.ptyProcessReady.then(() => this._processManager.setDimensions(cols, rows));
		}
	}

	public setTitle(title: string, eventFromProcess: boolean): void {
		if (!title) {
			return;
		}
		if (eventFromProcess) {
			title = paths.basename(title);
			if (platform.isWindows) {
				// Remove the .exe extension
				title = title.split('.exe')[0];
			}
		} else {
			// If the title has not been set by the API or the rename command, unregister the handler that
			// automatically updates the terminal name
			if (this._messageTitleDisposable) {
				lifecycle.dispose(this._messageTitleDisposable);
				this._messageTitleDisposable = null;
			}
		}
		const didTitleChange = title !== this._title;
		const oldTitle = this._title;
		this._title = title;
		if (didTitleChange) {
			if (!oldTitle) {
				this._titleReadyComplete(title);
			}
			this._onTitleChanged.fire(this);
		}
	}

	public waitForTitle(): Promise<string> {
		return this._titleReadyPromise;
	}

	public setDimensions(dimensions: ITerminalDimensions): void {
		this._dimensionsOverride = dimensions;
		this._resize();
	}

	private _getXtermTheme(theme?: ITheme): any {
		if (!theme) {
			theme = this._themeService.getTheme();
		}

		const foregroundColor = theme.getColor(TERMINAL_FOREGROUND_COLOR);
		const backgroundColor = theme.getColor(TERMINAL_BACKGROUND_COLOR) || theme.getColor(PANEL_BACKGROUND);
		const cursorColor = theme.getColor(TERMINAL_CURSOR_FOREGROUND_COLOR) || foregroundColor;
		const cursorAccentColor = theme.getColor(TERMINAL_CURSOR_BACKGROUND_COLOR) || backgroundColor;
		const selectionColor = theme.getColor(TERMINAL_SELECTION_BACKGROUND_COLOR);

		return {
			background: backgroundColor ? backgroundColor.toString() : null,
			foreground: foregroundColor ? foregroundColor.toString() : null,
			cursor: cursorColor ? cursorColor.toString() : null,
			cursorAccent: cursorAccentColor ? cursorAccentColor.toString() : null,
			selection: selectionColor ? selectionColor.toString() : null,
			black: theme.getColor(ansiColorIdentifiers[0]).toString(),
			red: theme.getColor(ansiColorIdentifiers[1]).toString(),
			green: theme.getColor(ansiColorIdentifiers[2]).toString(),
			yellow: theme.getColor(ansiColorIdentifiers[3]).toString(),
			blue: theme.getColor(ansiColorIdentifiers[4]).toString(),
			magenta: theme.getColor(ansiColorIdentifiers[5]).toString(),
			cyan: theme.getColor(ansiColorIdentifiers[6]).toString(),
			white: theme.getColor(ansiColorIdentifiers[7]).toString(),
			brightBlack: theme.getColor(ansiColorIdentifiers[8]).toString(),
			brightRed: theme.getColor(ansiColorIdentifiers[9]).toString(),
			brightGreen: theme.getColor(ansiColorIdentifiers[10]).toString(),
			brightYellow: theme.getColor(ansiColorIdentifiers[11]).toString(),
			brightBlue: theme.getColor(ansiColorIdentifiers[12]).toString(),
			brightMagenta: theme.getColor(ansiColorIdentifiers[13]).toString(),
			brightCyan: theme.getColor(ansiColorIdentifiers[14]).toString(),
			brightWhite: theme.getColor(ansiColorIdentifiers[15]).toString()
		};
	}

	private _updateTheme(theme?: ITheme): void {
		this._xterm.setOption('theme', this._getXtermTheme(theme));
	}

	public toggleEscapeSequenceLogging(): void {
		this._xterm._core.debug = !this._xterm._core.debug;
		this._xterm.setOption('debug', this._xterm._core.debug);
	}
}

registerThemingParticipant((theme: ITheme, collector: ICssStyleCollector) => {
	// Border
	const border = theme.getColor(activeContrastBorder);
	if (border) {
		collector.addRule(`
			.hc-black .monaco-workbench .panel.integrated-terminal .xterm.focus::before,
			.hc-black .monaco-workbench .panel.integrated-terminal .xterm:focus::before { border-color: ${border}; }`
		);
	}

	// Scrollbar
	const scrollbarSliderBackgroundColor = theme.getColor(scrollbarSliderBackground);
	if (scrollbarSliderBackgroundColor) {
		collector.addRule(`
			.monaco-workbench .panel.integrated-terminal .find-focused .xterm .xterm-viewport,
			.monaco-workbench .panel.integrated-terminal .xterm.focus .xterm-viewport,
			.monaco-workbench .panel.integrated-terminal .xterm:focus .xterm-viewport,
			.monaco-workbench .panel.integrated-terminal .xterm:hover .xterm-viewport { background-color: ${scrollbarSliderBackgroundColor} !important; }`
		);
	}

	const scrollbarSliderHoverBackgroundColor = theme.getColor(scrollbarSliderHoverBackground);
	if (scrollbarSliderHoverBackgroundColor) {
		collector.addRule(`.monaco-workbench .panel.integrated-terminal .xterm .xterm-viewport::-webkit-scrollbar-thumb:hover { background-color: ${scrollbarSliderHoverBackgroundColor}; }`);
	}

	const scrollbarSliderActiveBackgroundColor = theme.getColor(scrollbarSliderActiveBackground);
	if (scrollbarSliderActiveBackgroundColor) {
		collector.addRule(`.monaco-workbench .panel.integrated-terminal .xterm .xterm-viewport::-webkit-scrollbar-thumb:active { background-color: ${scrollbarSliderActiveBackgroundColor}; }`);
	}
});