Finally get the terminal size via ansi codes for bun

justfile

@@ -5,6 +5,9 @@ default:
 # Typescript checking
 check: deno-check bun-check
 
+docs:
+	deno doc --html --unstable-ffi --private --name="Scroll" ./src/common/mod.ts
+
 # Reformat the code
 fmt:
 	deno fmt

src/bun/mod.ts

@@ -2,8 +2,26 @@
  * The main entrypoint when using Bun as the runtime
  */
 
-export * from './terminal_io.ts';
+import { getTermios, IRuntime, RunTimeType } from '../common/mod.ts';
+import BunFFI from './ffi.ts';
+import BunTerminalIO from './terminal_io.ts';
 
-export const onExit = (cb: () => void): void => {
+process.on('error', async (e) => {
+	(await getTermios()).disableRawMode();
+	console.error(e);
+	process.exit();
+});
+
+const BunRuntime: IRuntime = {
+	name: RunTimeType.Bun,
+	ffi: BunFFI,
+	io: BunTerminalIO,
+	onExit: (cb: () => void): void => {
 		process.on('beforeExit', cb);
+		process.on('exit', cb);
+		process.on('SIGINT', cb);
+	},
+	exit: (code?: number) => process.exit(code),
 };
+
+export default BunRuntime;

src/bun/terminal_io.ts

@@ -2,22 +2,7 @@
  * Wrap the runtime-specific hook into stdin
  */
 import { ITerminalIO, ITerminalSize } from '../common/mod.ts';
-
+import Ansi from '../common/editor/ansi.ts';
-function getSizeFromTput(): ITerminalSize {
-	const rows = parseInt(
-		Bun.spawnSync(['tput', 'lines']).stdout.toString().trim(),
-		10,
-	);
-	const cols = parseInt(
-		Bun.spawnSync(['tput', 'cols']).stdout.toString().trim(),
-		10,
-	);
-
-	return {
-		rows: (rows > 0) ? rows + 1 : 25,
-		cols: (cols > 0) ? cols + 1 : 80,
-	};
-}
 
 const BunTerminalIO: ITerminalIO = {
 	inputLoop: async function* inputLoop() {
@@ -25,8 +10,40 @@ const BunTerminalIO: ITerminalIO = {
 			yield chunk;
 		}
 	},
-	getSize: function getSize(): ITerminalSize {
+	getTerminalSize: async function getTerminalSize(): Promise<ITerminalSize> {
-		return getSizeFromTput();
+		const encoder = new TextEncoder();
+		const write = (s: string) => Bun.write(Bun.stdout, encoder.encode(s));
+
+		// Tell the cursor to move to Row 999 and Column 999
+		// Since this command specifically doesn't go off the screen
+		// When we ask where the cursor is, we should get the size of the screen
+		await write(Ansi.moveCursorForward(999) + Ansi.moveCursorDown(999));
+
+		// Ask where the cursor is
+		await write(Ansi.GetCursorLocation);
+
+		// Get the first chunk from stdin
+		// The response is \x1b[(rows);(cols)R..
+		for await (const chunk of Bun.stdin.stream()) {
+			const rawCode = (new TextDecoder()).decode(chunk);
+			const res = rawCode.trim().replace(/^.\[([0-9]+;[0-9]+)R$/, '$1');
+			const [srows, scols] = res.split(';');
+			const rows = parseInt(srows, 10);
+			const cols = parseInt(scols, 10);
+
+			// Clear the screen
+			await write(Ansi.ClearScreen + Ansi.ResetCursor);
+
+			return {
+				rows,
+				cols,
+			};
+		}
+
+		return {
+			rows: 24,
+			cols: 80,
+		};
 	},
 	write: async function write(s: string): Promise<void> {
 		const buffer = new TextEncoder().encode(s);

src/common/editor/ansi.ts

@@ -1,5 +1,17 @@
+export const ANSI_PREFIX = '\x1b[';
+
 function esc(pieces: TemplateStringsArray): string {
-	return '\x1b[' + pieces[0];
+	return ANSI_PREFIX + pieces[0];
+}
+
+/**
+ * ANSI escapes for various inputs
+ */
+export enum KeyCommand {
+	ArrowUp = `${ANSI_PREFIX}A`,
+	ArrowDown = `${ANSI_PREFIX}B`,
+	ArrowRight = `${ANSI_PREFIX}C`,
+	ArrowLeft = `${ANSI_PREFIX}D`,
 }
 
 export const Ansi = {
@@ -8,9 +20,16 @@ export const Ansi = {
 	ResetCursor: esc`H`,
 	HideCursor: esc`?25l`,
 	ShowCursor: esc`?25h`,
+	GetCursorLocation: esc`6n`,
 	moveCursor: function moveCursor(row: number, col: number): string {
+		// Convert to 1-based counting
+		row++;
+		col++;
+
 		return `\x1b[${row};${col}H`;
 	},
+	moveCursorForward: (col: number): string => `${ANSI_PREFIX}${col}C`,
+	moveCursorDown: (row: number): string => `${ANSI_PREFIX}${row}B`,
 };
 
 export default Ansi;

src/common/editor/buffer.ts

@@ -1,4 +1,5 @@
 import { strlen } from '../utils.ts';
+import { getRuntime } from '../runtime.ts';
 
 class Buffer {
 	#b = '';
@@ -22,6 +23,12 @@ class Buffer {
 		return this.#b;
 	}
 
+	async flush() {
+		const { io } = await getRuntime();
+		await io.write(this.#b);
+		this.clear();
+	}
+
 	strlen(): number {
 		return strlen(this.#b);
 	}

src/common/editor/editor.ts

@@ -1,13 +1,6 @@
-import Ansi from './ansi.ts';
+import Ansi, { KeyCommand } from './ansi.ts';
 import Buffer from './buffer.ts';
-import {
+import { ctrl_key, IPoint, ITerminalSize, truncate, VERSION } from '../mod.ts';
-	ctrl_key,
-	importDefaultForRuntime,
-	IPoint,
-	ITerminalSize,
-	truncate,
-	VERSION,
-} from '../mod.ts';
 
 export class Editor {
 	#buffer: Buffer;
@@ -36,10 +29,10 @@ export class Editor {
 				this.clearScreen().then(() => {});
 				return false;
 
-			case 'w':
+			case KeyCommand.ArrowUp:
-			case 's':
+			case KeyCommand.ArrowDown:
-			case 'a':
+			case KeyCommand.ArrowRight:
-			case 'd':
+			case KeyCommand.ArrowLeft:
 				this.moveCursor(input);
 				break;
 		}
@@ -49,16 +42,16 @@ export class Editor {
 
 	private moveCursor(char: string): void {
 		switch (char) {
-			case 'a':
+			case KeyCommand.ArrowLeft:
 				this.#cursor.x--;
 				break;
-			case 'd':
+			case KeyCommand.ArrowRight:
 				this.#cursor.x++;
 				break;
-			case 'w':
+			case KeyCommand.ArrowUp:
 				this.#cursor.y--;
 				break;
-			case 's':
+			case KeyCommand.ArrowDown:
 				this.#cursor.y++;
 				break;
 		}
@@ -76,18 +69,18 @@ export class Editor {
 		this.#buffer.append(Ansi.ResetCursor);
 		this.drawRows();
 		this.#buffer.append(
-			Ansi.moveCursor(this.#cursor.y + 1, this.#cursor.x + 1),
+			Ansi.moveCursor(this.#cursor.y, this.#cursor.x),
 		);
 		this.#buffer.append(Ansi.ShowCursor);
 
-		await this.writeToScreen();
+		await this.#buffer.flush();
 	}
 
 	private async clearScreen(): Promise<void> {
 		this.#buffer.append(Ansi.ClearScreen);
 		this.#buffer.append(Ansi.ResetCursor);
 
-		await this.writeToScreen();
+		await this.#buffer.flush();
 	}
 
 	private drawRows(): void {
@@ -120,11 +113,4 @@ export class Editor {
 			}
 		}
 	}
-
-	private async writeToScreen(): Promise<void> {
-		const io = await importDefaultForRuntime('terminal_io');
-
-		await io.write(this.#buffer.getBuffer());
-		this.#buffer.clear();
-	}
 }

src/common/mod.ts

@@ -2,7 +2,7 @@ export * from './editor/mod.ts';
 export * from './runtime.ts';
 export * from './termios.ts';
 export * from './utils.ts';
-
+export * from './types.ts';
 export type * from './types.ts';
 
 export const VERSION = '0.0.1';

src/common/runtime.ts

@@ -1,31 +1,47 @@
 import { getTermios } from './termios.ts';
+import { IRuntime, RunTimeType } from './types.ts';
 
-export enum RunTime {
+let scrollRuntime: IRuntime | null = null;
-	Bun = 'bun',
-	Deno = 'deno',
-	Unknown = 'common',
-}
 
-export function die(s: string): void {
+/**
-	getTermios().then((t) => t.disableRawMode());
+ * Kill program, displaying an error message
+ * @param s
+ */
+export async function die(s: string | Error): Promise<void> {
+	(await getTermios()).disableRawMode();
 	console.error(s);
+	(await getRuntime()).exit();
 }
 
 /**
  * Determine which Typescript runtime we are operating under
  */
-export const getRuntime = (): RunTime => {
+export function getRuntimeType(): RunTimeType {
-	let runtime = RunTime.Unknown;
+	let runtime = RunTimeType.Unknown;
 
 	if ('Deno' in globalThis) {
-		runtime = RunTime.Deno;
+		runtime = RunTimeType.Deno;
 	}
 	if ('Bun' in globalThis) {
-		runtime = RunTime.Bun;
+		runtime = RunTimeType.Bun;
 	}
 
 	return runtime;
-};
+}
+
+export async function getRuntime(): Promise<IRuntime> {
+	if (scrollRuntime === null) {
+		const runtime = getRuntimeType();
+		const path = `../${runtime}/mod.ts`;
+
+		const pkg = await import(path);
+		if ('default' in pkg) {
+			scrollRuntime = pkg.default;
+		}
+	}
+
+	return Promise.resolve(scrollRuntime!);
+}
 
 /**
  * Import a runtime-specific module
@@ -36,7 +52,7 @@ export const getRuntime = (): RunTime => {
  * @param path - the path within the runtime module
  */
 export const importForRuntime = async (path: string) => {
-	const runtime = getRuntime();
+	const runtime = getRuntimeType();
 	const suffix = '.ts';
 	const base = `../${runtime}/`;
 

src/common/termios.ts

@@ -1,4 +1,4 @@
-import { die, IFFI, importDefaultForRuntime } from './mod.ts';
+import { die, getRuntime, IFFI } from './mod.ts';
 
 export const STDIN_FILENO = 0;
 export const TCSANOW = 0;
@@ -63,7 +63,7 @@ class Termios {
 		// Get the current termios settings
 		let res = this.#ffi.tcgetattr(STDIN_FILENO, this.#ptr);
 		if (res === -1) {
-			die('Failed to get terminal settings');
+			die('Failed to get terminal settings').then(() => {});
 		}
 
 		// The #ptr property is pointing to the #termios TypedArray. As the pointer
@@ -80,7 +80,9 @@ class Termios {
 		// Actually set the new termios settings
 		res = this.#ffi.tcsetattr(STDIN_FILENO, TCSANOW, this.#ptr);
 		if (res === -1) {
-			die('Failed to update terminal settings. Can\'t enter raw mode');
+			die('Failed to update terminal settings. Can\'t enter raw mode').then(
+				() => {},
+			);
 		}
 
 		this.#inRawMode = true;
@@ -96,7 +98,7 @@ class Termios {
 		const oldTermiosPtr = this.#ffi.getPointer(this.#cookedTermios);
 		const res = this.#ffi.tcsetattr(STDIN_FILENO, TCSANOW, oldTermiosPtr);
 		if (res === -1) {
-			die('Failed to restore canonical mode.');
+			die('Failed to restore canonical mode.').then(() => {});
 		}
 
 		this.#inRawMode = false;
@@ -111,7 +113,7 @@ export const getTermios = async () => {
 	}
 
 	// Get the runtime-specific ffi wrappers
-	const ffi: IFFI = await importDefaultForRuntime('ffi');
+	const { ffi } = await getRuntime();
 	termiosSingleton = new Termios(ffi);
 
 	return termiosSingleton;

src/common/types.ts

@@ -10,6 +10,12 @@ export interface IPoint {
 // ----------------------------------------------------------------------------
 // Runtime adapter interfaces
 // ----------------------------------------------------------------------------
+export enum RunTimeType {
+	Bun = 'bun',
+	Deno = 'deno',
+	Unknown = 'common',
+}
+
 /**
  * The native functions for terminal settings
  */
@@ -52,7 +58,7 @@ export interface ITerminalIO {
 	/**
 	 * Get the size of the terminal
 	 */
-	getSize(): ITerminalSize;
+	getTerminalSize(): Promise<ITerminalSize>;
 
 	/**
 	 * Pipe a string to stdout
@@ -61,11 +67,31 @@ export interface ITerminalIO {
 }
 
 export interface IRuntime {
+	/**
+	 * The name of the runtime
+	 */
+	name: RunTimeType;
+	/**
+	 * Runtime-specific FFI
+	 */
+	ffi: IFFI;
+	/**
+	 * Runtime-specific terminal functionality
+	 */
+	io: ITerminalIO;
+
 	/**
 	 * Set a beforeExit/beforeUnload event handler for the runtime
 	 * @param cb - The event handler
 	 */
 	onExit(cb: () => void): void;
+
+	/**
+	 * Stop execution
+	 *
+	 * @param code
+	 */
+	exit(code?: number): void;
 }
 
 // ----------------------------------------------------------------------------

src/common/utils.ts

@@ -55,11 +55,7 @@ export function is_control(char: string): boolean {
 export function ctrl_key(char: string): string {
 	// This is the normal use case, of course
 	if (is_ascii(char)) {
-		const point = char.codePointAt(0);
+		const point = char.codePointAt(0)!;
-		if (point === undefined) {
-			return char;
-		}
-
 		return String.fromCodePoint(point & 0x1f);
 	}
 

src/deno/mod.ts

@@ -1,16 +1,19 @@
 /**
  * The main entrypoint when using Deno as the runtime
  */
-import { IRuntime } from '../common/types.ts';
+import { IRuntime, RunTimeType } from '../common/mod.ts';
-
+import DenoFFI from './ffi.ts';
-export * from './terminal_io.ts';
+import DenoTerminalIO from './terminal_io.ts';
-
-export const onExit = (cb: () => void): void => {
-	globalThis.addEventListener('onbeforeunload', cb);
-};
 
 const DenoRuntime: IRuntime = {
-	onExit,
+	name: RunTimeType.Deno,
+	ffi: DenoFFI,
+	io: DenoTerminalIO,
+	onExit: (cb: () => void): void => {
+		globalThis.addEventListener('onbeforeunload', cb);
+		globalThis.onbeforeunload = cb;
+	},
+	exit: (code?: number) => Deno.exit(code),
 };
 
 export default DenoRuntime;

src/deno/terminal_io.ts

@@ -4,29 +4,27 @@ const DenoTerminalIO: ITerminalIO = {
 	/**
 	 * Wrap the runtime-specific hook into stdin
 	 */
-	inputLoop: async function* inputLoop(): AsyncGenerator<
+	inputLoop: async function* inputLoop() {
-		Uint8Array,
-		void,
-		unknown
-	> {
 		for await (const chunk of Deno.stdin.readable) {
 			yield chunk;
 		}
 	},
-	getSize: function getSize(): ITerminalSize {
+	getTerminalSize: function getSize(): Promise<ITerminalSize> {
 		const size: { rows: number; columns: number } = Deno.consoleSize();
 
-		return {
+		return Promise.resolve({
 			rows: size.rows,
 			cols: size.columns,
-		};
+		});
 	},
 	write: async function write(s: string): Promise<void> {
-		const buffer = new TextEncoder().encode(s);
+		const buffer: Uint8Array = new TextEncoder().encode(s);
+		const stdout: WritableStream<Uint8Array> = Deno.stdout.writable;
 
-		const stdout = Deno.stdout.writable.getWriter();
+		const writer: WritableStreamDefaultWriter<Uint8Array> = stdout.getWriter();
-		await stdout.write(buffer);
+		await writer.ready;
-		stdout.releaseLock();
+		await writer.write(buffer);
+		writer.releaseLock();
 	},
 };
 

src/scroll.ts

@@ -1,47 +1,38 @@
 /**
  * The starting point for running scroll
  */
-import {
+import { Editor, getRuntime, getTermios } from './common/mod.ts';
-	Editor,
-	getTermios,
-	importDefaultForRuntime,
-	importForRuntime,
-} from './common/mod.ts';
 
 const decoder = new TextDecoder();
 
 export async function main() {
-	const { inputLoop, getSize } = await importDefaultForRuntime(
+	const runTime = await getRuntime();
-		'terminal_io.ts',
+	const { io, onExit } = runTime;
-	);
-	const { onExit } = await importForRuntime('mod.ts');
 
 	// Setup raw mode, and tear down on error or normal exit
 	const t = await getTermios();
 	t.enableRawMode();
 	onExit(() => {
-		console.log('Exit handler called, disabling raw mode\r\n');
 		t.disableRawMode();
 	});
 
+	const terminalSize = await io.getTerminalSize();
+
 	// Create the editor itself
-	const terminalSize = getSize();
 	const editor = new Editor(terminalSize);
 	await editor.refreshScreen();
 
 	// The main event loop
-	for await (const chunk of inputLoop()) {
+	for await (const chunk of io.inputLoop()) {
-		const char = String(decoder.decode(chunk));
-
-		// Clear the screen for output
-		await editor.refreshScreen();
-
 		// Process input
+		const char = String(decoder.decode(chunk));
 		const shouldLoop = editor.processKeyPress(char);
-
 		if (!shouldLoop) {
 			return 0;
 		}
+
+		// Render output
+		await editor.refreshScreen();
 	}
 
 	return -1;