add code

Author: zhangfuxing

README.md

@@ -1,2 +1,44 @@
 # termbox
-Termbox is a deno package that provides a cell based view for text terminals. 
+
+Termbox is a deno package that provides a cell based view for text terminals.
+
+## Usage
+
+```ts
+import TermBox from "https://deno.land/x/termbox@v0.1.0/mod.ts";
+
+const termbox = new TermBox();
+
+termbox.setCell(x, y, "a");
+```
+
+## Interface
+
+```ts
+class TermBox {
+  constructor(size?: Size);
+  flush(): Promise<void>;
+  size(): Size;
+  end(): void;
+
+  setCell(x: number, y: number, char: string): void;
+
+  cursorHide(): Promise<void>;
+  cursorShow(): Promise<void>;
+  cursorSave(): Promise<void>;
+  cursorRestore(): Promise<void>;
+  cursorTo(x: number, y: number): Promise<void>;
+
+  screenClear(): Promise<void>;
+  screenReset(): Promise<void>;
+}
+
+interface Size {
+  columns: number;
+  rows: number;
+}
+```
+
+## example
+
+> https://github.com/deno-library/sl

mod.test.ts

@@ -0,0 +1,29 @@
+import TermBox from "./mod.ts";
+import { assertThrows } from "https://deno.land/std@0.186.0/testing/asserts.ts";
+
+Deno.test(`test Hello world`, async () => {
+  const termbox = new TermBox();
+
+  await termbox.hideCursor();
+  await termbox.clearScreen();
+
+  let i = 0;
+  for (const char of "Hello world!") {
+    termbox.setCell(i++, 0, char);
+  }
+
+  await termbox.flush();
+  termbox.cursorTo(0, 0);
+  await termbox.showCursor();
+  termbox.end();
+});
+
+Deno.test(`Throw error`, () => {
+  const termbox = new TermBox();
+
+  assertThrows((): void => {
+    termbox.setCell(0, 0, "Hello world!");
+  });
+
+  termbox.end();
+});

mod.ts

@@ -0,0 +1,109 @@
+const ESC = "\x1B[";
+
+const SAVE = "\x1B7";
+const RESTORE = "\x1B8";
+const HIDE = "?25l";
+const SHOW = "?25h";
+
+const CLEAR_SCREEN = "2J";
+
+const HOME = "H";
+
+const isTTY = Deno.isatty(Deno.stdout.rid);
+
+interface Size {
+  columns: number;
+  rows: number;
+}
+
+export default class TermBox {
+  private encoder = new TextEncoder();
+  private writer = Deno.stdout.writable.getWriter();
+  private cells: string[][];
+  private columns: number;
+  private rows: number;
+
+  constructor(size?: Size) {
+    const { columns, rows } = size ?? this.size();
+    this.columns = columns;
+    this.rows = rows;
+    this.cells = new Array(rows).fill(null).map(() =>
+      new Array(columns).fill(null).map(() => " ")
+    );
+  }
+
+  private cursor(action: string): Promise<void> {
+    return this.write(ESC + action);
+  }
+
+  private write(msg: string): Promise<void> {
+    return this.writer.write(this.encoder.encode(msg));
+  }
+
+  flush(): Promise<void> {
+    this.cursorTo(0, 0);
+    return this.write(this.cells.map((v) => v.join("")).join("\n"));
+  }
+
+  setCell(x: number, y: number, char: string): void {
+    if (x >= this.columns || x < 0) return;
+    if (y >= this.rows || y < 0) return;
+    if (stripAnsiCode(char).length > 1) {
+      throw new Error("char length cannot be greater than 1");
+    }
+    this.cells[y][x] = char;
+  }
+
+  cursorHide(): Promise<void> {
+    return this.cursor(HIDE);
+  }
+
+  cursorShow(): Promise<void> {
+    return this.cursor(SHOW);
+  }
+
+  cursorSave(): Promise<void> {
+    return this.cursor(SAVE);
+  }
+
+  cursorRestore(): Promise<void> {
+    return this.cursor(RESTORE);
+  }
+
+  cursorTo(x: number, y: number): Promise<void> {
+    return this.cursor(`${y};${x}${HOME}`);
+  }
+
+  screenClear(): Promise<void> {
+    return this.cursor(CLEAR_SCREEN);
+  }
+
+  screenReset(): Promise<void> {
+    return this.write("\x1b[" + (this.rows - 1) + "A\r\x1b[?0J");
+  }
+
+  size(): Size {
+    if (!isTTY) return { columns: 100, rows: 50 };
+    return {
+      columns: Deno.consoleSize().columns,
+      rows: Deno.consoleSize().rows,
+    };
+  }
+
+  end(): void {
+    this.writer.releaseLock();
+  }
+}
+
+// https://github.com/chalk/ansi-regex/blob/02fa893d619d3da85411acc8fd4e2eea0e95a9d9/index.js
+const ANSI_PATTERN = new RegExp(
+  [
+    "[\\u001B\\u009B][[\\]()#;?]*(?:(?:(?:(?:;[-a-zA-Z\\d\\/#&.:=?%@~_]+)*|[a-zA-Z\\d]+(?:;[-a-zA-Z\\d\\/#&.:=?%@~_]*)*)?\\u0007)",
+    "(?:(?:\\d{1,4}(?:;\\d{0,4})*)?[\\dA-PR-TXZcf-nq-uy=><~]))",
+  ].join("|"),
+  "g",
+);
+
+function stripAnsiCode(string: string): string {
+  return string.replace(ANSI_PATTERN, "");
+}