Start of documents

README.md

@@ -1,13 +1,15 @@
 # Scroll
 
-Making a text editor in Typescript based on Kilo (Script + Kilo = Scroll).
-This runs on [Bun](https://bun.sh/) and [Deno](https://deno.com/). 
+Making a text editor in Typescript based on Kilo (Script + Kilo = Scroll). This
+runs on [Bun](https://bun.sh/) and [Deno](https://deno.com/).
 
 To simplify running, I'm using [Just](https://github.com/casey/just)
-* Bun: `just bun-run`
-* Deno: `just deno-run`
+
+- Bun: `just bun-run`
+- Deno: `just deno-run`
 
 ## Development Notes
-* Runtime differences are adapted into a common interface
-* Runtime implementations are in the `src/deno` and `src/bun` folders
-* The main implementation is in `src/common`
+
+- Runtime differences are adapted into a common interface
+- Runtime implementations are in the `src/deno` and `src/bun` folders
+- The main implementation is in `src/common`

src/common/editor/ansi.ts

@@ -14,6 +14,7 @@ export enum KeyCommand {
 	ArrowLeft = ANSI_PREFIX + 'D',
 	PageUp = ANSI_PREFIX + '5~',
 	PageDown = ANSI_PREFIX + '6~',
+	Delete = ANSI_PREFIX + '3~',
 
 	// These keys have several possible escape sequences
 	Home = 'LineHome',

src/common/editor/document.ts

@@ -0,0 +1,49 @@
+import { chars } from '../utils.ts';
+
+export class Row {
+	chars: string[] = [];
+
+	constructor(s: string = '') {
+		this.chars = chars(s);
+	}
+
+	public toString(): string {
+		return this.chars.join('');
+	}
+}
+
+export class Document {
+	#rows: Row[];
+
+	private constructor() {
+		this.#rows = [];
+	}
+
+	get numrows(): number {
+		return this.#rows.length;
+	}
+
+	public static empty(): Document {
+		return new Document();
+	}
+
+	public static open(): Document {
+		const doc = new Document();
+		const line = 'Hello, World!';
+		const row = new Row(line);
+
+		doc.#rows.push(row);
+
+		return doc;
+	}
+
+	public getRow(i: number): Row | null {
+		if (this.#rows[i] !== undefined) {
+			return this.#rows[i];
+		}
+
+		return null;
+	}
+}
+
+export default Document;

src/common/editor/editor.ts

@@ -1,11 +1,13 @@
 import Ansi, { KeyCommand } from './ansi.ts';
 import Buffer from './buffer.ts';
+import Document from './document.ts';
 import { ctrl_key, IPoint, ITerminalSize, truncate, VERSION } from '../mod.ts';
 
 export class Editor {
 	#buffer: Buffer;
 	#screen: ITerminalSize;
 	#cursor: IPoint;
+	#document: Document;
 	constructor(terminalSize: ITerminalSize) {
 		this.#buffer = new Buffer();
 		this.#screen = terminalSize;
@@ -13,6 +15,7 @@ export class Editor {
 			x: 0,
 			y: 0,
 		};
+		this.#document = Document.open();
 	}
 
 	// --------------------------------------------------------------------------
@@ -114,11 +117,26 @@ export class Editor {
 	}
 
 	private drawRows(): void {
-		this.drawPlaceholderRows();
+		for (let y = 0; y < this.#screen.rows; y++) {
+			if (y >= this.#document.numrows) {
+				this.drawPlaceholderRow(y);
+			} else {
+				this.drawFileRow(y);
+			}
+		}
 	}
 
-	private drawPlaceholderRows(): void {
-		for (let y = 0; y < this.#screen.rows; y++) {
+	private drawFileRow(_y: number): void {
+		const row = this.#document.getRow(0);
+		let len = row?.chars.length ?? 0;
+		if (len > this.#screen.cols) {
+			len = this.#screen.cols;
+		}
+
+		this.#buffer.appendLine(truncate(row!.toString(), len));
+	}
+
+	private drawPlaceholderRow(y: number): void {
 		if (y === Math.trunc(this.#screen.rows / 2)) {
 			const message = `Kilo editor -- version ${VERSION}`;
 			const messageLen = (message.length > this.#screen.cols)
@@ -142,5 +160,4 @@ export class Editor {
 			this.#buffer.appendLine('');
 		}
 	}
-	}
 }