Complete the text viewer functionality

src/common/editor.ts

@@ -33,17 +33,27 @@ export class Editor {
 	 * The scrolling offset for the rendered row
 	 * @private
 	 */
-	#renderX: number;
+	#renderX: number = 0;
 	/**
 	 * The name of the currently open file
 	 * @private
 	 */
-	#filename: string;
+	#filename: string = '';
+	/**
+	 * A message to display at the bottom of the screen
+	 * @private
+	 */
+	#statusMessage: string = '';
+	/**
+	 * Timeout for status messages
+	 * @private
+	 */
+	#statusTimeout: number = 0;
 
 	constructor(terminalSize: ITerminalSize) {
 		this.#buffer = new Buffer();
 		this.#screen = terminalSize;
-		this.#screen.rows -= 1;
+		this.#screen.rows -= 2;
 		this.#cursor = {
 			x: 0,
 			y: 0,
@@ -52,10 +62,7 @@ export class Editor {
 			x: 0,
 			y: 0,
 		};
-		this.#renderX = 0;
-
 		this.#document = Document.empty();
-		this.#filename = '';
 	}
 
 	private get currentRow(): Row | null {
@@ -195,6 +202,12 @@ export class Editor {
 	// Terminal Output / Drawing
 	// --------------------------------------------------------------------------
 
+	public setStatusMessage(msg: string): void {
+		// TODO: consider some sort of formatting for passed strings
+		this.#statusMessage = msg;
+		this.#statusTimeout = Date.now();
+	}
+
 	/**
 	 * Clear the screen and write out the buffer
 	 */
@@ -204,6 +217,7 @@ export class Editor {
 		this.#buffer.append(Ansi.ResetCursor);
 		this.drawRows();
 		this.drawStatusBar();
+		this.drawMessageBar();
 		this.#buffer.append(
 			Ansi.moveCursor(
 				this.#cursor.y - this.#offset.y,
@@ -288,6 +302,14 @@ export class Editor {
 				len++;
 			}
 		}
-		this.#buffer.append(Ansi.ResetFormatting);
+		this.#buffer.appendLine(Ansi.ResetFormatting);
+	}
+
+	private drawMessageBar(): void {
+		this.#buffer.append(Ansi.ClearLine);
+		const msgLen = this.#statusMessage.length;
+		if (msgLen > 0 && (Date.now() - this.#statusTimeout < 5000)) {
+			this.#buffer.append(this.#statusMessage, this.#screen.cols);
+		}
 	}
 }

src/common/main.ts

@@ -26,6 +26,8 @@ export async function main() {
 
 	// Create the editor itself
 	const editor = new Editor(terminalSize);
+	editor.setStatusMessage('HELP: Ctrl-Q = quit');
+
 	if (term.argv.length > 0) {
 		const filename = term.argv[0];
 		if (filename.trim() !== '') {