From e5988c173d001ce8e747dfabb5f290435ea26167 Mon Sep 17 00:00:00 2001
From: "Timothy J. Warren" <tim@timshome.page>
Date: Mon, 20 Nov 2023 15:39:27 -0500
Subject: [PATCH] Add status bar

---
 src/common/ansi.ts   |  2 ++
 src/common/editor.ts | 42 ++++++++++++++++++++++++++++++++++++++----
 2 files changed, 40 insertions(+), 4 deletions(-)

diff --git a/src/common/ansi.ts b/src/common/ansi.ts
index d4d5873..3a4ba13 100644
--- a/src/common/ansi.ts
+++ b/src/common/ansi.ts
@@ -28,6 +28,8 @@ export const Ansi = {
 	HideCursor: ANSI_PREFIX + '?25l',
 	ShowCursor: ANSI_PREFIX + '?25h',
 	GetCursorLocation: ANSI_PREFIX + '6n',
+	InvertColor: ANSI_PREFIX + '7m',
+	ResetFormatting: ANSI_PREFIX + 'm',
 	moveCursor: function moveCursor(row: number, col: number): string {
 		// Convert to 1-based counting
 		row++;
diff --git a/src/common/editor.ts b/src/common/editor.ts
index 51b1bba..1261276 100644
--- a/src/common/editor.ts
+++ b/src/common/editor.ts
@@ -1,7 +1,14 @@
 import Ansi, { KeyCommand } from './ansi.ts';
 import Buffer from './buffer.ts';
 import Document, { Row } from './document.ts';
-import { IPoint, ITerminalSize, logToFile, maxAdd, VERSION } from './mod.ts';
+import {
+	IPoint,
+	ITerminalSize,
+	logToFile,
+	maxAdd,
+	truncate,
+	VERSION,
+} from './mod.ts';
 import { ctrlKey, posSub } from './utils.ts';
 
 export class Editor {
@@ -34,10 +41,16 @@ export class Editor {
 	 * @private
 	 */
 	#render: IPoint;
+	/**
+	 * The name of the currently open file
+	 * @private
+	 */
+	#filename: string;
 
 	constructor(terminalSize: ITerminalSize) {
 		this.#buffer = new Buffer();
 		this.#screen = terminalSize;
+		this.#screen.rows -= 1;
 		this.#cursor = {
 			x: 0,
 			y: 0,
@@ -52,6 +65,7 @@ export class Editor {
 		};
 
 		this.#document = Document.empty();
+		this.#filename = '';
 	}
 
 	private get currentRow(): Row | null {
@@ -60,6 +74,7 @@ export class Editor {
 
 	public async open(filename: string): Promise<Editor> {
 		await this.#document.open(filename);
+		this.#filename = filename;
 
 		return this;
 	}
@@ -198,6 +213,7 @@ export class Editor {
 		this.#buffer.append(Ansi.HideCursor);
 		this.#buffer.append(Ansi.ResetCursor);
 		this.drawRows();
+		this.drawStatusBar();
 		this.#buffer.append(
 			Ansi.moveCursor(
 				this.#cursor.y - this.#offset.y,
@@ -226,9 +242,7 @@ export class Editor {
 				this.drawFileRow(filerow);
 			}
 
-			if (y < this.#screen.rows - 1) {
-				this.#buffer.appendLine();
-			}
+			this.#buffer.appendLine();
 		}
 	}
 
@@ -266,4 +280,24 @@ export class Editor {
 			this.#buffer.append('~');
 		}
 	}
+
+	private drawStatusBar(): void {
+		this.#buffer.append(Ansi.InvertColor);
+		const name = (this.#filename !== '') ? this.#filename : '[No Name]';
+		const status = `${truncate(name, 20)} - ${this.#document.numRows} lines`;
+		const rstatus = `${this.#cursor.y + 1}/${this.#document.numRows}`;
+		let len = Math.min(status.length, this.#screen.cols);
+		this.#buffer.append(status, len);
+
+		while (len < this.#screen.cols) {
+			if (this.#screen.cols - len === rstatus.length) {
+				this.#buffer.append(rstatus);
+				break;
+			} else {
+				this.#buffer.append(' ');
+				len++;
+			}
+		}
+		this.#buffer.append(Ansi.ResetFormatting);
+	}
 }