Command navigation highlight

Fixes #46561

src/vs/workbench/contrib/terminal/browser/media/terminal.css

@@ -417,3 +417,9 @@
 .terminal-command-decoration.default {
 	pointer-events: none;
 }
+
+.terminal-scroll-highlight {
+	left: 0;
+	right: 0;
+	border: 1px solid #ffffff;
+}

src/vs/workbench/contrib/terminal/browser/xterm/commandTrackerAddon.ts

@@ -8,6 +8,9 @@ import { Disposable } from 'vs/base/common/lifecycle';
 import { ICommandTracker } from 'vs/workbench/contrib/terminal/browser/terminal';
 import { ICommandDetectionCapability, IPartialCommandDetectionCapability, ITerminalCapabilityStore, TerminalCapability } from 'vs/platform/terminal/common/capabilities/capabilities';
 import type { Terminal, IMarker, ITerminalAddon } from 'xterm';
+import { timeout } from 'vs/base/common/async';
+import { IColorTheme, ICssStyleCollector, registerThemingParticipant } from 'vs/platform/theme/common/themeService';
+import { focusBorder } from 'vs/platform/theme/common/colorRegistry';
 
 enum Boundary {
 	Top,
@@ -152,6 +155,23 @@ export class CommandTrackerAddon extends Disposable implements ICommandTracker,
 			line = Math.max(line - Math.floor(this._terminal.rows / 2), 0);
 		}
 		this._terminal.scrollToLine(line);
+		const decoration = this._terminal.registerDecoration({
+			marker,
+			width: this._terminal.cols
+		});
+		if (decoration) {
+			let isRendered = false;
+			decoration.onRender(element => {
+				if (!isRendered) {
+					// TODO: Remove when https://github.com/xtermjs/xterm.js/issues/3686 is fixed
+					if (!element.classList.contains('xterm-decoration-overview-ruler')) {
+						element.classList.add('terminal-scroll-highlight');
+					}
+				}
+			});
+			// Number picked to align with symbol highlight in the editor
+			timeout(350).then(() => decoration.dispose());
+		}
 	}
 
 	selectToPreviousCommand(): void {
@@ -332,3 +352,11 @@ export class CommandTrackerAddon extends Disposable implements ICommandTracker,
 		return this._getCommandMarkers().length;
 	}
 }
+
+registerThemingParticipant((theme: IColorTheme, collector: ICssStyleCollector) => {
+	const focusBorderColor = theme.getColor(focusBorder);
+
+	if (focusBorderColor) {
+		collector.addRule(`.terminal-scroll-highlight { border-color: ${focusBorderColor.toString()}; } `);
+	}
+});