fix(tui): full redraw on terminal width/height resize\n\ncloses #1844

packages/coding-agent/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Fixed
+
+- Fixed editor/footer visibility drift during terminal resize by forcing full redraws when terminal width or height changes ([#1844](https://github.com/badlogic/pi-mono/pull/1844) by [@ghoulr](https://github.com/ghoulr)).
+
 ## [0.56.1] - 2026-03-05
 
 ### Fixed

packages/tui/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Fixed
+
+- Fixed editor/footer visibility drift during terminal resize by forcing full redraws when terminal width or height changes ([#1844](https://github.com/badlogic/pi-mono/pull/1844) by [@ghoulr](https://github.com/ghoulr)).
+
 ## [0.56.1] - 2026-03-05
 
 ### Fixed

packages/tui/src/tui.ts

@@ -202,6 +202,7 @@ export class TUI extends Container {
 	public terminal: Terminal;
 	private previousLines: string[] = [];
 	private previousWidth = 0;
+	private previousHeight = 0;
 	private focusedComponent: Component | null = null;
 	private inputListeners = new Set<InputListener>();
 
@@ -425,6 +426,7 @@ export class TUI extends Container {
 		if (force) {
 			this.previousLines = [];
 			this.previousWidth = -1; // -1 triggers widthChanged, forcing a full clear
+			this.previousHeight = -1; // -1 triggers heightChanged, forcing a full clear
 			this.cursorRow = 0;
 			this.hardwareCursorRow = 0;
 			this.maxLinesRendered = 0;
@@ -871,8 +873,9 @@ export class TUI extends Container {
 
 		newLines = this.applyLineResets(newLines);
 
-		// Width changed - need full re-render (line wrapping changes)
+		// Width or height changed - need full re-render
 		const widthChanged = this.previousWidth !== 0 && this.previousWidth !== width;
+		const heightChanged = this.previousHeight !== 0 && this.previousHeight !== height;
 
 		// Helper to clear scrollback and viewport and render all new lines
 		const fullRender = (clear: boolean): void => {
@@ -897,6 +900,7 @@ export class TUI extends Container {
 			this.positionHardwareCursor(cursorPos, newLines.length);
 			this.previousLines = newLines;
 			this.previousWidth = width;
+			this.previousHeight = height;
 		};
 
 		const debugRedraw = process.env.PI_DEBUG_REDRAW === "1";
@@ -908,15 +912,15 @@ export class TUI extends Container {
 		};
 
 		// First render - just output everything without clearing (assumes clean screen)
-		if (this.previousLines.length === 0 && !widthChanged) {
+		if (this.previousLines.length === 0 && !widthChanged && !heightChanged) {
 			logRedraw("first render");
 			fullRender(false);
 			return;
 		}
 
-		// Width changed - full re-render (line wrapping changes)
+		// Width or height changed - full re-render
-		if (widthChanged) {
+		if (widthChanged || heightChanged) {
-			logRedraw(`width changed (${this.previousWidth} -> ${width})`);
+			logRedraw(`terminal size changed (${this.previousWidth}x${this.previousHeight} -> ${width}x${height})`);
 			fullRender(true);
 			return;
 		}
@@ -958,6 +962,7 @@ export class TUI extends Container {
 		if (firstChanged === -1) {
 			this.positionHardwareCursor(cursorPos, newLines.length);
 			this.previousViewportTop = Math.max(0, this.maxLinesRendered - height);
+			this.previousHeight = height;
 			return;
 		}
 
@@ -996,6 +1001,7 @@ export class TUI extends Container {
 			this.positionHardwareCursor(cursorPos, newLines.length);
 			this.previousLines = newLines;
 			this.previousWidth = width;
+			this.previousHeight = height;
 			this.previousViewportTop = Math.max(0, this.maxLinesRendered - height);
 			return;
 		}
@@ -1144,6 +1150,7 @@ export class TUI extends Container {
 
 		this.previousLines = newLines;
 		this.previousWidth = width;
+		this.previousHeight = height;
 	}
 
 	/**

packages/tui/test/tui-render.test.ts

@@ -23,6 +23,31 @@ function getCellItalic(terminal: VirtualTerminal, row: number, col: number): num
 }
 
 describe("TUI resize handling", () => {
+	it("triggers full re-render when terminal height changes", async () => {
+		const terminal = new VirtualTerminal(40, 10);
+		const tui = new TUI(terminal);
+		const component = new TestComponent();
+		tui.addChild(component);
+
+		component.lines = ["Line 0", "Line 1", "Line 2"];
+		tui.start();
+		await terminal.flush();
+
+		const initialRedraws = tui.fullRedraws;
+
+		// Resize height
+		terminal.resize(40, 15);
+		await terminal.flush();
+
+		// Should have triggered a full redraw
+		assert.ok(tui.fullRedraws > initialRedraws, "Height change should trigger full redraw");
+
+		const viewport = terminal.getViewport();
+		assert.ok(viewport[0]?.includes("Line 0"), "Content preserved after height change");
+
+		tui.stop();
+	});
+
 	it("triggers full re-render when terminal width changes", async () => {
 		const terminal = new VirtualTerminal(40, 10);
 		const tui = new TUI(terminal);