fix(coding-agent): fix IME candidate window positioning in menu selectors

Components with search inputs now implement Focusable interface and
propagate focus state to their child Input components. This allows
the hardware cursor to be positioned correctly for IME candidate
window placement.

Affected components:
- ModelSelectorComponent
- ScopedModelsSelectorComponent
- SessionSelectorComponent (and SessionList)
- ExtensionInputComponent
- LoginDialogComponent
- TreeSelectorComponent (and LabelInput)

fixes #827

packages/coding-agent/src/modes/interactive/components/extension-input.ts

@@ -2,7 +2,7 @@
  * Simple text input component for extensions.
  */
 
-import { Container, getEditorKeybindings, Input, Spacer, Text, type TUI } from "@mariozechner/pi-tui";
+import { Container, type Focusable, getEditorKeybindings, Input, Spacer, Text, type TUI } from "@mariozechner/pi-tui";
 import { theme } from "../theme/theme.js";
 import { CountdownTimer } from "./countdown-timer.js";
 import { DynamicBorder } from "./dynamic-border.js";
@@ -13,7 +13,7 @@ export interface ExtensionInputOptions {
 	timeout?: number;
 }
 
-export class ExtensionInputComponent extends Container {
+export class ExtensionInputComponent extends Container implements Focusable {
 	private input: Input;
 	private onSubmitCallback: (value: string) => void;
 	private onCancelCallback: () => void;
@@ -21,6 +21,16 @@ export class ExtensionInputComponent extends Container {
 	private baseTitle: string;
 	private countdown: CountdownTimer | undefined;
 
+	// Focusable implementation - propagate to input for IME cursor positioning
+	private _focused = false;
+	get focused(): boolean {
+		return this._focused;
+	}
+	set focused(value: boolean) {
+		this._focused = value;
+		this.input.focused = value;
+	}
+
 	constructor(
 		title: string,
 		_placeholder: string | undefined,

packages/coding-agent/src/modes/interactive/components/login-dialog.ts

@@ -1,5 +1,5 @@
 import { getOAuthProviders } from "@mariozechner/pi-ai";
-import { Container, getEditorKeybindings, Input, Spacer, Text, type TUI } from "@mariozechner/pi-tui";
+import { Container, type Focusable, getEditorKeybindings, Input, Spacer, Text, type TUI } from "@mariozechner/pi-tui";
 import { exec } from "child_process";
 import { theme } from "../theme/theme.js";
 import { DynamicBorder } from "./dynamic-border.js";
@@ -8,7 +8,7 @@ import { keyHint } from "./keybinding-hints.js";
 /**
  * Login dialog component - replaces editor during OAuth login flow
  */
-export class LoginDialogComponent extends Container {
+export class LoginDialogComponent extends Container implements Focusable {
 	private contentContainer: Container;
 	private input: Input;
 	private tui: TUI;
@@ -16,6 +16,16 @@ export class LoginDialogComponent extends Container {
 	private inputResolver?: (value: string) => void;
 	private inputRejecter?: (error: Error) => void;
 
+	// Focusable implementation - propagate to input for IME cursor positioning
+	private _focused = false;
+	get focused(): boolean {
+		return this._focused;
+	}
+	set focused(value: boolean) {
+		this._focused = value;
+		this.input.focused = value;
+	}
+
 	constructor(
 		tui: TUI,
 		providerId: string,

packages/coding-agent/src/modes/interactive/components/model-selector.ts

@@ -1,5 +1,14 @@
 import { type Model, modelsAreEqual } from "@mariozechner/pi-ai";
-import { Container, fuzzyFilter, getEditorKeybindings, Input, Spacer, Text, type TUI } from "@mariozechner/pi-tui";
+import {
+	Container,
+	type Focusable,
+	fuzzyFilter,
+	getEditorKeybindings,
+	Input,
+	Spacer,
+	Text,
+	type TUI,
+} from "@mariozechner/pi-tui";
 import type { ModelRegistry } from "../../../core/model-registry.js";
 import type { SettingsManager } from "../../../core/settings-manager.js";
 import { theme } from "../theme/theme.js";
@@ -19,8 +28,18 @@ interface ScopedModelItem {
 /**
  * Component that renders a model selector with search
  */
-export class ModelSelectorComponent extends Container {
+export class ModelSelectorComponent extends Container implements Focusable {
 	private searchInput: Input;
+
+	// Focusable implementation - propagate to searchInput for IME cursor positioning
+	private _focused = false;
+	get focused(): boolean {
+		return this._focused;
+	}
+	set focused(value: boolean) {
+		this._focused = value;
+		this.searchInput.focused = value;
+	}
 	private listContainer: Container;
 	private allModels: ModelItem[] = [];
 	private filteredModels: ModelItem[] = [];

packages/coding-agent/src/modes/interactive/components/scoped-models-selector.ts

@@ -1,6 +1,7 @@
 import type { Model } from "@mariozechner/pi-ai";
 import {
 	Container,
+	type Focusable,
 	fuzzyFilter,
 	getEditorKeybindings,
 	Input,
@@ -92,13 +93,23 @@ export interface ModelsCallbacks {
  * Component for enabling/disabling models for Ctrl+P cycling.
  * Changes are session-only until explicitly persisted with Ctrl+S.
  */
-export class ScopedModelsSelectorComponent extends Container {
+export class ScopedModelsSelectorComponent extends Container implements Focusable {
 	private modelsById: Map<string, Model<any>> = new Map();
 	private allIds: string[] = [];
 	private enabledIds: EnabledIds = null;
 	private filteredItems: ModelItem[] = [];
 	private selectedIndex = 0;
 	private searchInput: Input;
+
+	// Focusable implementation - propagate to searchInput for IME cursor positioning
+	private _focused = false;
+	get focused(): boolean {
+		return this._focused;
+	}
+	set focused(value: boolean) {
+		this._focused = value;
+		this.searchInput.focused = value;
+	}
 	private listContainer: Container;
 	private footerText: Text;
 	private callbacks: ModelsCallbacks;

packages/coding-agent/src/modes/interactive/components/session-selector.ts

@@ -2,6 +2,7 @@ import * as os from "node:os";
 import {
 	type Component,
 	Container,
+	type Focusable,
 	getEditorKeybindings,
 	Input,
 	matchesKey,
@@ -105,7 +106,7 @@ class SessionSelectorHeader implements Component {
 /**
  * Custom session list component with multi-line items and search
  */
-class SessionList implements Component {
+class SessionList implements Component, Focusable {
 	private allSessions: SessionInfo[] = [];
 	private filteredSessions: SessionInfo[] = [];
 	private selectedIndex: number = 0;
@@ -119,6 +120,16 @@ class SessionList implements Component {
 	public onToggleSort?: () => void;
 	private maxVisible: number = 5; // Max sessions visible (each session is 3 lines: msg + metadata + blank)
 
+	// Focusable implementation - propagate to searchInput for IME cursor positioning
+	private _focused = false;
+	get focused(): boolean {
+		return this._focused;
+	}
+	set focused(value: boolean) {
+		this._focused = value;
+		this.searchInput.focused = value;
+	}
+
 	constructor(sessions: SessionInfo[], showCwd: boolean, sortMode: SortMode) {
 		this.allSessions = sessions;
 		this.filteredSessions = sessions;
@@ -290,7 +301,7 @@ type SessionsLoader = (onProgress?: SessionListProgress) => Promise<SessionInfo[
 /**
  * Component that renders a session selector
  */
-export class SessionSelectorComponent extends Container {
+export class SessionSelectorComponent extends Container implements Focusable {
 	private sessionList: SessionList;
 	private header: SessionSelectorHeader;
 	private scope: SessionScope = "current";
@@ -302,6 +313,16 @@ export class SessionSelectorComponent extends Container {
 	private onCancel: () => void;
 	private requestRender: () => void;
 
+	// Focusable implementation - propagate to sessionList for IME cursor positioning
+	private _focused = false;
+	get focused(): boolean {
+		return this._focused;
+	}
+	set focused(value: boolean) {
+		this._focused = value;
+		this.sessionList.focused = value;
+	}
+
 	constructor(
 		currentSessionsLoader: SessionsLoader,
 		allSessionsLoader: SessionsLoader,

packages/coding-agent/src/modes/interactive/components/tree-selector.ts

@@ -1,6 +1,7 @@
 import {
 	type Component,
 	Container,
+	type Focusable,
 	getEditorKeybindings,
 	Input,
 	matchesKey,
@@ -889,12 +890,22 @@ class SearchLine implements Component {
 }
 
 /** Label input component shown when editing a label */
-class LabelInput implements Component {
+class LabelInput implements Component, Focusable {
 	private input: Input;
 	private entryId: string;
 	public onSubmit?: (entryId: string, label: string | undefined) => void;
 	public onCancel?: () => void;
 
+	// Focusable implementation - propagate to input for IME cursor positioning
+	private _focused = false;
+	get focused(): boolean {
+		return this._focused;
+	}
+	set focused(value: boolean) {
+		this._focused = value;
+		this.input.focused = value;
+	}
+
 	constructor(entryId: string, currentLabel: string | undefined) {
 		this.entryId = entryId;
 		this.input = new Input();
@@ -933,13 +944,26 @@ class LabelInput implements Component {
 /**
  * Component that renders a session tree selector for navigation
  */
-export class TreeSelectorComponent extends Container {
+export class TreeSelectorComponent extends Container implements Focusable {
 	private treeList: TreeList;
 	private labelInput: LabelInput | null = null;
 	private labelInputContainer: Container;
 	private treeContainer: Container;
 	private onLabelChangeCallback?: (entryId: string, label: string | undefined) => void;
 
+	// Focusable implementation - propagate to labelInput when active for IME cursor positioning
+	private _focused = false;
+	get focused(): boolean {
+		return this._focused;
+	}
+	set focused(value: boolean) {
+		this._focused = value;
+		// Propagate to labelInput when it's active
+		if (this.labelInput) {
+			this.labelInput.focused = value;
+		}
+	}
+
 	constructor(
 		tree: SessionTreeNode[],
 		currentLeafId: string | null,
@@ -997,6 +1021,9 @@ export class TreeSelectorComponent extends Container {
 		};
 		this.labelInput.onCancel = () => this.hideLabelInput();
 
+		// Propagate current focused state to the new labelInput
+		this.labelInput.focused = this._focused;
+
 		this.treeContainer.clear();
 		this.labelInputContainer.clear();
 		this.labelInputContainer.addChild(this.labelInput);