---
name: Window management
type: architecture-map-page
slice: 02-tauri-runtime
last_verified: 2026/05/09
---

# `commands::windows`

> **Where you are:** [Architecture map](../../README.md) → [Tauri runtime](../README.md) → [Commands](README.md) → Window management

**Plain English summary.** The imperative builder for the three secondary windows: a floating always-on-top task list, a transcript viewer / editor, and a transient transcription preview overlay. Each command is idempotent: an existing window is shown and focused; otherwise a new one is built. Linux uses native KWin/Mutter decorations; macOS and Windows draw the custom frameless chrome. The preview overlay is configured to follow the user across virtual desktops and stay out of the alt-tab list (KWin sticky + GTK Utility hint). Android stubs return a clear error so the frontend can detect and route to in-window routes instead.

## At a glance

- Path: `src-tauri/src/commands/windows.rs`.
- LOC: 197.
- Tauri commands exposed (4 total):
  - `open_task_window(app) -> Result<(), String>`.
  - `open_preview_window(app) -> Result<(), String>`.
  - `close_preview_window(app) -> Result<(), String>`.
  - `open_viewer_window(app) -> Result<(), String>`.
- Events emitted: `task-window-focus` (no payload) when `open_task_window` brings an existing task float forward (`src-tauri/src/commands/windows.rs:49`).
- Depends on: `tauri::{Emitter, Manager, WebviewUrl, WebviewWindowBuilder}` (desktop-only). `gdk::WindowTypeHint`, `gtk::prelude::GtkWindowExt` for the Linux preview hint.
- Called from frontend at: dictation page (preview open / close around recording), Tasks page header button (task float), History page row click (viewer).

## What's in here

### Android stubs (`src-tauri/src/commands/windows.rs:14`)

`#[cfg(target_os = "android")]` versions of all four commands return `Err("Multi-window is not supported on Android; this command is desktop-only")`. The frontend detects Android via `isAndroid()` and routes the formerly-secondary content into routes inside the main window.

### `open_task_window` (`:43`)

If a `tasks-float` window already exists, show + focus and emit `task-window-focus`. Otherwise build a new one at `/float`, 480×520 (min 360×480), `always_on_top: true`, decorations native on Linux / frameless elsewhere, resizable. Inject the `PreferencesScript` if present so prefs land before Svelte mounts.

### `open_preview_window` (`:88`)

If a `transcription-preview` exists, show (NOT focus — the overlay must not steal focus from whatever the user is typing into). Otherwise build a new one at `/preview`, 420×200 (min 360×140, max 520×360), `always_on_top: true`, `skip_taskbar: true`, `visible_on_all_workspaces: true` (KWin sticky), `focused: false`, `visible: false` (built hidden so the GTK type-hint can be set pre-realize). Inject prefs.

After the build:

- On Linux, fetch the `gtk_window()` and call `set_type_hint(WindowTypeHint::Utility)`. This signals to Hyprland / Sway / GNOME Mutter compositors that the window is auxiliary and should not show in alt-tab. KWin already obeys SKIP_TASKBAR; this is defence in depth for non-KDE compositors.

Then call `window.show()` to actually surface it.

### `close_preview_window` (`:158`)

If the preview window exists, hide it (don't destroy — the next open is instant). No-op if it doesn't exist. Idempotent return Ok.

### `open_viewer_window` (`:168`)

If a `transcript-viewer` exists, show + focus. Otherwise build a new one at `/viewer`, 600×700 (min 560×520), Linux native decorations / frameless elsewhere, resizable. Inject prefs. NOT always-on-top — the viewer is a primary surface, not an overlay.

## Data flow

```
Tasks page header button -> invoke('open_task_window')
  -> if exists: show + focus + emit('task-window-focus')
  -> else: WebviewWindowBuilder('/float', ..., always_on_top=true)

Dictation start -> invoke('open_preview_window')
  -> build hidden, set GTK Utility hint on Linux, show

Dictation end / paste -> invoke('close_preview_window') -> hide

History row click -> invoke('open_viewer_window')
  -> if exists: show + focus
  -> else: WebviewWindowBuilder('/viewer', ...)
```

## Watch-outs

- **No `ensure_main_window` guard, but the ACL guards effectively.** The main capability gates these commands; the secondary windows do not have permission to invoke them. If you ever expand the secondary-windows capability, double-check.
- **Preview overlay focus quirks.** Even with `focused: false`, KWin and Mutter Wayland sometimes route the next keystroke to the overlay. `commands::paste::hide_preview_overlay_for_paste` is the partner workaround that hides the preview before firing a paste.
- **The GTK type hint is set *before* `show()`** (`:151`). GTK3 only honours type hints pre-realize. Don't reorder.
- **Linux native decorations vs frameless.** The `let use_native_decorations = cfg!(target_os = "linux");` call is the cross-cutting decision: Linux wins native via Tauri's frameless-Wayland resize quirk; macOS and Windows draw the custom Titlebar. If you ever ship a Windows build, audit this.
- **`open_task_window` emits `task-window-focus` only on the "already exists" path.** A first-build does not emit it. The Tasks page should listen and re-render the float regardless of which path was taken — but if you have logic that fires only on the event, the first-build will silently miss.
- **`always_on_top` plus visible-on-all-workspaces** is the right combination for the preview, but it can feel intrusive. If the user's workflow shifts to a single-workspace setup, consider an opt-out toggle in Settings.

## See also

- [App lifecycle](../app-lifecycle.md) — `PreferencesScript` is what gets injected.
- [Capabilities and ACL](../capabilities-and-acl.md) — the secondary-windows capability is bound to the labels declared here.
- [Paste](paste.md) — `hide_preview_overlay_for_paste` is the partner hide call.
- [Tauri config](../tauri-config.md) — the main window is declared statically; the three windows here are imperative.
