Glossary

A

Anchor A property that attaches a PanelWindow to one or more edges of the screen. Anchors determine window placement and sizing. At least two opposite anchors are needed for a visible panel.

Attached Property A QML mechanism that allows objects to access properties from a related type. For example, Keys.onPressed is an attached property from the Keys type.

B

Binding A QML expression that automatically updates a property when its dependencies change. Bindings are the core reactive mechanism in QML.

BlueZ The Linux Bluetooth protocol stack. Exposes a D-Bus API for Bluetooth adapter and device management.

C

Component In QML, a reusable unit defined in a .qml file. In architecture, a visual element that renders UI and reads data from services.

Compositor A Wayland compositor (e.g., Hyprland, Sway, KWin) that manages windows, input, and rendering on a Wayland display.

D

D-Bus An inter-process communication (IPC) system for the Linux desktop. Applications expose services, methods, and signals for other applications to call.

Desktop Entry A .desktop file following the freedesktop specification that describes an application: its name, icon, executable path, and categories.

E

Exclusion Zone Screen space reserved by a PanelWindow so that maximized windows don't overlap it. Defined by the panel's geometry and anchor configuration.

ext-session-lock A Wayland protocol for secure session locking. Used by lock screens to prevent input from reaching other windows.

F

FloatingWindow A Quickshell window type that creates a standard desktop window with decorations. Less control over positioning than PanelWindow.

I

Import A QML statement that makes types from another module or file available in the current document.

L

Layer Shell A Wayland protocol (wlr-layer-shell) for creating surfaces in desktop layers. Used by panels, popups, wallpapers, and lock screens.

ListModel A QML type that stores a list of items with named properties, typically used as the model for a ListView.

Loader A QML type that dynamically creates a component on demand. Useful for lazy-loading non-essential UI.

M

MPRIS Media Player Remote Interfacing Specification. A D-Bus interface for controlling media players (play, pause, next, previous, metadata).

P

PanelWindow A Quickshell window type for bars and panels. Attached to screen edges via anchors. The most commonly used window type.

PopupWindow A Quickshell window type for popups and dialogs. Positioned relative to a parent window, with optional auto-dismiss on outside click.

Property A named attribute of a QML object that can hold a value. Properties can be static or bound to expressions.

Q

QML Qt Modeling Language — a declarative language for designing user interfaces. Used by Quickshell for configuration.

qs Import Quickshell's module import system (v0.2.0+). import qs.widgets imports all QML files in the widgets/ directory.

Quickshell A toolkit for building Wayland shell components using Qt Quick and QML.

S

Service A non-visual singleton that manages data, state, and side effects. Components read from services; services never render UI.

ShellRoot The invisible root element of every Quickshell configuration. Manages screen enumeration and relaod lifecycle.

Signal A QML mechanism for emitting events. Components connect to signals to react to changes.

Singleton A class that can have at most one instance. In QML, declared with pragma Singleton. Used for shared state and services.

Surface A Wayland drawing area. Each Quickshell window creates a wl_surface that the compositor renders.

T

Timer A QML type that fires an onTriggered signal at a specified interval. Used for periodic updates and delayed execution.

U

Utility A pure JavaScript function or constant defined in a .js file with .pragma library. Stateless, side-effect-free helpers.

V

Variants A Quickshell type that creates multiple instances of a delegate component — one per item in a model (typically one per screen).

W

Wayland A display server protocol for Linux. The modern replacement for X11. Quickshell requires a Wayland compositor.

wlr-layer-shell A Wayland protocol for placing surfaces in z-ordered layers (background, bottom, top, overlay). Used by all Quickshell window types.

X

XDG Cross-Desktop Group (formerly freedesktop.org). Defines standards for the Linux desktop: base directory paths, autostart, notifications, and more.

✅What You've Learned

• PanelWindow, PopupWindow, and FloatingWindow are the three window types
• Services are non-visual singletons; components render UI
• Layer-shell protocol enables shell surface layering and anchoring
• D-Bus connects your shell to the broader Linux desktop ecosystem