Deep Dive: The Settings Module

The Settings module (src/modules/settings/) is the most complex module in ashell. It composes multiple sub-modules and interacts with several services simultaneously.

Structure

modules/settings/
├── mod.rs          # Main settings container, sub-menu navigation
├── audio.rs        # Volume control, sink/source selection
├── bluetooth.rs    # Bluetooth device management
├── brightness.rs   # Screen brightness slider
├── network.rs      # WiFi and VPN management
└── power.rs        # Power menu (shutdown, reboot, sleep, logout)

The Settings panel uses a SubMenu enum for navigation:

#![allow(unused)]
fn main() {
pub enum SubMenu {
    Audio,
    Bluetooth,
    Network,
    // ... other sub-menus
}
}

The main settings view shows quick-access buttons. Clicking one navigates to the sub-menu view.

The Action Enum

Settings is one of the modules that uses the Action pattern:

#![allow(unused)]
fn main() {
pub enum Action {
    None,
    Command(Task<Message>),
    CloseMenu,
    RequestKeyboard,
    ReleaseKeyboard,
    ReleaseKeyboardWithCommand(Task<Message>),
}
}

RequestKeyboard: When the WiFi password input field needs keyboard focus, the module requests keyboard interactivity for the menu surface.
ReleaseKeyboard: When the password dialog is dismissed.
CloseMenu: When an action should close the settings panel.

Service Integration

The Settings module interacts with multiple services:

Sub-module	Service	Operations
Audio	`AudioService`	List sinks/sources, set volume, toggle mute
Bluetooth	`BluetoothService`	List devices, connect/disconnect, toggle power
Brightness	`BrightnessService`	Get/set brightness level
Network	`NetworkService`	List WiFi networks, connect, manage VPN
Power	`LogindService`	Shutdown, reboot, sleep, hibernate

The network sub-module can trigger a password dialog for WiFi authentication. This is handled through the password_dialog.rs module at the app level, since the dialog needs its own input focus and keyboard interactivity.

Custom Buttons

The Settings config supports user-defined buttons with status indicators:

[settings]
custom_buttons = [
    { icon = "\u{f023}", label = "VPN", status_cmd = "vpn-status", on_click = "vpn-toggle" }
]

These execute shell commands and display the result as a status indicator.

Idle Inhibitor

The Settings panel includes an idle inhibitor toggle that prevents the system from going to sleep. This uses the IdleInhibitorManager service, which interacts with systemd-logind’s inhibit API.

ashell Developer Guide