add volume and brightness control

README.md

@@ -7,7 +7,7 @@ A bottom desktop-environment panel for wlroots-based compositors, built on
 | ------- | ----------------------------------------------------------------- |
 | Left    | Application menu built from `.desktop` entries, with search, and pinned quick-launch icons |
 | Middle  | Open windows (task list), click to focus, middle-click to close    |
-| Right   | On-screen keyboard, wifi, bluetooth, and a session menu: log out, suspend, restart, shut down |
+| Right   | On-screen keyboard, volume and brightness sliders, wifi, bluetooth, and a session menu: log out, suspend, restart, shut down |
 
 No clock, no tray, no status readouts — it is designed to sit alongside a
 separate status bar.
@@ -27,6 +27,13 @@ separate status bar.
   against — since the connection still goes through iwd underneath
 - squeekboard, as a systemd user unit, for the keyboard button — also optional;
   where the unit is not installed the button is absent
+- pipewire for the volume slider. Quickshell speaks to it directly, so there is
+  no `wpctl` or `pactl` in the loop; without a default sink the slider is absent
+- `brightnessctl` for the brightness slider — bundled with the package, and
+  optional in the sense that a machine with no controllable backlight (a
+  desktop) simply does not get that row. It writes through logind where the
+  session cannot write `/sys/class/backlight` itself, so no udev rule or setuid
+  binary is needed
 
 The window list uses the foreign-toplevel protocol rather than any single
 compositor's IPC, so it works the same everywhere — except under river 0.4,
@@ -81,7 +88,7 @@ exec attwm
 
 Either order works: whichever starts first waits for the other.
 
-The `launcher`, `wifi`, `bluetooth` and `power` IPC targets each accept
+The `launcher`, `controls`, `wifi`, `bluetooth` and `power` IPC targets each accept
 `toggle`, `open` and `close`. When opened by keybind the menu appears on the screen holding the
 focused window. Only one menu is open at a time, so `close` closes whichever it
 is.
@@ -93,6 +100,17 @@ which is what to bind to a hardware key or a tablet-mode switch:
 att_menu ipc call osk toggle
 ```
 
+The `volume` and `brightness` targets move the level without putting anything on
+screen, which is what the media keys want — `volume` takes `up`, `down` and
+`mute`, `brightness` takes `up` and `down`, each one step of the size configured
+in `volumeStep` / `brightnessStep`:
+
+```sh
+att_menu ipc call volume up
+att_menu ipc call volume mute
+att_menu ipc call brightness down
+```
+
 ## Behaviour
 
 **Placement.** The panel is a layer-shell surface anchored to the left, right and
@@ -139,6 +157,30 @@ The keyboard also raises and lowers itself when a text field takes or loses
 focus, so the button follows squeekboard's own `Visible` property rather than
 remembering what it last asked for, and stays right either way.
 
+**Volume and brightness.** One button carries the speaker and the volume of the
+default sink; clicking it opens a small panel holding both sliders. Drag or
+press anywhere along a slider to set it, scroll it to nudge it, and scroll the
+panel button itself to change the volume without opening anything. Clicking the
+speaker — on the button with the middle mouse button, or in the panel — mutes.
+`Up`/`Down` pick a slider, `Left`/`Right` move it a step, `Enter` mutes,
+`Escape` closes.
+
+Volume goes through pipewire directly and follows the *default* sink, so
+plugging in a headset moves the slider with the sound. Moving the slider
+unmutes: a slider that changes a number and produces no sound reads as broken.
+
+Brightness goes through `brightnessctl`, which falls back to logind when the
+session cannot write `/sys/class/backlight` itself. It never goes fully dark
+(`minBrightness`), since on most laptops the only way back from a black screen
+is a hardware key. sysfs raises no change events, so the current value is
+re-read on a timer — but only while the panel is open, and the panel is what
+sees the hardware keys move it. Rapid changes coalesce onto the newest, so a
+drag never queues up a hundred processes.
+
+The volume row is absent where pipewire has no default sink, and the brightness
+row where there is no controllable backlight; with neither, the whole button
+goes.
+
 **Wifi.** The button shows signal strength in the arcs and the SSID in use next
 to them, struck through when the radio is off. The menu lists the networks in
 range — connected first, then saved, then by strength — with the switch in the
@@ -207,6 +249,12 @@ running with `qs --path .`).
     desktop file names without the extension (`ls /usr/share/applications`).
   - `showOsk` — set `false` to drop the on-screen keyboard button entirely.
   - `oskUnit` — the systemd user unit squeekboard runs as.
+  - `showVolume` / `showBrightness` — set `false` to drop that slider. With both
+    off the panel button goes too.
+  - `volumeStep` / `brightnessStep` — one wheel notch, one arrow key, one
+    `ipc call volume up`. `0.05` is five percent.
+  - `minBrightness` — floor on the backlight, as a fraction of its maximum.
+  - `controlsMenuWidth` — width of the slider panel, clamped to the screen.
   - `showWifi` — set `false` to drop the wifi button entirely.
   - `wifiLabelMaxWidth` — cap on the SSID shown on the panel.
   - `wifiMenuWidth` / `wifiMenuHeight` — also clamped to the screen.
@@ -228,6 +276,8 @@ services/Session.qml   Which menu is open, and on which screen
 services/AppLauncher.qml  Desktop-entry launching
 services/Attwm.qml     attwm's IPC socket, when there is one
 services/Osk.qml       squeekboard: its unit, and its DBus state
+services/Audio.qml     The default pipewire sink: volume and mute
+services/Brightness.qml The backlight: sysfs to read, brightnessctl to write
 modules/Bar.qml        The panel window and its three sections
 modules/AppMenu.qml    Left: launcher button
 modules/Launcher.qml   The application menu overlay
@@ -236,6 +286,8 @@ modules/QuickLaunch.qml Left: pinned app icons
 modules/WindowList.qml Middle: task list
 modules/WindowButton.qml  One task button
 modules/OskMenu.qml    Right: on-screen keyboard button
+modules/ControlsMenu.qml Right: volume button
+modules/ControlsPanel.qml The volume and brightness sliders overlay
 modules/WifiMenu.qml   Right: wifi button
 modules/WifiPanel.qml  The network list overlay
 modules/WifiNetworkEntry.qml One network row
@@ -250,7 +302,11 @@ components/PanelButton.qml Shared hover/press surface
 components/BluetoothGlyph.qml The bluetooth rune, drawn
 components/WifiGlyph.qml      The wifi fan, drawn
 components/KeyboardGlyph.qml  The keyboard, drawn
+components/VolumeGlyph.qml    The speaker, drawn
+components/BrightnessGlyph.qml The sun, drawn
 components/ToggleSwitch.qml   On/off switch
+components/Slider.qml         0-1 slider, touch sized
+components/SliderRow.qml      A slider with a glyph, label and reading
 ```
 
 ## Notes