Settings and displays

Denial Settings is a standalone Flutter Wayland application. It sends typed requests over the private control socket; deniald validates hardware and persistent state and remains the sole authority that writes configuration. Most changes apply to the running session.

Settings pages

Preferences live in:

$XDG_CONFIG_HOME/denial/settings.json

or ~/.config/denial/settings.json when XDG_CONFIG_HOME is unset. The file is versioned, migrated, revision-checked, and atomically replaced with mode 0600 by deniald. Use Settings instead of editing it while Denial is running; concurrent external changes are rejected instead of overwriting a newer revision.

Keyboard and shortcut candidates are compiled or validated before they become live. A failed update leaves both the active state and saved file unchanged. Shortcut bindings are stored separately in ~/.config/denial/shortcuts.json and are migrated as defaults evolve.

Live display configuration

Open Settings → Displays & video to:

• drag monitors into logical desktop positions;
• select the primary display, or let Denial choose the enabled output with the highest refresh rate;
• select resolution and refresh rate;
• set a 50–600% scale from the UI, including fractional values;
• rotate a display by 90°, 180°, or 270°;
• enable VRR when the connector supports adaptive sync; and
• control brightness through an associated kernel backlight or DDC/CI display.

Denial submits the complete output state as one transaction, validates it with DRM/KMS before replacing live state, and presents a ten-second confirmation. Choose Keep changes to persist it or Revert now to roll back. If the dialog is not confirmed, the previous configuration is restored automatically. Failed renderer replacement or modesetting also returns to the retained working output and Flutter resources.

Display changes are persisted to:

$XDG_CONFIG_HOME/denial/outputs.conf

The packaged template is copied on first login and an existing user file is never replaced. Settings rewrites only its connector directives and preserves unrelated comments and shell-layout entries. If persistence is unavailable, Settings clearly labels the change as session-only.

Manual output file

With no connector entries, Denial discovers displays, arranges them from left to right, and selects the fastest mode at each native resolution. Inspect the authoritative live state with:

denialctl outputs

A manual layout can contain:

primary=eDP-1
eDP-1=0,0
mode=eDP-1,2560,1600,120000
scale=eDP-1,1.5
DP-1=1707,0
mode=DP-1,3840,2160,144000
transform=DP-1,90
vrr=DP-1
disabled=HDMI-A-1
system_bar=top,32,eDP-1+DP-1
maximize_padding=10

Prefer the transactional Settings UI. If manual edits prevent a usable login, follow Recover an output layout.

When iio-sensor-proxy exposes an accelerometer, Denial can automatically rotate built-in DSI-*, eDP-*, and LVDS-* panels. The configured transform describes the fixed mounting orientation; sensor rotation is temporary and is not written to outputs.conf.

Display scaling

Coordinates and window geometry stay logical. Flutter renders each output at its physical target resolution, while fractional-scale-aware Wayland clients receive the exact preferred scale for their current output. Older clients receive the next integer buffer scale and are downsampled.

Xwayland uses one density for the session because a single X server cannot give each X11 window a different coordinate scale. Denial now uses the exact fractional desktop density by default, so DPI-aware X11 applications can render directly at 125% or 150%. For an application stack that cannot handle fractional X11 DPI, select the former integer-upscale policy in /etc/denial/session.conf and restart the session:

DENIAL_XWAYLAND_SCALE_MODE=integer

Accepted values are fractional and integer.

Appearance and application themes

The colour-scheme preference changes Denial’s complete semantic palette. The resolved scheme and accent are also published through the standard desktop Settings portal, so portal-aware applications can follow the shell. No preference keeps Denial’s dark fallback while allowing applications to make their own choice.

The launcher defaults Qt applications to the portal-backed theme provider:

QT_QPA_PLATFORMTHEME=xdgdesktopportal

An inherited value or an explicit entry in /etc/denial/session.conf wins. Denial does not rewrite KDE configuration or force a widget style.

Cursor selection follows the XCursor theme search path. Appearance can choose an imported theme and its physical size; animated cursors and client-provided Wayland cursor surfaces retain their own hotspot and frame timing.

Application environment and autostart

Settings → App environment defines literal variables for all processes launched by Denial and optional deltas keyed by desktop-file ID. A rule can set a value, preserve an empty string, or hide an inherited variable. Changes affect subsequent launcher and shortcut starts without restarting Denial.

Application targets keep their desktop-file identity and receive both default and per-application rules. Raw Program and Shell command targets receive only the defaults. These rules do not modify deniald, D-Bus activation, systemd services, or XDG autostart entries.

On systemd-managed sessions, Denial starts the standard xdg-desktop-autostart.target only after the compositor and initial outputs are ready. Entries can use OnlyShowIn=Denial;. On systems without a systemd user manager, use that system’s session-service mechanism; Denial does not run a second autostart implementation.

Machine-level overrides

Administrator overrides belong in:

/etc/denial/session.conf

The launcher normally chooses the connected boot GPU. Split-GPU machines can keep display control on one device and rendering on another:

DENIAL_DRM_DEVICE=/dev/dri/card0
DENIAL_RENDER_DEVICE=/dev/dri/renderD128

The file can also override the Flutter bundle, output-config path, Qt platform theme, Xwayland scale mode, shell profile, and native logging. Canonical Denial variables use the DENIAL_* prefix. Older DENIA_* spellings remain temporary compatibility aliases, and DENIAL_* wins when both exist.

Renderer fallback

Impeller GLES is the default. Select the retained Skia/Ganesh fallback only for a driver-specific rendering problem:

DENIAL_FLUTTER_RENDERER=skia

Restart the Denial session after changing it. Remove the override or set it to impeller to return to the default. For one controlled launch, use denial-session --flutter-renderer skia.