[FEAT] Add clipboard support for xwayland to support pixelflux

[visbits]

Is this a new feature request?

• I have searched the existing issues

Wanted change

Summary

In current Wayland/Pixelflux paths using KDE X11 session (startplasma-x11 under Xwayland), clipboard domains can be split between:

• Wayland clipboard (used by Selkies wl-copy / wl-paste)
• X11 clipboard (used by Plasma X11 apps via X selections / xclip)

This can cause clipboard sync to work in one direction/path but not consistently across both app domains without a manual bridge.

---

Environment

• Repo: linuxserver/docker-baseimage-selkies
• Distro path tested: ubuntunoble
• Wayland mode: PIXELFLUX_WAYLAND=true
• Session observed: startplasma-x11, kwin_x11, Xwayland :1
• Wayland socket observed: wayland-1
• Selkies clipboard monitor active

---

Problem

In this hybrid mode, users can observe:

• Browser/Selkies clipboard content reaches the Wayland domain
• X11 desktop apps do not always receive it automatically
• Reverse direction can also be inconsistent

This is understandable due to separate domains, but currently requires hand-rolled custom scripts.

---

Why this matters

• Wayland/Pixelflux support is newer and still evolving
• Clipboard UX is a core expectation for remote desktop
• Many “clipboard broken” reports are likely domain-bridge gaps in hybrid mode

---

Proposed solution

Add an optional custom service in baseimage:

• Service name example: custom-svc-clipboard-bridge
• Default: disabled (opt-in)
• Env toggle:
  • SELKIES_CLIPBOARD_BRIDGE_ENABLED=true|false (default false)

Bridge behavior

• Sync Wayland → X11 (wl-paste -> xclip)
• Sync X11 → Wayland (xclip -o -> wl-copy)
• Include loop suppression (hash/last-seen dedupe)
• Keep CPU/memory conservative (watch or low-frequency poll)
• Keep logs bounded/quiet

---

Why custom service

• Fits existing s6 service architecture cleanly
• No heavy new dependencies (wl-clipboard and xclip already present)
• Easy to disable
• Deterministic startup/runtime behavior

---

Acceptance criteria

1. With SELKIES_CLIPBOARD_BRIDGE_ENABLED=false

   • behavior remains unchanged

2. With SELKIES_CLIPBOARD_BRIDGE_ENABLED=true

   • Browser/Selkies clipboard becomes available in X11 desktop apps
   • X11 app clipboard becomes visible to Wayland-side clipboard path (and outbound Selkies if enabled)

3. No feedback loop

   • no sustained high CPU from bridge
   • no unbounded memory growth caused by bridge

4. Works on hybrid path

   • Wayland backend + Plasma X11/Xwayland session

---

Notes from local validation

• Hybrid process model confirmed (startplasma-x11, kwin_x11, Xwayland :1) with wayland-1 socket present
• Clipboard domains are separate without explicit bridging
• Local custom service bridge resolves functional sync gap

---

Potential follow-up (optional)

• Direction controls:
  • SELKIES_CLIPBOARD_BRIDGE_DIRECTION=both|wayland-to-x11|x11-to-wayland
• Complementary to Selkies in/out clipboard controls

Reason for change

Clipboard currently does not work with pixelflux.

Proposed code change

`#!/usr/bin/with-contenv bash
set -eu

USER_NAME="abc"
BRIDGE_ENABLED="${SELKIES_CLIPBOARD_BRIDGE_ENABLED:-false}"

if [ "${BRIDGE_ENABLED}" != "true" ]; then
echo "[clipboard-bridge] disabled (SELKIES_CLIPBOARD_BRIDGE_ENABLED=${BRIDGE_ENABLED})" >&2
exec tail -f /dev/null
fi

DISPLAY="${DISPLAY:-:1}"
XDG_RUNTIME_DIR="${XDG_RUNTIME_DIR:-/config/.XDG}"
WAYLAND_DISPLAY="${WAYLAND_DISPLAY:-wayland-1}"
LOG_DIR="/config/.streamology/tmp"
LOG_FILE="${LOG_DIR}/clipboard-bridge.log"

mkdir -p "${LOG_DIR}"
chown "${USER_NAME}:${USER_NAME}" "${LOG_DIR}" || true

wait_for_endpoints() {
local tries=0
while [ ! -S "${XDG_RUNTIME_DIR}/${WAYLAND_DISPLAY}" ] || [ ! -S "/tmp/.X11-unix/X${DISPLAY#:}" ]; do
tries=$((tries + 1))
if [ $((tries % 20)) -eq 0 ]; then
echo "[clipboard-bridge] waiting for ${XDG_RUNTIME_DIR}/${WAYLAND_DISPLAY} and ${DISPLAY}" >&2
fi
sleep 1
done
}

clipboard_hash() {
printf '%s' "$1" | sha256sum | awk '{print $1}'
}

read_wayland_clipboard() {
s6-setuidgid "${USER_NAME}" env DISPLAY="${DISPLAY}" XDG_RUNTIME_DIR="${XDG_RUNTIME_DIR}" WAYLAND_DISPLAY="${WAYLAND_DISPLAY}"
wl-paste --no-newline 2>/dev/null || true
}

read_x11_clipboard() {
s6-setuidgid "${USER_NAME}" env DISPLAY="${DISPLAY}" XDG_RUNTIME_DIR="${XDG_RUNTIME_DIR}" WAYLAND_DISPLAY="${WAYLAND_DISPLAY}"
xclip -selection clipboard -o 2>/dev/null || true
}

write_wayland_clipboard() {
printf '%s' "$1" | s6-setuidgid "${USER_NAME}" env DISPLAY="${DISPLAY}" XDG_RUNTIME_DIR="${XDG_RUNTIME_DIR}" WAYLAND_DISPLAY="${WAYLAND_DISPLAY}"
wl-copy >/dev/null 2>&1 || true
}

write_x11_clipboard() {
printf '%s' "$1" | s6-setuidgid "${USER_NAME}" env DISPLAY="${DISPLAY}" XDG_RUNTIME_DIR="${XDG_RUNTIME_DIR}" WAYLAND_DISPLAY="${WAYLAND_DISPLAY}"
xclip -selection clipboard -in >/dev/null 2>&1 || true
}

echo "[clipboard-bridge] starting bidirectional bridge (Wayland <-> X11)" >&2

last_wayland_seen=""
last_x11_seen=""
last_from_wayland=""
last_from_x11=""

while true; do
wait_for_endpoints

wayland_text="$(read_wayland_clipboard)"
wayland_hash="$(clipboard_hash "${wayland_text}")"
if [ "${wayland_hash}" != "${last_wayland_seen}" ]; then
last_wayland_seen="${wayland_hash}"
if [ "${wayland_hash}" != "${last_from_x11}" ]; then
write_x11_clipboard "${wayland_text}"
last_from_wayland="${wayland_hash}"
last_x11_seen="${wayland_hash}"
echo "[clipboard-bridge] synced Wayland -> X11" >>"${LOG_FILE}" 2>&1 || true
fi
fi

x11_text="$(read_x11_clipboard)"
x11_hash="$(clipboard_hash "${x11_text}")"
if [ "${x11_hash}" != "${last_x11_seen}" ]; then
last_x11_seen="${x11_hash}"
if [ "${x11_hash}" != "${last_from_wayland}" ]; then
write_wayland_clipboard "${x11_text}"
last_from_x11="${x11_hash}"
last_wayland_seen="${x11_hash}"
echo "[clipboard-bridge] synced X11 -> Wayland" >>"${LOG_FILE}" 2>&1 || true
fi
fi

sleep 0.35
done`

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