# -*- coding: utf-8 -*-
"""
:File: EuljiroWorship/core/plugin/controller_launcher.py
:Author: Benjamin Jaedon Choi - https://github.com/saintbenjamin
:Affiliated Church: The Eulji-ro Presbyterian Church [대한예수교장로회(통합) 을지로교회]
:Address: The Eulji-ro Presbyterian Church, 24-10, Eulji-ro 20-gil, Jung-gu, Seoul 04549, South Korea
:Telephone: +82-2-2266-3070
:E-mail: euljirochurch [at] G.M.A.I.L. (replace [at] with @ and G.M.A.I.L as you understood.)
:License: MIT License with Attribution Requirement (see LICENSE file for details); Copyright (c) 2025 The Eulji-ro Presbyterian Church.
Launches and manages the slide controller subprocess for integrated slide output control.
This module provides a small utility class responsible for starting the
slide controller (:mod:`controller.slide_controller`) as a subprocess.
It ensures that the controller is launched only once and keeps track
of the running process for basic status checks.
The launcher is intended to be used by the slide generator or main
application entry point, allowing the controller to behave as a managed
child process rather than a standalone application.
"""
import subprocess
from PySide6.QtWidgets import QMessageBox
from core.utils.runtime_launcher import build_entry_command, get_runtime_base_dir
[docs]
class SlideControllerLauncher:
"""
Manages the lifecycle of the slide controller subprocess.
This class provides a minimal supervisory layer for launching and tracking
the slide controller process from the generator UI. Its responsibility is
limited to preventing duplicate launches and reporting basic runtime status;
it does not attempt to restart, monitor health, or forcibly terminate the
controller.
The launcher maintains an internal reference to the subprocess handle and
uses it to determine whether the controller is currently active. Launch
requests issued while the controller is already running are safely ignored.
Error handling is intentionally lightweight and UI-aware: if a Qt parent
widget is available, launch failures are reported via a warning dialog;
otherwise, errors are emitted to standard output.
This design is suited for a user-driven workflow where the controller is
started explicitly by the generator and stopped externally or by user action,
rather than by automatic process management.
Attributes:
proc (subprocess.Popen | None):
Handle to the currently running slide controller subprocess, or None
if no controller has been launched.
"""
[docs]
def __init__(self):
"""
Initialize the slide controller launcher.
The launcher starts with no active subprocess. Once the slide
controller is launched, the subprocess handle is stored internally
and reused for subsequent status checks.
Returns:
None
"""
self.proc = None # Currently tracked controller process
[docs]
def is_running(self) -> bool:
"""
Check whether the slide controller process is currently running.
This method verifies that a subprocess has been launched and that
it has not yet terminated.
Returns:
bool:
True if the controller subprocess is active,
False otherwise.
"""
return self.proc is not None and self.proc.poll() is None
[docs]
def launch_if_needed(self, parent_widget=None):
"""
Launch the slide controller subprocess if it is not already running.
If the controller process is already active, this method exits
without performing any action.
If the launch fails, an error message is reported as follows:
- If a Qt parent widget is provided, a warning dialog is shown.
- Otherwise, the error is printed to standard output.
Args:
parent_widget (QWidget | None):
Optional parent widget used for displaying error dialogs.
Returns:
None
"""
if self.is_running():
print("[i] Slide controller is already running")
return
try:
# Attempt to launch the controller subprocess
self.proc = subprocess.Popen(
build_entry_command("--controller"),
cwd=str(get_runtime_base_dir())
)
print("[✓] Slide controller started")
except Exception as e:
# Display error dialog if parent is a Qt widget
if parent_widget:
QMessageBox.warning(
parent_widget,
"Failed to launch slide controller",
f"Error:\n{e}"
)
else:
print(f"[!] Failed to launch slide controller: {e}")