ENH: Background daemon/agent/service for fast startup with hotkey

efck/__init__.py

@@ -11,6 +11,7 @@
 if not QApplication.instance():
     import sys
     qApp = QApplication(sys.argv)
+    qApp.setQuitOnLastWindowClosed(False)
     qApp.setApplicationName('efck-chat-keyboard')
     qApp.setApplicationDisplayName('Efck Chat Keyboard')
     qApp.setApplicationVersion(__version__)

efck/__main__.py

@@ -1,11 +1,15 @@
 import argparse
 import logging
+import os
 import sys
 import time
 import tempfile
 from pathlib import Path
 
+import psutil
+
 from . import __version__, CONFIG_DIRS, cli_args
+from .gui import OUR_SIGUSR1
 from .qt import QApplication, QT_API, QT_VERSION_STR
 
 logger = logging.getLogger(__name__)
@@ -49,13 +53,37 @@ def main():
     logger.info('Qt version: %s %s, platform: %s', QT_API, QT_VERSION_STR, QApplication.platformName())
     logger.info('Config directories: %s', CONFIG_DIRS)
 
+    check_if_another_process_is_running_and_raise_it()
+
     from .gui import MainWindow
     from .config import load_config
 
     load_config()
     window = MainWindow()
     window.show()
+    window.reset_hotkey_listener()
     sys.exit(QApplication.instance().exec())
 
 
+def check_if_another_process_is_running_and_raise_it():
+    def is_process_running():
+        our_pid = os.getpid()
+        p = psutil.Process(our_pid)
+        key = {'name': p.name(), 'exe': p.exe(), 'cmdline': p.cmdline()}
+        for proc in filter(None, psutil.process_iter(attrs=['name', 'exe', 'cmdline', 'pid'],
+                                                     ad_value=None)):
+            pinfo = proc.info
+            pinfo.pop('pid')
+            if pinfo == key and proc.pid != our_pid:
+                logger.debug('Process match: %s %s', proc, proc.info)
+                return proc
+
+    proc = is_process_running()
+    if proc:
+        os.kill(proc.pid, OUR_SIGUSR1)
+        logger.info('efck-chat-keyboard instance is already running, '
+                    'sending SIGUSR1 to pid %d. Quitting.', proc.pid)
+        sys.exit(0)
+
+
 main()

efck/_qt/pyqt5.py

@@ -9,6 +9,7 @@
     QPoint,
     QRect,
     QSize,
+    QSocketNotifier,
     QSortFilterProxyModel,
     QStandardPaths,
     Qt,

efck/_qt/pyqt6.py

@@ -9,6 +9,7 @@
     QPoint,
     QRect,
     QSize,
+    QSocketNotifier,
     QSortFilterProxyModel,
     QStandardPaths,
     Qt,

efck/_qt/pyside6.py

@@ -9,6 +9,7 @@
     QPoint,
     QRect,
     QSize,
+    QSocketNotifier,
     QSortFilterProxyModel,
     QStandardPaths,
     Qt,

efck/_qt/qtpy.py

@@ -9,6 +9,7 @@
     QPoint,
     QRect,
     QSize,
+    QSocketNotifier,
     QSortFilterProxyModel,
     QStandardPaths,
     Qt,

efck/config.py

@@ -3,6 +3,7 @@
 import os
 from pathlib import Path
 
+from . import IS_WIDOWS
 from .tabs import EmojiTab
 
 logger = logging.getLogger(__name__)
@@ -39,6 +40,8 @@
     'window_geometry': [360, 400],
     'zoom': 100,
     'force_clipboard': False,
+    'tray_agent': True,
+    'hotkey': ('<cmd>+.' if not IS_WIDOWS else '<ctrl>+<alt>+.'),  # TODO: test windows cmd
     EmojiTab.__name__: _emoji_filters,
 }
 
@@ -85,4 +88,5 @@ def dump_config():
             logger.info('Error opening config file for writing: %s', e)
             continue
     logger.info('Config dumped %ssuccessfully to "%s"', "UN" if not success else "", fd.name)
+    logger.debug('User config: %s', config_state)
     return success and fd.name

efck/gui.py

@@ -1,8 +1,10 @@
 import atexit
 import logging
+import os
+import signal
 from pathlib import Path
 
-from . import IS_MACOS
+from . import IS_MACOS, IS_WIDOWS
 from .qt import *
 
 logger = logging.getLogger(__name__)
@@ -13,6 +15,8 @@
                 Qt.Key.Key_4, Qt.Key.Key_5, Qt.Key.Key_6,
                 Qt.Key.Key_7, Qt.Key.Key_8, Qt.Key.Key_9}
 
+OUR_SIGUSR1 = signal.SIGBREAK if IS_WIDOWS else signal.SIGUSR1
+
 
 def fire_after(self, timer_attr, callback, interval_ms):
     try:
@@ -71,28 +75,16 @@ def __init__(self):
         from .config import config_state
 
         # Init the main app/tabbed widget
-
-        def _initial_window_geometry():
-            mouse_pos = QCursor.pos()
-            geometry = config_state['window_geometry']
-            logger.debug('Window geometry: %s', geometry)
-            valid_geom = QGuiApplication.primaryScreen().availableGeometry()
-            PAD_PX = 50
-            top_left = [max(mouse_pos.x() - geometry[0], valid_geom.x() + PAD_PX),
-                        max(mouse_pos.y() - geometry[1], valid_geom.y() + PAD_PX)]
-            geometry = [min(geometry[0], valid_geom.width() - 2 * PAD_PX),
-                        min(geometry[1], valid_geom.height() - 2 * PAD_PX)]
-            return top_left + geometry
-
         super().__init__(
             windowTitle=QApplication.instance().applicationName(),
-            geometry=QRect(*_initial_window_geometry()),
             windowIcon=QIcon(str(ICON_DIR / 'logo.png')),
             documentMode=True,
             usesScrollButtons=True,
             # FIXME: Reduce tabs right margin on macOS
             #  https://forum.qt.io/topic/119371/text-in-qtabbar-on-macos-is-truncated-or-elided-by-default-although-there-is-empty-space/10
         )
+        self.reset_window_position()
+        self.install_sigusr1_handler()
         self.setWindowFlags(
             Qt.WindowType.Dialog |
             Qt.WindowType.FramelessWindowHint |
@@ -201,11 +193,6 @@ def _on_tab_changed(idx):
                     tab.line_edit.setText(prev_text)
                 tab.line_edit.setFocus()
 
-            if prev_idx == OPTIONS_TAB_IDX:
-                # Reload models
-                if options_tab.save_dirty():
-                    for tab in self.tabs:
-                        tab.reset_model()
             prev_idx = idx
 
         self.currentChanged.connect(_on_tab_changed)
@@ -242,9 +229,9 @@ def keyPressEvent(self, event: QKeyEvent):
                      key,
                      getattr(event.modifiers(), 'value', event.modifiers()),  # PyQt6
                      text)
-        # Escape key exits the app
+        # Escape key exits the app / minimizes to tray
         if key == Qt.Key.Key_Escape or event.matches(QKeySequence.StandardKey.Cancel):
-            QApplication.instance().quit()
+            self.exit()
 
         tab = self.current_tab
         # Don't handle other keypresses on Options tab here
@@ -324,7 +311,80 @@ def on_activated(self):
 
             tab.activated(force_clipboard=force_clipboard)
 
-        QApplication.instance().quit()
+        self.exit()
+
+    def exit(self):
+        from .config import config_state
+
+        if config_state['tray_agent']:
+            super().close()
+            if self.current_tab:
+                self.current_tab.line_edit.clear()
+        else:
+            QApplication.instance().quit()
+
+    _listener = None
+
+    def reset_hotkey_listener(self):
+        import pynput.keyboard
+
+        from .config import config_state
+
+        if self._listener:
+            self._listener.stop()
+
+        def on_hotkey():
+            logger.info(f'Hotkey "{config_state["hotkey"]}" pressed. Raising window.')
+            nonlocal self
+            self.reset_window_position()
+            self.show()
+            self.raise_()
+            return True
+
+        if config_state['tray_agent']:
+            try:
+                self._listener = pynput.keyboard.GlobalHotKeys({config_state['hotkey']: on_hotkey})
+                self._listener.start()
+            except ValueError:
+                logger.exception('Invalid hotkey??? %s', config_state)
+
+    def reset_window_position(self):
+        from .config import config_state
+
+        mouse_pos = QCursor.pos() + QPoint(0, -40)  # distance from mouse padding
+        geometry = config_state['window_geometry']
+        logger.debug('Window geometry: %s', geometry)
+        valid_geom = QGuiApplication.primaryScreen().availableGeometry()
+        PAD_PX = 50
+        top_left = [max(mouse_pos.x() - geometry[0], valid_geom.x() + PAD_PX),
+                    max(mouse_pos.y() - geometry[1], valid_geom.y() + PAD_PX)]
+        geometry = [min(geometry[0], valid_geom.width() - 2 * PAD_PX),
+                    min(geometry[1], valid_geom.height() - 2 * PAD_PX)]
+        self.setGeometry(QRect(*top_left + geometry))
+
+    def install_sigusr1_handler(self):
+        r_fd, w_fd = os.pipe()
+        if not IS_WIDOWS:
+            os.set_blocking(w_fd, False)
+        atexit.register(os.close, r_fd)
+        atexit.register(os.close, w_fd)
+        self._notifier = notifier = QSocketNotifier(r_fd, QSocketNotifier.Type.Read, self)
+        # https://stackoverflow.com/questions/4938723/what-is-the-correct-way-to/37229299#37229299
+        signal.set_wakeup_fd(w_fd)
+        signal.signal(OUR_SIGUSR1, lambda sig, frame: None)
+
+        def sigusr1_received():
+            nonlocal notifier, self, r_fd
+            notifier.setEnabled(False)
+            signum = ord(os.read(r_fd, 1))
+            if signum == OUR_SIGUSR1:
+                logger.info('Handled SIGUSR1. Showing up!')
+                self.reset_window_position()
+                self.show()
+                self.raise_()
+            notifier.setEnabled(True)
+
+        notifier.activated.connect(sigusr1_received)
 
 
 class _TabPrivate(QWidget):

efck/tabs/_options.py

@@ -1,6 +1,8 @@
 import copy
 import logging
 
+import pynput.keyboard
+
 from ..qt import *
 
 
@@ -35,15 +37,53 @@ def _change_zoom():
         main_box = QGroupBox(self)
         self.layout().addWidget(main_box)
         main_box.setLayout(QVBoxLayout(main_box))
-        force_clipboard_cb = QCheckBox(
+
+        check = QCheckBox(
             'Force &clipboard',
             parent=self,
             checked=config_state['force_clipboard'],
             toolTip='Copy selected emoji/text into the clipboard in addition to typing it out. \n'
                     "Useful if typeout (default action) doesn't work on your system.")
-        force_clipboard_cb.stateChanged.connect(
+        check.stateChanged.connect(
             lambda state: config_state.__setitem__('force_clipboard', bool(state)))
-        main_box.layout().addWidget(force_clipboard_cb)
+        main_box.layout().addWidget(check)
+
+        check = QCheckBox(
+            'Fast startup (background service) with keyboard hotkey:',
+            parent=self,
+            checked=config_state['tray_agent'],
+            toolTip='Minimize app to background instead of closing it. '
+                    'This enables much faster subsequent startup.')
+        check.stateChanged.connect(
+            lambda state: (config_state.__setitem__('tray_agent', bool(state)),
+                           hotkey_edit.setEnabled(state)))
+
+        url = 'https://pynput.readthedocs.io/en/latest/keyboard.html#pynput.keyboard.Key'
+        hotkey_edit = QLineEdit(
+            config_state['hotkey'],
+            parent=self,
+            enabled=check.isChecked(),
+            toolTip=f'Hotkey syntax format is as accepted by '
+                    f'<b><code>pynput.keyboard.HotKey</code></b>: <a href="{url}">{url}</a>'
+        )
+        hotkey_edit.textEdited.connect(
+            lambda text: is_hotkey_valid(text) and config_state.__setitem__('hotkey', text))
+
+        def is_hotkey_valid(text):
+            try:
+                pynput.keyboard.HotKey.parse(text)
+            except ValueError:
+                hotkey_edit.setStyleSheet('QLineEdit {border: 3px solid red}')
+                return False
+            hotkey_edit.setStyleSheet('')
+            return True
+
+        box = QWidget()
+        box.setLayout(QHBoxLayout())
+        box.layout().setContentsMargins(0, 0, 0, 0)
+        box.layout().addWidget(check)
+        box.layout().addWidget(hotkey_edit)
+        main_box.layout().addWidget(box)
 
         box = QWidget(self)
         main_box.layout().addWidget(box)
@@ -75,6 +115,12 @@ def add_section(self, name, widget: QWidget):
         box.layout().addWidget(widget)
         self.layout().addWidget(box)
 
+    def hideEvent(self, event):
+        if self.save_dirty():
+            # Reload models
+            for tab in self.nativeParentWidget().tabs:
+                tab.reset_model()
+
     def save_dirty(self, exiting=False) -> bool:
         """Returns True if config had changed and emoji need reloading"""
         from ..config import dump_config, config_state
@@ -84,6 +130,8 @@ def save_dirty(self, exiting=False) -> bool:
             self._initial_config = copy.deepcopy(config_state)
 
             if not exiting:
+                self.nativeParentWidget().reset_hotkey_listener()
+
                 for tab in self.nativeParentWidget().tabs:
                     tab.init_delegate(config=config_state.get(tab.__class__.__name__),
                                       zoom=config_state.get('zoom', 100) / 100)

packaging/debian/control

@@ -20,6 +20,8 @@ Architecture: all
 Depends: ${python3:Depends},
          ${misc:Depends},
          python3-pyqt6 | python3-pyqt5,
+         python3-psutil,
+         python3-pynput,
          fonts-noto-color-emoji
 Recommends: python3-unicodedata2,
             xdotool,

requirements.txt

@@ -1,2 +1,4 @@
 unicodedata2
 pyqt6  # or pyside6 or pyqt5
+psutil
+pynput

setup.py

@@ -32,6 +32,8 @@
             'setuptools_scm',
         ],
         install_requires=[
+            'psutil',
+            'pynput',
         ],
         extras_require={
             'doc': [