Re-org main window singleton into a new module

Avoids some cyclical and confusing import time stuff that we needed to get
DPI aware fonts configured from the active display. Move the main window
singleton into its own module and add a `main_window()` getter for it.
Make `current_screen()` a ``MainWindow` method to avoid so many module
variables.

piker/ui/_chart.py

@@ -52,7 +52,6 @@ from ._l1 import L1Labels
 from ._graphics._ohlc import BarItems
 from ._graphics._curve import FastAppendCurve
 from ._style import (
-    _config_fonts_to_screen,
     hcolor,
     CHART_MARGINS,
     _xaxis_at,
@@ -68,7 +67,7 @@ from ..data import maybe_open_shm_array
 from .. import brokers
 from .. import data
 from ..log import get_logger
-from ._exec import run_qtractor, current_screen
+from ._exec import run_qtractor
 from ._interaction import ChartView
 from .order_mode import start_order_mode
 from .. import fsp
@@ -1687,7 +1686,7 @@ async def _async_main(
     chart_app = main_widget
 
     # attempt to configure DPI aware font size
-    screen = current_screen()
+    screen = chart_app.window.current_screen()
 
     # configure graphics update throttling based on display refresh rate
     global _clear_throttle_rate
@@ -1697,9 +1696,6 @@ async def _async_main(
     )
     log.info(f'Set graphics update rate to {_clear_throttle_rate} Hz')
 
-    # configure global DPI aware font size
-    _config_fonts_to_screen()
-
     # TODO: do styling / themeing setup
     # _style.style_ze_sheets(chart_app)
 

piker/ui/_exec.py

@@ -21,10 +21,7 @@ Run ``trio`` in guest mode on top of the Qt event loop.
 All global Qt runtime settings are mostly defined here.
 """
 from typing import Tuple, Callable, Dict, Any
-import os
 import platform
-import signal
-import time
 import traceback
 
 # Qt specific
@@ -32,7 +29,7 @@ import PyQt5  # noqa
 import pyqtgraph as pg
 from pyqtgraph import QtGui
 from PyQt5 import QtCore
-from PyQt5.QtGui import QLabel, QStatusBar
+# from PyQt5.QtGui import QLabel, QStatusBar
 from PyQt5.QtCore import (
     pyqtRemoveInputHook,
     Qt,
@@ -47,6 +44,7 @@ from outcome import Error
 from .._daemon import maybe_open_pikerd, _tractor_kwargs
 from ..log import get_logger
 from ._pg_overrides import _do_overrides
+from . import _style
 
 log = get_logger(__name__)
 
@@ -60,34 +58,6 @@ pg.enableExperimental = True
 _do_overrides()
 
 
-# singleton app per actor
-_qt_app: QtGui.QApplication = None
-_qt_win: QtGui.QMainWindow = None
-
-
-def current_screen() -> QtGui.QScreen:
-    """Get a frickin screen (if we can, gawd).
-
-    """
-    global _qt_win, _qt_app
-
-    for _ in range(3):
-        screen = _qt_app.screenAt(_qt_win.pos())
-        print('trying to access QScreen...')
-        if screen is None:
-            time.sleep(0.5)
-            continue
-
-        break
-    else:
-        if screen is None:
-            # try for the first one we can find
-            screen = _qt_app.screens()[0]
-
-    assert screen, "Wow Qt is dumb as shit and has no screen..."
-    return screen
-
-
 # XXX: pretty sure none of this shit works on linux as per:
 # https://bugreports.qt.io/browse/QTBUG-53022
 # it seems to work on windows.. no idea wtf is up.
@@ -102,126 +72,12 @@ if platform.system() == "Windows":
         QCoreApplication.setAttribute(Qt.AA_UseHighDpiPixmaps, True)
 
 
-class MultiStatus:
-
-    bar: QStatusBar
-    statuses: list[str]
-
-    def __init__(self, bar, statuses) -> None:
-        self.bar = bar
-        self.statuses = statuses
-
-    def open_status(
-        self,
-        msg: str,
-    ) -> Callable[..., None]:
-        '''Add a status to the status bar and return a close callback which
-        when called will remove the status ``msg``.
-
-        '''
-        self.statuses.append(msg)
-
-        def remove_msg() -> None:
-            self.statuses.remove(msg)
-            self.render()
-
-        self.render()
-        return remove_msg
-
-    def render(self) -> None:
-        if self.statuses:
-            self.bar.showMessage(f'{" ".join(self.statuses)}')
-        else:
-            self.bar.clearMessage()
-
-
-class MainWindow(QtGui.QMainWindow):
-
-    size = (800, 500)
-    title = 'piker chart (ur symbol is loading bby)'
-
-    def __init__(self, parent=None):
-        super().__init__(parent)
-        self.setMinimumSize(*self.size)
-        self.setWindowTitle(self.title)
-
-        self._status_bar: QStatusBar = None
-        self._status_label: QLabel = None
-
-    @property
-    def mode_label(self) -> QtGui.QLabel:
-
-        # init mode label
-        if not self._status_label:
-            # TODO: i guess refactor stuff to avoid having to import here?
-            from ._style import _font_small, hcolor
-            self._status_label = label = QtGui.QLabel()
-            label.setStyleSheet(
-                f"QLabel {{ color : {hcolor('gunmetal')}; }}"
-            )
-            label.setTextFormat(3)  # markdown
-            label.setFont(_font_small.font)
-            label.setMargin(2)
-            label.setAlignment(
-                QtCore.Qt.AlignVCenter
-                | QtCore.Qt.AlignRight
-            )
-            self.statusBar().addPermanentWidget(label)
-            label.show()
-
-        return self._status_label
-
-    def closeEvent(
-        self,
-        event: QtGui.QCloseEvent,
-    ) -> None:
-        """Cancel the root actor asap.
-
-        """
-        # raising KBI seems to get intercepted by by Qt so just use the system.
-        os.kill(os.getpid(), signal.SIGINT)
-
-    @property
-    def status_bar(self) -> QStatusBar:
-
-        # style and cached the status bar on first access
-        if not self._status_bar:
-            # TODO: i guess refactor stuff to avoid having to import here?
-            from ._style import _font_small, hcolor
-            sb = self.statusBar()
-            sb.setStyleSheet((
-                f"color : {hcolor('gunmetal')};"
-                f"background : {hcolor('default_dark')};"
-                f"font-size : {_font_small.px_size}px;"
-                "padding : 0px;"
-                # "min-height : 19px;"
-                # "qproperty-alignment: AlignVCenter;"
-            ))
-            self.setStatusBar(sb)
-            self._status_bar = MultiStatus(sb, [])
-
-        return self._status_bar
-
-    def on_focus_change(
-        self,
-        old: QtGui.QWidget,
-        new: QtGui.QWidget,
-    ) -> None:
-
-        log.debug(f'widget focus changed from {old} -> {new}')
-
-        if new is not None:
-            # cursor left window?
-            name = getattr(new, 'mode_name', '')
-            self.mode_label.setText(name)
-
-
 def run_qtractor(
     func: Callable,
     args: Tuple,
     main_widget: QtGui.QWidget,
     tractor_kwargs: Dict[str, Any] = {},
-    window_type: QtGui.QMainWindow = MainWindow,
+    window_type: QtGui.QMainWindow = None,
 ) -> None:
     # avoids annoying message when entering debugger from qt loop
     pyqtRemoveInputHook()
@@ -239,10 +95,6 @@ def run_qtractor(
     # XXX: lmfao, this is how you disable text edit cursor blinking..smh
     app.setCursorFlashTime(0)
 
-    # set global app singleton
-    global _qt_app
-    _qt_app = app
-
     # This code is from Nathaniel, and I quote:
     # "This is substantially faster than using a signal... for some
     # reason Qt signal dispatch is really slow (and relies on events
@@ -286,8 +138,20 @@ def run_qtractor(
     app.setStyleSheet(stylesheet)
 
     # make window and exec
+    from . import _window
+
+    if window_type is None:
+        window_type = _window.MainWindow
+
     window = window_type()
 
+    # set global app's main window singleton
+    _window._qt_win = window
+
+    # configure global DPI aware font sizes now that a screen
+    # should be active from which we can read a DPI.
+    _style._config_fonts_to_screen()
+
     # hook into app focus change events
     app.focusChanged.connect(window.on_focus_change)
 
@@ -316,11 +180,6 @@ def run_qtractor(
     window.main_widget = main_widget
     window.setCentralWidget(instance)
 
-    # store global ref
-    # set global app singleton
-    global _qt_win
-    _qt_win = window
-
     # actually render to screen
     window.show()
     app.exec_()

piker/ui/_style.py

@@ -25,7 +25,6 @@ from PyQt5 import QtCore, QtGui
 from qdarkstyle import DarkPalette
 
 from ..log import get_logger
-from ._exec import current_screen
 
 log = get_logger(__name__)
 
@@ -69,13 +68,15 @@ class DpiAwareFont:
 
     @property
     def screen(self) -> QtGui.QScreen:
+        from ._window import main_window
+
         if self._screen is not None:
             try:
                 self._screen.refreshRate()
             except RuntimeError:
-                self._screen = current_screen()
+                self._screen = main_window().current_screen()
         else:
-            self._screen = current_screen()
+            self._screen = main_window().current_screen()
 
         return self._screen
 
@@ -151,6 +152,8 @@ _font_small = DpiAwareFont(font_size='small')
 
 
 def _config_fonts_to_screen() -> None:
+    'configure global DPI aware font sizes'
+
     global _font, _font_small
     _font.configure_to_dpi()
     _font_small.configure_to_dpi()

piker/ui/_window.py

@@ -0,0 +1,180 @@
+# piker: trading gear for hackers
+# Copyright (C) Tyler Goodlet (in stewardship for piker0)
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+"""
+Qt main window singletons and stuff.
+
+"""
+import os
+import signal
+import time
+from typing import Callable
+
+from pyqtgraph import QtGui
+from PyQt5 import QtCore
+from PyQt5.QtGui import QLabel, QStatusBar
+
+from ..log import get_logger
+from ._style import _font_small, hcolor
+
+
+log = get_logger(__name__)
+
+
+class MultiStatus:
+
+    bar: QStatusBar
+    statuses: list[str]
+
+    def __init__(self, bar, statuses) -> None:
+        self.bar = bar
+        self.statuses = statuses
+
+    def open_status(
+        self,
+        msg: str,
+    ) -> Callable[..., None]:
+        '''Add a status to the status bar and return a close callback which
+        when called will remove the status ``msg``.
+
+        '''
+        self.statuses.append(msg)
+
+        def remove_msg() -> None:
+            self.statuses.remove(msg)
+            self.render()
+
+        self.render()
+        return remove_msg
+
+    def render(self) -> None:
+        if self.statuses:
+            self.bar.showMessage(f'{" ".join(self.statuses)}')
+        else:
+            self.bar.clearMessage()
+
+
+class MainWindow(QtGui.QMainWindow):
+
+    size = (800, 500)
+    title = 'piker chart (ur symbol is loading bby)'
+
+    def __init__(self, parent=None):
+        super().__init__(parent)
+        self.setMinimumSize(*self.size)
+        self.setWindowTitle(self.title)
+
+        self._status_bar: QStatusBar = None
+        self._status_label: QLabel = None
+
+    @property
+    def mode_label(self) -> QtGui.QLabel:
+
+        # init mode label
+        if not self._status_label:
+
+            self._status_label = label = QtGui.QLabel()
+            label.setStyleSheet(
+                f"QLabel {{ color : {hcolor('gunmetal')}; }}"
+            )
+            label.setTextFormat(3)  # markdown
+            label.setFont(_font_small.font)
+            label.setMargin(2)
+            label.setAlignment(
+                QtCore.Qt.AlignVCenter
+                | QtCore.Qt.AlignRight
+            )
+            self.statusBar().addPermanentWidget(label)
+            label.show()
+
+        return self._status_label
+
+    def closeEvent(
+        self,
+        event: QtGui.QCloseEvent,
+    ) -> None:
+        """Cancel the root actor asap.
+
+        """
+        # raising KBI seems to get intercepted by by Qt so just use the system.
+        os.kill(os.getpid(), signal.SIGINT)
+
+    @property
+    def status_bar(self) -> QStatusBar:
+
+        # style and cached the status bar on first access
+        if not self._status_bar:
+
+            sb = self.statusBar()
+            sb.setStyleSheet((
+                f"color : {hcolor('gunmetal')};"
+                f"background : {hcolor('default_dark')};"
+                f"font-size : {_font_small.px_size}px;"
+                "padding : 0px;"
+                # "min-height : 19px;"
+                # "qproperty-alignment: AlignVCenter;"
+            ))
+            self.setStatusBar(sb)
+            self._status_bar = MultiStatus(sb, [])
+
+        return self._status_bar
+
+    def on_focus_change(
+        self,
+        old: QtGui.QWidget,
+        new: QtGui.QWidget,
+    ) -> None:
+
+        log.debug(f'widget focus changed from {old} -> {new}')
+
+        if new is not None:
+            # cursor left window?
+            name = getattr(new, 'mode_name', '')
+            self.mode_label.setText(name)
+
+    def current_screen(self) -> QtGui.QScreen:
+        """Get a frickin screen (if we can, gawd).
+
+        """
+        app = QtGui.QApplication.instance()
+
+        for _ in range(3):
+            screen = app.screenAt(self.pos())
+            print('trying to access QScreen...')
+            if screen is None:
+                time.sleep(0.5)
+                continue
+
+            break
+        else:
+            if screen is None:
+                # try for the first one we can find
+                screen = app.screens()[0]
+
+        assert screen, "Wow Qt is dumb as shit and has no screen..."
+        return screen
+
+
+# singleton app per actor
+_qt_win: QtGui.QMainWindow = None
+
+
+def main_window() -> MainWindow:
+    'Return the actor-global Qt window.'
+
+    global _qt_win
+    assert _qt_win
+    return _qt_win