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bec_widgets/bec_widgets/utils/busy_loader.py

326 lines
10 KiB
Python

from __future__ import annotations
from bec_lib.logger import bec_logger
from qtpy.QtCore import QEvent, QObject, Qt, QTimer, Signal
from qtpy.QtGui import QColor
from qtpy.QtWidgets import (
QApplication,
QFrame,
QHBoxLayout,
QLabel,
QMainWindow,
QPushButton,
QVBoxLayout,
QWidget,
)
from bec_widgets.utils.colors import apply_theme
from bec_widgets.utils.error_popups import SafeProperty
logger = bec_logger.logger
class _OverlayEventFilter(QObject):
"""Keeps the overlay sized and stacked over its target widget."""
def __init__(self, target: QWidget, overlay: QWidget):
super().__init__(target)
self._target = target
self._overlay = overlay
def eventFilter(self, obj, event):
if not hasattr(self, "_target") or self._target is None:
return False
if not hasattr(self, "_overlay") or self._overlay is None:
return False
if obj is self._target and event.type() in (
QEvent.Resize,
QEvent.Show,
QEvent.LayoutRequest,
QEvent.Move,
):
self._overlay.setGeometry(self._target.rect())
self._overlay.raise_()
return False
class BusyLoaderOverlay(QWidget):
"""
A semi-transparent scrim with centered text and an animated spinner.
Call show()/hide() directly, or use via `install_busy_loader(...)`.
Args:
parent(QWidget): The parent widget to overlay.
text(str): Initial text to display.
opacity(float): Overlay opacity (0..1).
Returns:
BusyLoaderOverlay: The overlay instance.
"""
foreground_color_changed = Signal(QColor)
scrim_color_changed = Signal(QColor)
def __init__(self, parent: QWidget, opacity: float = 0.35, **kwargs):
super().__init__(parent=parent, **kwargs)
self.setAttribute(Qt.WA_StyledBackground, True)
self.setAutoFillBackground(False)
self.setAttribute(Qt.WA_TranslucentBackground, True)
self._opacity = opacity
self._scrim_color = QColor(128, 128, 128, 110)
self._label_color = QColor(240, 240, 240)
self._filter: QObject | None = None
# Set Main Layout
layout = QVBoxLayout(self)
layout.setContentsMargins(24, 24, 24, 24)
layout.setSpacing(10)
self.setLayout(layout)
# Custom widget placeholder
self._custom_widget: QWidget | None = None
# Add a frame around the content
self._frame = QFrame(self)
self._frame.setObjectName("busyFrame")
self._frame.setAttribute(Qt.WA_TransparentForMouseEvents, True)
self._frame.lower()
# Defaults
self._update_palette()
# Start hidden; interactions beneath are blocked while visible
self.hide()
@SafeProperty(QColor, notify=scrim_color_changed)
def scrim_color(self) -> QColor:
"""
The overlay scrim color.
"""
return self._scrim_color
@scrim_color.setter
def scrim_color(self, value: QColor):
if not isinstance(value, QColor):
raise TypeError("scrim_color must be a QColor")
self._scrim_color = value
self.update()
@SafeProperty(QColor, notify=foreground_color_changed)
def foreground_color(self) -> QColor:
"""
The overlay foreground color (text, spinner).
"""
return self._label_color
@foreground_color.setter
def foreground_color(self, value: QColor):
if not isinstance(value, QColor):
try:
color = QColor(value)
if not color.isValid():
raise ValueError(f"Invalid color: {value}")
except Exception:
# pylint: disable=raise-missing-from
raise ValueError(f"Color {value} is invalid, cannot be converted to QColor")
self._label_color = value
self.update()
def set_filter(self, filt: _OverlayEventFilter):
"""
Set an event filter to keep the overlay sized and stacked over its target.
Args:
filt(QObject): The event filter instance.
"""
self._filter = filt
target = filt._target
if self.parent() != target:
logger.warning(f"Overlay parent {self.parent()} does not match filter target {target}")
target.installEventFilter(self._filter)
######################
### Public methods ###
######################
def set_widget(self, widget: QWidget):
"""
Set a custom widget as an overlay for the busy overlay.
Args:
widget(QWidget): The custom widget to display.
"""
lay = self.layout()
if lay is None:
return
self._custom_widget = widget
lay.addWidget(widget, 0, Qt.AlignHCenter)
def set_opacity(self, opacity: float):
"""
Set the overlay opacity. Only values between 0.0 and 1.0 are accepted. If a
value outside this range is provided, it will be clamped.
Args:
opacity(float): The opacity value between 0.0 (fully transparent) and 1.0 (fully opaque).
"""
self._opacity = max(0.0, min(1.0, float(opacity)))
# Re-apply alpha using the current theme color
base = self.scrim_color
base.setAlpha(int(255 * self._opacity))
self.scrim_color = base
self._update_palette()
##########################
### Internal methods ###
##########################
def _update_palette(self):
"""
Update colors from the current application theme.
"""
_app = QApplication.instance()
if hasattr(_app, "theme"):
theme = _app.theme # type: ignore[attr-defined]
_bg = theme.color("BORDER")
_fg = theme.color("FG")
else:
# Fallback neutrals
_bg = QColor(30, 30, 30)
_fg = QColor(230, 230, 230)
# Semi-transparent scrim derived from bg
base = _bg if isinstance(_bg, QColor) else QColor(str(_bg))
base.setAlpha(int(255 * max(0.0, min(1.0, getattr(self, "_opacity", 0.35)))))
self.scrim_color = base
fg = _fg if isinstance(_fg, QColor) else QColor(str(_fg))
self.foreground_color = fg
# Set the frame style with updated foreground colors
r, g, b, a = base.getRgb()
self._frame.setStyleSheet(
f"#busyFrame {{ border: 2px dashed {self.foreground_color.name()}; border-radius: 9px; background-color: rgba({r}, {g}, {b}, {a}); }}"
)
self.update()
#############################
### Custom Event Handlers ###
#############################
def showEvent(self, e):
# Call showEvent on custom widget if present
if self._custom_widget is not None:
self._custom_widget.showEvent(e)
super().showEvent(e)
def hideEvent(self, e):
# Call hideEvent on custom widget if present
if self._custom_widget is not None:
self._custom_widget.hideEvent(e)
super().hideEvent(e)
def resizeEvent(self, e):
# Call resizeEvent on custom widget if present
if self._custom_widget is not None:
self._custom_widget.resizeEvent(e)
super().resizeEvent(e)
r = self.rect().adjusted(10, 10, -10, -10)
self._frame.setGeometry(r)
# TODO should we have this cleanup here?
def cleanup(self):
"""Cleanup resources used by the overlay."""
if self._custom_widget is not None:
if hasattr(self._custom_widget, "cleanup"):
self._custom_widget.cleanup()
def install_busy_loader(
target: QWidget, start_loading: bool = False, opacity: float = 0.35
) -> BusyLoaderOverlay:
"""
Attach a BusyLoaderOverlay to `target` and keep it sized and stacked.
Args:
target(QWidget): The widget to overlay.
start_loading(bool): If True, show the overlay immediately.
opacity(float): Overlay opacity (0..1).
Returns:
BusyLoaderOverlay: The overlay instance.
"""
overlay = BusyLoaderOverlay(parent=target, opacity=opacity)
overlay.setGeometry(target.rect())
overlay.set_filter(_OverlayEventFilter(target=target, overlay=overlay))
if start_loading:
overlay.show()
return overlay
# --------------------------
# Launchable demo
# --------------------------
if __name__ == "__main__": # pragma: no cover
import sys
from bec_widgets.utils.bec_widget import BECWidget
from bec_widgets.widgets.plots.waveform.waveform import Waveform
class DemoWidget(BECWidget, QWidget): # pragma: no cover
def __init__(self, parent=None, start_busy: bool = False):
super().__init__(parent=parent, theme_update=True, start_busy=start_busy)
self._title = QLabel("Demo Content", self)
self._title.setAlignment(Qt.AlignCenter)
self._title.setFrameStyle(QFrame.Panel | QFrame.Sunken)
lay = QVBoxLayout(self)
lay.addWidget(self._title)
waveform = Waveform(self)
waveform.plot([1, 2, 3, 4, 5])
lay.addWidget(waveform, 1)
QTimer.singleShot(5000, self._ready)
def _ready(self):
self._title.setText("Ready ✓")
self.set_busy(False)
class DemoWindow(QMainWindow): # pragma: no cover
def __init__(self):
super().__init__()
self.setWindowTitle("Busy Loader — BECWidget demo")
left = DemoWidget(start_busy=True)
right = DemoWidget()
btn_on = QPushButton("Right → Loading")
btn_off = QPushButton("Right → Ready")
btn_text = QPushButton("Set custom text")
btn_on.clicked.connect(lambda: right.set_busy(True))
btn_off.clicked.connect(lambda: right.set_busy(False))
panel = QWidget()
prow = QVBoxLayout(panel)
prow.addWidget(btn_on)
prow.addWidget(btn_off)
prow.addWidget(btn_text)
prow.addStretch(1)
central = QWidget()
row = QHBoxLayout(central)
row.setContentsMargins(12, 12, 12, 12)
row.setSpacing(12)
row.addWidget(left, 1)
row.addWidget(right, 1)
row.addWidget(panel, 0)
self.setCentralWidget(central)
self.resize(900, 420)
app = QApplication(sys.argv)
apply_theme("light")
w = DemoWindow()
w.show()
sys.exit(app.exec())