class PyDMTerminator(QLabel, PyDMPrimitiveWidget):
"""
A watchdog widget to close a window after X seconds of inactivity.
"""
designer_icon = QIcon(get_icon_file("terminator.png"))
def __init__(self, parent=None, timeout=60, *args, **kwargs):
super(PyDMTerminator, self).__init__(parent=parent, *args, **kwargs)
self.setText("")
self._hook_setup = False
self._timeout = 60
self._time_rem_ms = 0
self._timer = QTimer()
self._timer.timeout.connect(self.handle_timeout)
self._timer.setSingleShot(True)
self._window = None
if timeout and timeout > 0:
self.timeout = timeout
else:
self._reset()
self._setup_activity_hook()
self._update_label()
def _find_window(self):
"""
Finds the first window available starting from this widget's parent
Returns
-------
QWidget
"""
# check buffer
if self._window:
return self._window
# go fish
w = self.parent()
while w is not None:
if w.isWindow():
return w
w = w.parent()
# we couldn't find it
return None
def _setup_activity_hook(self):
if is_qt_designer():
return
logger.debug('Setup Hook')
if self._hook_setup:
logger.debug('Setup Hook Already there')
return
self._window = self._find_window()
logger.debug('Install event filter at window')
# We must install the event filter in the application otherwise
# it won't stop when typing or moving over other widgets or even
# the PyDM main window if in use.
QApplication.instance().installEventFilter(self)
self._hook_setup = True
def eventFilter(self, obj, ev):
if ev.type() in (QEvent.MouseMove, QEvent.KeyPress, QEvent.KeyRelease):
self.reset()
return super(PyDMTerminator, self).eventFilter(obj, ev)
def reset(self):
if self._time_rem_ms != self._timeout * 1000:
self._time_rem_ms = self._timeout * 1000
self._update_label()
self.stop()
self.start()
def start(self):
if is_qt_designer():
return
interval = SLOW_TIMER_INTERVAL
if self._time_rem_ms < 60 * 1000:
interval = FAST_TIMER_INTERVAL
self._timer.setInterval(interval)
if not self._timer.isActive():
self._timer.start()
def stop(self):
if self._timer.isActive():
self._timer.stop()
def _get_time_text(self, value):
"""
Converts value in seconds into a text for days, hours, minutes and
seconds remaining.
Parameters
----------
value : int
The value in seconds to be converted
Returns
-------
str
"""
def time_msg(unit, val):
return "{} {}{}".format(val, unit, "s" if val > 1 else "")
units = ["day", "hour", "minute", "second"]
scale = [86400, 3600, 60, 1]
values = [0, 0, 0, 0]
rem = value
for idx, sc in enumerate(scale):
val_scaled, rem = int(rem // sc), rem % sc
if val_scaled >= 1:
val_scaled = math.ceil(val_scaled + (rem / sc))
values[idx] = val_scaled
break
values[idx] = val_scaled
time_items = []
for idx, un in enumerate(units):
v = values[idx]
if v > 0:
time_items.append(time_msg(un, v))
return ", ".join(time_items)
def _update_label(self):
"""Updates the label text with the remaining time."""
rem_time_s = self._time_rem_ms / 1000.0
text = self._get_time_text(rem_time_s)
self.setText("This screen will close in {}.".format(text))
@Property(int)
def timeout(self):
"""
Timeout in seconds.
Returns
-------
int
"""
return self._timeout
@timeout.setter
def timeout(self, seconds):
self.stop()
if seconds and seconds > 0:
self._timeout = seconds
self.reset()
def handle_timeout(self):
"""
Handles the timeout event for the timer.
Decreases the time remaining counter until 0 and when it is time,
cleans up the event filter and closes the window.
"""
if is_qt_designer():
return
# Decrease remaining time
self._time_rem_ms -= self._timer.interval()
# Update screen label with new remaining time
self._update_label()
if self._time_rem_ms > 0:
self.start()
return
QApplication.instance().removeEventFilter(self)
if self._window:
logger.debug('Time to close the window')
self._window.close()
msg = QMessageBox()
msg.setIcon(QMessageBox.Warning)
msg.setText(
"Your window was closed due to inactivity for {}.".format(
self._get_time_text(self.timeout)))
msg.setStandardButtons(QMessageBox.Ok)
msg.setDefaultButton(QMessageBox.Ok)
msg.exec_()
