class InitializerHelper(QtCore.QObject):
initializing = QtCore.Signal(object)
initialized = QtCore.Signal(object)
exception = QtCore.Signal(object, object)
finished = QtCore.Signal(float)
def __init__(self, drivers, register_finalizer, parallel, dependencies):
super().__init__()
self.drivers = drivers
self.register_finalizer = register_finalizer
self.parallel = parallel
self.dependencies = dependencies
def process(self):
start = time.time()
initialize_many(drivers=self.drivers,
register_finalizer=self.register_finalizer,
on_initializing=self.on_initializing,
on_initialized=self.on_initialized,
on_exception=self.on_exception,
concurrent=self.parallel,
dependencies=self.dependencies)
self.finished.emit(time.time() - start)
def on_initializing(self, driver):
self.initializing.emit(driver)
def on_initialized(self, driver):
self.initialized.emit(driver)
def on_exception(self, driver, ex):
self.exception.emit(driver, ex)
class FeatScan(Scan):
"""A backend to scan a feat for a given instrument.
"""
#: Signal emitted before starting a new iteration
#: Parameters: loop counter, step value, overrun
iteration = QtCore.Signal(int, int, bool)
#: Signal emitted when the loop finished.
#: The parameter is used to inform if the loop was canceled.
loop_done = QtCore.Signal(bool)
instrument = InstrumentSlot
#: Name of the scanned feat
#: :type: str
def __init__(self, feat_name, *args, **kwargs):
super().__init__(*args, **kwargs)
self.feat_name = feat_name
def _pre_body(self, counter, new_value, overrun):
setattr(self.instrument, self.feat_name, new_value)
@property
def feat_units(self):
"""Units of the scanned feat.
"""
target = self.instrument
feat_name = self.feat_name
feat = target.feats[feat_name]
return str(feat.units)
def setupUi(self, parent):
self.resize(275, 172)
self.setWindowTitle('Convert units')
self.layout = QtGui.QVBoxLayout(parent)
self.layout.setSizeConstraint(QtGui.QLayout.SetFixedSize)
align = (QtCore.Qt.AlignRight | QtCore.Qt.AlignTrailing
| QtCore.Qt.AlignVCenter)
self.layout1 = QtGui.QHBoxLayout()
self.label1 = QtGui.QLabel()
self.label1.setMinimumSize(QtCore.QSize(100, 0))
self.label1.setText('Convert from:')
self.label1.setAlignment(align)
self.layout1.addWidget(self.label1)
self.source_units = QtGui.QLineEdit()
self.source_units.setReadOnly(True)
self.layout1.addWidget(self.source_units)
self.layout.addLayout(self.layout1)
self.layout2 = QtGui.QHBoxLayout()
self.label2 = QtGui.QLabel()
self.label2.setMinimumSize(QtCore.QSize(100, 0))
self.label2.setText('to:')
self.label2.setAlignment(align)
self.layout2.addWidget(self.label2)
self.destination_units = QtGui.QLineEdit()
self.layout2.addWidget(self.destination_units)
self.layout.addLayout(self.layout2)
self.message = QtGui.QLabel()
self.message.setText('')
self.message.setAlignment(QtCore.Qt.AlignCenter)
self.layout.addWidget(self.message)
self.buttonBox = QtGui.QDialogButtonBox()
self.buttonBox.setOrientation(QtCore.Qt.Horizontal)
self.buttonBox.setStandardButtons(QtGui.QDialogButtonBox.Ok)
self.layout.addWidget(self.buttonBox)
self.buttonBox.setEnabled(False)
self.buttonBox.accepted.connect(self.accept)
self.destination_units.textChanged.connect(self.check)
self.setLayout(self.layout)
self.destination_units.setFocus()
class Loop(Backend):
#: Signal emitted before starting a new iteration
#: Parameters: loop counter, iterations, overrun
iteration = QtCore.Signal(int, int, bool)
#: Signal emitted when the loop finished.
#: The parameter is used to inform if the loop was canceled.
loop_done = QtCore.Signal(bool)
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.body = None
self._active = False
self._internal_func = None
def stop(self):
self._active = False
def start(self, body, interval=0, iterations=0, timeout=0):
self._active = True
body = body or self.body
def internal(counter,
overrun=False,
schedule=QtCore.QTimer.singleShot):
if not self._active:
self.loop_done.emit(True)
return
st = time.time()
self.iteration.emit(counter, iterations, overrun)
body(counter, iterations, overrun)
if iterations and counter + 1 == iterations:
self.loop_done.emit(False)
return
elif not self._active:
self.loop_done.emit(True)
return
sleep = interval - (time.time() - st)
schedule(sleep * 1000 if sleep > 0 else 0,
lambda: self._internal_func(counter + 1, sleep < 0))
self._internal_func = internal
if timeout:
QtCore.QTimer.singleShot(timeout * 1000, self.stop)
QtCore.QTimer.singleShot(0, lambda: self._internal_func(0))
class AmplitudeScannerUi(Frontend):
"""A frontend for the AmplitudeScanner backend.
Provides controls to select the scan range and to start and stop de scanning.
"""
# a declarative way to indicate the user interface file to use.
# The file must be located next to the python file where this class
# is defined.
gui = 'amplitude_scanner.ui'
# connect widgets to instruments using connect_setup automatically.
auto_connect = True
# amplitudes
request_start = QtCore.Signal(object)
def _scan(self):
start, stop, steps = (getattr(self.widget, name).value()
for name in ('start', 'stop', 'steps'))
amplitudes = Q_(np.linspace(start, stop, steps), 'volt')
self.request_start.emit(amplitudes)
def connect_backend(self):
# This method is called after gui has been loaded (referenced in self.widget)
# and the backend is connected to the frontend (referenced in self.backend).
# In this case, we use it to connect the scan button, to the scan method
# and the request_start signal to the _scan_amplitude
self.widget.scan_amplitudes.clicked.connect(self._scan)
self.request_start.connect(self.backend._scan_amplitude)
class AmplitudeScannerShutter(Backend):
"""A complex application that requires a function generator, an
oscilloscope and a shutter.
We could subclass AmplitudeScanner, but we have chosen to embed it instead.
"""
# Enumerate drivers required by the backend marking them with InstrumentSlot
osci = InstrumentSlot
fungen = InstrumentSlot
shutter = InstrumentSlot
# Embedded apps (Notice we embed the backend, not the Frontend)
scanner = AmplitudeScanner
# This signal will be emited when new data is available.
new_data = QtCore.Signal(object, object)
def scan_amplitude(self, amplitudes):
"""Open the shutter an then for each amplitude:
- scan the amplitude of the function generator.
- sleeps .3 seconds.
- measures the trace of the oscilloscope.
- yields amplitude, data for each amplitude.
Finally, close the shutter.
:param amplitudes: iterable of amplitudes.
"""
self.shutter.opened = True
# We use the embedded app to perform the actual operation.
# Notice that we have not explicitly instantiated the AmplitudeScanner
# nor provided the instruments. Lantz has done this in the back
# connecting InstrumentsSlots by name.
# i.e. self.osci is self.scanner.osci
for amplitude, data in self.scanner.scan_amplitude(amplitudes):
self.new_data.emit(amplitude, data)
yield amplitude, data
self.shutter.opened = False
def _scan_amplitude(self, amplitudes):
"""Because scan_amplitude is a generator, this helper functions is used
to iterate over all the items.
"""
return list(self.scan_amplitude(amplitudes))
def default_scan(self):
"""A linear scan from 1 to 19 Volts.
"""
return list(self.scan_amplitude(Q_(list(range(1, 20)), 'volt')))
class LoopOsciMeasure(Backend):
"""An application that measures from an Osci in a loop.
"""
# Enumerate drivers required by the backend marking them with InstrumentSlot
osci = InstrumentSlot
# Embedded apps (Notice we embed the backend, not the Frontend)
loop = Loop
# This signal will be emitted when new data is available.
new_data = QtCore.Signal(object)
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.loop.body = self.measure
def measure(self, counter, iterations, overrun):
data = self.osci.measure()
self.new_data.emit(data)
class LoopUi(Frontend):
gui = 'loop.ui'
auto_connect = False
request_start = QtCore.Signal(object, object, object, object)
request_stop = QtCore.Signal()
def connect_backend(self):
super().connect_backend()
self.widget.start_stop.clicked.connect(self.on_start_stop_clicked)
self.widget.mode.currentIndexChanged.connect(self.on_mode_changed)
self.widget.iterations.valueChanged.connect(self.recalculate)
self.widget.duration.valueChanged.connect(self.recalculate)
self.widget.interval.valueChanged.connect(self.recalculate)
self.widget.progress_bar.setValue(0)
self._ok_palette = QtGui.QPalette(self.widget.progress_bar.palette())
self._overrun_palette = QtGui.QPalette(
self.widget.progress_bar.palette())
self._overrun_palette.setColor(QtGui.QPalette.Highlight,
QtGui.QColor(QtCore.Qt.red))
self.backend.iteration.connect(self.on_iteration)
self.backend.loop_done.connect(self.on_loop_done)
self.request_start.connect(self.backend.start)
self.request_stop.connect(self.backend.stop)
def on_start_stop_clicked(self, value=None):
if self.backend._active:
self.widget.start_stop.setText('...')
self.widget.start_stop.setEnabled(False)
self.request_stop.emit()
return
self.widget.start_stop.setText('Stop')
self.widget.start_stop.setChecked(True)
mode = self.widget.mode.currentIndex()
interval, iterations, duration = [
getattr(self.widget, name).value()
for name in 'interval iterations duration'.split()
]
if mode == StopMode.Continuous:
self.request_start.emit(None, interval, 0, 0)
elif mode == StopMode.Iterations:
self.request_start.emit(None, interval, iterations, 0)
elif mode == StopMode.Duration:
self.request_start.emit(None, interval, 0, duration)
elif mode == StopMode.IterationsTimeOut:
self.request_start.emit(None, interval, iterations, duration)
def recalculate(self, *args):
mode = self.widget.mode.currentIndex()
if mode == StopMode.Duration:
iterations = self.widget.duration.value(
) / self.widget.interval.value()
self.widget.iterations.setValue(math.ceil(iterations))
elif mode == StopMode.Iterations:
self.widget.duration.setValue(self.widget.iterations.value() *
self.widget.interval.value())
def on_iteration(self, counter, iterations, overrun):
pbar = self.widget.progress_bar
if not counter:
if iterations:
pbar.setMaximum(iterations + 1)
else:
pbar.setMaximum(0)
if iterations:
pbar.setValue(counter + 1)
if overrun:
pbar.setPalette(self._overrun_palette)
else:
pbar.setPalette(self._ok_palette)
def on_mode_changed(self, new_index):
if new_index == StopMode.Continuous:
self.widget.duration.setEnabled(False)
self.widget.iterations.setEnabled(False)
elif new_index == StopMode.Duration:
self.widget.duration.setEnabled(True)
self.widget.iterations.setEnabled(True)
self.widget.duration.setReadOnly(False)
self.widget.iterations.setReadOnly(True)
elif new_index == StopMode.Iterations:
self.widget.duration.setEnabled(True)
self.widget.iterations.setEnabled(True)
self.widget.duration.setReadOnly(True)
self.widget.iterations.setReadOnly(False)
elif new_index == StopMode.IterationsTimeOut:
self.widget.duration.setEnabled(True)
self.widget.iterations.setEnabled(True)
self.widget.duration.setReadOnly(False)
self.widget.iterations.setReadOnly(False)
self.recalculate()
def on_loop_done(self, cancelled):
self.widget.start_stop.setText('Start')
self.widget.start_stop.setEnabled(True)
self.widget.start_stop.setChecked(False)
if self.widget.progress_bar.maximum():
self.widget.progress_bar.setValue(
self.widget.progress_bar.maximum())
else:
self.widget.progress_bar.setMaximum(1)
class Loop(Backend):
"""The Loop backend allows you to execute task periodically.
Usage:
from lantz.ui.blocks import Loop, LoopUi
def measure(counter, iterations, overrun):
print(counter, iterations, overrun)
data = osci.measure()
print(data)
app = Loop()
app.body = measure
start_gui_app(app, LoopUi)
"""
#: Signal emitted before starting a new iteration
#: Parameters: loop counter, iterations, overrun
iteration = QtCore.Signal(int, int, bool)
#: Signal emitted when the loop finished.
#: The parameter is used to inform if the loop was canceled.
loop_done = QtCore.Signal(bool)
#: The function to be called. It requires three parameters.
#: counter - the iteration number
#: iterations - total number of iterations
#: overrun - a boolean indicating if the time required for the operation
#: is longer than the interval.
#: :type: (int, int, bool) -> None
body = None
def __init__(self, **kwargs):
super().__init__(**kwargs)
self._active = False
self._internal_func = None
def stop(self):
"""Request the scanning to be stop.
Will stop when the current iteration is finished.
"""
self._active = False
def start(self, body, interval=0, iterations=0, timeout=0):
"""Request the scanning to be started.
:param body: function to be called at each iteration.
If None, the class body will be used.
:param interval: interval between starts of the iteration.
If the body takes too long, the iteration will
be as fast as possible and the overrun flag will be True
:param iterations: number of iterations
:param timeout: total time in seconds that the scanning will take.
If overdue, the scanning will be stopped.
If 0, there is no timeout.
"""
self._active = True
body = body or self.body
def internal(counter,
overrun=False,
schedule=QtCore.QTimer.singleShot):
if not self._active:
self.loop_done.emit(True)
return
st = time.time()
self.iteration.emit(counter, iterations, overrun)
body(counter, iterations, overrun)
if iterations and counter + 1 == iterations:
self._active = False
self.loop_done.emit(False)
return
elif not self._active:
self.loop_done.emit(True)
return
sleep = interval - (time.time() - st)
schedule(sleep * 1000 if sleep > 0 else 0,
lambda: self._internal_func(counter + 1, sleep < 0))
self._internal_func = internal
if timeout:
QtCore.QTimer.singleShot(timeout * 1000, self.stop)
QtCore.QTimer.singleShot(0, lambda: self._internal_func(0))
def update_progress_bar(new, old):
fraction = (new.magnitude - start.value()) / (stop.value() - start.value())
progress.setValue(fraction * 100)
inst.frequency_changed.connect(update_progress_bar)
# <--------- New code--------->
# Define a function to read the values from the widget and call scan_frequency
class Scanner(QtCore.QObject):
def scan(self):
# Call the scan frequency
scan_frequency(inst, start.value() * Hz, stop.value() * Hz,
step.value() * Hz, wait.value() * sec)
# When it finishes, set the progress to 100%
progress.setValue(100)
thread = QtCore.QThread()
scanner = Scanner()
scanner.moveToThread(thread)
thread.start()
# Connect the clicked signal of the scan button to the function
scan.clicked.connect(scanner.scan)
qapp.aboutToQuit.connect(thread.quit)
# <--------- End of new code --------->
main.show()
exit(qapp.exec_())
class Scan(Backend):
"""A backend that iterates over an list of values,
calling a `body` function in each step.
"""
#: Signal emitted before starting a new iteration
#: Parameters: loop counter, step value, overrun
iteration = QtCore.Signal(int, int, bool)
#: Signal emitted when the loop finished.
#: The parameter is used to inform if the loop was canceled.
loop_done = QtCore.Signal(bool)
#: The function to be called. It requires three parameters.
#: counter - the iteration number.
#: current value - the current value of the scan.
#: overrun - a boolean indicating if the time required for the operation
#: is longer than the interval.
#: :type: (int, int, bool) -> None
body = None
#: To be called before the body. Same signature as body
_pre_body = None
#: To be called after the body. Same signature as body
_post_body = None
def __init__(self, **kwargs):
super().__init__(**kwargs)
self._active = False
self._internal_func = None
def stop(self):
"""Request the scanning to be stop.
Will stop when the current iteration is finished.
"""
self._active = False
def start(self, body, interval=0, steps=(), timeout=0):
"""Request the scanning to be started.
:param body: function to be called at each iteration.
If None, the class body will be used.
:param interval: interval between starts of the iteration.
If the body takes too long, the iteration will
be as fast as possible and the overrun flag will be True
:param steps: iterable
:param timeout: total time in seconds that the scanning will take.
If overdue, the scanning will be stopped.
If 0, there is no timeout.
"""
self._active = True
body = body or self.body
iterations = len(steps)
def internal(counter,
overrun=False,
schedule=QtCore.QTimer.singleShot):
if not self._active:
self.loop_done.emit(True)
return
st = time.time()
self.iteration.emit(counter, iterations, overrun)
if self._pre_body is not None:
self._pre_body(counter, steps[counter], overrun)
if body is not None:
body(counter, steps[counter], overrun)
if self._post_body is not None:
self._post_body(counter, steps[counter], overrun)
if iterations and counter + 1 == iterations:
self._active = False
self.loop_done.emit(False)
return
elif not self._active:
self.loop_done.emit(True)
return
sleep = interval - (time.time() - st)
schedule(sleep * 1000 if sleep > 0 else 0,
lambda: self._internal_func(counter + 1, sleep < 0))
self._internal_func = internal
if timeout:
QtCore.QTimer.singleShot(timeout * 1000, self.stop)
QtCore.QTimer.singleShot(0, lambda: self._internal_func(0))
class ScanUi(Frontend):
"""A frontend to the Scan backend.
Allows you to create linear sequence of steps between a start a stop,
with selectable step size or number of steps.
"""
gui = 'scan.ui'
auto_connect = False
#: Signal emitted when a start is requested.
#: The parameters are None, interval, vector of steps
request_start = QtCore.Signal(object, object, object)
#: Signal emitted when a stop is requested.
request_stop = QtCore.Signal()
def connect_backend(self):
super().connect_backend()
self.widget.start_stop.clicked.connect(self.on_start_stop_clicked)
self.widget.mode.currentIndexChanged.connect(self.on_mode_changed)
self.widget.step_count.valueChanged.connect(self.recalculate)
self.widget.start.valueChanged.connect(self.recalculate)
self.widget.stop.valueChanged.connect(self.recalculate)
self.widget.step_size.valueChanged.connect(self.recalculate)
self.widget.progress_bar.setValue(0)
self._ok_palette = QtGui.QPalette(self.widget.progress_bar.palette())
self._overrun_palette = QtGui.QPalette(
self.widget.progress_bar.palette())
self._overrun_palette.setColor(QtGui.QPalette.Highlight,
QtGui.QColor(QtCore.Qt.red))
self.backend.iteration.connect(self.on_iteration)
self.backend.loop_done.connect(self.on_loop_done)
self.request_start.connect(self.backend.start)
self.request_stop.connect(self.backend.stop)
def on_start_stop_clicked(self, value=None):
if self.backend._active:
self.widget.start_stop.setText('...')
self.widget.start_stop.setEnabled(False)
self.request_stop.emit()
return
self.widget.start_stop.setText('Stop')
self.widget.start_stop.setChecked(True)
vals = [
getattr(self.widget, name).value()
for name in 'start stop step_size step_count wait'.split()
]
start, stop, step_size, step_count, interval = vals
steps = list(_linspace(start, stop, step_size))
self.request_start.emit(None, interval, steps)
def recalculate(self, *args):
mode = self.widget.mode.currentIndex()
if mode == StepsMode.step_size:
step_size, length = _linspace_args(self.widget.start.value(),
self.widget.stop.value(),
self.widget.step_size.value())
self.widget.step_count.setValue(length)
elif mode == StepsMode.step_count:
step_size, length = _linspace_args(
self.widget.start.value(),
self.widget.stop.value(),
length=self.widget.step_count.value())
self.widget.step_size.setValue(step_size)
def on_iteration(self, counter, iterations, overrun):
pbar = self.widget.progress_bar
if not counter:
if iterations:
pbar.setMaximum(iterations + 1)
else:
pbar.setMaximum(0)
if iterations:
pbar.setValue(counter + 1)
if overrun:
pbar.setPalette(self._overrun_palette)
else:
pbar.setPalette(self._ok_palette)
def on_mode_changed(self, new_index):
if new_index == StepsMode.step_size:
self.widget.step_count.setEnabled(False)
self.widget.step_size.setEnabled(True)
elif new_index == StepsMode.step_count:
self.widget.step_count.setEnabled(True)
self.widget.step_size.setEnabled(False)
self.recalculate()
def on_loop_done(self, cancelled):
self.widget.start_stop.setText('Start')
self.widget.start_stop.setEnabled(True)
self.widget.start_stop.setChecked(False)
if self.widget.progress_bar.maximum():
self.widget.progress_bar.setValue(
self.widget.progress_bar.maximum())
else:
self.widget.progress_bar.setMaximum(1)
def initialize_and_report(widget,
drivers,
register_finalizer=True,
initializing_msg='Initializing ...',
initialized_msg='Initialized',
concurrent=True,
dependencies=None):
"""Initialize drivers while reporting the status in a QtWidget.
:param widget: Qt Widget where the status information is going to be shown.
:param drivers: iterable of drivers to initialize.
:param register_finalizer: register driver.finalize method to be called at python exit.
:param initializing_msg: message to be displayed while initializing.
:param initialized_msg: message to be displayed after successful initialization.
:param concurrent: indicates that drivers with satisfied dependencies
should be initialized concurrently.
:param dependencies: indicates which drivers depend on others to be initialized.
each key is a driver name, and the corresponding
value is an iterable with its dependencies.
:return: the QThread doing the initialization.
"""
timing = {}
thread = QtCore.QThread()
helper = InitializerHelper(drivers, register_finalizer, concurrent,
dependencies)
helper.moveToThread(thread)
thread.helper = helper
if isinstance(widget, QtGui.QTableWidget):
def _initializing(driver):
timing[driver] = time.time()
row = drivers.index(driver)
widget.setItem(row, 2, QtGui.QTableWidgetItem(initializing_msg))
def _initialized(driver):
delta = time.time() - timing[driver]
row = drivers.index(driver)
widget.setItem(
row, 2,
QtGui.QTableWidgetItem(initialized_msg +
' ({:.1f} sec)'.format(delta)))
def _exception(driver, e):
delta = time.time() - timing[driver]
row = drivers.index(driver)
widget.setItem(
row, 2,
QtGui.QTableWidgetItem('{} ({:.1f} sec)'.format(e, delta)))
def _done(duration):
widget.setItem(
len(drivers), 2,
QtGui.QTableWidgetItem('{:.1f} sec'.format(duration)))
thread.quit()
widget.clearContents()
widget.setRowCount(len(drivers) + 1)
for row, driver in enumerate(drivers):
widget.setItem(row, 0, QtGui.QTableWidgetItem(driver.name))
widget.setItem(row, 1,
QtGui.QTableWidgetItem(driver.__class__.__name__))
widget.setItem(row, 2, QtGui.QTableWidgetItem(''))
widget.resizeColumnToContents(0)
widget.horizontalHeader().setStretchLastSection(True)
elif isinstance(widget, QtGui.QLineEdit):
def _initializing(driver):
timing[driver] = time.time()
widget.setText('{} ({}) > {}'.format(driver.name,
driver.__class__.__name__,
initializing_msg))
def _initialized(driver):
delta = time.time() - timing[driver]
widget.setText('{} ({}) > {} ({:.1f} sec)'.format(
driver.name, driver.__class__.__name__, initialized_msg,
delta))
def _exception(driver, e):
delta = time.time() - timing[driver]
widget.setText('{} ({}) > {} ({:.1f} sec)'.format(
driver.name, driver.__class__.__name__, e, delta))
def _done(duration):
widget.setText('Initialized in {:.1f} sec'.format(duration))
thread.quit()
widget.setReadOnly(True)
elif isinstance(widget, QtGui.QTextEdit):
def _initializing(driver):
timing[driver] = time.time()
widget.append('{} ({}) > {}'.format(driver.name,
driver.__class__.__name__,
initializing_msg))
def _initialized(driver):
delta = time.time() - timing[driver]
widget.append('{} ({}) > {} ({:.1f} sec)'.format(
driver.name, driver.__class__.__name__, initialized_msg,
delta))
def _exception(driver, e):
delta = time.time() - timing[driver]
widget.append('{} ({}) > {} ({:.1f} sec)'.format(
driver.name, driver.__class__.__name__, e, delta))
def _done(duration):
widget.append('Initialized in {:.1f} sec'.format(duration))
thread.quit()
widget.setReadOnly(True)
else:
raise TypeError('Unknown widget type {}.'.format(type(widget)))
thread.started.connect(helper.process)
helper.initializing.connect(_initializing)
helper.initialized.connect(_initialized)
helper.exception.connect(_exception)
helper.finished.connect(_done)
thread.start()
return thread
