import logging
import numpy as np
from decimal import Decimal
from qtpy.QtCore import Qt, Signal, Slot, Property, QRect, QPoint, QSize
from qtpy.QtWidgets import (
QFrame,
QLabel,
QSlider,
QVBoxLayout,
QHBoxLayout,
QSizePolicy,
QWidget,
QLineEdit,
QPushButton,
QCheckBox,
QComboBox,
)
from pydm.widgets import PyDMLabel
from .base import PyDMWritableWidget, TextFormatter, is_channel_valid
from .channel import PyDMChannel
logger = logging.getLogger(__name__)
_step_size_properties = {
"Set Step Size ": ["step_size", float],
}
class PyDMPrimitiveSlider(QSlider):
def __init__(self, orientation=Qt.Horizontal, parent=None):
super().__init__(orientation, parent)
self.isDraggingHandle = False
self.dragStartPos = None
self.dragStartValue = None
def mousePressEvent(self, event):
"""
Handle mouse press events on the slider.
Parameters
----------
event : QMouseEvent
The mouse event containing information about the press.
"""
if event.button() == Qt.MiddleButton:
return
if event.button() == Qt.RightButton:
super().mousePressEvent(event)
return
if event.button() == Qt.LeftButton:
handle_rect = self.getHandleRect()
if handle_rect.contains(event.pos()):
self.isDraggingHandle = True
self.dragStartPos = event.pos()
self.dragStartValue = self.value()
self.setCursor(Qt.ClosedHandCursor)
event.accept()
else:
handle_pos, click_pos = self.getPositions(event)
if self.shouldIncrement(handle_pos, click_pos):
self.setValue(self.value() + self.singleStep())
else:
self.setValue(self.value() - self.singleStep())
def mouseMoveEvent(self, event):
"""
Handle mouse move events to update the slider value during dragging.
Parameters
----------
event : QMouseEvent
The mouse event containing information about the movement.
"""
if self.isDraggingHandle:
delta = event.pos() - self.dragStartPos
if self.orientation() == Qt.Horizontal:
delta_value = (delta.x() / self.getSliderLength()) * (self.maximum() - self.minimum())
else:
delta_value = (-delta.y() / self.getSliderLength()) * (self.maximum() - self.minimum())
new_value = self.dragStartValue + delta_value
new_value = min(max(self.minimum(), new_value), self.maximum())
self.setValue(new_value)
event.accept()
else:
super().mouseMoveEvent(event)
def mouseReleaseEvent(self, event):
"""
Handle mouse release events to stop dragging.
Parameters
----------
event : QMouseEvent
The mouse event containing information about the release.
"""
if event.button() == Qt.LeftButton and self.isDraggingHandle:
self.isDraggingHandle = False
self.setCursor(Qt.ArrowCursor)
event.accept()
else:
super().mouseReleaseEvent(event)
def getHandleRect(self):
"""
Calculate the rectangle representing the slider handle's position and size.
Returns
-------
QRect
The rectangle of the slider handle.
"""
handle_size = self.getHandleSize()
slider_pos = self.getSliderPosition()
if self.orientation() == Qt.Horizontal:
x = slider_pos - handle_size.width() / 2
y = (self.height() - handle_size.height()) / 2
rect = QRect(QPoint(int(x), int(y)), handle_size)
else:
x = (self.width() - handle_size.width()) / 2
y = slider_pos - handle_size.height() / 2
rect = QRect(QPoint(int(x), int(y)), handle_size)
return rect
def getPositions(self, event):
"""
Retrieve the handle position and the click position based on the orientation.
Parameters
----------
event : QMouseEvent
The mouse event containing information about the press.
Returns
-------
tuple of float
A tuple containing the handle position and the click position.
"""
slider_pos = self.getSliderPosition()
handle_pos = slider_pos
if self.orientation() == Qt.Horizontal:
click_pos = event.pos().x()
else:
click_pos = event.pos().y()
return handle_pos, click_pos
def shouldIncrement(self, handle_pos, click_pos):
"""
Determine whether the slider value should be incremented based on positions.
Parameters
----------
handle_pos : float
The position of the slider handle.
click_pos : float
The position where the user clicked.
Returns
-------
bool
True if the slider value should be incremented, False otherwise.
"""
if self.orientation() == Qt.Horizontal:
return click_pos > handle_pos
else:
return click_pos < handle_pos
def getHandleSize(self):
"""
Compute the size of the slider handle.
Returns
-------
QSize
The size of the slider handle.
"""
handle_length = 20 # Fixed length for the handle
if self.orientation() == Qt.Horizontal:
return QSize(handle_length, self.height() // 2)
else:
return QSize(self.width() // 2, handle_length)
def getSliderLength(self):
"""
Calculate the usable length of the slider track excluding the handle size.
Returns
-------
float
The length of the slider track.
"""
handle_size = self.getHandleSize()
if self.orientation() == Qt.Horizontal:
return self.width() - handle_size.width()
else:
return self.height() - handle_size.height()
def getSliderPosition(self):
"""
Compute the position of the slider handle along the track.
Returns
-------
float
The position of the slider handle along the slider track.
"""
slider_min = self.minimum()
slider_max = self.maximum()
slider_range = slider_max - slider_min
slider_value = self.value() - slider_min
if slider_range == 0:
proportion = 0
else:
proportion = slider_value / slider_range
if self.orientation() == Qt.Horizontal:
slider_length = self.getSliderLength()
return proportion * slider_length + self.getHandleSize().width() / 2
else:
slider_length = self.getSliderLength()
# 1 - proportion, because the largest positional value is at the bottom of the slider.
return (1 - proportion) * slider_length + self.getHandleSize().height() / 2
[docs]class PyDMSlider(QFrame, TextFormatter, PyDMWritableWidget, new_properties=_step_size_properties):
"""
A QSlider with support for Channels and more from PyDM.
Parameters
----------
parent : QWidget
The parent widget for the Label
init_channel : str, optional
The channel to be used by the widget.
"""
actionTriggered = Signal(int)
rangeChanged = Signal(float, float)
sliderMoved = Signal(float)
sliderPressed = Signal()
sliderReleased = Signal()
valueChanged = Signal(float)
def __init__(self, parent=None, init_channel=None):
QFrame.__init__(self, parent)
self.remap_flag = False
PyDMWritableWidget.__init__(self, init_channel=init_channel)
self.alarmSensitiveContent = True
self.alarmSensitiveBorder = False
# Internal values for properties
self._ignore_mouse_wheel = True
self._show_limit_labels = True
self._show_value_label = True
self._user_defined_limits = False
self._needs_limit_info = True
self._minimum = None
self._maximum = None
self._user_minimum = -10.0
self._user_maximum = 10.0
self._step_size = 0
self._num_steps = 101
self._orientation = Qt.Horizontal
self._step_size_channel = None
# Set up all the internal widgets that make up a PyDMSlider.
# We'll add all these things to layouts when we call setup_widgets_for_orientation
label_size_policy = QSizePolicy(QSizePolicy.Maximum, QSizePolicy.Fixed)
self.low_lim_label = QLabel(self)
self.low_lim_label.setObjectName("lowLimLabel")
self.low_lim_label.setSizePolicy(label_size_policy)
self.low_lim_label.setAlignment(Qt.AlignLeft | Qt.AlignTrailing | Qt.AlignVCenter)
self.value_label = QLabel(self)
self.value_label.setObjectName("valueLabel")
self.value_label.setAlignment(Qt.AlignHCenter | Qt.AlignVCenter)
self.high_lim_label = QLabel(self)
self.high_lim_label.setObjectName("highLimLabel")
self.high_lim_label.setSizePolicy(label_size_policy)
self.high_lim_label.setAlignment(Qt.AlignRight | Qt.AlignTrailing | Qt.AlignVCenter)
self._slider = PyDMPrimitiveSlider(parent=self)
# Pass PyDMPrimitiveWidget eventfilter to self._slider so it will have the tooltip display
# the address name from middle clicking on the widget
self._slider.installEventFilter(self)
self._slider.setOrientation(Qt.Horizontal)
self._orig_wheel_event = self._slider.wheelEvent
self._slider.wheelEvent = self.wheelEvent
self._slider.sliderMoved.connect(self.internal_slider_moved)
self._slider.sliderPressed.connect(self.internal_slider_pressed)
self._slider.sliderReleased.connect(self.internal_slider_released)
self._slider.valueChanged.connect(self.internal_slider_value_changed)
# Other internal variables and final setup steps
self._slider_position_to_value_map = None
self._mute_internal_slider_changes = False
self.setup_widgets_for_orientation(self._orientation)
self.reset_slider_limits()
self.slider_parameters_menu_widget = None
self.slider_parameters_menu_input_widgets = None
self.slider_parameters_menu_labels = None
self.slider_parameters_menu_buttons = None
self.menu_layout = None
self._parameters_menu_flag = False
self.step_max = self.maximum
self._step_size_channel = None
self.step_size_channel_pv = None
[docs] def wheelEvent(self, e):
"""
Method to specifically ignore mouse wheel events.
"""
if self._ignore_mouse_wheel:
e.ignore()
else:
super(PyDMSlider, self).wheelEvent(e)
return
[docs] def mousePressEvent(self, mouse_event):
"""
Method to open slider parameters menu with a right click.
Parameters
----------
mouse_event : mousePressEvent
"""
if mouse_event.button() == Qt.RightButton:
position_of_click = mouse_event.pos()
self.slider_parameters_menu(position_of_click)
[docs] def apply_and_close_menu(self):
"""
Method for the 'ok' button in the slider parameters menu.
"""
self.apply_step_size_menu_changes()
self.slider_parameters_menu_widget.close()
[docs] def init_for_designer(self):
"""
Method called after the constructor to tweak configurations for
when using the widget with the Qt Designer
"""
self.value = 0.0
@Property(Qt.Orientation)
def orientation(self):
"""
The slider orientation (Horizontal or Vertical)
Returns
-------
int
Qt.Horizontal or Qt.Vertical
"""
return self._orientation
@orientation.setter
def orientation(self, new_orientation):
"""
The slider orientation (Horizontal or Vertical)
Parameters
----------
new_orientation : int
Qt.Horizontal or Qt.Vertical
"""
self._orientation = new_orientation
self.setup_widgets_for_orientation(new_orientation)
[docs] def update_labels(self, exp=False):
"""
Update the limits and value labels with the correct values.
"""
def set_label(value, label_widget, exp_format):
if value is None:
label_widget.setText("")
else:
if not exp_format:
label_widget.setText(self.format_string.format(value))
else:
text = "%." + str(self.precision) + "E"
text = text % Decimal(str(value))
if self._show_units and self._unit != "":
text += " {}".format(self._unit)
label_widget.setText(text)
set_label(self.minimum, self.low_lim_label, exp)
set_label(self.maximum, self.high_lim_label, exp)
set_label(self.value, self.value_label, exp)
[docs] def reset_slider_limits(self):
"""
Reset the limits and adjust the labels properly for the slider.
"""
logger.debug("Running reset_slider_limits.")
if self.minimum is None or self.maximum is None:
self._needs_limit_info = True
logger.debug("Need both limits before reset_slider_limits can work.")
self.set_enable_state()
return
logger.debug("Has both limits, proceeding.")
self._needs_limit_info = False
if self._parameters_menu_flag:
self._slider_position_to_value_map = self.create_slider_positions_to_value_map()
self._parameters_menu_flag = False
else:
# if no defaults. create a linear space from min to max from default num_steps = 101,
# this means we cant step to max, but also cant call create map without a value
self._slider_position_to_value_map = np.linspace(self.minimum, self.maximum, num=self._num_steps)
if is_channel_valid(self.step_size_channel):
self.init_step_size_channel(pv_address=self.step_size_channel, slot=self.step_size_changed)
self.update_labels()
self.rangeChanged.emit(self.minimum, self.maximum)
self._slider.setMinimum(0)
self._slider.valueChanged.disconnect(self.internal_slider_value_changed)
self._slider.setMaximum(self._num_steps)
self._slider.valueChanged.connect(self.internal_slider_value_changed)
self.set_slider_to_closest_value(self.value)
self._slider.setSingleStep(1)
self._slider.setPageStep(1)
self.set_enable_state()
[docs] def init_step_size_channel(self, pv_address: str, slot: callable):
"""
Connects instance attribute self.step_size_channel_pv to a PyDMChannel
Parameters
---------
pv_address: str
Channel name of PV that connection will be established too.
slot: callable
callback function to invoke when channel value changes.
"""
if self.step_size_channel_pv is None:
self.step_size_channel_pv = PyDMChannel(address=pv_address, value_slot=slot)
self.step_size_channel_pv.connect()
elif self.step_size_channel_pv is not None and self.step_size_channel_pv.address != pv_address:
self.step_size_channel_pv.disconnect()
self.step_size_channel_pv = None
self.step_size_channel_pv = PyDMChannel(address=pv_address, value_slot=slot)
self.step_size_channel_pv.connect()
[docs] def create_slider_positions_to_value_map(self):
"""
Wrapper around step_size_to_slider_positions_value_map to ensure
the func is only called after a step_size has been set
Returns
-------
positions_to_value_map: list
list with all possible allowed slider readback values
"""
if self._step_size > 0:
positions_to_values_map = self.step_size_to_slider_positions_value_map()
elif self._step_size == 0:
self.calc_step_size()
positions_to_values_map = self.step_size_to_slider_positions_value_map()
self.remap_flag = False
return positions_to_values_map
[docs] def step_size_to_slider_positions_value_map(self):
"""
Given a value increment by step size and record allowed values until self.maximum,
Repeat with decrementer until self.minimum, take results and create a linear
array of allowed values where the length of the array is the number of slider positions.
and the slider position i has value array[i].
"""
if self.value is not None and (self.value > self.maximum or self.value < self.minimum):
logger.debug("Slider out of bounds.")
self._slider.setEnabled(False)
raise ValueError("Slider is out of bounds either greater than max or less than min")
forward_map = []
backward_map = []
forward_map_value = self.value
backward_map_value = self.value
while forward_map_value < self.maximum:
forward_map.append(forward_map_value)
forward_map_value += self._step_size
# check if end points are less than or greater than correct vals,
# if less add a new point, is greater set endpoint to max/min
if len(forward_map) == 0:
# if len zero we are at or passed maximum. so all we need
# is the max ele for the map
forward_map.append(self.maximum)
elif round(float(forward_map[-1]), self.precision + 1) < round(float(self.maximum), self.precision + 1):
forward_map.append(self.maximum)
elif forward_map[-1] > self.maximum:
forward_map[-1] = self.maximum
while backward_map_value > self.minimum:
backward_map_value -= self._step_size
backward_map.append(backward_map_value)
if len(backward_map) == 0:
pass
elif round(float(backward_map[-1]), self.precision + 1) > round(float(self.minimum), self.precision + 1):
backward_map.append(self.minimum)
elif backward_map[-1] < self.minimum:
backward_map[-1] = self.minimum
backward_map = list(reversed(backward_map))
slider_position_map = np.array(backward_map + forward_map)
self._num_steps = len(slider_position_map) - 1
return slider_position_map
[docs] def calc_step_size(self):
"""
Given max, min, and num steps calculate step size
"""
self.step_size = (self.maximum - self.minimum) / self.num_steps
if self.step_size == 0:
self._slider.setEnabled(False)
raise ValueError("step size is zero afte calc step step size")
[docs] def find_closest_slider_position_to_value(self, val):
"""
Find and returns the index for the closest position on the slider
for a given value.
Parameters
----------
Returns
-------
int
"""
diff = abs(self._slider_position_to_value_map - float(val))
logger.debug("The closest value to %f is: %f", val, self._slider_position_to_value_map[np.argmin(diff)])
return np.argmin(diff)
[docs] def set_slider_to_closest_value(self, val):
"""
Set the value for the slider according to a given value.
Parameters
----------
val : float
"""
if val is None or self._needs_limit_info:
logger.debug("Not setting slider to closest value because we need limits.")
return
# When we set the slider to the closest value, it may end up at a slightly
# different position than val (if val is not in self._slider_position_to_value_map)
# We don't want that slight difference to get broacast out and put the channel
# somewhere new. For example, if the slider can only be at 0.4 or 0.5, but a
# new value comes in of 0.45, its more important to keep the 0.45 than to change
# it to where the slider gets set. Therefore, we mute the internal slider changes
# so that its valueChanged signal doesn't cause us to emit a signal to PyDM to change
# the value of the channel.
logger.debug("Setting slider to closest value.")
self._mute_internal_slider_changes = True
self._slider.setValue(self.find_closest_slider_position_to_value(val))
self._mute_internal_slider_changes = False
[docs] def connection_changed(self, connected):
"""
Callback invoked when the connection state of the Channel is changed.
This callback acts on the connection state to enable/disable the widget
and also trigger the change on alarm severity to ALARM_DISCONNECTED.
Parameters
----------
connected : int
When this value is 0 the channel is disconnected, 1 otherwise.
"""
super(PyDMSlider, self).connection_changed(connected)
self.set_enable_state()
[docs] def write_access_changed(self, new_write_access):
"""
Callback invoked when the Channel has new write access value.
This callback calls check_enable_state so it can act on the widget
enabling or disabling it accordingly
Parameters
----------
new_write_access : bool
True if write operations to the channel are allowed.
"""
super(PyDMSlider, self).write_access_changed(new_write_access)
self.set_enable_state()
[docs] def value_changed(self, new_val):
"""
Callback invoked when the Channel value is changed.
Parameters
----------
new_val : int or float
The new value from the channel.
"""
self.check_if_value_in_map(new_val)
# Calls find_closest_slider_position_to_value twice.
PyDMWritableWidget.value_changed(self, new_val)
if hasattr(self, "value_label"):
logger.debug("Setting text for value label.")
self.value_label.setText(self.format_string.format(self.value))
# isSliderDown code is probably deprecable, if you want use it
# PyDMWritableWidget.value_changed(self, new_val) should be moved inside
if not self._slider.isSliderDown():
self.set_slider_to_closest_value(self.value)
self.update_format_string()
def check_if_value_in_map(self, val):
if self._slider_position_to_value_map is not None:
arg_diff = self.find_closest_slider_position_to_value(val)
smallest_diff = self._slider_position_to_value_map[arg_diff] - float(val)
if smallest_diff != 0.0:
self.remap_flag = True
[docs] def ctrl_limit_changed(self, which, new_limit):
"""
Callback invoked when the Channel receives new control limit
values.
Parameters
----------
which : str
Which control limit was changed. "UPPER" or "LOWER"
new_limit : float
New value for the control limit
"""
logger.debug("%s limit changed to %f", which, new_limit)
PyDMWritableWidget.ctrl_limit_changed(self, which, new_limit)
if not self.userDefinedLimits:
self.reset_slider_limits()
[docs] def set_enable_state(self):
"""
Determines Whether or not the widget must be enabled or not depending
on the write access, connection state and presence of limits information
"""
# Even though by documentation disabling parent QFrame (self), should disable internal
# slider, in practice it still remains interactive (PyQt 5.12.1). Disabling explicitly, solves
# the problem.
should_enable = self._write_access and self._connected and not self._needs_limit_info
self.setEnabled(should_enable)
self._slider.setEnabled(should_enable)
@Slot(int)
def internal_slider_action_triggered(self, action):
self.actionTriggered.emit(action)
[docs] @Slot(int)
def internal_slider_moved(self, val):
"""
Method invoked when the slider is moved.
Parameters
----------
val : float
"""
self.sliderMoved.emit(self.value)
[docs] @Slot()
def internal_slider_pressed(self):
"""
Method invoked when the slider is pressed
"""
self.sliderPressed.emit()
[docs] @Slot()
def internal_slider_released(self):
"""
Method invoked when the slider is released
"""
self.sliderReleased.emit()
[docs] @Slot(int)
def internal_slider_value_changed(self, val):
"""
Method invoked when a new value is selected on the slider.
This will cause the new value to be emitted to the signal
unless `mute_internal_slider_changes` is True.
Parameters
----------
val : int
"""
# Avoid potential crash if limits are undefined
if self._slider_position_to_value_map is None:
return
if not self._mute_internal_slider_changes:
try:
self.value = self._slider_position_to_value_map[val]
self.send_value_signal[float].emit(self.value)
except IndexError:
pass
@Property(bool)
def tracking(self):
"""
If tracking is enabled (the default), the slider emits new values
while the slider is being dragged. If tracking is disabled, it will
only emit new values when the user releases the slider. Tracking can
cause PyDM to rapidly send new values to the channel. If you are using
the slider to control physical hardware, consider whether the device
you want to control can handle large amounts of changes in a short
timespan.
"""
return self._slider.hasTracking()
@tracking.setter
def tracking(self, checked):
self._slider.setTracking(checked)
[docs] def hasTracking(self):
"""
An alternative function to get the tracking property, to match what
Qt provides for QSlider.
"""
return self.tracking
[docs] def setTracking(self, checked):
"""
An alternative function to set the tracking property, to match what
Qt provides for QSlider.
"""
self.tracking = checked
@Property(bool)
def ignoreMouseWheel(self):
"""
If true, the mouse wheel will not change the value of the slider.
This is useful if you want to put sliders inside a scroll view, and
don't want to accidentally change the slider as you are scrolling.
"""
return self._ignore_mouse_wheel
@ignoreMouseWheel.setter
def ignoreMouseWheel(self, checked):
self._ignore_mouse_wheel = checked
if checked:
self._slider.wheelEvent = self.wheelEvent
else:
self._slider.wheelEvent = self._orig_wheel_event
@Property(bool)
def showLimitLabels(self):
"""
Whether or not the high and low limits should be displayed on the slider.
Returns
-------
bool
"""
return self._show_limit_labels
@showLimitLabels.setter
def showLimitLabels(self, checked):
"""
Whether or not the high and low limits should be displayed on the slider.
Parameters
----------
checked : bool
"""
self._show_limit_labels = checked
if checked:
self.low_lim_label.show()
self.high_lim_label.show()
else:
self.low_lim_label.hide()
self.high_lim_label.hide()
@Property(bool)
def showValueLabel(self):
"""
Whether or not the current value should be displayed on the slider.
Returns
-------
bool
"""
return self._show_value_label
@showValueLabel.setter
def showValueLabel(self, checked):
"""
Whether or not the current value should be displayed on the slider.
Parameters
----------
checked : bool
"""
self._show_value_label = checked
if checked:
self.value_label.show()
else:
self.value_label.hide()
@Property(QSlider.TickPosition)
def tickPosition(self):
"""
Where to draw tick marks for the slider.
Returns
-------
QSlider.TickPosition
"""
return self._slider.tickPosition()
@tickPosition.setter
def tickPosition(self, position):
"""
Where to draw tick marks for the slider.
Parameter
---------
position : QSlider.TickPosition
"""
self._slider.setTickPosition(position)
@Property(bool)
def userDefinedLimits(self):
"""
Whether or not to use limits defined by the user and not from the
channel
Returns
-------
bool
"""
return self._user_defined_limits
@userDefinedLimits.setter
def userDefinedLimits(self, user_defined_limits):
"""
Whether or not to use limits defined by the user and not from the
channel
Parameters
----------
user_defined_limits : bool
"""
self._user_defined_limits = user_defined_limits
self.reset_slider_limits()
@Property(float)
def userMinimum(self):
"""
Lower user defined limit value
Returns
-------
float
"""
return self._user_minimum
@userMinimum.setter
def userMinimum(self, new_min):
"""
Lower user defined limit value
Parameters
----------
new_min : float
"""
self._user_minimum = float(new_min) if new_min is not None else None
if self.userDefinedLimits:
self.reset_slider_limits()
@Property(float)
def userMaximum(self):
"""
Upper user defined limit value
Returns
-------
float
"""
return self._user_maximum
@userMaximum.setter
def userMaximum(self, new_max):
"""
Upper user defined limit value
Parameters
----------
new_max : float
"""
self._user_maximum = float(new_max) if new_max is not None else None
if self.userDefinedLimits:
self.reset_slider_limits()
@property
def minimum(self):
"""
The current value being used for the lower limit
Returns
-------
float
"""
if self.userDefinedLimits:
return self._user_minimum
return self._lower_ctrl_limit
@property
def maximum(self):
"""
The current value being used for the upper limit
Returns
-------
float
"""
if self.userDefinedLimits:
return self._user_maximum
return self._upper_ctrl_limit
@Property(int)
def num_steps(self):
"""
The number of steps on the slider
Returns
-------
int
"""
return self._num_steps
@num_steps.setter
def num_steps(self, new_steps):
"""
The number of steps on the slider
Parameters
----------
new_steps : int
"""
self._num_steps = int(new_steps)
self.reset_slider_limits()
@Property(float)
def step_size(self):
"""
The number of steps on the slider
Returns
-------
int
"""
return self._step_size
@step_size.setter
def step_size(self, new_step_size):
"""
The number of steps on the slider
Parameters
----------
new_step_size : float
"""
if self.maximum is None or self.minimum is None or new_step_size <= 0:
return False
self._step_size = float(new_step_size)
self._parameters_menu_flag = True
self.num_steps = (self.maximum - self.minimum) / self._step_size
if self.num_steps == 0:
raise ValueError("Num steps is set to zero")
return True
[docs] @Slot(str)
@Slot(float)
def step_size_changed(self, new_val):
"""
PyQT Slot for changes on the Value of the Channel
This slot sends the value to the step_size setter.
Parameters
----------
new_val : int, float
"""
try:
self.step_size = float(new_val)
except ValueError:
logger.debug("cannot cast PV value as float")
@Property(str)
def step_size_channel(self):
"""
String to connect to pydm channel after initialization
"""
return self._step_size_channel
@step_size_channel.setter
def step_size_channel(self, step_size_channel):
self._step_size_channel = step_size_channel
@property
def value(self):
"""
Channel readback value used to determine slider position
and generate a slider positions to value map
"""
return self._value
@value.setter
def value(self, new_value):
self._value = new_value
if self.remap_flag:
self._slider_position_to_value_map = self.create_slider_positions_to_value_map()