Source code for pydm.widgets.slider

import logging
import numpy as np
from decimal import Decimal
from qtpy.QtCore import Qt, Signal, Slot, Property
from qtpy.QtWidgets import (
from pydm.widgets import PyDMLabel
from .base import PyDMWritableWidget, TextFormatter, is_channel_valid
from .channel import PyDMChannel

logger = logging.getLogger(__name__)

[docs]class PyDMSlider(QFrame, TextFormatter, PyDMWritableWidget): """ 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) 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 # 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 = QSlider(parent=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) # self.vertical_layout.addWidget(self._slider) # 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
[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 slider_parameters_menu(self, position_of_click): """ Method that builds a menu to modify a set of Slider Parameters: 1) value 2) new step size (float or channel) and scale factor for step size 3) precision or if precision is defined from a channel 4) format of numbers on slider (min, max, value) - float or exp """ self.slider_parameters_menu_widget = QWidget() self.slider_parameters_menu_widget.move(self._slider.parentWidget().mapToGlobal(position_of_click)) self.slider_parameters_menu_widget.setWindowTitle("PyDM Slider Parameters") self.slider_parameters_menu_widget.resize(300, 200) main_layout = QVBoxLayout(self.slider_parameters_menu_widget) self.slider_parameters_menu_input_widgets = [] self.slider_parameters_menu_labels = [] self.slider_parameters_menu_buttons = [] self.menu_layout = [] text_info = [ "Value", "Increment", "Increment scale", "Precision", "Precision from PV", "Number Format", "OK", "Apply", "Cancel", ] combo_box_table_scale = ["1e0", "1e1", "1e2", "1e3", "1e4", "1e5"] combo_box_table_format = ["Float", "Exp"] for key in range(0, 6): self.slider_parameters_menu_input_widgets.append(key) self.slider_parameters_menu_labels.append(key) self.menu_layout.append(key) self.menu_layout[key] = QHBoxLayout() self.menu_layout[key].setAlignment(Qt.AlignLeft) self.slider_parameters_menu_labels[key] = PyDMLabel(self.slider_parameters_menu_widget) self.slider_parameters_menu_labels[key].setText(text_info[key]) self.menu_layout[key].addWidget(self.slider_parameters_menu_labels[key]) if key == 4: self.slider_parameters_menu_input_widgets[key] = QCheckBox() self.slider_parameters_menu_input_widgets[key].setTristate(on=False) self.slider_parameters_menu_input_widgets[key].setChecked(self.precisionFromPV) elif key == 2 or key == 5: self.slider_parameters_menu_input_widgets[key] = QComboBox() else: self.slider_parameters_menu_input_widgets[key] = QLineEdit() self.slider_parameters_menu_input_widgets[key].setText("") self.menu_layout[key].addWidget(self.slider_parameters_menu_input_widgets[key]) main_layout.addLayout(self.menu_layout[key]) self.menu_layout.append(3) self.menu_layout[3] = QHBoxLayout() self.slider_parameters_menu_input_widgets[0].setText(str(self.value)) self.slider_parameters_menu_input_widgets[1].setText(str(self._step_size)) self.slider_parameters_menu_input_widgets[3].setText(str(self.precision)) self.slider_parameters_menu_input_widgets[2].addItems(combo_box_table_scale) self.slider_parameters_menu_input_widgets[5].addItems(combo_box_table_format) for key in range(0, 3): self.slider_parameters_menu_buttons.append(key) self.slider_parameters_menu_buttons[key] = QPushButton(self.slider_parameters_menu_widget) self.slider_parameters_menu_buttons[key].setText(text_info[key + 6]) self.menu_layout[3].addWidget(self.slider_parameters_menu_buttons[key]) main_layout.addLayout(self.menu_layout[3]) self.slider_parameters_menu_buttons[0].clicked.connect(self.apply_and_close_menu) self.slider_parameters_menu_buttons[1].clicked.connect(self.apply_step_size_menu_changes) self.slider_parameters_menu_buttons[2].clicked.connect(self.slider_parameters_menu_widget.close)
[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 apply_step_size_menu_changes(self): """ Method which attempts to set the user imputed data from the slider parameters menu. """ try: new_step_size = float(self.slider_parameters_menu_input_widgets[1].text()) new_step_size_scaled = new_step_size * float(self.slider_parameters_menu_input_widgets[2].currentText()) if new_step_size_scaled > 0: self.step_size = new_step_size_scaled if self.step_size_channel is not None: self.step_size_channel.disconnect() self.step_size_channel = None else: logger.error("step input is incorrect or 0") except ValueError: if is_channel_valid(self.slider_parameters_menu_input_widgets[1].text()): address = self.slider_parameters_menu_input_widgets[1].text() self.step_size_channel = PyDMChannel(address=address, value_slot=self.step_size_changed) self.step_size_channel.connect() else: logger.error("step input is incorrect") precision_source = self.slider_parameters_menu_input_widgets[4].isChecked() self.precisionFromPV = precision_source try: user_inputted_precision = float(self.slider_parameters_menu_input_widgets[3].text()) self.precision = user_inputted_precision except ValueError: logger.error("precision input is incorrect") try: slider_value = float(self.slider_parameters_menu_input_widgets[0].text()) if slider_value < self.minimum or slider_value > self.maximum: raise ValueError if slider_value != self.value: self.value_changed(slider_value) self.send_value_signal[float].emit(self.value) except ValueError: logger.error("the given value is not a valid type or outside of the slider range") format_type = self.slider_parameters_menu_input_widgets[5].currentText() if format_type == "Float": self.update_labels() else: self.update_labels(True)
[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 setup_widgets_for_orientation(self, new_orientation): """ Reconstruct the widget given the orientation. Parameters ---------- new_orientation : int Qt.Horizontal or Qt.Vertical """ if new_orientation not in (Qt.Horizontal, Qt.Vertical): logger.error("Invalid orientation '{0}'. The existing layout will not change.".format(new_orientation)) return layout = None if new_orientation == Qt.Horizontal: layout = QVBoxLayout() layout.setContentsMargins(4, 0, 4, 4) label_layout = QHBoxLayout() label_layout.addWidget(self.low_lim_label) label_layout.addStretch(0) label_layout.addWidget(self.value_label) label_layout.addStretch(0) label_layout.addWidget(self.high_lim_label) layout.addLayout(label_layout) self._slider.setOrientation(new_orientation) layout.addWidget(self._slider) elif new_orientation == Qt.Vertical: layout = QHBoxLayout() layout.setContentsMargins(0, 4, 4, 4) label_layout = QVBoxLayout() label_layout.addWidget(self.high_lim_label) label_layout.addStretch(0) label_layout.addWidget(self.value_label) label_layout.addStretch(0) label_layout.addWidget(self.low_lim_label) layout.addLayout(label_layout) self._slider.setOrientation(new_orientation) layout.addWidget(self._slider) if self.layout() is not None: # Trick to remove the existing layout by re-parenting it in an empty widget. QWidget().setLayout(self.layout()) self.setLayout(layout)
[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 = np.array(self.float_range()) if self._slider_position_to_value_map[-1] > self.maximum: self._slider_position_to_value_map[-1] = self.maximum self._parameters_menu_flag = False else: self._slider_position_to_value_map = np.linspace(self.minimum, self.maximum, num=self._num_steps) self.update_labels() self.rangeChanged.emit(self.minimum, self.maximum) self.set_slider_to_closest_value(self.value) self._slider.setMinimum(0) self._slider.setMaximum(self._num_steps - 1) self._slider.setSingleStep(1) self._slider.setPageStep(10) self.set_enable_state()
[docs] def float_range(self): """ Creates a range of numbers from the min, max and given step size. Returns ------- new_indexes : list of floats """ scale = 10 ** (len(str(self.step_size)) - str(self.step_size).find(".") - 1) new_indexes_scaled = list( range(int(self.minimum * scale), int((self.maximum + self.step_size) * scale), int(self.step_size * scale)) ) new_indexes = [(index / scale) for index in new_indexes_scaled] return new_indexes
[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 ---------- val : float 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. """ 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)) if not self._slider.isSliderDown(): self.set_slider_to_closest_value(self.value) self.update_format_string()
[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 update_format_string(self): """ Reconstruct the format string to be used when representing the output value. Returns ------- format_string : str The format string to be used including or not the precision and unit """ fs = super(PyDMSlider, self).update_format_string() self.update_labels() return fs
[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: 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: 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(int) 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 + 1) + 1 return True
[docs] @Slot(int) @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 """ if new_val > 0: self.step_size = new_val