PyDMWidget

API Documentation

class pydm.widgets.base.PyDMWidget(init_channel=None)

Bases: PyDMPrimitiveWidget

PyDM base class for Read-Only widgets. This class implements all the functions of connection, alarm handling and more.

Parameters:

init_channel (str, optional) – The channel to be used by the widget.

PyDMToolTip

The tooltip for this widget.

Returns:

toolTip – tooltip info

Return type:

str

alarmSensitiveBorder

Whether or not the border color changes when alarm severity changes.

Returns:

True means that the border color will be changed in case of alarm severity changes.

Return type:

bool

alarmSensitiveContent

Whether or not the content color changes when alarm severity changes.

Returns:

True means that the content color will be changed in case of alarm severity changes.

Return type:

bool

alarmSeverityChanged(new_alarm_severity)

PyQT Slot for changes on the Alarm Severity of the Channel This slot sends the severity value to the `alarm_severity_changed` callback.

Parameters:

new_alarm_severity (int) –

alarm_limit_changed(which: AlarmLimit, new_limit: float) → None

Callback invoked when the channel receives new alarm limit values.

Parameters:

• which (AlarmLimit) – Which alarm limit was changed. “HIHI”, “HIGH”, “LOW”, “LOLO”

• new_limit (float) – New value for the alarm limit

alarm_severity_changed(new_alarm_severity)

Callback invoked when the Channel alarm severity is changed. This callback is not processed if the widget has no channel associated with it. This callback handles the composition of the stylesheet to be applied and the call to update to redraw the widget with the needed changes for the new state.

Parameters:

new_alarm_severity (int) – The new severity where 0 = NO_ALARM, 1 = MINOR, 2 = MAJOR and 3 = INVALID

channel

The channel address in use for this widget.

Returns:

channel – Channel address

Return type:

str

channelValueChanged(new_val)

PyQT Slot for changes on the Value of the Channel This slot sends the value to the `value_changed` callback.

Parameters:

new_val (int, float, str, bool or np.ndarray) –

channels()

Returns the channels being used for this Widget.

Returns:

channels – List of PyDMChannel objects

Return type:

list

channels_for_tools()

Returns a list of channels useful for external tools. The default implementation here is just to return self.channels(), but some widgets will want to re-implement this, especially if they have multiple channels, but only one real ‘signal’ channel.

Return type:

list

check_enable_state()

Checks whether or not the widget should be disable. This method also disables the widget and add a Tool Tip with the reason why it is disabled.

connectionStateChanged(connected)

PyQT Slot for changes on the Connection State of the Channel This slot sends the connection state to the `connection_changed` callback.

Parameters:

connected (bool) –

connection_changed(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.

ctrl_limit_changed(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

enumStringsChanged(new_enum_strings)

PyQT Slot for changes on the string values of the Channel This slot sends the new strings to the `enum_strings_changed` callback.

Parameters:

new_enum_strings (tuple) –

enum_strings_changed(new_enum_strings)

Callback invoked when the Channel has new enum values. This callback also triggers a value_changed call so the new enum values to be broadcasted

Parameters:

new_enum_strings (tuple) – The new list of values

eventFilter(obj, event)

Filters events on this object.

Params

objectQObject

The object that is being handled.

eventQEvent

The event that is happening.

returns:

True to stop the event from being handled further; otherwise return false.

rtype:

bool

force_redraw()

PyQT Slot to force a redraw on the widget.

generate_context_menu()

Generates the custom context menu, and populates it with any external tools that have been loaded. PyDMWidget subclasses should override this method (after calling superclass implementation) to add the menu.

Return type:

QMenu

get_ctrl_limits()

Returns a tuple with the control limits for the channel

Returns:

(lower, upper) – Lower and Upper control limits

Return type:

tuple

init_for_designer()

Method called after the constructor to tweak configurations for when using the widget with the Qt Designer

lowerCtrlLimitChanged(new_limit)

PyQT Slot for changes on the lower control limit value of the Channel This slot sends the new limit value to the `ctrl_limit_changed` callback.

Parameters:

new_limit (float) –

lower_alarm_limit_changed(new_limit: float)

PyQT slot for changes to the LOLO alarm limit of a PV

Parameters:

new_limit (float) – The new value for the LOLO limit

lower_warning_limit_changed(new_limit: float)

PyQT slot for changes to the LOW alarm limit of a PV

Parameters:

new_limit (float) – The new value for the LOW limit

open_context_menu(ev)

Handler for when the Default Context Menu is requested.

Parameters:

ev (QEvent) –

parseTip(new_tip)

Fetch the object attribute data for the tooltip.

Parameters:

new_tip (str) – given tooltip string

Returns:

tip_with_attribute_info – ToolTip string which has had the attribute names replaced with the attribute values.

Return type:

str

setX(new_x)

Set the X position of the Widget on the screen.

Parameters:

new_x (int) – The new X position

Return type:

None

setY(new_y)

Set the Y position of the Widget on the screen.

Parameters:

new_y (int) – The new Y position

Return type:

None

set_channel(value)

A setter method without a pyqt decorator so subclasses can use this functionality

timestamp_changed(new_timestamp)

Callback invoked when the Channel has new timestamp values.

Parameters:

new_timestamp (float) – The new timestamp value

upperCtrlLimitChanged(new_limit)

PyQT Slot for changes on the upper control limit value of the Channel This slot sends the new limit value to the `ctrl_limit_changed` callback.

Parameters:

new_limit (float) –

upper_alarm_limit_changed(new_limit: float)

PyQT slot for changes to the HIHI alarm limit of a PV

Parameters:

new_limit (float) – The new value for the HIHI limit

upper_warning_limit_changed(new_limit: float)

PyQT slot for changes to the HIGH alarm limit of a PV

Parameters:

new_limit (float) – The new value for the HIGH limit

value_changed(new_val)

Callback invoked when the Channel value is changed.

Parameters:

new_val (str, int, float, bool or np.ndarray) – The new value from the channel. The type depends on the channel.

widget_ctx_menu()

Fetch the Widget specific context menu which will be populated with additional tools by assemble_tools_menu.

Returns:

If the return of this method is None a new QMenu will be created by assemble_tools_menu.

Return type:

QMenu or None

PyDMToolTip Instructions

The PyDMToolTip property field takes a string. In the PyDMToolTip property field, the user can include the tag $(pv_value) to get the value of the channel displayed on the tool tip.

Note

If the toolTip property field is:

The value of the channel is $(pv_value)

The toolTip would read (assuming the value is 10 in this example):

The value of the channel is 10

A period followed by a field name can retrieve other properties of the channel (see the table below for all channel properties and associated field names.)

Note

If the toolTip property field is:

The timestamp of the channel is $(pv_value.TIME)

The toolTip would read:

The timestamp of the channel is 2022-09-15 09:56:47.099340

channel properties	pv_value.field	Description
channel value	$(pv_value)	Returns the value of the channel
channel address	.address	Returns the address of the channel
connection	.connection	Returns the connection status
alarm severity	.SEVR	Returns the alarm severity
enum string	.enum_strings
engineering unit	.EGU	Returns the engineering unit
precision	.PREC	Returns the precision of the channel
upper ctrl limit	.DRVH	Returns the upper ctrl limit
lower ctrl limit	.DRVL	Returns the lower ctrl limit
upper alarm limit	.HIHI	Returns the upper alarm limit
lower alarm limit	.LOLO	Returns the lower alarm limit
upper warning limit	.HIGH	Returns the upper warning limit
lower warning limit	.LOW	Returns the lower warning limit
timestamp	.TIME	Returns the timestamp of the channel