`TaurusBaseComponent`

class TaurusBaseComponent(name='', parent=None, designMode=False, **kwargs)[source]

A generic Taurus component.

Note

Any class which inherits from TaurusBaseComponent is expected to also inherit from QObject (or from a QObject derived class).

Note

getSignaller() is now unused and deprecated. This is because taurusEvent is implemented using baseSignal(), that doesn’t require the class to inherit from QObject.

Import from taurus.qt.qtgui.base as:

from taurus.qt.qtgui.base import TaurusBaseComponent

FORMAT = None

MLIST = 0: MLIST is a constant that can be passed as the value of the key kwarg in the multi-model API to indicate that the class should act as a model-container regarding to this key (e.g. TaurusBaseComponent.setModel(m, key=MLIST) will treat m as a list of models.

applyPendingOperations(ops=None)[source]

Applies operations without caring about danger messages. Use TaurusBaseWidget.safeApplyOperation() if you want to warn the user before applying

Parameters:: ops (sequence<taurus.core.taurusoperation.TaurusOperation> or None) – list of operations to apply. If None is given (default) the component fetches the pending operations

contextMenuEvent(event)[source]

DEPRECATED: Until v4.5.3a, the default implementation of contextMenuEvent showed the content of taurusMenu as a context menu. But this resulted in unwanted behaviour when the widget already implemented its own context menu (see https://gitlab.com/taurus-org/taurus/-/issues/905 )

Therefore this feature was disabled in 4.5.3a.

If you still want to show the contents of taurusMenu as a context menu, you can explicitly reimplement the contextMenuEvent method as:

def contextMenuEvent(self, event):
    self.taurusMenu.exec_(event.globalPos())

defaultFormatDict = {<class 'float'>: '{:.{bc.modelObj.precision}f}', <enum 'Enum'>: '{0.name}', <class 'pint.Quantity'>: '{:~.{bc.modelObj.precision}f}'}

deleteLater()[source]: Reimplements the Qt.QObject deleteLater method to ensure that the this object stops listening its model.

displayValue(v)[source]

Returns a string representation of the given value

This method will use a format string which is determined dynamically from FORMAT.

By default TaurusBaseComponent.FORMAT is set to defaultFormatter(), which makes use of defaultFormatDict.

In order to customize the formatting behaviour, one can use setFormat() to alter the formatter of an specific instance (recommended) or change defaultFormatDict or FORMAT directly at class level.

The formatter can be set to a python format string [1] or a callable that returns a python format string. If a callable is used, it will be called with the following keyword arguments:

dtype: the data type of the value to be formatted
basecomponent: the affected widget

The following are some examples for customizing the formatting:

- Change the format for widget instance `foo`::

foo.setFormat(“{:.2e}”)

Change FORMAT for all widgets (using a string):
```
TaurusBaseComponent.FORMAT = "{:.2e}"
```

Change FORMAT for all TaurusLabels (using a callable):

def baseFormatter(dtype=None, basecomponent=None, **kwargs):
    return "{:.1f}"

TaurusLabel.FORMAT = baseFormatter

Use the defaultFormatDict but modify the format string for dtype=str:
```
TaurusLabel.defaultFormatDict.update({"str": "{!r}"})
```

See also

tauruscustomsettings.DEFAULT_FORMATTER, –default-formatter option in TaurusApplication, TaurusBaseWidget.onSetFormatter()

[1] https://docs.python.org/2/library/string.html

Parameters:: v (object) – the value to be translated to string
Returns:: a string representing the given value
Return type:: str

eventReceived(evt_src, evt_type, evt_value)[source]

The basic implementation of the event handling chain is as follows:

eventReceived just calls fireEvent() which emits a “taurusEvent” PyQt signal that is connected (by preAttach()) to the filterEvent() method.

After filtering, handleEvent() is invoked with the resulting filtered event

Note

in the earlier steps of the chain (i.e., in eventReceived()/ fireEvent()), the code is executed in a Python thread, while from eventFilter ahead, the code is executed in a Qt thread. When writing widgets, one should normally work on the Qt thread (i.e. reimplementing handleEvent())

Parameters:

evt_src (object) – object that triggered the event
evt_type (taurus.core.taurusbasetypes.TaurusEventType) – type of event
evt_value (object) – event value

filterEvent(evt_src=-1, evt_type=-1, evt_value=-1)[source]

The event is processed by each and all filters in strict order unless one of them returns None (in which case the event is discarded)

Parameters:

evt_src (object) – object that triggered the event
evt_type (taurus.core.taurusbasetypes.TaurusEventType) – type of event
evt_value (object) – event value

findModelClass(**kwargs): Deprecated since version 5.1.0: Use getModelClass instead

fireBufferedEvents()[source]

Fire all events currently buffered (and flush the buffer)

Note: this method is normally called from an event buffer timer thread: but it can also be called any time the buffer needs to be flushed

fireEvent(evt_src=None, evt_type=None, evt_value=None)[source]

Emits a “taurusEvent” signal. It is unlikely that you need to reimplement this method in subclasses. Consider reimplementing eventReceived() or handleEvent() instead depending on whether you need to execute code in the python or Qt threads, respectively

Parameters:

evt_src (object or None) – object that triggered the event
evt_type (taurus.core.taurusbasetypes.TaurusEventType or None) – type of event
evt_value (object or None) – event value

getDangerMessage()[source]

Returns the current apply danger message or None if the apply operation is safe

Returns:: the apply danger message
Return type:: str or None

getDisplayValue(cache=True, fragmentName=None, *, key=<class 'taurus.qt.qtgui.base.taurusbase._DEFAULT'>)[source]

Returns a string representation of the model value associated with this component.

Parameters:

cache (bool) – (ignored, just for bck-compat).
fragmentName (str or None) – the returned value will correspond to the given fragmentName. If None passed, self.modelFragmentName will be used, and if None is set, the defaultFragmentName of the model will be used instead.
key (object) – the model key. Defaults to first element of .modelKeys

Returns:

a string representation of the model value.

Return type:

str

getEventBufferPeriod()[source]

Returns the event buffer period

Returns:: period (in s). 0 means event buffering is disabled.
Return type:: float

getEventFilters(preqt=False)[source]

Returns the list of event filters for this widget

Parameters:: preqt (bool) – If true, return the pre-filters (that are applied in eventReceived, at the python thread), otherwise, return the filters to be applied at the main Qt thread (default)
Returns:: the event filters
Return type:: sequence<callable>

getForceDangerousOperations()[source]

Returns if apply dangerous operations is forced

Returns:: wheter or not apply dangerous operations is forced
Return type:: bool

getFormat()[source]

Method to get the FORMAT attribute for this instance.

Returns:: a string of the current format. It could be a python format string or a callable string representation.
Return type:: str

getFormatedToolTip(cache=True)[source]

Returns a string with contents to be displayed in a tooltip.

Parameters:: cache (bool) – if set to True (default) use the cache value. If set to False will force a connection to the server.
Returns:: a tooltip
Return type:: str

getFullModelName(*, key=<class 'taurus.qt.qtgui.base.taurusbase._DEFAULT'>)[source]

Returns the full name of the model object for the given key.

Parameters:: key (object) – the model key. Defaults to first element of .modelKeys
Returns:: the model name
Return type:: str

getModel(*, key=<class 'taurus.qt.qtgui.base.taurusbase._DEFAULT'>)[source]

Returns the model name for this component.

Parameters:: key (object) – the model key. Defaults to first element of .modelKeys
Returns:: the model name.
Return type:: str

getModelClass(*, key=<class 'taurus.qt.qtgui.base.taurusbase._DEFAULT'>)[source]

Return the class object for the widget. Default behavior is to do a ‘best effort’ to determine which model type corresponds to the current model name. Overwrite as necessary.

Parameters:: key (object) – the model key. Defaults to first element of .modelKeys
Returns:: The class object corresponding to the type of Taurus model this widget handles or None if no valid class is found.
Return type:: class TaurusModel or None

getModelFragmentObj(fragmentName=None, *, key=<class 'taurus.qt.qtgui.base.taurusbase._DEFAULT'>)[source]

Returns a fragment object of the model. A fragment of a model is a python attribute of the model object.

Fragment names including dots will be used to recursively get fragments of fragments.

For a simple fragmentName (no dots), this is roughly equivalent to getattr(self.getModelObj(), fragmentName)

If the model does not have that fragment, AttributeError is raised (other exceptions may be raised when accessing the fragment as well)

Parameters:

fragmentName (str or None) – the returned value will correspond to the given fragmentName. If None passed, self.modelFragmentName will be used, and if None is set, the defaultFragmentName of the model will be used instead.
key (object) – the model key. Defaults to first element of .modelKeys

Returns:

the member of the modelObj referred by the fragment.

Return type:

obj

getModelInConfig()[source]

getModelIndexValue()[source]

Called inside getDisplayValue to use with spectrum attributes. By default not used, but some widget might want to support this feature.

Note

getModelIndexValue() is only supported for the default model key

Override when needed.

getModelName(*, key=<class 'taurus.qt.qtgui.base.taurusbase._DEFAULT'>)[source]

Returns the current model name.

Parameters:: key (object) – the model key. Defaults to first element of .modelKeys
Returns:: the model name
Return type:: str

getModelNames()[source]

Returns a dict of key:modelname

Returns:: dictionary mapping keys to model names
Return type:: dict

getModelObj(*, key=<class 'taurus.qt.qtgui.base.taurusbase._DEFAULT'>)[source]

Returns the taurus model object associated to the given key or None if no taurus model is associated.

Parameters:: key (object) – the model key. Defaults to first element of .modelKeys
Returns:: the taurus model object
Return type:: taurus.core.taurusmodel.TaurusModel or None

getModelType(*, key=<class 'taurus.qt.qtgui.base.taurusbase._DEFAULT'>)[source]

Returns the taurus model type associated with this key or taurus.core.taurusbasetypes.TaurusElementType.Unknown if no taurus model is associated.

Parameters:: key (object) – the model key. Defaults to first element of .modelKeys
Returns:: the taurus model type
Return type:: taurus.core.taurusbasetypes.TaurusElementType

getModelValueObj(cache=True, *, key=<class 'taurus.qt.qtgui.base.taurusbase._DEFAULT'>)[source]

Returns the current value of the taurus model associated with this key or None if no taurus model is associated.

Parameters:

cache (bool) – if set to True (default) use the cache value. If set to False will force a connection to the server.
key (object) – the model key. Defaults to first element of .modelKeys

Returns:

the tango value object.

Return type:

TaurusAttrValue

getNoneValue()[source]

Returns the current string representation when no valid model or model value exists.

Returns:: a string representation for an invalid value
Return type:: str

getParentModelName(**kwargs): Deprecated since version 4.3.2.

getParentModelObj(**kwargs): Deprecated since version 4.3.2.

getParentTaurusComponent(**kwargs): Deprecated since version 4.3.2.

getPendingOperations()[source]

Returns the sequence of pending operations

Returns:: a list of pending operations
Return type:: sequence<taurus.core.taurusoperation.TaurusOperation>

getShowQuality()[source]

Returns if showing the quality as a background color

Returns:: True if showing the quality or False otherwise
Return type:: bool

getShowText()[source]

Returns if showing the display value

Returns:: True if showing the display value or False otherwise
Return type:: bool

getSignaller(**kwargs): Deprecated since version 4.0.

getTaurusFactory(scheme='')[source]

Returns the taurus factory singleton for the given scheme. This is just a helper method. It is the equivalent of doing:

import taurus
factory = taurus.Factory(scheme)

Parameters:: scheme (str or None) – the scheme. If scheme is an empty string, or is not passed, the scheme will be obtained from the model name. For backwards compatibility (but deprecated), passing None is equivalent to ‘tango’.
Returns:: the TaurusFactory
Return type:: taurus.core.taurusfactory.TaurusFactory

getTaurusManager()[source]

Returns the taurus manager singleton. This is just a helper method. It is the equivalent of doing:

import taurus
manager = taurus.Manager()

Returns:: the TaurusManager
Return type:: taurus.core.taurusmanager.TaurusManager

getTaurusPopupMenu(**kwargs)

Returns an xml string representing the current taurus popup menu

return:

an xml string representing the current taurus popup menu

rtype:

str

Deprecated since version 4.5.3a.

getUseParentModel(**kwargs): Deprecated since version 4.3.2.

static get_registered_formatters()[source]: Static method to get the registered formatters :return: dict of registered formatter (keys are the registered names) :rtype: dict

handleEvent(evt_src, evt_type, evt_value)[source]

Event handling. Default implementation does nothing. Reimplement as necessary

Parameters:

evt_src (object or None) – object that triggered the event
evt_type (taurus.core.taurusbasetypes.TaurusEventType or None) – type of event
evt_value (object or None) – event value

hasPendingOperations()[source]

Returns if the component has pending operations

Returns:: True if there are pending operations or False otherwise
Return type:: bool

insertEventFilter(filter, index=-1, preqt=False)[source]

insert a filter in a given position

Parameters:

filter (callable(evt_src, evt_type, evt_value) – ) a filter
index (int) – index to place the filter (default = -1 meaning place at the end)
preqt (bool) – If true, set the pre-filters (that are applied in eventReceived, at the python thread), otherwise, set the filters to be applied at the main Qt thread (default)

See also: setEventFilters

isAttached(*, key=<class 'taurus.qt.qtgui.base.taurusbase._DEFAULT'>)[source]

Determines if this component is attached to the taurus model.

Parameters:: key (object) – the model key. Defaults to first element of .modelKeys
Returns:: True if the component is attached or False otherwise.
Return type:: bool

isAutoProtectOperation()[source]

Tells if this widget’s operations are protected against exceptions

Returns:: True if operations are protected against exceptions or False otherwise
Return type:: bool

isChangeable()[source]

Tells if this component value can be changed by the user. Default implementation will return True if and only if:

this component is attached to a valid taurus model and

the taurus model is writable and

this component is not read-only

Returns:: True if this component value can be changed by the user or False otherwise
Return type:: bool

isDangerous()[source]

Returns if the apply operation for this component is dangerous

Returns:: wheter or not the apply operation for this component is dangerous
Return type:: bool

isModifiableByUser()[source]

whether the user can change the contents of the widget

Returns:: True if the user is allowed to modify the look&feel
Return type:: bool

isPaused()[source]

Return the current pause state

Returns:: wheater or not the widget is paused
Return type:: bool

isReadOnly()[source]

Determines if this component is read-only or not in the sense that the user can interact with it. Default implementation returns True.

Override when necessary.

Returns:: whether or not this component is read-only
Return type:: bool

property modelFragmentName

modelKeys = ['']

property modelName

property modelObj

postAttach(*, key=<class 'taurus.qt.qtgui.base.taurusbase._DEFAULT'>)[source]

Called inside self.attach() after actual attach is performed. Default implementation does not do anything.

Override when necessary.

Parameters:: key (object) – the model key. Defaults to first element of .modelKeys

postDetach(*, key=<class 'taurus.qt.qtgui.base.taurusbase._DEFAULT'>)[source]

Called inside self.detach() after actual deattach is performed. Default implementation does not do anything.

Override when necessary.

Parameters:: key (object) – the model key. Defaults to first element of .modelKeys

preAttach(*, key=<class 'taurus.qt.qtgui.base.taurusbase._DEFAULT'>)[source]

Called inside self.attach() before actual attach is performed. Default implementation does nothing.

Override when necessary.

Parameters:: key (object) – the model key. Defaults to first element of .modelKeys

preDetach(*, key=<class 'taurus.qt.qtgui.base.taurusbase._DEFAULT'>)[source]

Called inside self.detach() before actual deattach is performed. Default implementation does nothing.

Override when necessary.

Parameters:: key (object) – the model key. Defaults to first element of .modelKeys

resetAutoProtectOperation()[source]: Resets protecting operations

resetDangerMessage()[source]: Clears the danger message. After this method is executed the apply operation for this component will be considered safe.

resetForceDangerousOperations()[source]: Clears forcing apply dangerous operations

resetFormat()[source]: Reset the internal format string. It forces a recalculation in the next call to displayValue().

resetModel(*, key=<class 'taurus.qt.qtgui.base.taurusbase._DEFAULT'>)[source]

Sets the model name to the empty string

Parameters:: key (object) – the model key. Defaults to first element of .modelKeys

resetModelInConfig()[source]

resetModifiableByUser()[source]: Equivalent to setModifiableByUser(self.__class__._modifiableByUser)

resetPendingOperations()[source]: Clears the list of pending operations

resetShowQuality()[source]: Resets the show quality to self.__class__._showQuality

resetShowText()[source]: Resets the showing of the display value to True

resetTaurusPopupMenu(**kwargs): Resets the taurus popup menu to empty

Deprecated since version 4.5.3a.

resetUseParentModel(**kwargs): Deprecated since version 4.3.2.

setAutoProtectOperation(protect)[source]

Sets/unsets this widget’s operations are protected against exceptions

Parameters:: protect (bool) – wheater or not to protect widget operations

setDangerMessage(dangerMessage='')[source]

Sets the danger message when applying an operation. If dangerMessage is None, the apply operation is considered safe

Parameters:: dangerMessage (str or None) – the danger message. If None is given (default) the apply operation is considered safe

setEventBufferPeriod(period)[source]

Set the period at wich fireBufferedEvents() will be called. If period is 0, the event buffering is disabled (i.e., events are fired as soon as they are received)

Parameters:: period (float) – period in seconds for the automatic event firing. period=0 will disable the event buffering.

setEventFilters(filters=None, preqt=False)[source]

sets the taurus event filters list. The filters are run in order, using each output to feed the next filter. A filter must be a function that accepts 3 arguments (evt_src, evt_type, evt_value) If the event is to be ignored, the filter must return None. If the event is not to be ignored, filter must return a (evt_src, evt_type, evt_value) tuple which may (or not) differ from the input.

For a library of common filters, see taurus/core/util/eventfilters.py

Parameters:

filters (sequence) – a sequence of filters
preqt (bool) – If true, set the pre-filters (that are applied in eventReceived, at the python thread), otherwise, set the filters to be applied at the main Qt thread (default)

Note: If you are setting a filter that applies a transformation on the parameters, you may want to generate a fake event to force the last value to be filtered as well. This can be done as in this example:

TaurusBaseComponent.fireEvent( TaurusBaseComponent.getModelObj(),
    taurus.core.taurusbasetypes.TaurusEventType.Periodic,
    TaurusBaseComponent.getModelObj().getValueObj())

TaurusBaseComponent

`TaurusBaseComponent`