TaurusBaseComponent

Inheritance diagram of TaurusBaseComponent
class TaurusBaseComponent(name, parent=None, designMode=False)[source]

Bases: taurus.core.tauruslistener.TaurusListener, taurus.qt.qtcore.configuration.configuration.BaseConfigurableClass

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.

FORMAT = None
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 <TaurusOperation> or None) – list of operations to apply. If None is given (default) the component fetches the pending operations
contextMenuEvent(event)[source]

Handle the popup menu event

Parameters:event – the popup menu event
defaultFormatDict = {<class 'pint.quantity.Quantity'>: '{:~.{bc.modelObj.precision}f}', <type 'float'>: '{:.{bc.modelObj.precision}f}', <enum 'Enum'>: '{0.name}'}
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
Return type:str
Returns:a string representing the given value
eventReceived(evt_src, evt_type, evt_value)[source]

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

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 (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 (TaurusEventType) – type of event
  • evt_value (object) – event value
findModelClass()[source]

Do a “best effort” to determine which model type corresponds to the given model name.

Return type:class TaurusModel or None
Returns:The class object corresponding to the type of Taurus model this widget handles or None if no valid class is found.
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 (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

Return type:str or None
Returns:the apply danger message
getDisplayValue(cache=True, fragmentName=None)[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.
Return type:

str

Returns:

a string representation of the model value.

getEventBufferPeriod()[source]

Returns the event buffer period

Return type:float
Returns:period (in s). 0 means event buffering is disabled.
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)
Return type:sequence <callable>
Returns:the event filters
getForceDangerousOperations()[source]

Returns if apply dangerous operations is forced

Return type:bool
Returns:wheter or not apply dangerous operations is forced
getFormat()[source]

Method to get the FORMAT attribute for this instance.

Return type:str
Returns:a string of the current format. It could be a python format string or a callable string representation.
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.
Return type:str
Returns:a tooltip
getFullModelName()[source]

Returns the full name of the current model object.

Return type:str
Returns:the model name
getModel()[source]

Returns the model name for this component.

Return type:str
Returns:the model name.
getModelClass()[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.

Return type:class TaurusModel or None
Returns:The class object corresponding to the type of Taurus model this widget handles or None if no valid class is found.
getModelFragmentObj(fragmentName=None)[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.
Return type:obj
Returns:the member of the modelObj referred by the fragment.
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.

Override when needed.

getModelName()[source]

Returns the current model name.

Return type:str
Returns:the model name
getModelObj()[source]

Returns the taurus model obj associated with this component or None if no taurus model is associated.

Return type:TaurusModel or None
Returns:the taurus model object
getModelType()[source]

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

Return type:TaurusElementType
Returns:the taurus model type
getModelValueObj(cache=True)[source]

Returns the tango obj value associated with this component 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.
Return type:TaurusAttrValue
Returns:the tango value object.
getNoneValue()[source]

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

Return type:str
Returns:a string representation for an invalid value
getParentModelName()[source]

Returns the parent model name or an empty string if the component has no parent

Return type:str
Returns:the parent model name
getParentModelObj()[source]

Returns the parent model object or None if the component has no parent or if the parent’s model is None

Return type:TaurusModel or None
Returns:the parent taurus model object
getParentTaurusComponent()[source]

Returns a parent Taurus component or None if no parent taurus.qt.qtgui.base.TaurusBaseComponent is found.

Raise:RuntimeError
getPendingOperations()[source]

Returns the sequence of pending operations

Return type:sequence <TaurusOperation>
Returns:a list of pending operations
getShowQuality()[source]

Returns if showing the quality as a background color

Return type:bool
Returns:True if showing the quality or False otherwise
getShowText()[source]

Returns if showing the display value

Return type:bool
Returns:True if showing the display value or False otherwise
getSignaller(*args, **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’.
Return type:TaurusFactory
Returns:the 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()
Return type:TaurusManager
Returns:the TaurusManager
getTaurusPopupMenu()[source]

Returns an xml string representing the current taurus popup menu

Return type:str
Returns:an xml string representing the current taurus popup menu
getUseParentModel()[source]

Returns whether this component is using the parent model

Return type:bool
Returns:True if using parent model or False otherwise
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 (TaurusEventType or None) – type of event
  • evt_value (object or None) – event value
hasPendingOperations()[source]

Returns if the component has pending operations

Return type:bool
Returns:True if there are pending operations or False otherwise
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()[source]

Determines if this component is attached to the taurus model.

Return type:bool
Returns:True if the component is attached or False otherwise.
isAutoProtectOperation()[source]

Tells if this widget’s operations are protected against exceptions

Return type:bool
Returns:True if operations are protected against exceptions or False otherwise
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
Return type:bool
Returns:True if this component value can be changed by the user or False otherwise
isDangerous()[source]

Returns if the apply operation for this component is dangerous

Return type:bool
Returns:wheter or not the apply operation for this component is dangerous
isModifiableByUser()[source]

whether the user can change the contents of the widget

Return type:bool
Returns:True if the user is allowed to modify the look&feel
isPaused()[source]

Return the current pause state

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

Return type:bool
Returns:whether or not this component is read-only
postAttach()[source]

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

Override when necessary.

postDetach()[source]

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

Override when necessary.

preAttach()[source]

Called inside self.attach() before actual attach is performed. Default implementation just emits a signal.

Override when necessary.

preDetach()[source]

Called inside self.detach() before actual deattach is performed. Default implementation just disconnects a signal.

Override when necessary.

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()[source]

Sets the model name to the empty string

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()[source]

Resets the taurus popup menu to empty

resetUseParentModel()[source]

Resets the usage of parent model to False

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())

See also: insertEventFilter

setForceDangerousOperations(yesno)[source]

Forces/clears the dangerous operations

Parameters:yesno (bool) – force or not the dangerous operations
setFormat(format)[source]

Method to set the FORMAT attribute for this instance. It also resets the internal format string, which will be recalculated in the next call to displayValue()

Parameters:format (str or callable) – A format string or a formatter callable (or the callable name in “full.module.callable” format)
setModel(model)[source]

Sets/unsets the model name for this component

Parameters:model (str) – the new model name
setModelCheck(model, check=True)[source]

Sets the component taurus model. Setting the check argument to True (default) will check if the current model is equal to the given argument. If so then nothing is done. This should be the standard way to call this method since it will avoid recursion.

Parameters:
  • model (str) – the new model name
  • check (bool) – whether or not to check against the actual model name
setModelInConfig(yesno)[source]

Sets whether the model-related properties should be stored for this widget when creating the config dict with createConfig() (and restored when calling applyConfig()). By default this is not enabled. The following properties are affected by this: - “model”

Parameters:yesno (bool) – If True, the model-related properties will be registered as config properties. If False, they will be unregistered.

See also

registerConfigProperty(), createConfig(), applyConfig()

setModelName(modelName, parent=None)[source]

This method will detach from the previous taurus model (if any), it will set the new model to the given modelName and it will attach this component to the new taurus model.

Parameters:
  • modelName (str) – the new taurus model name (according to the taurus convention)
  • parent (TaurusBaseComponent) – the parent or None (default) if this component does not have a parent Taurus component
setModifiableByUser(modifiable)[source]

sets whether the user is allowed to modify the look&feel

Parameters:modifiable (bool) –
setNoneValue(v)[source]

Sets the new string representation when no model or no model value exists.

Parameters:v (str) – the string representation for an invalid value
setPaused(paused=True)[source]

Toggles the pause mode.

Parameters:paused (bool) – whether or not to pause (default = True)
setShowQuality(showQuality)[source]

Sets/unsets the show quality property

Parameters:showQuality (bool) – whether or not to show the quality
setShowText(showText)[source]

Sets/unsets showing the display value of the model

Parameters:showText (bool) – whether or not to show the display value
setTaurusPopupMenu(menuData)[source]

Sets/unsets the taurus popup menu

Parameters:menuData (str) – an xml representing the popup menu
setUseParentModel(yesno)[source]

Sets/unsets using the parent model

Parameters:yesno (bool) – whether or not to use parent model
taurusEvent

Base signal taurusEvent

toolTipObjToStr(toolTipObj)[source]

Converts a python dict to a tooltip string.

Parameters:toolTipObj (dict) – a python object
Return type:str
Returns:a tooltip
updateStyle()[source]

Method called when the component detects an event that triggers a change in the style. Default implementation doesn’t do anything. Overwrite when necessary