DataModel

Inheritance diagram of DataModel
class DataModel(parent, dataUID, defaultData=None)[source]

Bases: PyQt4.QtCore.QObject

An object containing one piece of data which is intended to be shared. The data will be identified by its UID (a unique identifier known to objects that intend to access the data)

In general, you are not supposed to instantiate objects of this class directly. Instead, you should interact via the SharedDataManager, which uses SharedDataManager.__getDataModel() to ensure that the DataModels are singletons.

connectReader(slot, readOnConnect=True)[source]

Registers the given slot method to receive notifications whenever the data is changed.

Parameters:
  • slot (callable) – a method that will be called when the data changes. This slot will be the receiver of a signal which has the data as its first argument.
  • readOnConnect (bool) – if True (default) the slot will be called immediately with the current value of the data if the data has been already initialized
connectWriter(writer, signalname)[source]

Registers the given writer object as a writer of the data. The writer is then expected to emit a QtCore.SIGNAL(signalname) with the new data as the first parameter.

Parameters:
  • writer (QObject) – object that will change the data
  • signalname (str) – the signal name that will notify changes of the data
dataChanged
dataUID()[source]

returns the data unique identifier

Return type:str
Returns:
disconnectReader(slot)[source]

unregister a reader

Parameters:slot (callable) – the slot to which this was connected
disconnectWriter(writer, signalname)[source]

unregister a writer from this data model

Parameters:
  • writer (QObject) – object to unregister
  • signalname (str) – the signal that was registered
getData()[source]

Returns the data object.

Return type:object
Returns:the data object
info()[source]
isDataSet()[source]

Whether the data has been set at least once or if it is uninitialized

Return type:bool
Returns:True if the data has been set. False it is uninitialized
readerCount()[source]

returns the number of currently registered readers of this model

Return type:int
Returns:
setData(data)[source]

sets the data object and emits a “dataChanged” signal with the data as the parameter

Parameters:data (object) – the new value for the Model’s data
writerCount()[source]

returns the number of currently registered writers of this model

Return type:int
Returns: