dispatcher cutevariant

dispatcher.py

class QueryPluginWidget(PluginWidget):
  """ Base class for all query plugin """
  
  query_changed = Signal() # Signal to emit if UI change the query 
  
  @property
  def query(self):
     return self._query 
   
  @query.setter
  def query(self, query: Query):
       self._query = query
       
  def on_query_changed(self):
     """ Only this method should be implemented by children """
     raise NotImplemented()
      
      
 class ChildPlugin(QueryPluginWidget):
     
    def on_query_changed(self):
         """ Overrided """
         self.populate(self.query)   # Example : Populate ui on query changed 
        
    def button_pressed(self): # Example : Action from the UI which change query 
         self.query.columns = .... # Update query 
         self.query_changed.emit()  # Tell Other to update query 
    
class QueryDispatcher(object):
   def __init__(self, query: Query):
      self.query = query 
      
   def add_widget(self, widget: QueryPluginWidget) : 
      widget.query = self.query  # Link as reference ? Really ? All will point to the same query ? 
      widget.query_changed.connect(self.dispatch)
      self.widgets.append(widget)
      
  def dispatch(self):
    # Notify All widget except the sender that  query has changed 
     for widget in self.widgets:
         if widget is not self.sender():
             widget.on_query_changed()
          
  
      
# Usage 
query = Query()
dispatcher = QueryDispacher(query)
diaspacher.addWidget(ChildWidget())
diaspacher.addWidget(Child2Widget())
diaspacher.addWidget(Child3Widget())