Source code for pyface.i_widget

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""" The base interface for all pyface widgets. """


from traits.api import Any, Bool, HasTraits, Interface, Instance, Str


[docs]class IWidget(Interface): """ The base interface for all pyface widgets. Pyface widgets delegate to a toolkit specific control. """ #: The toolkit specific control that represents the widget. control = Any() #: The control's optional parent control. parent = Any() #: Whether or not the control is visible visible = Bool(True) #: Whether or not the control is enabled enabled = Bool(True) #: A tooltip for the widget. tooltip = Str() #: An optional context menu for the widget. context_menu = Instance("pyface.action.menu_manager.MenuManager") # ------------------------------------------------------------------------ # 'IWidget' interface. # ------------------------------------------------------------------------
[docs] def show(self, visible): """ Show or hide the widget. Parameters ---------- visible : bool Visible should be ``True`` if the widget should be shown. """
[docs] def enable(self, enabled): """ Enable or disable the widget. Parameters ---------- enabled : bool The enabled state to set the widget to. """
[docs] def focus(self): """ Set the keyboard focus to this widget. """
[docs] def has_focus(self): """ Does the widget currently have keyboard focus? Returns ------- focus_state : bool Whether or not the widget has keyboard focus. """
[docs] def create(self): """ Creates the toolkit specific control. This method should create the control and assign it to the :py:attr:``control`` trait. """
[docs] def destroy(self): """ Destroy the control if it exists. """
# ------------------------------------------------------------------------ # Protected 'IWidget' interface. # ------------------------------------------------------------------------ def _create_control(self, parent): """ Create toolkit specific control that represents the widget. Parameters ---------- parent : toolkit control The toolkit control to be used as the parent for the widget's control. Returns ------- control : toolkit control A control for the widget. """ def _add_event_listeners(self): """ Set up toolkit-specific bindings for events """ def _remove_event_listeners(self): """ Remove toolkit-specific bindings for events """
[docs]class MWidget(HasTraits): """ The mixin class that contains common code for toolkit specific implementations of the IWidget interface. """ #: A tooltip for the widget. tooltip = Str() #: An optional context menu for the widget. context_menu = Instance("pyface.action.menu_manager.MenuManager")
[docs] def create(self): """ Creates the toolkit specific control. The default implementation simply calls _create() """ self._create()
[docs] def destroy(self): """ Call clean-up code and destroy toolkit objects. Subclasses should override to perform any additional clean-up, ensuring that they call super() after that clean-up. """ if self.control is not None: self._remove_event_listeners() self.control = None
# ------------------------------------------------------------------------ # Protected 'IWidget' interface. # ------------------------------------------------------------------------ def _create(self): """ Creates the toolkit specific control. This method should create the control and assign it to the :py:attr:``control`` trait. """ self.control = self._create_control(self.parent) self._initialize_control() self._add_event_listeners() def _create_control(self, parent): """ Create toolkit specific control that represents the widget. Parameters ---------- parent : toolkit control The toolkit control to be used as the parent for the widget's control. Returns ------- control : toolkit control A control for the widget. """ raise NotImplementedError() def _initialize_control(self): """ Perform any post-creation initialization for the control. """ self._set_control_tooltip(self.tooltip) def _add_event_listeners(self): """ Set up toolkit-specific bindings for events """ self.observe(self._tooltip_updated, "tooltip", dispatch="ui") self.observe( self._context_menu_updated, "context_menu", dispatch="ui" ) if self.control is not None and self.context_menu is not None: self._observe_control_context_menu() def _remove_event_listeners(self): """ Remove toolkit-specific bindings for events """ if self.control is not None and self.context_menu is not None: self._observe_control_context_menu(remove=True) self.observe( self._context_menu_updated, "context_menu", dispatch="ui", remove=True, ) self.observe( self._tooltip_updated, "tooltip", dispatch="ui", remove=True ) # Toolkit control interface --------------------------------------------- def _get_control_tooltip(self): """ Toolkit specific method to get the control's tooltip. """ raise NotImplementedError() def _set_control_tooltip(self, tooltip): """ Toolkit specific method to set the control's tooltip. """ raise NotImplementedError() def _observe_control_context_menu(self, remove=False): """ Toolkit specific method to change the context menu observer. This should use _handle_control_context_menu as the event handler. Parameters ---------- remove : bool Whether the context menu handler should be removed or added. """ raise NotImplementedError() def _handle_control_context_menu(self, event): """ Handle a context menu event. Implementations should override this with a method suitable to be used as a toolkit event handler that invokes a context menu. The function signature will likely vary from toolkit to toolkit. """ raise NotImplementedError() # Trait change handlers ------------------------------------------------- def _tooltip_updated(self, event): tooltip = event.new if self.control is not None: self._set_control_tooltip(tooltip) def _context_menu_updated(self, event): if self.control is not None: if event.new is None: self._observe_control_context_menu(remove=True) if event.old is None: self._observe_control_context_menu()