""" A view whose content is provided by a traits UI. """


# Standard library imports.
import logging

# Enthought library imports.
from traits.api import Any, Instance, Str
from traitsui.api import UI

# Local imports.
from view import View


# Logging.
logger = logging.getLogger(__name__)


class TraitsUIView(View):
    """ A view whose content is provided by a traits UI. """

    #### 'TraitsUIView' interface #############################################

    # The object that we povide a traits UI of (this defaults to the view
    # iteself ie. 'self').
    obj = Any

    # The traits UI that represents the view.
    #
    # The framework sets this to the value returned by 'create_ui'.
    ui = Instance(UI)

    # The name of the traits UI view used to create the UI (if not specified,
    # the default traits UI view is used).
    view = Str

    ###########################################################################
    # 'IWorkbenchPart' interface.
    ###########################################################################

    #### Trait initializers ###################################################

    def _name_default(self):
        """ Trait initializer. """

        return str(self.obj)

    #### Methods ##############################################################

    def create_control(self, parent):
        """ Creates the toolkit-specific control that represents the editor.

        'parent' is the toolkit-specific control that is the editor's parent.

        Overridden to call 'create_ui' to get the traits UI.

        """

        self.ui = self.create_ui(parent)

        return self.ui.control

    def destroy_control(self):
        """ Destroys the toolkit-specific control that represents the editor.

        Overridden to call 'dispose' on the traits UI.

        """

        # Give the traits UI a chance to clean itself up.
        if self.ui is not None:
            logger.debug('disposing traits UI for view [%s]', self)
            self.ui.dispose()
            self.ui = None
            # Break reference to the control, so the view is created afresh
            # next time.
            self.control = None

        return

    ###########################################################################
    # 'TraitsUIView' interface.
    ###########################################################################

    #### Trait initializers ###################################################

    def _obj_default(self):
        """ Trait initializer. """

        return self

    #### Methods ##############################################################

    def create_ui(self, parent):
        """ Creates the traits UI that represents the editor.

        By default it calls 'edit_traits' on the view's 'model'. If you
        want more control over the creation of the traits UI then override!

        """

        ui = self.obj.edit_traits(
            parent=parent, view=self.view, kind='subpanel'
        )

        return ui

#### EOF ######################################################################