# (C) Copyright 2004-2021 Enthought, Inc., Austin, TX
# All rights reserved.
#
# This software is provided without warranty under the terms of the BSD
# license included in LICENSE.txt and may be redistributed only under
# the conditions described in the aforementioned license. The license
# is also available online at http://www.enthought.com/licenses/BSD.txt
#
# Thanks for using Enthought open source!

""" Defines the base class for wxPython editors.
"""


import wx

from traits.api import HasTraits, Int, Instance, Str, Callable

# CIRCULAR IMPORT FIXME:
# We are importing from the source instead of from the api in order to
# avoid circular imports. The 'toolkit.py' file imports from 'helper' which in
# turns imports from this file. Therefore, trying to import
# 'traitsui.wx' (which imports the toolkit) will lead to importing
# all of the editor factories declared in traitsui.api. In addition,# some of the editor factories have a Color trait defined, and this will lead
# to an import of the wx 'toolkit' causing a circular import problem.
# Another solution could be to move the GroupEditor object from helper to this
# file.
from traitsui.editor import Editor as UIEditor

from .constants import WindowColor, OKColor, ErrorColor


class Editor(UIEditor):
    """ Base class for wxPython editors for Traits-based UIs.
    """

    # -------------------------------------------------------------------------
    #  Trait definitions:
    # -------------------------------------------------------------------------

    #: Style for embedding control in a sizer:
    layout_style = Int(wx.EXPAND)

    #: The maximum extra padding that should be allowed around the editor:
    border_size = Int(4)

    def _control_changed(self, control):
        """ Handles the **control** trait being set.
        """
        if control is not None:
            control._editor = self

    def set_focus(self):
        """ Assigns focus to the editor's underlying toolkit widget.
        """
        if self.control is not None:
            self.control.SetFocus()

    def update_editor(self):
        """ Updates the editor when the object trait changes externally to the
            editor.
        """
        new_value = self.str_value
        if self.control.GetValue() != new_value:
            self.control.SetValue(new_value)

    def error(self, excp):
        """ Handles an error that occurs while setting the object's trait value.
        """
        dlg = wx.MessageDialog(
            self.control,
            str(excp),
            self.description + " value error",
            wx.OK | wx.ICON_INFORMATION,
        )
        dlg.ShowModal()
        dlg.Destroy()

    def set_tooltip_text(self, control, text):
        """ Sets the tooltip for a specified control.
        """
        control.SetToolTip(text)

    def _enabled_changed(self, enabled):
        """ Handles the **enabled** state of the editor being changed.
        """
        control = self.control
        if control is not None:
            control.Enable(enabled)
            control.Refresh()
        if self.label_control is not None:
            self.label_control.Enable(enabled)
            self.label_control.Refresh()

    def _visible_changed(self, visible):
        """ Handles the **visible** state of the editor being changed.
        """
        control = self.control
        parent = control.GetParent()

        # Handle the case where the item whose visibility has changed is a
        # notebook page:
        sizer = parent.GetSizer()
        from pyface.dock.api import DockSizer

        if isinstance(sizer, DockSizer):
            dock_controls = sizer.GetContents().get_controls(False)
            for dock_control in dock_controls:
                if dock_control.control is control:
                    dock_control.visible = visible
            sizer.Layout()

        # Handle a normal item:
        else:
            if self.label_control is not None:
                self.label_control.Show(visible)
            control.Show(visible)
            # If only control.Layout() is called there are certain cases where
            # the newly visible items are sized incorrectly (see ticket 1797)
            if parent is None:
                control.Layout()
            else:
                parent.Layout()

    def get_error_control(self):
        """ Returns the editor's control for indicating error status.
        """
        return self.control

    def in_error_state(self):
        """ Returns whether or not the editor is in an error state.
        """
        return False

    def set_error_state(self, state=None, control=None):
        """ Sets the editor's current error state.
        """
        if state is None:
            state = self.invalid
        state = state or self.in_error_state()

        if control is None:
            control = self.get_error_control() or []

        if not isinstance(control, list):
            control = [control]

        for item in control:
            if state:
                color = ErrorColor
                if getattr(item, "_ok_color", None) is None:
                    item._ok_color = item.GetBackgroundColour()
            else:
                color = getattr(item, "_ok_color", None)
                if color is None:
                    color = OKColor
                    if isinstance(item, wx.Panel):
                        color = WindowColor

            item.SetBackgroundColour(color)
            item.Refresh()

    def _invalid_changed(self, state):
        """ Handles the editor's invalid state changing.
        """
        self.set_error_state()


class EditorWithList(Editor):
    """ Editor for an object that contains a list.
    """

    # -------------------------------------------------------------------------
    #  Trait definitions:
    # -------------------------------------------------------------------------

    #: Object containing the list being monitored
    list_object = Instance(HasTraits)

    #: Name of the monitored trait
    list_name = Str()

    #: Function used to evaluate the current list object value:
    list_value = Callable()

    def init(self, parent):
        """ Initializes the object.
        """
        factory = self.factory
        name = factory.name
        if name != "":
            self.list_object, self.list_name, self.list_value = self.parse_extended_name(
                name
            )
        else:
            self.list_object, self.list_name = factory, "values"
            self.list_value = lambda: factory.values

        self.list_object.on_trait_change(
            self._list_updated, self.list_name + "[]", dispatch="ui"
        )

        self._list_updated()

    def dispose(self):
        """ Disconnects the listeners set up by the constructor.
        """
        self.list_object.on_trait_change(
            self._list_updated, self.list_name + "[]", remove=True
        )

        super().dispose()

    def _list_updated(self):
        """ Handles the monitored trait being updated.
        """
        self.list_updated(self.list_value())

    def list_updated(self, values):
        """ Handles the monitored list being updated.
        """
        raise NotImplementedError


class EditorFromView(Editor):
    """ An editor generated from a View object.
    """

    def init(self, parent):
        """ Initializes the object.
        """
        self._ui = ui = self.init_ui(parent)
        if ui.history is None:
            ui.history = self.ui.history

        self.control = ui.control

    def init_ui(self, parent):
        """ Creates and returns the traits UI defined by this editor.
            (Must be overridden by a subclass).
        """
        raise NotImplementedError

    def update_editor(self):
        """ Updates the editor when the object trait changes externally to the
            editor.
        """
        # Normally nothing needs to be done here, since it should all be handled
        # by the editor's internally created traits UI:
        pass

    def dispose(self):
        """ Disposes of the editor.
        """
        self._ui.dispose()

        super().dispose()
