# (C) Copyright 2005-2023 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!


""" Pyface 'DockWindow' support.

    This package provides a Pyface 'dockable' window component that allows
    child windows to be reorganized within the DockWindow using drag and drop.
    The component also allows multiple sub-windows to occupy the same
    sub-region of the DockWindow, in which case each sub-window appears as a
    separate notebook-like tab within the region.
"""


from operator import attrgetter
import os
import shelve
import sys

import wx

from traits.api import (
    HasPrivateTraits,
    Instance,
    Tuple,
    Property,
    Any,
    Str,
    List,
    Bool,
    observe,
)
from traits.trait_base import traits_home
from traitsui.api import View, HGroup, VGroup, Item, Handler, error
from traitsui.helper import user_name_for
from traitsui.menu import Menu, Action, Separator
from traitsui.dockable_view_element import DockableViewElement
from traitsui.dock_window_theme import dock_window_theme, DockWindowTheme

from pyface.api import SystemMetrics
from pyface.wx.drag_and_drop import PythonDropTarget, clipboard
from pyface.message_dialog import error as warning

from .dock_sizer import (
    DockSizer,
    DockControl,
    DockRegion,
    DockStyle,
    DockSplitter,
    no_dock_info,
    clear_window,
    features,
)
from .idockable import IDockable
from .idock_ui_provider import IDockUIProvider

is_mac = sys.platform == "darwin"

# -------------------------------------------------------------------------------
#  Global data:
# -------------------------------------------------------------------------------

# Dictionary of cursors in use:
cursor_map = {}

# -------------------------------------------------------------------------------
#  DockWindow context menu:
# -------------------------------------------------------------------------------

min_max_action = Action(name="Maximize", action="on_min_max")

undock_action = Action(name="Undock", action="on_undock")

lock_action = Action(
    name="Lock Layout", action="on_lock_layout", style="toggle"
)

layout_action = Action(name="Switch Layout", action="on_switch_layout")

save_action = Action(name="Save Layout...", action="on_save_layout")

# hide_action    = Action( name   = 'Hide',
#                         action = 'on_hide' )
#
# show_action    = Action( name   = 'Show',
#                         action = 'on_show' )

edit_action = Action(name="Edit Properties...", action="on_edit")

enable_features_action = Action(
    name="Show All", action="on_enable_all_features"
)

disable_features_action = Action(
    name="Hide All", action="on_disable_all_features"
)

# -------------------------------------------------------------------------------
#  'DockWindowHandler' class/interface:
# -------------------------------------------------------------------------------


class DockWindowHandler(HasPrivateTraits):

    # ---------------------------------------------------------------------------
    #  Returns whether or not a specified object can be inserted into the view:
    # ---------------------------------------------------------------------------

    def can_drop(self, object):
        """ Returns whether or not a specified object can be inserted into the
            view.
        """
        return True

    # ---------------------------------------------------------------------------
    #  Returns the DockControl object for a specified object:
    # ---------------------------------------------------------------------------

    def dock_control_for(self, parent, object):
        """ Returns the DockControl object for a specified object.
        """
        try:
            name = object.name
        except:
            try:
                name = object.label
            except:
                name = ""
        if name == "":
            name = user_name_for(object.__class__.__name__)

        image = None
        export = ""
        if isinstance(object, DockControl):
            dock_control = object
            image = dock_control.image
            export = dock_control.export
            dockable = dock_control.dockable
            close = dockable.dockable_should_close()
            if close:
                dock_control.close(force=True)

            control = dockable.dockable_get_control(parent)

            # If DockControl was closed, then reset it to point to the new
            # control:
            if close:
                dock_control.trait_set(
                    control=control, style=parent.owner.style
                )
                dockable.dockable_init_dockcontrol(dock_control)
                return dock_control

        elif isinstance(object, IDockable):
            dockable = object
            control = dockable.dockable_get_control(parent)
        else:
            ui = object.get_dockable_ui(parent)
            dockable = DockableViewElement(ui=ui)
            export = ui.view.export
            control = ui.control

        dc = DockControl(
            control=control,
            name=name,
            export=export,
            style=parent.owner.style,
            image=image,
            closeable=True,
        )

        dockable.dockable_init_dockcontrol(dc)

        return dc

    # ---------------------------------------------------------------------------
    #  Creates a new view of a specified control:
    # ---------------------------------------------------------------------------

    def open_view_for(self, control, use_mouse=True):
        """ Creates a new view of a specified control.
        """
        from .dock_window_shell import DockWindowShell

        DockWindowShell(control, use_mouse=use_mouse)

    # ---------------------------------------------------------------------------
    #  Handles the DockWindow becoming empty:
    # ---------------------------------------------------------------------------

    def dock_window_empty(self, dock_window):
        """ Handles the DockWindow becoming empty.
        """
        if dock_window.auto_close:
            dock_window.control.GetParent().Destroy()


# Create a singleton handler:
dock_window_handler = DockWindowHandler()

# -------------------------------------------------------------------------------
#  'LayoutName' class:
# -------------------------------------------------------------------------------


class LayoutName(Handler):

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

    # Name the user wants to assign to the layout:
    name = Str()

    # List of currently assigned names:
    names = List(Str)

    # ---------------------------------------------------------------------------
    #  Traits view definitions:
    # ---------------------------------------------------------------------------

    view = View(
        Item("name", label="Layout name"),
        title="Save Layout",
        kind="modal",
        buttons=["OK", "Cancel"],
    )

    # ---------------------------------------------------------------------------
    #  Handles a request to close a dialog-based user interface by the user:
    # ---------------------------------------------------------------------------

    def close(self, info, is_ok):
        if is_ok:
            name = info.object.name.strip()
            if name == "":
                warning(
                    info.ui.control,
                    "No name specified",
                    title="Save Layout Error",
                )
                return False
            if name in self.names:
                return error(
                    message="%s is already defined. Replace?" % name,
                    title="Save Layout Warning",
                    parent=info.ui.control,
                )

        return True


# -------------------------------------------------------------------------------
#  'DockWindow' class:
# -------------------------------------------------------------------------------


class DockWindow(HasPrivateTraits):

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

    # The wx.Window being used as the DockWindow:
    control = Instance(wx.Window)

    # The handler used to determine how certain events should be processed:
    handler = Any(dock_window_handler)

    # The 'extra' arguments to be passed to each handler call:
    handler_args = Tuple()

    # Close the parent window if the DockWindow becomes empty:
    auto_close = Bool(False)

    # The DockWindow graphical theme style information:
    theme = Instance(DockWindowTheme, allow_none=False)

    # Default style for external objects dragged into the window:
    style = DockStyle

    # Return the sizer associated with the control (i.e. window)
    sizer = Property

    # The id used to identify this DockWindow:
    id = Str()

    # ---------------------------------------------------------------------------
    #  Initializes the object:
    # ---------------------------------------------------------------------------

    def __init__(
        self,
        parent,
        wid=-1,
        pos=wx.DefaultPosition,
        size=wx.DefaultSize,
        style=wx.FULL_REPAINT_ON_RESIZE,
        **traits
    ):
        super().__init__(**traits)

        # Create the actual window:
        self.control = control = wx.Window(parent, wid, pos, size, style)
        control.owner = self

        # Set up the 'paint' event handler:
        control.Bind(wx.EVT_PAINT, self._paint)
        control.Bind(wx.EVT_SIZE, self._size)

        # Set up mouse event handlers:
        control.Bind(wx.EVT_LEFT_DOWN, self._left_down)
        control.Bind(wx.EVT_LEFT_UP, self._left_up)
        control.Bind(wx.EVT_LEFT_DCLICK, self._left_dclick)
        control.Bind(wx.EVT_RIGHT_DOWN, self._right_down)
        control.Bind(wx.EVT_RIGHT_UP, self.right_up)
        control.Bind(wx.EVT_MOTION, self._mouse_move)
        control.Bind(wx.EVT_LEAVE_WINDOW, self._mouse_leave)

        control.SetDropTarget(PythonDropTarget(self))

        # Initialize the window background color:
        if self.theme.use_theme_color:
            color = self.theme.tab.image_slice.bg_color
        else:
            color = SystemMetrics().dialog_background_color
            color = wx.Colour(
                int(color[0] * 255), int(color[1] * 255), int(color[2] * 255)
            )

        self.control.SetBackgroundColour(color)

    # -- Default Trait Values ---------------------------------------------------

    def _theme_default(self):
        return dock_window_theme()

    # -- Trait Event Handlers ---------------------------------------------------

    @observe("theme")
    def _update_background_color_and_layout(self, event):
        theme = event.new
        if self.control is not None:
            if theme.use_theme_color:
                color = theme.tab.image_slice.bg_color
            else:
                color = wx.NullColour
            self.control.SetBackgroundColour(color)

            self.update_layout()

    # ---------------------------------------------------------------------------
    #  Notifies the DockWindow that its contents are empty:
    # ---------------------------------------------------------------------------

    def dock_window_empty(self):
        """ Notifies the DockWindow that its contents are empty.
        """
        self.handler.dock_window_empty(self)

    # ---------------------------------------------------------------------------
    #  Sets the cursor to a specified cursor shape:
    # ---------------------------------------------------------------------------

    def set_cursor(self, cursor=None):
        """ Sets the cursor to a specified cursor shape.
        """
        if cursor is None:
            self.control.SetCursor(wx.NullCursor)
            return

        global cursor_map

        if cursor not in cursor_map:
            cursor_map[cursor] = wx.Cursor(cursor)

        self.control.SetCursor(cursor_map[cursor])

    # ---------------------------------------------------------------------------
    #  Releases ownership of the mouse capture:
    # ---------------------------------------------------------------------------

    def release_mouse(self):
        """ Releases ownership of the mouse capture.
        """
        if self._owner is not None:
            self._owner = None
            self.control.ReleaseMouse()

    # ---------------------------------------------------------------------------
    #  Updates the layout of the window:
    # ---------------------------------------------------------------------------

    def update_layout(self):
        """ Updates the layout of the window.
        """
        if self.control:
            self.control.Layout()
            self.control.Refresh()

    # ---------------------------------------------------------------------------
    #  Minimizes/Maximizes a specified DockControl:
    # ---------------------------------------------------------------------------

    def min_max(self, dock_control):
        """ Minimizes/maximizes a specified DockControl.
        """
        sizer = self.sizer
        if sizer is not None:
            sizer.MinMax(self.control, dock_control)
            self.update_layout()

    # ---------------------------------------------------------------------------
    #  Pops up the feature bar for a specified DockControl:
    # ---------------------------------------------------------------------------

    def feature_bar_popup(self, dock_control):
        """ Pops up the feature bar for a specified DockControl.
        """
        fb = self._feature_bar
        if fb is None:
            from .feature_bar import FeatureBar

            self._feature_bar = fb = FeatureBar(parent=self.control)
            fb.observe(self._feature_bar_closed, "completed")

        fb.dock_control = dock_control
        fb.show()

    # ---------------------------------------------------------------------------
    #  Handles closing the feature bar:
    # ---------------------------------------------------------------------------

    def _feature_bar_closed(self, event):
        fb = self._feature_bar
        fb.dock_control.feature_bar_closed()
        fb.hide()

    # ---------------------------------------------------------------------------
    #  Perform all operations needed to close the window:
    # ---------------------------------------------------------------------------

    def close(self):
        """ Closes the dock window.  In this case, all event handlers are
        unregistered.  Other cleanup operations go here, but at the moment Linux
        (and other non-Windows platforms?) are less forgiving when things like
        event handlers arent unregistered.
        """
        self._unregister_event_handlers()

    # ---------------------------------------------------------------------------
    #  Unregister all event handlers:
    # ---------------------------------------------------------------------------

    def _unregister_event_handlers(self):
        """ Unregister all event handlers setup in the constructor.  This is
        typically done prior to an app shutting down and is needed since Linux
        (and other non-Windows platforms?) trigger mouse, repaint, etc. events
        for controls which have already been deleted.
        """
        control = self.control
        if control is not None:
            control.Unbind(wx.EVT_PAINT)
            control.Unbind(wx.EVT_SIZE)
            control.Unbind(wx.EVT_LEFT_DOWN)
            control.Unbind(wx.EVT_LEFT_UP)
            control.Unbind(wx.EVT_LEFT_DCLICK)
            control.Unbind(wx.EVT_RIGHT_DOWN)
            control.Unbind(wx.EVT_RIGHT_UP)
            control.Unbind(wx.EVT_MOTION)
            control.Unbind(wx.EVT_LEAVE_WINDOW)

    # ---------------------------------------------------------------------------
    #  Handles repainting the window:
    # ---------------------------------------------------------------------------

    def _paint(self, event):
        """ Handles repainting the window.
        """
        # There is a problem on macs where we get paints when the update
        # is entirely within children.
        if is_mac and self._is_child_paint():
            return

        sizer = self.sizer
        if isinstance(sizer, DockSizer):
            sizer.Draw(self.control)
        else:
            clear_window(self.control)

    # ---------------------------------------------------------------------------
    #  Uses wx calls to determine if we really need to paint or the children will
    #  do it.
    # ---------------------------------------------------------------------------

    def _is_child_paint(self):
        """ Returns whether or not the current update region is entirely within a child.
        """
        if self.control.Children:
            update_rect = self.control.UpdateRegion.Box
            for child in self.control.Children:
                if not child.HasTransparentBackground() and child.Rect.Contains(
                    update_rect
                ):
                    return True
        return False

    # ---------------------------------------------------------------------------
    #  Handles the window being resized:
    # ---------------------------------------------------------------------------

    def _size(self, event):
        """ Handles the window being resized.
        """
        sizer = self.sizer
        if sizer is not None:
            try:
                dx, dy = self.control.GetSize().Get()
                sizer.SetDimension(0, 0, dx, dy)
            except:
                # fixme: This is temporary code to work around a problem in
                #        ProAVA2 that we are still trying to track down...
                pass

        event.Skip()

    # ---------------------------------------------------------------------------
    #  Handles the left mouse button being pressed:
    # ---------------------------------------------------------------------------

    def _left_down(self, event):
        """ Handles the left mouse button being pressed.
        """
        sizer = self.sizer
        if sizer is not None:
            object = sizer.ObjectAt(event.GetX(), event.GetY())
            if object is not None:
                self._owner = object
                self.control.CaptureMouse()
                object.mouse_down(event)

    # ---------------------------------------------------------------------------
    #  Handles the left mouse button being released:
    # ---------------------------------------------------------------------------

    def _left_up(self, event):
        """ Handles the left mouse button being released.
        """
        window = self.control
        if self._owner is not None:
            window.ReleaseMouse()
            self._owner.mouse_up(event)
            self._owner = None

        # Check for the user requesting that the layout structure be reset:
        if event.ShiftDown():
            if event.ControlDown():
                # Check for the developer requesting a structure dump (DEBUG):
                if event.AltDown():
                    contents = self.sizer.GetContents()
                    if contents is not None:
                        contents.dump()
                        sys.stdout.flush()
                else:
                    self.sizer.ResetStructure(window)
                    self.update_layout()
            elif event.AltDown():
                self.sizer.ToggleLock()
                self.update_layout()

    # ---------------------------------------------------------------------------
    #  Handles the left mouse button being double clicked:
    # ---------------------------------------------------------------------------

    def _left_dclick(self, event):
        """ Handles the left mouse button being double clicked.
        """
        sizer = self.sizer
        if sizer is not None:
            object = sizer.ObjectAt(event.GetX(), event.GetY(), True)
            if isinstance(object, DockControl):
                dockable = object.dockable
                if (
                    (dockable is None)
                    or (dockable.dockable_dclick(object, event) is False)
                ) and (object.style != "fixed"):
                    self.min_max(object)
            elif isinstance(object, DockRegion):
                self._owner = object
                self.control.CaptureMouse()
                object.mouse_down(event)

    # ---------------------------------------------------------------------------
    #  Handles the right mouse button being pressed:
    # ---------------------------------------------------------------------------

    def _right_down(self, event):
        """ Handles the right mouse button being pressed.
        """
        pass

    # ---------------------------------------------------------------------------
    #  Handles the right mouse button being released:
    # ---------------------------------------------------------------------------

    def right_up(self, event):
        """ Handles the right mouse button being released.
        """
        sizer = self.sizer
        if sizer is not None:
            object = sizer.ObjectAt(event.GetX(), event.GetY(), True)
            if object is not None:
                popup_menu = None
                window = self.control
                is_dock_control = isinstance(object, DockControl)

                if (
                    is_dock_control
                    and (object.dockable is not None)
                    and (
                        event.ShiftDown()
                        or event.ControlDown()
                        or event.AltDown()
                    )
                ):
                    self._menu_self = object.dockable
                    popup_menu = object.dockable.dockable_menu(object, event)

                if popup_menu is None:
                    self._menu_self = self
                    section = self.sizer.GetContents()
                    is_splitter = isinstance(object, DockSplitter)
                    self._object = object
                    if is_splitter:
                        self._object = object = object.parent
                    group = object
                    if is_dock_control:
                        group = group.parent
                    if sizer.IsMaximizable():
                        min_max_action.name = "Maximize"
                    else:
                        min_max_action.name = "Restore"
                    min_max_action.enabled = is_dock_control
                    undock_action.enabled = is_dock_control
                    edit_action.enabled = not is_splitter
                    controls = section.get_controls(False)
                    lock_action.checked = (len(controls) > 0) and controls[
                        0
                    ].locked
                    save_action.enabled = self.id != ""

                    feature_menu = self._get_feature_menu()
                    restore_menu, delete_menu = self._get_layout_menus()
                    popup_menu = Menu(
                        min_max_action,
                        undock_action,
                        Separator(),
                        feature_menu,
                        # Separator(),
                        # hide_action,
                        # show_action,
                        Separator(),
                        lock_action,
                        layout_action,
                        Separator(),
                        save_action,
                        restore_menu,
                        delete_menu,
                        Separator(),
                        edit_action,
                        name="popup",
                    )

                window.PopupMenu(
                    popup_menu.create_menu(window, self),
                    event.GetX() - 10,
                    event.GetY() - 10,
                )
                self._object = None

    # ---------------------------------------------------------------------------
    #  Handles the mouse moving over the window:
    # ---------------------------------------------------------------------------

    def _mouse_move(self, event):
        """ Handles the mouse moving over the window.
        """
        if self._last_dock_control is not None:
            self._last_dock_control.reset_feature_popup()
            self._last_dock_control = None

        if self._owner is not None:
            self._owner.mouse_move(event)
        else:
            sizer = self.sizer
            if sizer is not None:
                object = self._object or sizer.ObjectAt(
                    event.GetX(), event.GetY()
                )
                self._set_cursor(event, object)

                if object is not self._hover:
                    if self._hover is not None:
                        self._hover.hover_exit(event)

                    if object is not None:
                        object.hover_enter(event)

                    self._hover = object

                # Handle feature related processing:
                if isinstance(object, DockControl) and object.feature_activate(
                    event
                ):
                    self._last_dock_control = object

    # ---------------------------------------------------------------------------
    #  Handles the mouse leaving the window:
    # ---------------------------------------------------------------------------

    def _mouse_leave(self, event):
        """ Handles the mouse leaving the window.
        """
        if self._hover is not None:
            self._hover.hover_exit(event)
            self._hover = None
        self._set_cursor(event)

    # ---------------------------------------------------------------------------
    #  Sets the cursor for a specified object:
    # ---------------------------------------------------------------------------

    def _set_cursor(self, event, object=None):
        """ Sets the cursor for a specified object.
        """
        if object is None:
            self.set_cursor()
        else:
            self.set_cursor(object.get_cursor(event))

    # -- Context menu action handlers -----------------------------------------------

    # ---------------------------------------------------------------------------
    #  Handles the user asking for a DockControl to be maximized/restored:
    # ---------------------------------------------------------------------------

    def on_min_max(self):
        """ Handles the user asking for a DockControl to be maximized/restored.
        """
        self.min_max(self._object)

    # ---------------------------------------------------------------------------
    #  Handles the user requesting an element to be undocked:
    # ---------------------------------------------------------------------------

    def on_undock(self):
        """ Handles the user requesting an element to be undocked.
        """
        self.handler.open_view_for(self._object, use_mouse=False)

    # ---------------------------------------------------------------------------
    #  Handles the user requesting an element to be hidden:
    # ---------------------------------------------------------------------------

    def on_hide(self):
        """ Handles the user requesting an element to be hidden.
        """
        self._object.show(False)

    # ---------------------------------------------------------------------------
    #  Handles the user requesting an element to be shown:
    # ---------------------------------------------------------------------------

    def on_show(self):
        """ Handles the user requesting an element to be shown.
        """
        object = self._object
        if isinstance(object, DockControl):
            object = object.parent
        self._hidden_group_for(object).show(True)

    # ---------------------------------------------------------------------------
    #  Handles the user requesting that the current layout be switched:
    # ---------------------------------------------------------------------------

    def on_switch_layout(self):
        """ Handles the user requesting that the current layout be switched.
        """
        self.sizer.ResetStructure(self.control)
        self.update_layout()

    # ---------------------------------------------------------------------------
    #  Handles the user requesting that the layout be locked/unlocked:
    # ---------------------------------------------------------------------------

    def on_lock_layout(self):
        """ Handles the user requesting that the layout be locked/unlocked.
        """
        self.sizer.ToggleLock()
        self.update_layout()

    # ---------------------------------------------------------------------------
    #  Handles the user requesting that the layout be saved:
    # ---------------------------------------------------------------------------

    def on_save_layout(self):
        """ Handles the user requesting that the layout be saved.
        """
        layout_name = LayoutName(names=self._get_layout_names())
        if layout_name.edit_traits(parent=self.control).result:
            self._set_layout(layout_name.name, self.sizer.GetStructure())

    # ---------------------------------------------------------------------------
    #  Handles the user requesting a specified layout to be restored:
    # ---------------------------------------------------------------------------

    def on_restore_layout(self, name):
        """ Handles the user requesting a specified layout to be restored.
        """
        self.sizer.SetStructure(self.control, self._get_layout(name))
        self.update_layout()

    # ---------------------------------------------------------------------------
    #  Handles the user reqesting a specified layout to be deleted:
    # ---------------------------------------------------------------------------

    def on_delete_layout(self, name):
        """ Handles the user reqesting a specified layout to be deleted.
        """
        if error(
            message="Delete the '%s' layout?" % name,
            title="Delete Layout Warning",
            parent=self.control,
        ):
            self._delete_layout(name)

    # ---------------------------------------------------------------------------
    #  Handles the user requesting to edit an item:
    # ---------------------------------------------------------------------------

    def on_edit(self, object=None):
        """ Handles the user requesting to edit an item.
        """
        if object is None:
            object = self._object
        control_info = ControlInfo(
            **object.get("name", "user_name", "style", "user_style")
        )
        if control_info.edit_traits(parent=self.control).result:
            name = control_info.name.strip()
            if name != "":
                object.name = name
            object.trait_set(
                **control_info.get("user_name", "style", "user_style")
            )
            self.update_layout()

    # ---------------------------------------------------------------------------
    #  Enables all features:
    # ---------------------------------------------------------------------------

    def on_enable_all_features(self, action):
        """ Enables all features.
        """
        for feature in features:
            if (feature.feature_name != "") and (feature.state != 1):
                feature.toggle_feature(action)

    # ---------------------------------------------------------------------------
    #  Disables all features:
    # ---------------------------------------------------------------------------

    def on_disable_all_features(self, action):
        """ Disables all features.
        """
        for feature in features:
            if (feature.feature_name != "") and (feature.state == 1):
                feature.toggle_feature(action)

    # ---------------------------------------------------------------------------
    #  Toggles the enabled/disabled state of the action's associated feature:
    # ---------------------------------------------------------------------------

    def on_toggle_feature(self, action):
        """ Toggles the enabled/disabled state of the action's associated
            feature.
        """
        action._feature.toggle_feature(action)

    # -- DockWindow user preference database methods --------------------------------

    # ---------------------------------------------------------------------------
    #  Gets the layout dictionary for the DockWindow:
    # ---------------------------------------------------------------------------

    def _get_layouts(self):
        """ Gets the layout dictionary for the DockWindow.
        """
        id = self.id
        if id != "":
            db = self._get_dw_db()
            if db is not None:
                layouts = db.get(id)
                db.close()
                return layouts

        return None

    # ---------------------------------------------------------------------------
    #  Gets the names of all current layouts defined for the DockWindow:
    # ---------------------------------------------------------------------------

    def _get_layout_names(self):
        """ Gets the names of all current layouts defined for the DockWindow.
        """
        layouts = self._get_layouts()
        if layouts is not None:
            return list(layouts.keys())

        return []

    # ---------------------------------------------------------------------------
    #  Gets the layout data for a specified layout name:
    # ---------------------------------------------------------------------------

    def _get_layout(self, name):
        """ Gets the layout data for a specified layout name.
        """
        layouts = self._get_layouts()
        if layouts is not None:
            return layouts.get(name)

        return None

    # ---------------------------------------------------------------------------
    #  Deletes the layout data for a specified layout name:
    # ---------------------------------------------------------------------------

    def _delete_layout(self, name):
        """ Deletes the layout data for a specified layout name.
        """
        id = self.id
        if id != "":
            db = self._get_dw_db(mode="c")
            if db is not None:
                layouts = db.get(id)
                if layouts is not None:
                    del layouts[name]
                    db[id] = layouts
                db.close()

    # ---------------------------------------------------------------------------
    #  Sets the layout data for a specified layout name:
    # ---------------------------------------------------------------------------

    def _set_layout(self, name, layout):
        """ Sets the layout data for a specified layout name.
        """
        id = self.id
        if id != "":
            db = self._get_dw_db(mode="c")
            if db is not None:
                layouts = db.get(id)
                if layouts is None:
                    layouts = {}
                layouts[name] = layout
                db[id] = layouts
                db.close()

    # ---------------------------------------------------------------------------
    #  Gets a reference to the DockWindow UI preference database:
    # ---------------------------------------------------------------------------

    def _get_dw_db(self, mode="r"):
        try:
            return shelve.open(
                os.path.join(traits_home(), "dock_window"),
                flag=mode,
                protocol=-1,
            )
        except:
            return None

    # ---------------------------------------------------------------------------
    #  Returns the 'Features' sub_menu:
    # ---------------------------------------------------------------------------

    def _get_feature_menu(self):
        """ Returns the 'Features' sub_menu.
        """
        enable_features_action.enabled = (
            disable_features_action.enabled
        ) = False
        for feature in features:
            if feature.feature_name != "":
                if feature.state == 1:
                    disable_features_action.enabled = True
                    if enable_features_action.enabled:
                        break
                else:
                    enable_features_action.enabled = True
                    if disable_features_action.enabled:
                        break

        actions = []
        for feature in features:
            if feature.feature_name != "":
                actions.append(
                    Action(
                        name=feature.feature_name,
                        action="on_toggle_feature",
                        _feature=feature,
                        style="toggle",
                        checked=(feature.state == 1),
                    )
                )

        if len(actions) > 0:
            actions.sort(key=attrgetter("name"))
            actions[0:0] = [Separator()]

        return Menu(
            name="Features",
            *([enable_features_action, disable_features_action] + actions)
        )

    # ---------------------------------------------------------------------------
    #  Gets the sub-menus for the 'Restore layout' and 'Delete layout' menu
    #  options:
    # ---------------------------------------------------------------------------

    def _get_layout_menus(self):
        """ Gets the sub-menus for the 'Restore layout' and 'Delete layout' menu
            options.
        """
        names = self._get_layout_names()
        if len(names) == 0:
            restore_actions = [Action(name="<empty>", enabled=False)]
            delete_actions = [Action(name="<empty>", enabled=False)]
        else:
            names.sort()
            restore_actions = [
                Action(
                    name=name, action="self.on_restore_layout(%s)" % repr(name)
                )
                for name in names
            ]
            delete_actions = [
                Action(
                    name=name, action="self.on_delete_layout(%s)" % repr(name)
                )
                for name in names
            ]
        return [
            Menu(name="Restore Layout", *restore_actions),
            Menu(name="Delete Layout", *delete_actions),
        ]

    # -- Drag and drop event handlers: ----------------------------------------------

    # ---------------------------------------------------------------------------
    #  Handles a Python object being dropped on the control:
    # ---------------------------------------------------------------------------

    def wx_dropped_on(self, x, y, data, drag_result):
        """ Handles a Python object being dropped on the window.
        """
        if isinstance(data, (IDockUIProvider, DockControl)):
            window = self.control
            dock_info = self._dock_info

            # See the 'wx_drag_leave' method for an explanation of this code:
            if dock_info is None:
                dock_info = self._leave_info

            dock_info.draw(window)
            self._dock_info = None
            try:
                control = self.handler.dock_control_for(
                    *(self.handler_args + (window, data))
                )
                # Safely check to see if the object quacks like a Binding
                binding = getattr(clipboard, "node", None)
                if (
                    hasattr(binding, "obj")
                    and (binding.obj is data)
                    and hasattr(binding, "namespace_name")
                ):
                    control.id = "@@%s" % binding.namespace_name
                dock_info.dock(control, window)
                return drag_result
            except:
                warning(
                    window,
                    "An error occurred while attempting to add an item of "
                    "type '%s' to the window." % data.__class__.__name__,
                    title="Cannot add item to window",
                )

        return wx.DragNone

    # ---------------------------------------------------------------------------
    #  Handles a Python object being dragged over the control:
    # ---------------------------------------------------------------------------

    def wx_drag_any(self, x, y, data, drag_result):
        """ Handles a Python object being dragged over the control.
        """
        ui_provider = isinstance(data, IDockUIProvider)
        if ui_provider or isinstance(data, DockControl):
            if ui_provider and (
                not self.handler.can_drop(*(self.handler_args + (data,)))
            ):
                return wx.DragNone

            # Check to see if we are in 'drag mode' yet:
            cur_dock_info = self._dock_info
            if cur_dock_info is None:
                cur_dock_info = no_dock_info
                if isinstance(data, DockControl):
                    self._dock_size = data.tab_width
                else:
                    self._dock_size = 80

            # Get the window and DockInfo object associated with the event:
            window = self.control
            self._dock_info = dock_info = self.sizer.DockInfoAt(
                x, y, self._dock_size, False
            )

            # If the DockInfo has changed, then update the screen:
            if (
                (cur_dock_info.kind != dock_info.kind)
                or (cur_dock_info.region is not dock_info.region)
                or (cur_dock_info.bounds != dock_info.bounds)
                or (cur_dock_info.tab_bounds != dock_info.tab_bounds)
            ):

                # Erase the old region:
                cur_dock_info.draw(window)

                # Draw the new region:
                dock_info.draw(window)

            return drag_result

        # Handle the case of dragging a normal object over a 'feature':
        if self._can_drop_on_feature(x, y, data) is not None:
            return drag_result

        return wx.DragNone

    # ---------------------------------------------------------------------------
    #  Handles a dragged Python object leaving the window:
    # ---------------------------------------------------------------------------

    def wx_drag_leave(self, data):
        """ Handles a dragged Python object leaving the window.
        """
        if self._dock_info is not None:
            self._dock_info.draw(self.control)

            # Save the current '_dock_info' in '_leave_info' because under
            # Linux the drag and drop code sends a spurious 'drag_leave' event
            # immediately before a 'dropped_on' event, so we need to remember
            # the '_dock_info' value just in case the next event is
            # 'dropped_on':
            self._leave_info, self._dock_info = self._dock_info, None

    # -- Pyface menu interface implementation ---------------------------------------

    # ---------------------------------------------------------------------------
    #  Adds a menu item to the menu bar being constructed:
    # ---------------------------------------------------------------------------

    def add_to_menu(self, menu_item):
        """ Adds a menu item to the menu bar being constructed.
        """
        pass

    # ---------------------------------------------------------------------------
    #  Adds a tool bar item to the tool bar being constructed:
    # ---------------------------------------------------------------------------

    def add_to_toolbar(self, toolbar_item):
        """ Adds a tool bar item to the tool bar being constructed.
        """
        pass

    # ---------------------------------------------------------------------------
    #  Returns whether the menu action should be defined in the user interface:
    # ---------------------------------------------------------------------------

    def can_add_to_menu(self, action):
        """ Returns whether the action should be defined in the user interface.
        """
        return True

    # ---------------------------------------------------------------------------
    #  Returns whether the toolbar action should be defined in the user
    #  interface:
    # ---------------------------------------------------------------------------

    def can_add_to_toolbar(self, action):
        """ Returns whether the toolbar action should be defined in the user
            interface.
        """
        return True

    # ---------------------------------------------------------------------------
    #  Performs the action described by a specified Action object:
    # ---------------------------------------------------------------------------

    def perform(self, action_object):
        """ Performs the action described by a specified Action object.
        """
        action = action_object.action
        if action[:5] == "self.":
            eval(action, globals(), {"self": self._menu_self})
        else:
            method = getattr(self, action)
            try:
                method()
            except:
                method(action_object)

    # -- Property implementations ---------------------------------------------------

    # ---------------------------------------------------------------------------
    #  Implementation of the 'sizer' property:
    # ---------------------------------------------------------------------------

    def _get_sizer(self):
        if self.control is not None:
            return self.control.GetSizer()
        return None

    def _set_sizer(self, sizer):
        self.control.SetSizer(sizer)

    # -- Private methods ------------------------------------------------------------

    # ---------------------------------------------------------------------------
    #  Finds the first group with any hidden items (if any):
    # ---------------------------------------------------------------------------

    def _hidden_group_for(self, group):
        """ Finds the first group with any hidden items (if any).
        """
        while True:
            if group is None:
                return None
            if len(group.contents) > len(group.visible_contents):
                return group
            group = group.parent

    # ---------------------------------------------------------------------------
    #  Returns a feature that the pointer is over and which can accept the
    #  specified data:
    # ---------------------------------------------------------------------------

    def _can_drop_on_feature(self, x, y, data):
        """ Returns a feature that the pointer is over and which can accept the
            specified data.
        """
        if self.sizer is not None:
            object = self.sizer.ObjectAt(x, y)
            if isinstance(object, DockControl):
                event = FakeEvent(x, y, self.control)

                if object.feature_activate(event, data):
                    ldc = self._last_dock_control
                    if (ldc is not None) and (ldc is not object):
                        ldc.reset_feature_popup()
                    self._last_dock_control = object
                    return None

        if self._last_dock_control is not None:
            self._last_dock_control.reset_feature_popup()
            self._last_dock_control = None

        return None


# -------------------------------------------------------------------------------
#  'FakeEvent' class:
# -------------------------------------------------------------------------------


class FakeEvent(object):
    def __init__(self, x, y, object):
        self.x, self.y, self.object = x, y, object

    def GetX(self):
        return self.x

    def GetY(self):
        return self.y

    def GetEventObject(self):
        return self.object


# -------------------------------------------------------------------------------
#  'ControlInfo' class:
# -------------------------------------------------------------------------------


class ControlInfo(HasPrivateTraits):

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

    # Name to be edited:
    name = Str()

    # Has the user set the name of the control?
    user_name = Bool(False)
    id = Str()

    # Style of drag bar/tab:
    style = DockStyle

    # Has the user set the style for this control:
    user_style = Bool(False)

    # ---------------------------------------------------------------------------
    #  Traits view definition:
    # ---------------------------------------------------------------------------

    traits_view = View(
        VGroup(
            HGroup(
                HGroup("name<100>{Label}", "3"),
                HGroup("user_name{Remember label}", show_left=False),
            ),
            HGroup(
                HGroup("style<101>", "3"),
                HGroup("user_style{Remember style}", show_left=False),
            ),
        ),
        title="Edit properties",
        kind="modal",
        buttons=["OK", "Cancel"],
    )