Source code for traitsui.qt4.editor
# (C) Copyright 2008-2022 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!
# ------------------------------------------------------------------------------
# Copyright (c) 2007, Riverbank Computing Limited
# All rights reserved.
#
# This software is provided without warranty under the terms of the BSD license.
# However, when used with the GPL version of PyQt the additional terms
# described in the PyQt GPL exception also apply
#
# Author: Riverbank Computing Limited
# ------------------------------------------------------------------------------
""" Defines the base class for PyQt editors.
"""
from pyface.qt import QtCore, QtGui
from traits.api import HasTraits, Instance, Str, Callable
from traitsui.api import Editor as UIEditor
from .constants import OKColor, ErrorColor
[docs]class Editor(UIEditor):
"""Base class for PyQt editors for Traits-based UIs."""
[docs] def clear_layout(self):
"""Delete the contents of a control's layout."""
layout = self.control.layout()
while True:
itm = layout.takeAt(0)
if itm is None:
break
itm.widget().setParent(None)
def _control_changed(self, control):
"""Handles the **control** trait being set."""
# FIXME: Check we actually make use of this.
if control is not None:
control._editor = self
[docs] def set_focus(self):
"""Assigns focus to the editor's underlying toolkit widget."""
if self.control is not None:
self.control.setFocus()
[docs] def update_editor(self):
"""Updates the editor when the object trait changes externally to the
editor.
"""
new_value = self.str_value
if self.control.text() != new_value:
self.control.setText(new_value)
[docs] def get_control_widget(self):
"""Get the concrete widget for the control.
Some editors may use a QLayout instead of a Qwidget, which may not be
suitable for certain usages (eg. for parenting other widgets).
"""
if isinstance(self.control, QtGui.QLayout):
return self.control.parentWidget()
else:
return self.control
[docs] 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."""
if self.control is not None:
self._enabled_changed_helper(self.control, enabled)
if self.label_control is not None:
self.label_control.setEnabled(enabled)
def _enabled_changed_helper(self, control, enabled):
"""A helper that allows the control to be a layout and recursively
manages all its widgets.
"""
if isinstance(control, QtGui.QWidget):
control.setEnabled(enabled)
else:
for i in range(control.count()):
itm = control.itemAt(i)
self._enabled_changed_helper(
(itm.widget() or itm.layout()), enabled
)
def _visible_changed(self, visible):
"""Handles the **visible** state of the editor being changed."""
if self.label_control is not None:
self.label_control.setVisible(visible)
if self.control is None:
# We are being called after the editor has already gone away.
return
self._visible_changed_helper(self.control, visible)
page = self.control.parent()
if (
page is None
or page.parent() is None
or page.parent().parent() is None
or page.layout() is None
or page.layout().count() != 1
):
return
# The TabWidget (representing the notebook) has a StackedWidget inside it,
# which then contains our parent.
# Even after the tab is removed, the parent-child relationship between
# our container widget (representing the page) and the enclosing TabWidget,
# so the following reference is still valid.
stack_widget = page.parent()
notebook = stack_widget.parent()
is_tabbed_group = notebook.property("traits_tabbed_group")
if (
notebook is None
or not isinstance(notebook, QtGui.QTabWidget)
or not is_tabbed_group
):
return
if not visible:
# Store the page number and name on the parent
for i in range(0, notebook.count()):
if notebook.widget(i) == page:
self._tab_index = i
self._tab_text = notebook.tabText(i)
page.setVisible(False)
notebook.removeTab(i)
break
else:
# Check to see if our parent has previously-stored tab
# index and text attributes
if (
getattr(self, "_tab_index", None) is not None
and getattr(self, "_tab_text", None) is not None
):
page.setVisible(True)
notebook.insertTab(self._tab_index, page, self._tab_text)
return
def _visible_changed_helper(self, control, visible):
"""A helper that allows the control to be a layout and recursively
manages all its widgets.
"""
if isinstance(control, QtGui.QWidget):
control.setVisible(visible)
else:
for i in range(control.count()):
itm = control.itemAt(i)
self._visible_changed_helper(
(itm.widget() or itm.layout()), visible
)
[docs] def get_error_control(self):
"""Returns the editor's control for indicating error status."""
return self.control
[docs] def in_error_state(self):
"""Returns whether or not the editor is in an error state."""
return False
[docs] 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()
if not isinstance(control, list):
control = [control]
for item in control:
if item is None:
continue
pal = QtGui.QPalette(item.palette())
if state:
color = ErrorColor
if getattr(item, "_ok_color", None) is None:
item._ok_color = QtGui.QColor(
pal.color(QtGui.QPalette.ColorRole.Base)
)
else:
color = getattr(item, "_ok_color", OKColor)
pal.setColor(QtGui.QPalette.ColorRole.Base, color)
item.setPalette(pal)
def _invalid_changed(self, state):
"""Handles the editor's invalid state changing."""
self.set_error_state()
[docs] def perform(self, action, action_event=None):
"""Performs the action described by a specified Action object."""
self.ui.do_undoable(self._perform, action)
def _perform(self, action):
method_name = action.action
info = self._menu_context["info"]
handler = self._menu_context["handler"]
object = self._menu_context["object"]
selection = self._menu_context["selection"]
self._menu_context["action"] = action
if method_name.find(".") >= 0:
if method_name.find("(") < 0:
method_name += "()"
try:
eval(method_name, globals(), self._menu_context)
except:
from traitsui.api import raise_to_debug
raise_to_debug()
return
method = getattr(handler, method_name, None)
if method is not None:
method(info, selection)
return
if action.on_perform is not None:
action.on_perform(selection)
return
action.perform(selection)
[docs] def eval_when(self, condition, object, trait):
"""Evaluates a condition within a defined context, and sets a
specified object trait based on the result, which is assumed to be a
Boolean.
"""
if condition != "":
value = True
try:
if not eval(condition, globals(), self._menu_context):
value = False
except:
from traitsui.api import raise_to_debug
raise_to_debug()
setattr(object, trait, value)
# TODO: move this method, it should be part of ui_panel or some other
# place that is responsible for setting up the Qt layout.
[docs] def set_size_policy(self, direction, resizable, springy, stretch):
"""Set the size policy of the editor's controller.
Based on the "direction" of the group that contains this editor
(VGroup or HGroup), set the stretch factor and the resizing
policy of the control.
Parameters
----------
direction : QtGui.QBoxLayout.Direction
Directionality of the group that contains this editor. Either
QtGui.QBoxLayout.Direction.LeftToRight or QtGui.QBoxLayout.Direction.TopToBottom
resizable : bool
True if control should be resizable in the orientation opposite
to the group directionality
springy : bool
True if control should be resizable in the orientation equal
to the group directionality
stretch : int
Stretch factor used by Qt to distribute the total size to
each component.
"""
policy = self.control.sizePolicy()
if direction == QtGui.QBoxLayout.Direction.LeftToRight:
if springy:
policy.setHorizontalStretch(stretch)
policy.setHorizontalPolicy(QtGui.QSizePolicy.Policy.Expanding)
if resizable:
policy.setVerticalStretch(stretch)
policy.setVerticalPolicy(QtGui.QSizePolicy.Policy.Expanding)
else: # TopToBottom
if springy:
policy.setVerticalStretch(stretch)
policy.setVerticalPolicy(QtGui.QSizePolicy.Policy.Expanding)
if resizable:
policy.setHorizontalStretch(stretch)
policy.setHorizontalPolicy(QtGui.QSizePolicy.Policy.Expanding)
self.control.setSizePolicy(policy)
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_object.on_trait_change(
self._list_updated, self.list_name + "_items", 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
)
self.list_object.on_trait_change(
self._list_updated, self.list_name + "_items", 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()
