Fixes for PythonEditor and Python Widget (#980)

This mainly kicks off the deprecation of automatic creation of the widgets
in the __init__ method.  This also deprecates the very old wx IPython widget.

pyface/tests/test_python_editor.py

@@ -45,8 +45,26 @@ def tearDown(self):
     def test_lifecycle(self):
         # test that destroy works
         with self.event_loop():
-            self.widget = PythonEditor(self.window.control)
+            with self.assertWarns(PendingDeprecationWarning):
+                self.widget = PythonEditor(self.window.control)
 
+        self.assertIsNotNone(self.widget.control)
+        self.assertFalse(self.widget.dirty)
+
+        with self.event_loop():
+            self.widget.destroy()
+
+    def test_two_stage_create(self):
+        # test that create and destroy work
+        self.widget = PythonEditor(create=False)
+
+        self.assertIsNone(self.widget.control)
+
+        with self.event_loop():
+            self.widget.parent = self.window.control
+            self.widget.create()
+
+        self.assertIsNotNone(self.widget.control)
         self.assertFalse(self.widget.dirty)
 
         with self.event_loop():
@@ -56,19 +74,29 @@ def test_show_line_numbers(self):
         # test that destroy works
         with self.event_loop():
             self.widget = PythonEditor(
-                self.window.control, show_line_numbers=False
+                parent=self.window.control,
+                show_line_numbers=False,
+                create=False,
             )
+            self.widget.create()
+
         with self.event_loop():
             self.widget.show_line_numbers = True
+
         with self.event_loop():
             self.widget.show_line_numbers = False
+
         with self.event_loop():
             self.widget.destroy()
 
     def test_load(self):
         # test that destroy works
         with self.event_loop():
-            self.widget = PythonEditor(self.window.control)
+            self.widget = PythonEditor(
+                parent=self.window.control,
+                create=False,
+            )
+            self.widget.create()
 
         with self.assertTraitChanges(self.widget, "changed", count=1):
             with self.event_loop():
@@ -81,7 +109,12 @@ def test_load(self):
     def test_select_line(self):
         # test that destroy works
         with self.event_loop():
-            self.widget = PythonEditor(self.window.control, path=PYTHON_SCRIPT)
+            self.widget = PythonEditor(
+                parent=self.window.control,
+                path=PYTHON_SCRIPT,
+                create=False,
+            )
+            self.widget.create()
 
         with self.event_loop():
             self.widget.select_line(3)

pyface/tests/test_python_shell.py

@@ -46,14 +46,34 @@ def tearDown(self):
     def test_lifecycle(self):
         # test that destroy works
         with self.event_loop():
-            self.widget = PythonShell(self.window.control)
+            with self.assertWarns(PendingDeprecationWarning):
+                self.widget = PythonShell(self.window.control)
+
+        self.assertIsNotNone(self.widget.control)
+
+        with self.event_loop():
+            self.widget.destroy()
+
+    def test_two_stage_create(self):
+        # test that create=False works
+        self.widget = PythonShell(create=False)
+
+        self.assertIsNone(self.widget.control)
+
+        with self.event_loop():
+            self.widget.parent = self.window.control
+            self.widget.create()
+
+        self.assertIsNotNone(self.widget.control)
+
         with self.event_loop():
             self.widget.destroy()
 
     def test_bind(self):
         # test that binding a variable works
+        self.widget = PythonShell(parent=self.window.control, create=False)
         with self.event_loop():
-            self.widget = PythonShell(self.window.control)
+            self.widget.create()
         with self.event_loop():
             self.widget.bind("x", 1)
 
@@ -64,8 +84,9 @@ def test_bind(self):
 
     def test_execute_command(self):
         # test that executing a command works
+        self.widget = PythonShell(parent=self.window.control, create=False)
         with self.event_loop():
-            self.widget = PythonShell(self.window.control)
+            self.widget.create()
 
         with self.assertTraitChanges(self.widget, "command_executed", count=1):
             with self.event_loop():
@@ -78,8 +99,9 @@ def test_execute_command(self):
 
     def test_execute_command_not_hidden(self):
         # test that executing a non-hidden command works
+        self.widget = PythonShell(parent=self.window.control, create=False)
         with self.event_loop():
-            self.widget = PythonShell(self.window.control)
+            self.widget.create()
 
         with self.assertTraitChanges(self.widget, "command_executed", count=1):
             with self.event_loop():
@@ -92,8 +114,9 @@ def test_execute_command_not_hidden(self):
 
     def test_execute_file(self):
         # test that executing a file works
+        self.widget = PythonShell(parent=self.window.control, create=False)
         with self.event_loop():
-            self.widget = PythonShell(self.window.control)
+            self.widget.create()
 
         # XXX inconsistent behaviour between backends
         # with self.assertTraitChanges(self.widget, 'command_executed', count=1):
@@ -108,8 +131,9 @@ def test_execute_file(self):
 
     def test_execute_file_not_hidden(self):
         # test that executing a file works
+        self.widget = PythonShell(parent=self.window.control, create=False)
         with self.event_loop():
-            self.widget = PythonShell(self.window.control)
+            self.widget.create()
 
         # XXX inconsistent behaviour between backends
         # with self.assertTraitChanges(self.widget, 'command_executed', count=1):
@@ -123,9 +147,10 @@ def test_execute_file_not_hidden(self):
             self.widget.destroy()
 
     def test_get_history(self):
-        # test that executing a command works
+        # test that command history can be extracted
+        self.widget = PythonShell(parent=self.window.control, create=False)
         with self.event_loop():
-            self.widget = PythonShell(self.window.control)
+            self.widget.create()
 
         with self.event_loop():
             self.widget.execute_command("x = 1", hidden=False)
@@ -139,9 +164,10 @@ def test_get_history(self):
             self.widget.destroy()
 
     def test_set_history(self):
-        # test that executing a command works
+        # test that command history can be updated
+        self.widget = PythonShell(parent=self.window.control, create=False)
         with self.event_loop():
-            self.widget = PythonShell(self.window.control)
+            self.widget.create()
 
         with self.event_loop():
             self.widget.set_history(["x = 1", "y = x + 1"], 1)

pyface/ui/qt4/python_editor.py

@@ -9,6 +9,7 @@
 #
 # Thanks for using Enthought open source!
 
+import warnings
 
 from pyface.qt import QtCore, QtGui
 
@@ -46,9 +47,20 @@ class PythonEditor(MPythonEditor, Widget):
     # 'object' interface.
     # ------------------------------------------------------------------------
 
-    def __init__(self, parent, **traits):
+    def __init__(self, parent=None, **traits):
+
+        create = traits.pop("create", True)
+
         super().__init__(parent=parent, **traits)
-        self._create()
+
+        if create:
+            self.create()
+            warnings.warn(
+                "automatic widget creation is deprecated and will be removed "
+                "in a future Pyface version, use create=False and explicitly "
+                "call create() for future behaviour",
+                PendingDeprecationWarning,
+            )
 
     # ------------------------------------------------------------------------
     # 'PythonEditor' interface.

pyface/ui/qt4/python_shell.py

@@ -16,6 +16,7 @@
 from io import StringIO
 import sys
 from time import time
+import warnings
 
 
 from pyface.qt import QtCore, QtGui
@@ -56,11 +57,21 @@ class PythonShell(MPythonShell, Widget):
 
     # FIXME v3: Either make this API consistent with other Widget sub-classes
     # or make it a sub-class of HasTraits.
-    def __init__(self, parent, **traits):
+    def __init__(self, parent=None, **traits):
+
+        create = traits.pop("create", True)
+
         super().__init__(parent=parent, **traits)
 
-        # Create the toolkit-specific control that represents the widget.
-        self._create()
+        if create:
+            # Create the toolkit-specific control that represents the widget.
+            self.create()
+            warnings.warn(
+                "automatic widget creation is deprecated and will be removed "
+                "in a future Pyface version, use create=False and explicitly "
+                "call create() for future behaviour",
+                PendingDeprecationWarning,
+            )
 
     # --------------------------------------------------------------------------
     # 'IPythonShell' interface

pyface/ui/wx/ipython_widget.py

@@ -17,6 +17,7 @@
 import codeop
 import re
 import sys
+import warnings
 
 
 import IPython
@@ -345,6 +346,12 @@ class IPythonWidget(Widget):
     def __init__(self, parent, **traits):
         """ Creates a new pager. """
 
+        warnings.warn(
+            "the Wx IPython widget us deprecated and will be removed in a "
+            "future Pyface version",
+            PendingDeprecationWarning,
+        )
+
         # Base class constructor.
         super().__init__(**traits)
 

pyface/ui/wx/python_editor.py

@@ -12,6 +12,7 @@
 """ Enthought pyface package component
 """
 
+import warnings
 
 import wx.stc
 
@@ -49,14 +50,23 @@ class PythonEditor(MPythonEditor, Widget):
     # 'object' interface.
     # ------------------------------------------------------------------------
 
-    def __init__(self, parent, **traits):
+    def __init__(self, parent=None, **traits):
         """ Creates a new pager. """
 
-        # Base class constructor.
-        super().__init__(**traits)
+        create = traits.pop("create", True)
 
-        # Create the toolkit-specific control that represents the widget.
-        self.control = self._create_control(parent)
+        # Base class constructor.
+        super().__init__(parent=parent, **traits)
+
+        if create:
+            # Create the widget's toolkit-specific control.
+            self.create()
+            warnings.warn(
+                "automatic widget creation is deprecated and will be removed "
+                "in a future Pyface version, use create=False and explicitly "
+                "call create() for future behaviour",
+                PendingDeprecationWarning,
+            )
 
         return
 

pyface/ui/wx/python_shell.py

@@ -16,6 +16,7 @@
 import os
 import sys
 import types
+import warnings
 
 
 from wx.py.shell import Shell as PyShellBase
@@ -52,17 +53,23 @@ class PythonShell(MPythonShell, Widget):
 
     # FIXME v3: Either make this API consistent with other Widget sub-classes
     # or make it a sub-class of HasTraits.
-    def __init__(self, parent, **traits):
+    def __init__(self, parent=None, **traits):
         """ Creates a new pager. """
 
-        # Base class constructor.
-        super().__init__(**traits)
-
-        # Create the toolkit-specific control that represents the widget.
-        self.control = self._create_control(parent)
+        create = traits.pop("create", True)
 
-        # Set up to be notified whenever a Python statement is executed:
-        self.control.handlers.append(self._on_command_executed)
+        # Base class constructor.
+        super().__init__(parent=parent, **traits)
+
+        if create:
+            # Create the toolkit-specific control that represents the widget.
+            self.control = self.create()
+            warnings.warn(
+                "automatic widget creation is deprecated and will be removed "
+                "in a future Pyface version, use create=False and explicitly "
+                "call create() for future behaviour",
+                PendingDeprecationWarning,
+            )
 
     # ------------------------------------------------------------------------
     # 'IPythonShell' interface.
@@ -172,6 +179,9 @@ def _create_control(self, parent):
         # Enable the shell as a drag and drop target.
         shell.SetDropTarget(PythonDropTarget(self))
 
+        # Set up to be notified whenever a Python statement is executed:
+        shell.handlers.append(self._on_command_executed)
+
         return shell
 
     # ------------------------------------------------------------------------