From 87bbf257ef6e8d1e5876776094db609702ee468a Mon Sep 17 00:00:00 2001
From: Serhiy Storchaka <storchaka@gmail.com>
Date: Sun, 17 Aug 2014 15:31:59 +0300
Subject: Issue #22068: Avoided reference loops with Variables and Fonts in
Tkinter.
---
Lib/tkinter/__init__.py | 34 +++++++++++++++++++++++++++++-----
Lib/tkinter/font.py | 19 +++++++++----------
Misc/NEWS | 2 ++
3 files changed, 40 insertions(+), 15 deletions(-)
diff --git a/Lib/tkinter/__init__.py b/Lib/tkinter/__init__.py
index 75e5fb1..5447732 100644
--- a/Lib/tkinter/__init__.py
+++ b/Lib/tkinter/__init__.py
@@ -191,6 +191,7 @@ class Variable:
that constrain the type of the value returned from get()."""
_default = ""
_tk = None
+ _tclCommands = None
def __init__(self, master=None, value=None, name=None):
"""Construct a variable
@@ -209,7 +210,7 @@ class Variable:
global _varnum
if not master:
master = _default_root
- self._master = master
+ self._root = master._root()
self._tk = master.tk
if name:
self._name = name
@@ -222,9 +223,15 @@ class Variable:
self.initialize(self._default)
def __del__(self):
"""Unset the variable in Tcl."""
- if (self._tk is not None and
- self._tk.getboolean(self._tk.call("info", "exists", self._name))):
+ if self._tk is None:
+ return
+ if self._tk.getboolean(self._tk.call("info", "exists", self._name)):
self._tk.globalunsetvar(self._name)
+ if self._tclCommands is not None:
+ for name in self._tclCommands:
+ #print '- Tkinter: deleted command', name
+ self._tk.deletecommand(name)
+ self._tclCommands = None
def __str__(self):
"""Return the name of the variable in Tcl."""
return self._name
@@ -244,7 +251,20 @@ class Variable:
Return the name of the callback.
"""
- cbname = self._master._register(callback)
+ f = CallWrapper(callback, None, self).__call__
+ cbname = repr(id(f))
+ try:
+ callback = callback.__func__
+ except AttributeError:
+ pass
+ try:
+ cbname = cbname + callback.__name__
+ except AttributeError:
+ pass
+ self._tk.createcommand(cbname, f)
+ if self._tclCommands is None:
+ self._tclCommands = []
+ self._tclCommands.append(cbname)
self._tk.call("trace", "variable", self._name, mode, cbname)
return cbname
trace = trace_variable
@@ -255,7 +275,11 @@ class Variable:
CBNAME is the name of the callback returned from trace_variable or trace.
"""
self._tk.call("trace", "vdelete", self._name, mode, cbname)
- self._master.deletecommand(cbname)
+ self._tk.deletecommand(cbname)
+ try:
+ self._tclCommands.remove(cbname)
+ except ValueError:
+ pass
def trace_vinfo(self):
"""Return all trace callback information."""
return [self._tk.split(x) for x in self._tk.splitlist(
diff --git a/Lib/tkinter/font.py b/Lib/tkinter/font.py
index 2096093..b966732 100644
--- a/Lib/tkinter/font.py
+++ b/Lib/tkinter/font.py
@@ -69,9 +69,10 @@ class Font:
**options):
if not root:
root = tkinter._default_root
+ tk = getattr(root, 'tk', root)
if font:
# get actual settings corresponding to the given font
- font = root.tk.splitlist(root.tk.call("font", "actual", font))
+ font = tk.splitlist(tk.call("font", "actual", font))
else:
font = self._set(options)
if not name:
@@ -81,21 +82,19 @@ class Font:
if exists:
self.delete_font = False
# confirm font exists
- if self.name not in root.tk.splitlist(
- root.tk.call("font", "names")):
+ if self.name not in tk.splitlist(tk.call("font", "names")):
raise tkinter._tkinter.TclError(
"named font %s does not already exist" % (self.name,))
# if font config info supplied, apply it
if font:
- root.tk.call("font", "configure", self.name, *font)
+ tk.call("font", "configure", self.name, *font)
else:
# create new font (raises TclError if the font exists)
- root.tk.call("font", "create", self.name, *font)
+ tk.call("font", "create", self.name, *font)
self.delete_font = True
- # backlinks!
- self._root = root
- self._split = root.tk.splitlist
- self._call = root.tk.call
+ self._tk = tk
+ self._split = tk.splitlist
+ self._call = tk.call
def __str__(self):
return self.name
@@ -120,7 +119,7 @@ class Font:
def copy(self):
"Return a distinct copy of the current font"
- return Font(self._root, **self.actual())
+ return Font(self._tk, **self.actual())
def actual(self, option=None, displayof=None):
"Return actual font attributes"
diff --git a/Misc/NEWS b/Misc/NEWS
index 15f2b82..58d23dd 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -27,6 +27,8 @@ Core and Builtins
Library
-------
+- Issue #22068: Avoided reference loops with Variables and Fonts in Tkinter.
+
- Issue #22165: SimpleHTTPRequestHandler now supports undecodable file names.
- Issue #20729: Restored the use of lazy iterkeys()/itervalues()/iteritems()
--
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