diff options
Diffstat (limited to 'Lib/tkinter/__init__.py')
| -rw-r--r-- | Lib/tkinter/__init__.py | 51 |
1 files changed, 30 insertions, 21 deletions
diff --git a/Lib/tkinter/__init__.py b/Lib/tkinter/__init__.py index 2175afc..bf0342e 100644 --- a/Lib/tkinter/__init__.py +++ b/Lib/tkinter/__init__.py @@ -270,7 +270,7 @@ class Event: ) -_support_default_root = 1 +_support_default_root = True _default_root = None @@ -280,13 +280,26 @@ def NoDefaultRoot(): Call this function to inhibit that the first instance of Tk is used for windows without an explicit parent window. """ - global _support_default_root - _support_default_root = 0 - global _default_root + global _support_default_root, _default_root + _support_default_root = False + # Delete, so any use of _default_root will immediately raise an exception. + # Rebind before deletion, so repeated calls will not fail. _default_root = None del _default_root +def _get_default_root(what=None): + if not _support_default_root: + raise RuntimeError("No master specified and tkinter is " + "configured to not support default root") + if not _default_root: + if what: + raise RuntimeError(f"Too early to {what}: no default root window") + root = Tk() + assert _default_root is root + return _default_root + + def _tkerror(err): """Internal function.""" pass @@ -330,7 +343,7 @@ class Variable: raise TypeError("name must be a string") global _varnum if not master: - master = _default_root + master = _get_default_root('create variable') self._root = master._root() self._tk = master.tk if name: @@ -591,7 +604,7 @@ class BooleanVar(Variable): def mainloop(n=0): """Run the main loop of Tcl.""" - _default_root.tk.mainloop(n) + _get_default_root('run the main loop').tk.mainloop(n) getint = int @@ -600,9 +613,9 @@ getdouble = float def getboolean(s): - """Convert true and false to integer values 1 and 0.""" + """Convert Tcl object to True or False.""" try: - return _default_root.tk.getboolean(s) + return _get_default_root('use getboolean()').tk.getboolean(s) except TclError: raise ValueError("invalid literal for getboolean()") @@ -2248,7 +2261,7 @@ class Tk(Misc, Wm): is the name of the widget class.""" self.master = None self.children = {} - self._tkloaded = 0 + self._tkloaded = False # to avoid recursions in the getattr code in case of failure, we # ensure that self.tk is always _something_. self.tk = None @@ -2272,7 +2285,7 @@ class Tk(Misc, Wm): self._loadtk() def _loadtk(self): - self._tkloaded = 1 + self._tkloaded = True global _default_root # Version sanity checks tk_version = self.tk.getvar('tk_version') @@ -2521,12 +2534,8 @@ class BaseWidget(Misc): def _setup(self, master, cnf): """Internal function. Sets up information about children.""" - if _support_default_root: - global _default_root - if not master: - if not _default_root: - _default_root = Tk() - master = _default_root + if not master: + master = _get_default_root() self.master = master self.tk = master.tk name = None @@ -3990,9 +3999,7 @@ class Image: def __init__(self, imgtype, name=None, cnf={}, master=None, **kw): self.name = None if not master: - master = _default_root - if not master: - raise RuntimeError('Too early to create image') + master = _get_default_root('create image') self.tk = getattr(master, 'tk', master) if not name: Image._last_id += 1 @@ -4146,11 +4153,13 @@ class BitmapImage(Image): def image_names(): - return _default_root.tk.splitlist(_default_root.tk.call('image', 'names')) + tk = _get_default_root('use image_names()').tk + return tk.splitlist(tk.call('image', 'names')) def image_types(): - return _default_root.tk.splitlist(_default_root.tk.call('image', 'types')) + tk = _get_default_root('use image_types()').tk + return tk.splitlist(tk.call('image', 'types')) class Spinbox(Widget, XView): |