# Tkinter font wrapper # # written by Fredrik Lundh, February 1998 # import itertools import tkinter __version__ = "0.9" __all__ = ["NORMAL", "ROMAN", "BOLD", "ITALIC", "nametofont", "Font", "families", "names"] # weight/slant NORMAL = "normal" ROMAN = "roman" BOLD = "bold" ITALIC = "italic" def nametofont(name): """Given the name of a tk named font, returns a Font representation. """ return Font(name=name, exists=True) class Font: """Represents a named font. Constructor options are: font -- font specifier (name, system font, or (family, size, style)-tuple) name -- name to use for this font configuration (defaults to a unique name) exists -- does a named font by this name already exist? Creates a new named font if False, points to the existing font if True. Raises _tkinter.TclError if the assertion is false. the following are ignored if font is specified: family -- font 'family', e.g. Courier, Times, Helvetica size -- font size in points weight -- font thickness: NORMAL, BOLD slant -- font slant: ROMAN, ITALIC underline -- font underlining: false (0), true (1) overstrike -- font strikeout: false (0), true (1) """ counter = itertools.count(1) def _set(self, kw): options = [] for k, v in kw.items(): options.append("-"+k) options.append(str(v)) return tuple(options) def _get(self, args): options = [] for k in args: options.append("-"+k) return tuple(options) def _mkdict(self, args): options = {} for i in range(0, len(args), 2): options[args[i][1:]] = args[i+1] return options def __init__(self, root=None, font=None, name=None, exists=False, **options): if not root: root = tkinter._get_default_root('use font') tk = getattr(root, 'tk', root) if font: # get actual settings corresponding to the given font font = tk.splitlist(tk.call("font", "actual", font)) else: font = self._set(options) if not name: name = "font" + str(next(self.counter)) self.name = name if exists: self.delete_font = False # confirm font exists 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: tk.call("font", "configure", self.name, *font) else: # create new font (raises TclError if the font exists) tk.call("font", "create", self.name, *font) self.delete_font = True self._tk = tk self._split = tk.splitlist self._call = tk.call def __str__(self): return self.name def __repr__(self): return f"<{self.__class__.__module__}.{self.__class__.__qualname__}" \ f" object {self.name!r}>" def __eq__(self, other): if not isinstance(other, Font): return NotImplemented return self.name == other.name def __getitem__(self, key): return self.cget(key) def __setitem__(self, key, value): self.configure(**{key: value}) def __del__(self): try: if self.delete_font: self._call("font", "delete", self.name) except Exception: pass def copy(self): "Return a distinct copy of the current font" return Font(self._tk, **self.actual()) def actual(self, option=None, displayof=None): "Return actual font attributes" args = () if displayof: args = ('-displayof', displayof) if option: args = args + ('-' + option, ) return self._call("font", "actual", self.name, *args) else: return self._mkdict( self._split(self._call("font", "actual", self.name, *args))) def cget(self, option): "Get font attribute" return self._call("font", "config", self.name, "-"+option) def config(self, **options): "Modify font attributes" if options: self._call("font", "config", self.name, *self._set(options)) else: return self._mkdict( self._split(self._call("font", "config", self.name))) configure = config def measure(self, text, displayof=None): "Return text width" args = (text,) if displayof: args = ('-displayof', displayof, text) return self._tk.getint(self._call("font", "measure", self.name, *args)) def metrics(self, *options, **kw): """Return font metrics. For best performance, create a dummy widget using this font before calling this method.""" args = () displayof = kw.pop('displayof', None) if displayof: args = ('-displayof', displayof) if options: args = args + self._get(options) return self._tk.getint( self._call("font", "metrics", self.name, *args)) else: res = self._split(self._call("font", "metrics", self.name, *args)) options = {} for i in range(0, len(res), 2): options[res[i][1:]] = self._tk.getint(res[i+1]) return options def families(root=None, displayof=None): "Get font families (as a tuple)" if not root: root = tkinter._get_default_root('use font.families()') args = () if displayof: args = ('-displayof', displayof) return root.tk.splitlist(root.tk.call("font", "families", *args)) def names(root=None): "Get names of defined fonts (as a tuple)" if not root: root = tkinter._get_default_root('use font.names()') return root.tk.splitlist(root.tk.call("font", "names")) # -------------------------------------------------------------------- # test stuff if __name__ == "__main__": root = tkinter.Tk() # create a font f = Font(family="times", size=30, weight=NORMAL) print(f.actual()) print(f.actual("family")) print(f.actual("weight")) print(f.config()) print(f.cget("family")) print(f.cget("weight")) print(names()) print(f.measure("hello"), f.metrics("linespace")) print(f.metrics(displayof=root)) f = Font(font=("Courier", 20, "bold")) print(f.measure("hello"), f.metrics("linespace", displayof=root)) w = tkinter.Label(root, text="Hello, world", font=f) w.pack() w = tkinter.Button(root, text="Quit!", command=root.destroy) w.pack() fb = Font(font=w["font"]).copy() fb.config(weight=BOLD) w.config(font=fb) tkinter.mainloop()