python (3.11.7)
1 # Tkinter font wrapper
2 #
3 # written by Fredrik Lundh, February 1998
4 #
5
6 import itertools
7 import tkinter
8
9 __version__ = "0.9"
10 __all__ = ["NORMAL", "ROMAN", "BOLD", "ITALIC",
11 "nametofont", "Font", "families", "names"]
12
13 # weight/slant
14 NORMAL = "normal"
15 ROMAN = "roman"
16 BOLD = "bold"
17 ITALIC = "italic"
18
19
20 def nametofont(name, root=None):
21 """Given the name of a tk named font, returns a Font representation.
22 """
23 return Font(name=name, exists=True, root=root)
24
25
26 class ESC[4;38;5;81mFont:
27 """Represents a named font.
28
29 Constructor options are:
30
31 font -- font specifier (name, system font, or (family, size, style)-tuple)
32 name -- name to use for this font configuration (defaults to a unique name)
33 exists -- does a named font by this name already exist?
34 Creates a new named font if False, points to the existing font if True.
35 Raises _tkinter.TclError if the assertion is false.
36
37 the following are ignored if font is specified:
38
39 family -- font 'family', e.g. Courier, Times, Helvetica
40 size -- font size in points
41 weight -- font thickness: NORMAL, BOLD
42 slant -- font slant: ROMAN, ITALIC
43 underline -- font underlining: false (0), true (1)
44 overstrike -- font strikeout: false (0), true (1)
45
46 """
47
48 counter = itertools.count(1)
49
50 def _set(self, kw):
51 options = []
52 for k, v in kw.items():
53 options.append("-"+k)
54 options.append(str(v))
55 return tuple(options)
56
57 def _get(self, args):
58 options = []
59 for k in args:
60 options.append("-"+k)
61 return tuple(options)
62
63 def _mkdict(self, args):
64 options = {}
65 for i in range(0, len(args), 2):
66 options[args[i][1:]] = args[i+1]
67 return options
68
69 def __init__(self, root=None, font=None, name=None, exists=False,
70 **options):
71 if root is None:
72 root = tkinter._get_default_root('use font')
73 tk = getattr(root, 'tk', root)
74 if font:
75 # get actual settings corresponding to the given font
76 font = tk.splitlist(tk.call("font", "actual", font))
77 else:
78 font = self._set(options)
79 if not name:
80 name = "font" + str(next(self.counter))
81 self.name = name
82
83 if exists:
84 self.delete_font = False
85 # confirm font exists
86 if self.name not in tk.splitlist(tk.call("font", "names")):
87 raise tkinter._tkinter.TclError(
88 "named font %s does not already exist" % (self.name,))
89 # if font config info supplied, apply it
90 if font:
91 tk.call("font", "configure", self.name, *font)
92 else:
93 # create new font (raises TclError if the font exists)
94 tk.call("font", "create", self.name, *font)
95 self.delete_font = True
96 self._tk = tk
97 self._split = tk.splitlist
98 self._call = tk.call
99
100 def __str__(self):
101 return self.name
102
103 def __repr__(self):
104 return f"<{self.__class__.__module__}.{self.__class__.__qualname__}" \
105 f" object {self.name!r}>"
106
107 def __eq__(self, other):
108 if not isinstance(other, Font):
109 return NotImplemented
110 return self.name == other.name and self._tk == other._tk
111
112 def __getitem__(self, key):
113 return self.cget(key)
114
115 def __setitem__(self, key, value):
116 self.configure(**{key: value})
117
118 def __del__(self):
119 try:
120 if self.delete_font:
121 self._call("font", "delete", self.name)
122 except Exception:
123 pass
124
125 def copy(self):
126 "Return a distinct copy of the current font"
127 return Font(self._tk, **self.actual())
128
129 def actual(self, option=None, displayof=None):
130 "Return actual font attributes"
131 args = ()
132 if displayof:
133 args = ('-displayof', displayof)
134 if option:
135 args = args + ('-' + option, )
136 return self._call("font", "actual", self.name, *args)
137 else:
138 return self._mkdict(
139 self._split(self._call("font", "actual", self.name, *args)))
140
141 def cget(self, option):
142 "Get font attribute"
143 return self._call("font", "config", self.name, "-"+option)
144
145 def config(self, **options):
146 "Modify font attributes"
147 if options:
148 self._call("font", "config", self.name,
149 *self._set(options))
150 else:
151 return self._mkdict(
152 self._split(self._call("font", "config", self.name)))
153
154 configure = config
155
156 def measure(self, text, displayof=None):
157 "Return text width"
158 args = (text,)
159 if displayof:
160 args = ('-displayof', displayof, text)
161 return self._tk.getint(self._call("font", "measure", self.name, *args))
162
163 def metrics(self, *options, **kw):
164 """Return font metrics.
165
166 For best performance, create a dummy widget
167 using this font before calling this method."""
168 args = ()
169 displayof = kw.pop('displayof', None)
170 if displayof:
171 args = ('-displayof', displayof)
172 if options:
173 args = args + self._get(options)
174 return self._tk.getint(
175 self._call("font", "metrics", self.name, *args))
176 else:
177 res = self._split(self._call("font", "metrics", self.name, *args))
178 options = {}
179 for i in range(0, len(res), 2):
180 options[res[i][1:]] = self._tk.getint(res[i+1])
181 return options
182
183
184 def families(root=None, displayof=None):
185 "Get font families (as a tuple)"
186 if root is None:
187 root = tkinter._get_default_root('use font.families()')
188 args = ()
189 if displayof:
190 args = ('-displayof', displayof)
191 return root.tk.splitlist(root.tk.call("font", "families", *args))
192
193
194 def names(root=None):
195 "Get names of defined fonts (as a tuple)"
196 if root is None:
197 root = tkinter._get_default_root('use font.names()')
198 return root.tk.splitlist(root.tk.call("font", "names"))
199
200
201 # --------------------------------------------------------------------
202 # test stuff
203
204 if __name__ == "__main__":
205
206 root = tkinter.Tk()
207
208 # create a font
209 f = Font(family="times", size=30, weight=NORMAL)
210
211 print(f.actual())
212 print(f.actual("family"))
213 print(f.actual("weight"))
214
215 print(f.config())
216 print(f.cget("family"))
217 print(f.cget("weight"))
218
219 print(names())
220
221 print(f.measure("hello"), f.metrics("linespace"))
222
223 print(f.metrics(displayof=root))
224
225 f = Font(font=("Courier", 20, "bold"))
226 print(f.measure("hello"), f.metrics("linespace", displayof=root))
227
228 w = tkinter.Label(root, text="Hello, world", font=f)
229 w.pack()
230
231 w = tkinter.Button(root, text="Quit!", command=root.destroy)
232 w.pack()
233
234 fb = Font(font=w["font"]).copy()
235 fb.config(weight=BOLD)
236
237 w.config(font=fb)
238
239 tkinter.mainloop()
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