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1# Tkinter font wrapper
2#
3# written by Fredrik Lundh, February 1998
4#
5
6import itertools
7import tkinter
8
9__version__ = "0.9"
10__all__ = ["NORMAL", "ROMAN", "BOLD", "ITALIC",
11           "nametofont", "Font", "families", "names"]
12
13# weight/slant
14NORMAL = "normal"
15ROMAN = "roman"
16BOLD   = "bold"
17ITALIC = "italic"
18
19
20def 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
26class Font:
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
184def 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
194def 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
204if __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()
240