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):
21    """Given the name of a tk named font, returns a Font representation.
22    """
23    return Font(name=name, exists=True)
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 not root:
72            root = tkinter._default_root
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 __eq__(self, other):
104        if not isinstance(other, Font):
105            return NotImplemented
106        return self.name == other.name
107
108    def __getitem__(self, key):
109        return self.cget(key)
110
111    def __setitem__(self, key, value):
112        self.configure(**{key: value})
113
114    def __del__(self):
115        try:
116            if self.delete_font:
117                self._call("font", "delete", self.name)
118        except Exception:
119            pass
120
121    def copy(self):
122        "Return a distinct copy of the current font"
123        return Font(self._tk, **self.actual())
124
125    def actual(self, option=None, displayof=None):
126        "Return actual font attributes"
127        args = ()
128        if displayof:
129            args = ('-displayof', displayof)
130        if option:
131            args = args + ('-' + option, )
132            return self._call("font", "actual", self.name, *args)
133        else:
134            return self._mkdict(
135                self._split(self._call("font", "actual", self.name, *args)))
136
137    def cget(self, option):
138        "Get font attribute"
139        return self._call("font", "config", self.name, "-"+option)
140
141    def config(self, **options):
142        "Modify font attributes"
143        if options:
144            self._call("font", "config", self.name,
145                  *self._set(options))
146        else:
147            return self._mkdict(
148                self._split(self._call("font", "config", self.name)))
149
150    configure = config
151
152    def measure(self, text, displayof=None):
153        "Return text width"
154        args = (text,)
155        if displayof:
156            args = ('-displayof', displayof, text)
157        return self._tk.getint(self._call("font", "measure", self.name, *args))
158
159    def metrics(self, *options, **kw):
160        """Return font metrics.
161
162        For best performance, create a dummy widget
163        using this font before calling this method."""
164        args = ()
165        displayof = kw.pop('displayof', None)
166        if displayof:
167            args = ('-displayof', displayof)
168        if options:
169            args = args + self._get(options)
170            return self._tk.getint(
171                self._call("font", "metrics", self.name, *args))
172        else:
173            res = self._split(self._call("font", "metrics", self.name, *args))
174            options = {}
175            for i in range(0, len(res), 2):
176                options[res[i][1:]] = self._tk.getint(res[i+1])
177            return options
178
179
180def families(root=None, displayof=None):
181    "Get font families (as a tuple)"
182    if not root:
183        root = tkinter._default_root
184    args = ()
185    if displayof:
186        args = ('-displayof', displayof)
187    return root.tk.splitlist(root.tk.call("font", "families", *args))
188
189
190def names(root=None):
191    "Get names of defined fonts (as a tuple)"
192    if not root:
193        root = tkinter._default_root
194    return root.tk.splitlist(root.tk.call("font", "names"))
195
196
197# --------------------------------------------------------------------
198# test stuff
199
200if __name__ == "__main__":
201
202    root = tkinter.Tk()
203
204    # create a font
205    f = Font(family="times", size=30, weight=NORMAL)
206
207    print(f.actual())
208    print(f.actual("family"))
209    print(f.actual("weight"))
210
211    print(f.config())
212    print(f.cget("family"))
213    print(f.cget("weight"))
214
215    print(names())
216
217    print(f.measure("hello"), f.metrics("linespace"))
218
219    print(f.metrics(displayof=root))
220
221    f = Font(font=("Courier", 20, "bold"))
222    print(f.measure("hello"), f.metrics("linespace", displayof=root))
223
224    w = tkinter.Label(root, text="Hello, world", font=f)
225    w.pack()
226
227    w = tkinter.Button(root, text="Quit!", command=root.destroy)
228    w.pack()
229
230    fb = Font(font=w["font"]).copy()
231    fb.config(weight=BOLD)
232
233    w.config(font=fb)
234
235    tkinter.mainloop()
236