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