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