# Tkinter font wrapper

#

# written by Fredrik Lundh, February 1998

#

# FIXME: should add 'displayof' option where relevant (actual, families,

#        measure, and metrics)

#

__version__ = "0.9"

import Tkinter

# weight/slant

NORMAL = "normal"

ROMAN = "roman"

BOLD   = "bold"

ITALIC = "italic"

def nametofont(name):

    """Given the name of a tk named font, returns a Font representation.

    """

    return Font(name=name, exists=True)

class Font:

    """Represents a named font.

    Constructor options are:

    font -- font specifier (name, system font, or (family, size, style)-tuple)

    name -- name to use for this font configuration (defaults to a unique name)

    exists -- does a named font by this name already exist?

       Creates a new named font if False, points to the existing font if True.

       Raises _tkinter.TclError if the assertion is false.

       the following are ignored if font is specified:

    family -- font 'family', e.g. Courier, Times, Helvetica

    size -- font size in points

    weight -- font thickness: NORMAL, BOLD

    slant -- font slant: ROMAN, ITALIC

    underline -- font underlining: false (0), true (1)

    overstrike -- font strikeout: false (0), true (1)

    """

    def _set(self, kw):

        options = []

        for k, v in kw.items():

            options.append("-"+k)

            options.append(str(v))

        return tuple(options)

    def _get(self, args):

        options = []

        for k in args:

            options.append("-"+k)

        return tuple(options)

    def _mkdict(self, args):

        options = {}

        for i in range(0, len(args), 2):

            options[args[i][1:]] = args[i+1]

        return options

    def __init__(self, root=None, font=None, name=None, exists=False, **options):

        if not root:

            root = Tkinter._default_root

        if font:

            # get actual settings corresponding to the given font

            font = root.tk.splitlist(root.tk.call("font", "actual", font))

        else:

            font = self._set(options)

        if not name:

            name = "font" + str(id(self))

        self.name = name

        if exists:

            self.delete_font = False

            # confirm font exists

            if self.name not in root.tk.call("font", "names"):

                raise Tkinter._tkinter.TclError, "named font %s does not already exist" % (self.name,)

            # if font config info supplied, apply it

            if font:

                root.tk.call("font", "configure", self.name, *font)

        else:

            # create new font (raises TclError if the font exists)

            root.tk.call("font", "create", self.name, *font)

            self.delete_font = True

        # backlinks!

        self._root  = root

        self._split = root.tk.splitlist

        self._call  = root.tk.call

    def __str__(self):

        return self.name

    def __eq__(self, other):

        return self.name == other.name and isinstance(other, Font)

    def __getitem__(self, key):

        return self.cget(key)

    def __setitem__(self, key, value):

        self.configure(**{key: value})

    def __del__(self):

        try:

            if self.delete_font:

                self._call("font", "delete", self.name)

        except (KeyboardInterrupt, SystemExit):

            raise

        except Exception:

            pass

    def copy(self):

        "Return a distinct copy of the current font"

        return Font(self._root, **self.actual())

    def actual(self, option=None):

        "Return actual font attributes"

        if option:

            return self._call("font", "actual", self.name, "-"+option)

        else:

            return self._mkdict(

                self._split(self._call("font", "actual", self.name))

                )

    def cget(self, option):

        "Get font attribute"

        return self._call("font", "config", self.name, "-"+option)

    def config(self, **options):

        "Modify font attributes"

        if options:

            self._call("font", "config", self.name,

                  *self._set(options))

        else:

            return self._mkdict(

                self._split(self._call("font", "config", self.name))

                )

    configure = config

    def measure(self, text):

        "Return text width"

        return int(self._call("font", "measure", self.name, text))

    def metrics(self, *options):

        """Return font metrics.

        For best performance, create a dummy widget

        using this font before calling this method."""

        if options:

            return int(

                self._call("font", "metrics", self.name, self._get(options))

                )

        else:

            res = self._split(self._call("font", "metrics", self.name))

            options = {}

            for i in range(0, len(res), 2):

                options[res[i][1:]] = int(res[i+1])

            return options

def families(root=None):

    "Get font families (as a tuple)"

    if not root:

        root = Tkinter._default_root

    return root.tk.splitlist(root.tk.call("font", "families"))

def names(root=None):

    "Get names of defined fonts (as a tuple)"

    if not root:

        root = Tkinter._default_root

    return root.tk.splitlist(root.tk.call("font", "names"))

# --------------------------------------------------------------------

# test stuff

if __name__ == "__main__":

    root = Tkinter.Tk()

    # create a font

    f = Font(family="times", size=30, weight=NORMAL)

    print f.actual()

    print f.actual("family")

    print f.actual("weight")

    print f.config()

    print f.cget("family")

    print f.cget("weight")

    print names()

    print f.measure("hello"), f.metrics("linespace")

    print f.metrics()

    f = Font(font=("Courier", 20, "bold"))

    print f.measure("hello"), f.metrics("linespace")

    w = Tkinter.Label(root, text="Hello, world", font=f)

    w.pack()

    w = Tkinter.Button(root, text="Quit!", command=root.destroy)

    w.pack()

    fb = Font(font=w["font"]).copy()

    fb.config(weight=BOLD)

    w.config(font=fb)

    Tkinter.mainloop()