1"""
2Simple calendar using ttk Treeview together with calendar and datetime
3classes.
4"""
5import calendar
6import Tkinter
7import tkFont
8import ttk
9
10def get_calendar(locale, fwday):
11    # instantiate proper calendar class
12    if locale is None:
13        return calendar.TextCalendar(fwday)
14    else:
15        return calendar.LocaleTextCalendar(fwday, locale)
16
17class Calendar(ttk.Frame):
18    # XXX ToDo: cget and configure
19
20    datetime = calendar.datetime.datetime
21    timedelta = calendar.datetime.timedelta
22
23    def __init__(self, master=None, **kw):
24        """
25        WIDGET-SPECIFIC OPTIONS
26
27            locale, firstweekday, year, month, selectbackground,
28            selectforeground
29        """
30        # remove custom options from kw before initializating ttk.Frame
31        fwday = kw.pop('firstweekday', calendar.MONDAY)
32        year = kw.pop('year', self.datetime.now().year)
33        month = kw.pop('month', self.datetime.now().month)
34        locale = kw.pop('locale', None)
35        sel_bg = kw.pop('selectbackground', '#ecffc4')
36        sel_fg = kw.pop('selectforeground', '#05640e')
37
38        self._date = self.datetime(year, month, 1)
39        self._selection = None # no date selected
40
41        ttk.Frame.__init__(self, master, **kw)
42
43        self._cal = get_calendar(locale, fwday)
44
45        self.__setup_styles()       # creates custom styles
46        self.__place_widgets()      # pack/grid used widgets
47        self.__config_calendar()    # adjust calendar columns and setup tags
48        # configure a canvas, and proper bindings, for selecting dates
49        self.__setup_selection(sel_bg, sel_fg)
50
51        # store items ids, used for insertion later
52        self._items = [self._calendar.insert('', 'end', values='')
53                            for _ in range(6)]
54        # insert dates in the currently empty calendar
55        self._build_calendar()
56
57        # set the minimal size for the widget
58        self._calendar.bind('<Map>', self.__minsize)
59
60    def __setitem__(self, item, value):
61        if item in ('year', 'month'):
62            raise AttributeError("attribute '%s' is not writeable" % item)
63        elif item == 'selectbackground':
64            self._canvas['background'] = value
65        elif item == 'selectforeground':
66            self._canvas.itemconfigure(self._canvas.text, item=value)
67        else:
68            ttk.Frame.__setitem__(self, item, value)
69
70    def __getitem__(self, item):
71        if item in ('year', 'month'):
72            return getattr(self._date, item)
73        elif item == 'selectbackground':
74            return self._canvas['background']
75        elif item == 'selectforeground':
76            return self._canvas.itemcget(self._canvas.text, 'fill')
77        else:
78            r = ttk.tclobjs_to_py({item: ttk.Frame.__getitem__(self, item)})
79            return r[item]
80
81    def __setup_styles(self):
82        # custom ttk styles
83        style = ttk.Style(self.master)
84        arrow_layout = lambda dir: (
85            [('Button.focus', {'children': [('Button.%sarrow' % dir, None)]})]
86        )
87        style.layout('L.TButton', arrow_layout('left'))
88        style.layout('R.TButton', arrow_layout('right'))
89
90    def __place_widgets(self):
91        # header frame and its widgets
92        hframe = ttk.Frame(self)
93        lbtn = ttk.Button(hframe, style='L.TButton', command=self._prev_month)
94        rbtn = ttk.Button(hframe, style='R.TButton', command=self._next_month)
95        self._header = ttk.Label(hframe, width=15, anchor='center')
96        # the calendar
97        self._calendar = ttk.Treeview(show='', selectmode='none', height=7)
98
99        # pack the widgets
100        hframe.pack(in_=self, side='top', pady=4, anchor='center')
101        lbtn.grid(in_=hframe)
102        self._header.grid(in_=hframe, column=1, row=0, padx=12)
103        rbtn.grid(in_=hframe, column=2, row=0)
104        self._calendar.pack(in_=self, expand=1, fill='both', side='bottom')
105
106    def __config_calendar(self):
107        cols = self._cal.formatweekheader(3).split()
108        self._calendar['columns'] = cols
109        self._calendar.tag_configure('header', background='grey90')
110        self._calendar.insert('', 'end', values=cols, tag='header')
111        # adjust its columns width
112        font = tkFont.Font()
113        maxwidth = max(font.measure(col) for col in cols)
114        for col in cols:
115            self._calendar.column(col, width=maxwidth, minwidth=maxwidth,
116                anchor='e')
117
118    def __setup_selection(self, sel_bg, sel_fg):
119        self._font = tkFont.Font()
120        self._canvas = canvas = Tkinter.Canvas(self._calendar,
121            background=sel_bg, borderwidth=0, highlightthickness=0)
122        canvas.text = canvas.create_text(0, 0, fill=sel_fg, anchor='w')
123
124        canvas.bind('<ButtonPress-1>', lambda evt: canvas.place_forget())
125        self._calendar.bind('<Configure>', lambda evt: canvas.place_forget())
126        self._calendar.bind('<ButtonPress-1>', self._pressed)
127
128    def __minsize(self, evt):
129        width, height = self._calendar.master.geometry().split('x')
130        height = height[:height.index('+')]
131        self._calendar.master.minsize(width, height)
132
133    def _build_calendar(self):
134        year, month = self._date.year, self._date.month
135
136        # update header text (Month, YEAR)
137        header = self._cal.formatmonthname(year, month, 0)
138        self._header['text'] = header.title()
139
140        # update calendar shown dates
141        cal = self._cal.monthdayscalendar(year, month)
142        for indx, item in enumerate(self._items):
143            week = cal[indx] if indx < len(cal) else []
144            fmt_week = [('%02d' % day) if day else '' for day in week]
145            self._calendar.item(item, values=fmt_week)
146
147    def _show_selection(self, text, bbox):
148        """Configure canvas for a new selection."""
149        x, y, width, height = bbox
150
151        textw = self._font.measure(text)
152
153        canvas = self._canvas
154        canvas.configure(width=width, height=height)
155        canvas.coords(canvas.text, width - textw, height / 2 - 1)
156        canvas.itemconfigure(canvas.text, text=text)
157        canvas.place(in_=self._calendar, x=x, y=y)
158
159    # Callbacks
160
161    def _pressed(self, evt):
162        """Clicked somewhere in the calendar."""
163        x, y, widget = evt.x, evt.y, evt.widget
164        item = widget.identify_row(y)
165        column = widget.identify_column(x)
166
167        if not column or not item in self._items:
168            # clicked in the weekdays row or just outside the columns
169            return
170
171        item_values = widget.item(item)['values']
172        if not len(item_values): # row is empty for this month
173            return
174
175        text = item_values[int(column[1]) - 1]
176        if not text: # date is empty
177            return
178
179        bbox = widget.bbox(item, column)
180        if not bbox: # calendar not visible yet
181            return
182
183        # update and then show selection
184        text = '%02d' % text
185        self._selection = (text, item, column)
186        self._show_selection(text, bbox)
187
188    def _prev_month(self):
189        """Updated calendar to show the previous month."""
190        self._canvas.place_forget()
191
192        self._date = self._date - self.timedelta(days=1)
193        self._date = self.datetime(self._date.year, self._date.month, 1)
194        self._build_calendar() # reconstruct calendar
195
196    def _next_month(self):
197        """Update calendar to show the next month."""
198        self._canvas.place_forget()
199
200        year, month = self._date.year, self._date.month
201        self._date = self._date + self.timedelta(
202            days=calendar.monthrange(year, month)[1] + 1)
203        self._date = self.datetime(self._date.year, self._date.month, 1)
204        self._build_calendar() # reconstruct calendar
205
206    # Properties
207
208    @property
209    def selection(self):
210        """Return a datetime representing the current selected date."""
211        if not self._selection:
212            return None
213
214        year, month = self._date.year, self._date.month
215        return self.datetime(year, month, int(self._selection[0]))
216
217def test():
218    import sys
219    root = Tkinter.Tk()
220    root.title('Ttk Calendar')
221    ttkcal = Calendar(firstweekday=calendar.SUNDAY)
222    ttkcal.pack(expand=1, fill='both')
223
224    if 'win' not in sys.platform:
225        style = ttk.Style()
226        style.theme_use('clam')
227
228    root.mainloop()
229
230if __name__ == '__main__':
231    test()
232