September 16, 2014 19:05 · Sep 16, 2014
diff --git a/ttkcalendar.py b/ttkcalendar.py
@@ -0,0 +1,232 @@
+"""
+Simple calendar using ttk Treeview together with calendar and datetime
+classes.
+"""
+import calendar
+import tkinter
+import tkinter.font
+from tkinter import ttk
+
+def get_calendar(locale, fwday):
+    # instantiate proper calendar class
+    if locale is None:
+        return calendar.TextCalendar(fwday)
+    else:
+        return calendar.LocaleTextCalendar(fwday, locale)
+
+class Calendar(ttk.Frame):
+    # XXX ToDo: cget and configure
+
+    datetime = calendar.datetime.datetime
+    timedelta = calendar.datetime.timedelta
+
+    def __init__(self, master=None, **kw):
+        """
+        WIDGET-SPECIFIC OPTIONS
+
+            locale, firstweekday, year, month, selectbackground,
+            selectforeground
+        """
+        # remove custom options from kw before initializating ttk.Frame
+        fwday = kw.pop('firstweekday', calendar.MONDAY)
+        year = kw.pop('year', self.datetime.now().year)
+        month = kw.pop('month', self.datetime.now().month)
+        locale = kw.pop('locale', None)
+        sel_bg = kw.pop('selectbackground', '#ecffc4')
+        sel_fg = kw.pop('selectforeground', '#05640e')
+
+        self._date = self.datetime(year, month, 1)
+        self._selection = None # no date selected
+
+        ttk.Frame.__init__(self, master, **kw)
+
+        self._cal = get_calendar(locale, fwday)
+
+        self.__setup_styles()       # creates custom styles
+        self.__place_widgets()      # pack/grid used widgets
+        self.__config_calendar()    # adjust calendar columns and setup tags
+        # configure a canvas, and proper bindings, for selecting dates
+        self.__setup_selection(sel_bg, sel_fg)
+
+        # store items ids, used for insertion later
+        self._items = [self._calendar.insert('', 'end', values='')
+                            for _ in range(6)]
+        # insert dates in the currently empty calendar
+        self._build_calendar()
+
+        # set the minimal size for the widget
+        #self._calendar.bind('<Map>', self.__minsize)
+
+    def __setitem__(self, item, value):
+           if item in ('year', 'month'):
+               raise AttributeError("attribute '%s' is not writeable" % item)
+           elif item == 'selectbackground':
+               self._canvas['background'] = value
+           elif item == 'selectforeground':
+               self._canvas.itemconfigure(self._canvas.text, item=value)
+           else:
+               ttk.Frame.__setitem__(self, item, value)
+
+    def __getitem__(self, item):
+        if item in ('year', 'month'):
+            return getattr(self._date, item)
+        elif item == 'selectbackground':
+            return self._canvas['background']
+        elif item == 'selectforeground':
+            return self._canvas.itemcget(self._canvas.text, 'fill')
+        else:
+            r = ttk.tclobjs_to_py({item: ttk.Frame.__getitem__(self, item)})
+            return r[item]
+
+    def __setup_styles(self):
+        # custom ttk styles
+        style = ttk.Style(self.master)
+        arrow_layout = lambda dir: (
+            [('Button.focus', {'children': [('Button.%sarrow' % dir, None)]})]
+        )
+        style.layout('L.TButton', arrow_layout('left'))
+        style.layout('R.TButton', arrow_layout('right'))
+
+    def __place_widgets(self):
+        # header frame and its widgets
+        hframe = ttk.Frame(self)
+        lbtn = ttk.Button(hframe, style='L.TButton', command=self._prev_month)
+        rbtn = ttk.Button(hframe, style='R.TButton', command=self._next_month)
+        self._header = ttk.Label(hframe, width=15, anchor='center')
+        # the calendar
+        #self._calendar = ttk.Treeview(show='', selectmode='none', height=7)
+        self._calendar = ttk.Treeview(self, show='', selectmode='none', height=7)
+
+        # pack the widgets
+        hframe.pack(in_=self, side='top', pady=4, anchor='center')
+        lbtn.grid(in_=hframe)
+        self._header.grid(in_=hframe, column=1, row=0, padx=12)
+        rbtn.grid(in_=hframe, column=2, row=0)
+        self._calendar.pack(in_=self, expand=1, fill='both', side='bottom')
+
+    def __config_calendar(self):
+        cols = self._cal.formatweekheader(3).split()
+        self._calendar['columns'] = cols
+        self._calendar.tag_configure('header', background='grey90')
+        self._calendar.insert('', 'end', values=cols, tag='header')
+        # adjust its columns width
+        font = tkinter.font.Font()
+        maxwidth = max(font.measure(col) for col in cols)
+        for col in cols:
+            self._calendar.column(col, width=maxwidth, minwidth=maxwidth,
+                anchor='e')
+
+    def __setup_selection(self, sel_bg, sel_fg):
+        self._font = tkinter.font.Font()
+        self._canvas = canvas = tkinter.Canvas(self._calendar,
+            background=sel_bg, borderwidth=0, highlightthickness=0)
+        canvas.text = canvas.create_text(0, 0, fill=sel_fg, anchor='w')
+
+        canvas.bind('<ButtonPress-1>', lambda evt: canvas.place_forget())
+        self._calendar.bind('<Configure>', lambda evt: canvas.place_forget())
+        self._calendar.bind('<ButtonPress-1>', self._pressed)
+
+    #def __minsize(self, evt):
+    #    width, height = self._calendar.master.geometry().split('x')
+    #    height = height[:height.index('+')]
+    #    self._calendar.master.minsize(width, height)
+
+    def _build_calendar(self):
+        year, month = self._date.year, self._date.month
+
+        # update header text (Month, YEAR)
+        header = self._cal.formatmonthname(year, month, 0)
+        self._header['text'] = header.title()
+
+        # update calendar shown dates
+        cal = self._cal.monthdayscalendar(year, month)
+        for indx, item in enumerate(self._items):
+            week = cal[indx] if indx < len(cal) else []
+            fmt_week = [('%02d' % day) if day else '' for day in week]
+            self._calendar.item(item, values=fmt_week)
+
+    def _show_selection(self, text, bbox):
+        """Configure canvas for a new selection."""
+        x, y, width, height = bbox
+
+        textw = self._font.measure(text)
+
+        canvas = self._canvas
+        canvas.configure(width=width, height=height)
+        canvas.coords(canvas.text, width - textw, height / 2 - 1)
+        canvas.itemconfigure(canvas.text, text=text)
+        canvas.place(in_=self._calendar, x=x, y=y)
+
+    # Callbacks
+
+    def _pressed(self, evt):
+        """Clicked somewhere in the calendar."""
+        x, y, widget = evt.x, evt.y, evt.widget
+        item = widget.identify_row(y)
+        column = widget.identify_column(x)
+
+        if not column or not item in self._items:
+            # clicked in the weekdays row or just outside the columns
+            return
+
+        item_values = widget.item(item)['values']
+        if not len(item_values): # row is empty for this month
+            return
+
+        text = item_values[int(column[1]) - 1]
+        if not text: # date is empty
+            return
+
+        bbox = widget.bbox(item, column)
+        if not bbox: # calendar not visible yet
+            return
+
+        # update and then show selection
+        text = '%02d' % text
+        self._selection = (text, item, column)
+        self._show_selection(text, bbox)
+
+    def _prev_month(self):
+        """Updated calendar to show the previous month."""
+        self._canvas.place_forget()
+
+        self._date = self._date - self.timedelta(days=1)
+        self._date = self.datetime(self._date.year, self._date.month, 1)
+        self._build_calendar() # reconstuct calendar
+
+    def _next_month(self):
+        """Update calendar to show the next month."""
+        self._canvas.place_forget()
+
+        year, month = self._date.year, self._date.month
+        self._date = self._date + self.timedelta(
+            days=calendar.monthrange(year, month)[1] + 1)
+        self._date = self.datetime(self._date.year, self._date.month, 1)
+        self._build_calendar() # reconstruct calendar
+
+    # Properties
+
+    @property
+    def selection(self):
+        """Return a datetime representing the current selected date."""
+        if not self._selection:
+            return None
+
+        year, month = self._date.year, self._date.month
+        return self.datetime(year, month, int(self._selection[0]))
+
+def test():
+    import sys
+    root = tkinter.Tk()
+    root.title('Ttk Calendar')
+    ttkcal = Calendar(firstweekday=calendar.SUNDAY)
+    ttkcal.pack(expand=1, fill='both')
+
+    if 'win' not in sys.platform:
+        style = ttk.Style()
+        style.theme_use('clam')
+
+    root.mainloop()
+
+if __name__ == '__main__':
+    test()