/Demo/tkinter/guido/ss1.py

  1"""SS1 -- a spreadsheet."""
  2
  3import os
  4import re
  5import sys
  6import cgi
  7import rexec
  8from xml.parsers import expat
  9
 10LEFT, CENTER, RIGHT = "LEFT", "CENTER", "RIGHT"
 11
 12def ljust(x, n):
 13    return x.ljust(n)
 14def center(x, n):
 15    return x.center(n)
 16def rjust(x, n):
 17    return x.rjust(n)
 18align2action = {LEFT: ljust, CENTER: center, RIGHT: rjust}
 19
 20align2xml = {LEFT: "left", CENTER: "center", RIGHT: "right"}
 21xml2align = {"left": LEFT, "center": CENTER, "right": RIGHT}
 22
 23align2anchor = {LEFT: "w", CENTER: "center", RIGHT: "e"}
 24
 25def sum(seq):
 26    total = 0
 27    for x in seq:
 28        if x is not None:
 29            total += x
 30    return total
 31
 32class Sheet:
 33
 34    def __init__(self):
 35        self.cells = {} # {(x, y): cell, ...}
 36        self.rexec = rexec.RExec()
 37        m = self.rexec.add_module('__main__')
 38        m.cell = self.cellvalue
 39        m.cells = self.multicellvalue
 40        m.sum = sum
 41
 42    def cellvalue(self, x, y):
 43        cell = self.getcell(x, y)
 44        if hasattr(cell, 'recalc'):
 45            return cell.recalc(self.rexec)
 46        else:
 47            return cell
 48
 49    def multicellvalue(self, x1, y1, x2, y2):
 50        if x1 > x2:
 51            x1, x2 = x2, x1
 52        if y1 > y2:
 53            y1, y2 = y2, y1
 54        seq = []
 55        for y in range(y1, y2+1):
 56            for x in range(x1, x2+1):
 57                seq.append(self.cellvalue(x, y))
 58        return seq
 59
 60    def getcell(self, x, y):
 61        return self.cells.get((x, y))
 62
 63    def setcell(self, x, y, cell):
 64        assert x > 0 and y > 0
 65        assert isinstance(cell, BaseCell)
 66        self.cells[x, y] = cell
 67
 68    def clearcell(self, x, y):
 69        try:
 70            del self.cells[x, y]
 71        except KeyError:
 72            pass
 73
 74    def clearcells(self, x1, y1, x2, y2):
 75        for xy in self.selectcells(x1, y1, x2, y2):
 76            del self.cells[xy]
 77
 78    def clearrows(self, y1, y2):
 79        self.clearcells(0, y1, sys.maxint, y2)
 80
 81    def clearcolumns(self, x1, x2):
 82        self.clearcells(x1, 0, x2, sys.maxint)
 83
 84    def selectcells(self, x1, y1, x2, y2):
 85        if x1 > x2:
 86            x1, x2 = x2, x1
 87        if y1 > y2:
 88            y1, y2 = y2, y1
 89        return [(x, y) for x, y in self.cells
 90                if x1 <= x <= x2 and y1 <= y <= y2]
 91
 92    def movecells(self, x1, y1, x2, y2, dx, dy):
 93        if dx == 0 and dy == 0:
 94            return
 95        if x1 > x2:
 96            x1, x2 = x2, x1
 97        if y1 > y2:
 98            y1, y2 = y2, y1
 99        assert x1+dx > 0 and y1+dy > 0
100        new = {}
101        for x, y in self.cells:
102            cell = self.cells[x, y]
103            if hasattr(cell, 'renumber'):
104                cell = cell.renumber(x1, y1, x2, y2, dx, dy)
105            if x1 <= x <= x2 and y1 <= y <= y2:
106                x += dx
107                y += dy
108            new[x, y] = cell
109        self.cells = new
110
111    def insertrows(self, y, n):
112        assert n > 0
113        self.movecells(0, y, sys.maxint, sys.maxint, 0, n)
114
115    def deleterows(self, y1, y2):
116        if y1 > y2:
117            y1, y2 = y2, y1
118        self.clearrows(y1, y2)
119        self.movecells(0, y2+1, sys.maxint, sys.maxint, 0, y1-y2-1)
120
121    def insertcolumns(self, x, n):
122        assert n > 0
123        self.movecells(x, 0, sys.maxint, sys.maxint, n, 0)
124
125    def deletecolumns(self, x1, x2):
126        if x1 > x2:
127            x1, x2 = x2, x1
128        self.clearcells(x1, x2)
129        self.movecells(x2+1, 0, sys.maxint, sys.maxint, x1-x2-1, 0)
130
131    def getsize(self):
132        maxx = maxy = 0
133        for x, y in self.cells:
134            maxx = max(maxx, x)
135            maxy = max(maxy, y)
136        return maxx, maxy
137
138    def reset(self):
139        for cell in self.cells.itervalues():
140            if hasattr(cell, 'reset'):
141                cell.reset()
142
143    def recalc(self):
144        self.reset()
145        for cell in self.cells.itervalues():
146            if hasattr(cell, 'recalc'):
147                cell.recalc(self.rexec)
148
149    def display(self):
150        maxx, maxy = self.getsize()
151        width, height = maxx+1, maxy+1
152        colwidth = [1] * width
153        full = {}
154        # Add column heading labels in row 0
155        for x in range(1, width):
156            full[x, 0] = text, alignment = colnum2name(x), RIGHT
157            colwidth[x] = max(colwidth[x], len(text))
158        # Add row labels in column 0
159        for y in range(1, height):
160            full[0, y] = text, alignment = str(y), RIGHT
161            colwidth[0] = max(colwidth[0], len(text))
162        # Add sheet cells in columns with x>0 and y>0
163        for (x, y), cell in self.cells.iteritems():
164            if x <= 0 or y <= 0:
165                continue
166            if hasattr(cell, 'recalc'):
167                cell.recalc(self.rexec)
168            if hasattr(cell, 'format'):
169                text, alignment = cell.format()
170                assert isinstance(text, str)
171                assert alignment in (LEFT, CENTER, RIGHT)
172            else:
173                text = str(cell)
174                if isinstance(cell, str):
175                    alignment = LEFT
176                else:
177                    alignment = RIGHT
178            full[x, y] = (text, alignment)
179            colwidth[x] = max(colwidth[x], len(text))
180        # Calculate the horizontal separator line (dashes and dots)
181        sep = ""
182        for x in range(width):
183            if sep:
184                sep += "+"
185            sep += "-"*colwidth[x]
186        # Now print The full grid
187        for y in range(height):
188            line = ""
189            for x in range(width):
190                text, alignment = full.get((x, y)) or ("", LEFT)
191                text = align2action[alignment](text, colwidth[x])
192                if line:
193                    line += '|'
194                line += text
195            print line
196            if y == 0:
197                print sep
198
199    def xml(self):
200        out = ['<spreadsheet>']
201        for (x, y), cell in self.cells.iteritems():
202            if hasattr(cell, 'xml'):
203                cellxml = cell.xml()
204            else:
205                cellxml = '<value>%s</value>' % cgi.escape(cell)
206            out.append('<cell row="%s" col="%s">\n  %s\n</cell>' %
207                       (y, x, cellxml))
208        out.append('</spreadsheet>')
209        return '\n'.join(out)
210
211    def save(self, filename):
212        text = self.xml()
213        f = open(filename, "w")
214        f.write(text)
215        if text and not text.endswith('\n'):
216            f.write('\n')
217        f.close()
218
219    def load(self, filename):
220        f = open(filename, 'r')
221        SheetParser(self).parsefile(f)
222        f.close()
223
224class SheetParser:
225
226    def __init__(self, sheet):
227        self.sheet = sheet
228
229    def parsefile(self, f):
230        parser = expat.ParserCreate()
231        parser.StartElementHandler = self.startelement
232        parser.EndElementHandler = self.endelement
233        parser.CharacterDataHandler = self.data
234        parser.ParseFile(f)
235
236    def startelement(self, tag, attrs):
237        method = getattr(self, 'start_'+tag, None)
238        if method:
239            for key, value in attrs.iteritems():
240                attrs[key] = str(value) # XXX Convert Unicode to 8-bit
241            method(attrs)
242        self.texts = []
243
244    def data(self, text):
245        text = str(text) # XXX Convert Unicode to 8-bit
246        self.texts.append(text)
247
248    def endelement(self, tag):
249        method = getattr(self, 'end_'+tag, None)
250        if method:
251            method("".join(self.texts))
252
253    def start_cell(self, attrs):
254        self.y = int(attrs.get("row"))
255        self.x = int(attrs.get("col"))
256
257    def start_value(self, attrs):
258        self.fmt = attrs.get('format')
259        self.alignment = xml2align.get(attrs.get('align'))
260
261    start_formula = start_value
262
263    def end_int(self, text):
264        try:
265            self.value = int(text)
266        except:
267            self.value = None
268
269    def end_long(self, text):
270        try:
271            self.value = long(text)
272        except:
273            self.value = None
274
275    def end_double(self, text):
276        try:
277            self.value = float(text)
278        except:
279            self.value = None
280
281    def end_complex(self, text):
282        try:
283            self.value = complex(text)
284        except:
285            self.value = None
286
287    def end_string(self, text):
288        try:
289            self.value = text
290        except:
291            self.value = None
292
293    def end_value(self, text):
294        if isinstance(self.value, BaseCell):
295            self.cell = self.value
296        elif isinstance(self.value, str):
297            self.cell = StringCell(self.value,
298                                   self.fmt or "%s",
299                                   self.alignment or LEFT)
300        else:
301            self.cell = NumericCell(self.value,
302                                    self.fmt or "%s",
303                                    self.alignment or RIGHT)
304
305    def end_formula(self, text):
306        self.cell = FormulaCell(text,
307                                self.fmt or "%s",
308                                self.alignment or RIGHT)
309
310    def end_cell(self, text):
311        self.sheet.setcell(self.x, self.y, self.cell)
312
313class BaseCell:
314    __init__ = None # Must provide
315    """Abstract base class for sheet cells.
316
317    Subclasses may but needn't provide the following APIs:
318
319    cell.reset() -- prepare for recalculation
320    cell.recalc(rexec) -> value -- recalculate formula
321    cell.format() -> (value, alignment) -- return formatted value
322    cell.xml() -> string -- return XML
323    """
324
325class NumericCell(BaseCell):
326
327    def __init__(self, value, fmt="%s", alignment=RIGHT):
328        assert isinstance(value, (int, long, float, complex))
329        assert alignment in (LEFT, CENTER, RIGHT)
330        self.value = value
331        self.fmt = fmt
332        self.alignment = alignment
333
334    def recalc(self, rexec):
335        return self.value
336
337    def format(self):
338        try:
339            text = self.fmt % self.value
340        except:
341            text = str(self.value)
342        return text, self.alignment
343
344    def xml(self):
345        method = getattr(self, '_xml_' + type(self.value).__name__)
346        return '<value align="%s" format="%s">%s</value>' % (
347                align2xml[self.alignment],
348                self.fmt,
349                method())
350
351    def _xml_int(self):
352        if -2**31 <= self.value < 2**31:
353            return '<int>%s</int>' % self.value
354        else:
355            return self._xml_long()
356
357    def _xml_long(self):
358        return '<long>%s</long>' % self.value
359
360    def _xml_float(self):
361        return '<double>%s</double>' % repr(self.value)
362
363    def _xml_complex(self):
364        return '<complex>%s</double>' % repr(self.value)
365
366class StringCell(BaseCell):
367
368    def __init__(self, text, fmt="%s", alignment=LEFT):
369        assert isinstance(text, (str, unicode))
370        assert alignment in (LEFT, CENTER, RIGHT)
371        self.text = text
372        self.fmt = fmt
373        self.alignment = alignment
374
375    def recalc(self, rexec):
376        return self.text
377
378    def format(self):
379        return self.text, self.alignment
380
381    def xml(self):
382        s = '<value align="%s" format="%s"><string>%s</string></value>'
383        return s % (
384            align2xml[self.alignment],
385            self.fmt,
386            cgi.escape(self.text))
387
388class FormulaCell(BaseCell):
389
390    def __init__(self, formula, fmt="%s", alignment=RIGHT):
391        assert alignment in (LEFT, CENTER, RIGHT)
392        self.formula = formula
393        self.translated = translate(self.formula)
394        self.fmt = fmt
395        self.alignment = alignment
396        self.reset()
397
398    def reset(self):
399        self.value = None
400
401    def recalc(self, rexec):
402        if self.value is None:
403            try:
404                # A hack to evaluate expressions using true division
405                rexec.r_exec("from __future__ import division\n" +
406                             "__value__ = eval(%s)" % repr(self.translated))
407                self.value = rexec.r_eval("__value__")
408            except:
409                exc = sys.exc_info()[0]
410                if hasattr(exc, "__name__"):
411                    self.value = exc.__name__
412                else:
413                    self.value = str(exc)
414        return self.value
415
416    def format(self):
417        try:
418            text = self.fmt % self.value
419        except:
420            text = str(self.value)
421        return text, self.alignment
422
423    def xml(self):
424        return '<formula align="%s" format="%s">%s</formula>' % (
425            align2xml[self.alignment],
426            self.fmt,
427            self.formula)
428
429    def renumber(self, x1, y1, x2, y2, dx, dy):
430        out = []
431        for part in re.split('(\w+)', self.formula):
432            m = re.match('^([A-Z]+)([1-9][0-9]*)$', part)
433            if m is not None:
434                sx, sy = m.groups()
435                x = colname2num(sx)
436                y = int(sy)
437                if x1 <= x <= x2 and y1 <= y <= y2:
438                    part = cellname(x+dx, y+dy)
439            out.append(part)
440        return FormulaCell("".join(out), self.fmt, self.alignment)
441
442def translate(formula):
443    """Translate a formula containing fancy cell names to valid Python code.
444
445    Examples:
446        B4 -> cell(2, 4)
447        B4:Z100 -> cells(2, 4, 26, 100)
448    """
449    out = []
450    for part in re.split(r"(\w+(?::\w+)?)", formula):
451        m = re.match(r"^([A-Z]+)([1-9][0-9]*)(?::([A-Z]+)([1-9][0-9]*))?$", part)
452        if m is None:
453            out.append(part)
454        else:
455            x1, y1, x2, y2 = m.groups()
456            x1 = colname2num(x1)
457            if x2 is None:
458                s = "cell(%s, %s)" % (x1, y1)
459            else:
460                x2 = colname2num(x2)
461                s = "cells(%s, %s, %s, %s)" % (x1, y1, x2, y2)
462            out.append(s)
463    return "".join(out)
464
465def cellname(x, y):
466    "Translate a cell coordinate to a fancy cell name (e.g. (1, 1)->'A1')."
467    assert x > 0 # Column 0 has an empty name, so can't use that
468    return colnum2name(x) + str(y)
469
470def colname2num(s):
471    "Translate a column name to number (e.g. 'A'->1, 'Z'->26, 'AA'->27)."
472    s = s.upper()
473    n = 0
474    for c in s:
475        assert 'A' <= c <= 'Z'
476        n = n*26 + ord(c) - ord('A') + 1
477    return n
478
479def colnum2name(n):
480    "Translate a column number to name (e.g. 1->'A', etc.)."
481    assert n > 0
482    s = ""
483    while n:
484        n, m = divmod(n-1, 26)
485        s = chr(m+ord('A')) + s
486    return s
487
488import Tkinter as Tk
489
490class SheetGUI:
491
492    """Beginnings of a GUI for a spreadsheet.
493
494    TO DO:
495    - clear multiple cells
496    - Insert, clear, remove rows or columns
497    - Show new contents while typing
498    - Scroll bars
499    - Grow grid when window is grown
500    - Proper menus
501    - Undo, redo
502    - Cut, copy and paste
503    - Formatting and alignment
504    """
505
506    def __init__(self, filename="sheet1.xml", rows=10, columns=5):
507        """Constructor.
508
509        Load the sheet from the filename argument.
510        Set up the Tk widget tree.
511        """
512        # Create and load the sheet
513        self.filename = filename
514        self.sheet = Sheet()
515        if os.path.isfile(filename):
516            self.sheet.load(filename)
517        # Calculate the needed grid size
518        maxx, maxy = self.sheet.getsize()
519        rows = max(rows, maxy)
520        columns = max(columns, maxx)
521        # Create the widgets
522        self.root = Tk.Tk()
523        self.root.wm_title("Spreadsheet: %s" % self.filename)
524        self.beacon = Tk.Label(self.root, text="A1",
525                               font=('helvetica', 16, 'bold'))
526        self.entry = Tk.Entry(self.root)
527        self.savebutton = Tk.Button(self.root, text="Save",
528                                    command=self.save)
529        self.cellgrid = Tk.Frame(self.root)
530        # Configure the widget lay-out
531        self.cellgrid.pack(side="bottom", expand=1, fill="both")
532        self.beacon.pack(side="left")
533        self.savebutton.pack(side="right")
534        self.entry.pack(side="left", expand=1, fill="x")
535        # Bind some events
536        self.entry.bind("<Return>", self.return_event)
537        self.entry.bind("<Shift-Return>", self.shift_return_event)
538        self.entry.bind("<Tab>", self.tab_event)
539        self.entry.bind("<Shift-Tab>", self.shift_tab_event)
540        self.entry.bind("<Delete>", self.delete_event)
541        self.entry.bind("<Escape>", self.escape_event)
542        # Now create the cell grid
543        self.makegrid(rows, columns)
544        # Select the top-left cell
545        self.currentxy = None
546        self.cornerxy = None
547        self.setcurrent(1, 1)
548        # Copy the sheet cells to the GUI cells
549        self.sync()
550
551    def delete_event(self, event):
552        if self.cornerxy != self.currentxy and self.cornerxy is not None:
553            self.sheet.clearcells(*(self.currentxy + self.cornerxy))
554        else:
555            self.sheet.clearcell(*self.currentxy)
556        self.sync()
557        self.entry.delete(0, 'end')
558        return "break"
559
560    def escape_event(self, event):
561        x, y = self.currentxy
562        self.load_entry(x, y)
563
564    def load_entry(self, x, y):
565        cell = self.sheet.getcell(x, y)
566        if cell is None:
567            text = ""
568        elif isinstance(cell, FormulaCell):
569            text = '=' + cell.formula
570        else:
571            text, alignment = cell.format()
572        self.entry.delete(0, 'end')
573        self.entry.insert(0, text)
574        self.entry.selection_range(0, 'end')
575
576    def makegrid(self, rows, columns):
577        """Helper to create the grid of GUI cells.
578
579        The edge (x==0 or y==0) is filled with labels; the rest is real cells.
580        """
581        self.rows = rows
582        self.columns = columns
583        self.gridcells = {}
584        # Create the top left corner cell (which selects all)
585        cell = Tk.Label(self.cellgrid, relief='raised')
586        cell.grid_configure(column=0, row=0, sticky='NSWE')
587        cell.bind("<ButtonPress-1>", self.selectall)
588        # Create the top row of labels, and confiure the grid columns
589        for x in range(1, columns+1):
590            self.cellgrid.grid_columnconfigure(x, minsize=64)
591            cell = Tk.Label(self.cellgrid, text=colnum2name(x), relief='raised')
592            cell.grid_configure(column=x, row=0, sticky='WE')
593            self.gridcells[x, 0] = cell
594            cell.__x = x
595            cell.__y = 0
596            cell.bind("<ButtonPress-1>", self.selectcolumn)
597            cell.bind("<B1-Motion>", self.extendcolumn)
598            cell.bind("<ButtonRelease-1>", self.extendcolumn)
599            cell.bind("<Shift-Button-1>", self.extendcolumn)
600        # Create the leftmost column of labels
601        for y in range(1, rows+1):
602            cell = Tk.Label(self.cellgrid, text=str(y), relief='raised')
603            cell.grid_configure(column=0, row=y, sticky='WE')
604            self.gridcells[0, y] = cell
605            cell.__x = 0
606            cell.__y = y
607            cell.bind("<ButtonPress-1>", self.selectrow)
608            cell.bind("<B1-Motion>", self.extendrow)
609            cell.bind("<ButtonRelease-1>", self.extendrow)
610            cell.bind("<Shift-Button-1>", self.extendrow)
611        # Create the real cells
612        for x in range(1, columns+1):
613            for y in range(1, rows+1):
614                cell = Tk.Label(self.cellgrid, relief='sunken',
615                                bg='white', fg='black')
616                cell.grid_configure(column=x, row=y, sticky='NSWE')
617                self.gridcells[x, y] = cell
618                cell.__x = x
619                cell.__y = y
620                # Bind mouse events
621                cell.bind("<ButtonPress-1>", self.press)
622                cell.bind("<B1-Motion>", self.motion)
623                cell.bind("<ButtonRelease-1>", self.release)
624                cell.bind("<Shift-Button-1>", self.release)
625
626    def selectall(self, event):
627        self.setcurrent(1, 1)
628        self.setcorner(sys.maxint, sys.maxint)
629
630    def selectcolumn(self, event):
631        x, y = self.whichxy(event)
632        self.setcurrent(x, 1)
633        self.setcorner(x, sys.maxint)
634
635    def extendcolumn(self, event):
636        x, y = self.whichxy(event)
637        if x > 0:
638            self.setcurrent(self.currentxy[0], 1)
639            self.setcorner(x, sys.maxint)
640
641    def selectrow(self, event):
642        x, y = self.whichxy(event)
643        self.setcurrent(1, y)
644        self.setcorner(sys.maxint, y)
645
646    def extendrow(self, event):
647        x, y = self.whichxy(event)
648        if y > 0:
649            self.setcurrent(1, self.currentxy[1])
650            self.setcorner(sys.maxint, y)
651
652    def press(self, event):
653        x, y = self.whichxy(event)
654        if x > 0 and y > 0:
655            self.setcurrent(x, y)
656
657    def motion(self, event):
658        x, y = self.whichxy(event)
659        if x > 0 and y > 0:
660            self.setcorner(x, y)
661
662    release = motion
663
664    def whichxy(self, event):
665        w = self.cellgrid.winfo_containing(event.x_root, event.y_root)
666        if w is not None and isinstance(w, Tk.Label):
667            try:
668                return w.__x, w.__y
669            except AttributeError:
670                pass
671        return 0, 0
672
673    def save(self):
674        self.sheet.save(self.filename)
675
676    def setcurrent(self, x, y):
677        "Make (x, y) the current cell."
678        if self.currentxy is not None:
679            self.change_cell()
680        self.clearfocus()
681        self.beacon['text'] = cellname(x, y)
682        self.load_entry(x, y)
683        self.entry.focus_set()
684        self.currentxy = x, y
685        self.cornerxy = None
686        gridcell = self.gridcells.get(self.currentxy)
687        if gridcell is not None:
688            gridcell['bg'] = 'yellow'
689
690    def setcorner(self, x, y):
691        if self.currentxy is None or self.currentxy == (x, y):
692            self.setcurrent(x, y)
693            return
694        self.clearfocus()
695        self.cornerxy = x, y
696        x1, y1 = self.currentxy
697        x2, y2 = self.cornerxy or self.currentxy
698        if x1 > x2:
699            x1, x2 = x2, x1
700        if y1 > y2:
701            y1, y2 = y2, y1
702        for (x, y), cell in self.gridcells.iteritems():
703            if x1 <= x <= x2 and y1 <= y <= y2:
704                cell['bg'] = 'lightBlue'
705        gridcell = self.gridcells.get(self.currentxy)
706        if gridcell is not None:
707            gridcell['bg'] = 'yellow'
708        self.setbeacon(x1, y1, x2, y2)
709
710    def setbeacon(self, x1, y1, x2, y2):
711        if x1 == y1 == 1 and x2 == y2 == sys.maxint:
712            name = ":"
713        elif (x1, x2) == (1, sys.maxint):
714            if y1 == y2:
715                name = "%d" % y1
716            else:
717                name = "%d:%d" % (y1, y2)
718        elif (y1, y2) == (1, sys.maxint):
719            if x1 == x2:
720                name = "%s" % colnum2name(x1)
721            else:
722                name = "%s:%s" % (colnum2name(x1), colnum2name(x2))
723        else:
724            name1 = cellname(*self.currentxy)
725            name2 = cellname(*self.cornerxy)
726            name = "%s:%s" % (name1, name2)
727        self.beacon['text'] = name
728
729
730    def clearfocus(self):
731        if self.currentxy is not None:
732            x1, y1 = self.currentxy
733            x2, y2 = self.cornerxy or self.currentxy
734            if x1 > x2:
735                x1, x2 = x2, x1
736            if y1 > y2:
737                y1, y2 = y2, y1
738            for (x, y), cell in self.gridcells.iteritems():
739                if x1 <= x <= x2 and y1 <= y <= y2:
740                    cell['bg'] = 'white'
741
742    def return_event(self, event):
743        "Callback for the Return key."
744        self.change_cell()
745        x, y = self.currentxy
746        self.setcurrent(x, y+1)
747        return "break"
748
749    def shift_return_event(self, event):
750        "Callback for the Return key with Shift modifier."
751        self.change_cell()
752        x, y = self.currentxy
753        self.setcurrent(x, max(1, y-1))
754        return "break"
755
756    def tab_event(self, event):
757        "Callback for the Tab key."
758        self.change_cell()
759        x, y = self.currentxy
760        self.setcurrent(x+1, y)
761        return "break"
762
763    def shift_tab_event(self, event):
764        "Callback for the Tab key with Shift modifier."
765        self.change_cell()
766        x, y = self.currentxy
767        self.setcurrent(max(1, x-1), y)
768        return "break"
769
770    def change_cell(self):
771        "Set the current cell from the entry widget."
772        x, y = self.currentxy
773        text = self.entry.get()
774        cell = None
775        if text.startswith('='):
776            cell = FormulaCell(text[1:])
777        else:
778            for cls in int, long, float, complex:
779                try:
780                    value = cls(text)
781                except:
782                    continue
783                else:
784                    cell = NumericCell(value)
785                    break
786        if cell is None and text:
787            cell = StringCell(text)
788        if cell is None:
789            self.sheet.clearcell(x, y)
790        else:
791            self.sheet.setcell(x, y, cell)
792        self.sync()
793
794    def sync(self):
795        "Fill the GUI cells from the sheet cells."
796        self.sheet.recalc()
797        for (x, y), gridcell in self.gridcells.iteritems():
798            if x == 0 or y == 0:
799                continue
800            cell = self.sheet.getcell(x, y)
801            if cell is None:
802                gridcell['text'] = ""
803            else:
804                if hasattr(cell, 'format'):
805                    text, alignment = cell.format()
806                else:
807                    text, alignment = str(cell), LEFT
808                gridcell['text'] = text
809                gridcell['anchor'] = align2anchor[alignment]
810
811
812def test_basic():
813    "Basic non-gui self-test."
814    import os
815    a = Sheet()
816    for x in range(1, 11):
817        for y in range(1, 11):
818            if x == 1:
819                cell = NumericCell(y)
820            elif y == 1:
821                cell = NumericCell(x)
822            else:
823                c1 = cellname(x, 1)
824                c2 = cellname(1, y)
825                formula = "%s*%s" % (c1, c2)
826                cell = FormulaCell(formula)
827            a.setcell(x, y, cell)
828##    if os.path.isfile("sheet1.xml"):
829##        print "Loading from sheet1.xml"
830##        a.load("sheet1.xml")
831    a.display()
832    a.save("sheet1.xml")
833
834def test_gui():
835    "GUI test."
836    if sys.argv[1:]:
837        filename = sys.argv[1]
838    else:
839        filename = "sheet1.xml"
840    g = SheetGUI(filename)
841    g.root.mainloop()
842
843if __name__ == '__main__':
844    #test_basic()
845    test_gui()