PythonSTC.py
author greg
Mon, 18 May 2009 07:58:41 +0200
changeset 345 a3520d75a722
parent 332 4f0e1d66bba5
permissions -rw-r--r--
get the WaitPythonCommands return (semaphore error code) to quit python_iterator loop when semaphore is destroyed
import  keyword
import  os
import  wx
import  wx.stc  as  stc

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

"""
This Python editor class comes from the wxPython demo, a bit tweaked
"""

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


if wx.Platform == '__WXMSW__':
    faces = { 'times': 'Times New Roman',
              'mono' : 'Courier New',
              'helv' : 'Arial',
              'other': 'Comic Sans MS',
              'size' : 10,
              'size2': 8,
             }
elif wx.Platform == '__WXMAC__':
    faces = { 'times': 'Times New Roman',
              'mono' : 'Monaco',
              'helv' : 'Arial',
              'other': 'Comic Sans MS',
              'size' : 12,
              'size2': 10,
             }
else:
    faces = { 'times': 'Times',
              'mono' : 'Courier',
              'helv' : 'Helvetica',
              'other': 'new century schoolbook',
              'size' : 12,
              'size2': 10,
             }


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

class PythonSTC(stc.StyledTextCtrl):

    fold_symbols = 2
    
    def __init__(self, parent, ID,
                 pos=wx.DefaultPosition, size=wx.DefaultSize,
                 style=0):
        stc.StyledTextCtrl.__init__(self, parent, ID, pos, size, style)

        self.CmdKeyAssign(ord('B'), stc.STC_SCMOD_CTRL, stc.STC_CMD_ZOOMIN)
        self.CmdKeyAssign(ord('N'), stc.STC_SCMOD_CTRL, stc.STC_CMD_ZOOMOUT)

        self.SetLexer(stc.STC_LEX_PYTHON)
        self.SetKeyWords(0, " ".join(keyword.kwlist))

        self.SetProperty("fold", "1")
        self.SetProperty("tab.timmy.whinge.level", "1")
        self.SetMargins(0,0)

        self.SetViewWhiteSpace(False)
        #self.SetBufferedDraw(False)
        #self.SetViewEOL(True)
        #self.SetEOLMode(stc.STC_EOL_CRLF)
        #self.SetUseAntiAliasing(True)
        
        self.SetEdgeMode(stc.STC_EDGE_BACKGROUND)
        self.SetEdgeColumn(78)

        # Setup a margin to hold fold markers
        #self.SetFoldFlags(16)  ###  WHAT IS THIS VALUE?  WHAT ARE THE OTHER FLAGS?  DOES IT MATTER?
        self.SetMarginType(2, stc.STC_MARGIN_SYMBOL)
        self.SetMarginMask(2, stc.STC_MASK_FOLDERS)
        self.SetMarginSensitive(2, True)
        self.SetMarginWidth(2, 12)

        if self.fold_symbols == 0:
            # Arrow pointing right for contracted folders, arrow pointing down for expanded
            self.MarkerDefine(stc.STC_MARKNUM_FOLDEROPEN,    stc.STC_MARK_ARROWDOWN, "black", "black")
            self.MarkerDefine(stc.STC_MARKNUM_FOLDER,        stc.STC_MARK_ARROW, "black", "black")
            self.MarkerDefine(stc.STC_MARKNUM_FOLDERSUB,     stc.STC_MARK_EMPTY, "black", "black")
            self.MarkerDefine(stc.STC_MARKNUM_FOLDERTAIL,    stc.STC_MARK_EMPTY, "black", "black")
            self.MarkerDefine(stc.STC_MARKNUM_FOLDEREND,     stc.STC_MARK_EMPTY,     "white", "black")
            self.MarkerDefine(stc.STC_MARKNUM_FOLDEROPENMID, stc.STC_MARK_EMPTY,     "white", "black")
            self.MarkerDefine(stc.STC_MARKNUM_FOLDERMIDTAIL, stc.STC_MARK_EMPTY,     "white", "black")
            
        elif self.fold_symbols == 1:
            # Plus for contracted folders, minus for expanded
            self.MarkerDefine(stc.STC_MARKNUM_FOLDEROPEN,    stc.STC_MARK_MINUS, "white", "black")
            self.MarkerDefine(stc.STC_MARKNUM_FOLDER,        stc.STC_MARK_PLUS,  "white", "black")
            self.MarkerDefine(stc.STC_MARKNUM_FOLDERSUB,     stc.STC_MARK_EMPTY, "white", "black")
            self.MarkerDefine(stc.STC_MARKNUM_FOLDERTAIL,    stc.STC_MARK_EMPTY, "white", "black")
            self.MarkerDefine(stc.STC_MARKNUM_FOLDEREND,     stc.STC_MARK_EMPTY, "white", "black")
            self.MarkerDefine(stc.STC_MARKNUM_FOLDEROPENMID, stc.STC_MARK_EMPTY, "white", "black")
            self.MarkerDefine(stc.STC_MARKNUM_FOLDERMIDTAIL, stc.STC_MARK_EMPTY, "white", "black")

        elif self.fold_symbols == 2:
            # Like a flattened tree control using circular headers and curved joins
            self.MarkerDefine(stc.STC_MARKNUM_FOLDEROPEN,    stc.STC_MARK_CIRCLEMINUS,          "white", "#404040")
            self.MarkerDefine(stc.STC_MARKNUM_FOLDER,        stc.STC_MARK_CIRCLEPLUS,           "white", "#404040")
            self.MarkerDefine(stc.STC_MARKNUM_FOLDERSUB,     stc.STC_MARK_VLINE,                "white", "#404040")
            self.MarkerDefine(stc.STC_MARKNUM_FOLDERTAIL,    stc.STC_MARK_LCORNERCURVE,         "white", "#404040")
            self.MarkerDefine(stc.STC_MARKNUM_FOLDEREND,     stc.STC_MARK_CIRCLEPLUSCONNECTED,  "white", "#404040")
            self.MarkerDefine(stc.STC_MARKNUM_FOLDEROPENMID, stc.STC_MARK_CIRCLEMINUSCONNECTED, "white", "#404040")
            self.MarkerDefine(stc.STC_MARKNUM_FOLDERMIDTAIL, stc.STC_MARK_TCORNERCURVE,         "white", "#404040")

        elif self.fold_symbols == 3:
            # Like a flattened tree control using square headers
            self.MarkerDefine(stc.STC_MARKNUM_FOLDEROPEN,    stc.STC_MARK_BOXMINUS,          "white", "#808080")
            self.MarkerDefine(stc.STC_MARKNUM_FOLDER,        stc.STC_MARK_BOXPLUS,           "white", "#808080")
            self.MarkerDefine(stc.STC_MARKNUM_FOLDERSUB,     stc.STC_MARK_VLINE,             "white", "#808080")
            self.MarkerDefine(stc.STC_MARKNUM_FOLDERTAIL,    stc.STC_MARK_LCORNER,           "white", "#808080")
            self.MarkerDefine(stc.STC_MARKNUM_FOLDEREND,     stc.STC_MARK_BOXPLUSCONNECTED,  "white", "#808080")
            self.MarkerDefine(stc.STC_MARKNUM_FOLDEROPENMID, stc.STC_MARK_BOXMINUSCONNECTED, "white", "#808080")
            self.MarkerDefine(stc.STC_MARKNUM_FOLDERMIDTAIL, stc.STC_MARK_TCORNER,           "white", "#808080")


        self.Bind(stc.EVT_STC_UPDATEUI, self.OnUpdateUI)
        self.Bind(stc.EVT_STC_MARGINCLICK, self.OnMarginClick)
        self.Bind(wx.EVT_KEY_DOWN, self.OnKeyPressed)

        # Make some styles,  The lexer defines what each style is used for, we
        # just have to define what each style looks like.  This set is adapted from
        # Scintilla sample property files.

        # Global default styles for all languages
        self.StyleSetSpec(stc.STC_STYLE_DEFAULT,     "face:%(helv)s,size:%(size)d" % faces)
        self.StyleClearAll()  # Reset all to be like the default

        # Global default styles for all languages
        self.StyleSetSpec(stc.STC_STYLE_DEFAULT,     "face:%(helv)s,size:%(size)d" % faces)
        self.StyleSetSpec(stc.STC_STYLE_LINENUMBER,  "back:#C0C0C0,face:%(helv)s,size:%(size2)d" % faces)
        self.StyleSetSpec(stc.STC_STYLE_CONTROLCHAR, "face:%(other)s" % faces)
        self.StyleSetSpec(stc.STC_STYLE_BRACELIGHT,  "fore:#FFFFFF,back:#0000FF,bold")
        self.StyleSetSpec(stc.STC_STYLE_BRACEBAD,    "fore:#000000,back:#FF0000,bold")

        # Python styles
        # Default 
        self.StyleSetSpec(stc.STC_P_DEFAULT, "fore:#000000,face:%(helv)s,size:%(size)d" % faces)
        # Comments
        self.StyleSetSpec(stc.STC_P_COMMENTLINE, "fore:#007F00,face:%(other)s,size:%(size)d" % faces)
        # Number
        self.StyleSetSpec(stc.STC_P_NUMBER, "fore:#007F7F,size:%(size)d" % faces)
        # String
        self.StyleSetSpec(stc.STC_P_STRING, "fore:#7F007F,face:%(helv)s,size:%(size)d" % faces)
        # Single quoted string
        self.StyleSetSpec(stc.STC_P_CHARACTER, "fore:#7F007F,face:%(helv)s,size:%(size)d" % faces)
        # Keyword
        self.StyleSetSpec(stc.STC_P_WORD, "fore:#00007F,bold,size:%(size)d" % faces)
        # Triple quotes
        self.StyleSetSpec(stc.STC_P_TRIPLE, "fore:#7F0000,size:%(size)d" % faces)
        # Triple double quotes
        self.StyleSetSpec(stc.STC_P_TRIPLEDOUBLE, "fore:#7F0000,size:%(size)d" % faces)
        # Class name definition
        self.StyleSetSpec(stc.STC_P_CLASSNAME, "fore:#0000FF,bold,underline,size:%(size)d" % faces)
        # Function or method name definition
        self.StyleSetSpec(stc.STC_P_DEFNAME, "fore:#007F7F,bold,size:%(size)d" % faces)
        # Operators
        self.StyleSetSpec(stc.STC_P_OPERATOR, "bold,size:%(size)d" % faces)
        # Identifiers
        self.StyleSetSpec(stc.STC_P_IDENTIFIER, "fore:#000000,face:%(helv)s,size:%(size)d" % faces)
        # Comment-blocks
        self.StyleSetSpec(stc.STC_P_COMMENTBLOCK, "fore:#7F7F7F,size:%(size)d" % faces)
        # End of line where string is not closed
        self.StyleSetSpec(stc.STC_P_STRINGEOL, "fore:#000000,face:%(mono)s,back:#E0C0E0,eol,size:%(size)d" % faces)

        self.SetCaretForeground("BLUE")

    def OnKeyPressed(self, event):
        if self.CallTipActive():
            self.CallTipCancel()

        event.Skip()
## For later use
#        key = event.GetKeyCode()
#        if key == 32 and event.ControlDown():
#            pos = self.GetCurrentPos()
#
#            # Tips
#            if event.ShiftDown():
#                self.CallTipSetBackground("yellow")
#                self.CallTipShow(pos, 'lots of of text: blah, blah, blah\n\n'
#                                 'show some suff, maybe parameters..\n\n'
#                                 'fubar(param1, param2)')
#            # Code completion
#            else:
#                #lst = []
#                #for x in range(50000):
#                #    lst.append('%05d' % x)
#                #st = " ".join(lst)
#                #print len(st)
#                #self.AutoCompShow(0, st)
#
#                kw = keyword.kwlist[:]
#                kw.append("zzzzzz?2")
#                kw.append("aaaaa?2")
#                kw.append("__init__?3")
#                kw.append("zzaaaaa?2")
#                kw.append("zzbaaaa?2")
#                kw.append("this_is_a_longer_value")
#                #kw.append("this_is_a_much_much_much_much_much_much_much_longer_value")
#
#                kw.sort()  # Python sorts are case sensitive
#                self.AutoCompSetIgnoreCase(False)  # so this needs to match
#
#                # Images are specified with a appended "?type"
#                for i in range(len(kw)):
#                    if kw[i] in keyword.kwlist:
#                        kw[i] = kw[i] + "?1"
#
#                self.AutoCompShow(0, " ".join(kw))
#        else:
#            event.Skip()


    def OnUpdateUI(self, evt):
        # check for matching braces
        braceAtCaret = -1
        braceOpposite = -1
        charBefore = None
        caretPos = self.GetCurrentPos()

        if caretPos > 0:
            charBefore = self.GetCharAt(caretPos - 1)
            styleBefore = self.GetStyleAt(caretPos - 1)

        # check before
        if charBefore and chr(charBefore) in "[]{}()" and styleBefore == stc.STC_P_OPERATOR:
            braceAtCaret = caretPos - 1

        # check after
        if braceAtCaret < 0:
            charAfter = self.GetCharAt(caretPos)
            styleAfter = self.GetStyleAt(caretPos)

            if charAfter and chr(charAfter) in "[]{}()" and styleAfter == stc.STC_P_OPERATOR:
                braceAtCaret = caretPos

        if braceAtCaret >= 0:
            braceOpposite = self.BraceMatch(braceAtCaret)

        if braceAtCaret != -1  and braceOpposite == -1:
            self.BraceBadLight(braceAtCaret)
        else:
            self.BraceHighlight(braceAtCaret, braceOpposite)
            #pt = self.PointFromPosition(braceOpposite)
            #self.Refresh(True, wxRect(pt.x, pt.y, 5,5))
            #print pt
            #self.Refresh(False)


    def OnMarginClick(self, evt):
        # fold and unfold as needed
        if evt.GetMargin() == 2:
            if evt.GetShift() and evt.GetControl():
                self.FoldAll()
            else:
                lineClicked = self.LineFromPosition(evt.GetPosition())

                if self.GetFoldLevel(lineClicked) & stc.STC_FOLDLEVELHEADERFLAG:
                    if evt.GetShift():
                        self.SetFoldExpanded(lineClicked, True)
                        self.Expand(lineClicked, True, True, 1)
                    elif evt.GetControl():
                        if self.GetFoldExpanded(lineClicked):
                            self.SetFoldExpanded(lineClicked, False)
                            self.Expand(lineClicked, False, True, 0)
                        else:
                            self.SetFoldExpanded(lineClicked, True)
                            self.Expand(lineClicked, True, True, 100)
                    else:
                        self.ToggleFold(lineClicked)


    def FoldAll(self):
        lineCount = self.GetLineCount()
        expanding = True

        # find out if we are folding or unfolding
        for lineNum in range(lineCount):
            if self.GetFoldLevel(lineNum) & stc.STC_FOLDLEVELHEADERFLAG:
                expanding = not self.GetFoldExpanded(lineNum)
                break

        lineNum = 0

        while lineNum < lineCount:
            level = self.GetFoldLevel(lineNum)
            if level & stc.STC_FOLDLEVELHEADERFLAG and \
               (level & stc.STC_FOLDLEVELNUMBERMASK) == stc.STC_FOLDLEVELBASE:

                if expanding:
                    self.SetFoldExpanded(lineNum, True)
                    lineNum = self.Expand(lineNum, True)
                    lineNum = lineNum - 1
                else:
                    lastChild = self.GetLastChild(lineNum, -1)
                    self.SetFoldExpanded(lineNum, False)

                    if lastChild > lineNum:
                        self.HideLines(lineNum+1, lastChild)

            lineNum = lineNum + 1



    def Expand(self, line, doExpand, force=False, visLevels=0, level=-1):
        lastChild = self.GetLastChild(line, level)
        line = line + 1

        while line <= lastChild:
            if force:
                if visLevels > 0:
                    self.ShowLines(line, line)
                else:
                    self.HideLines(line, line)
            else:
                if doExpand:
                    self.ShowLines(line, line)

            if level == -1:
                level = self.GetFoldLevel(line)

            if level & stc.STC_FOLDLEVELHEADERFLAG:
                if force:
                    if visLevels > 1:
                        self.SetFoldExpanded(line, True)
                    else:
                        self.SetFoldExpanded(line, False)

                    line = self.Expand(line, doExpand, force, visLevels-1)

                else:
                    if doExpand and self.GetFoldExpanded(line):
                        line = self.Expand(line, True, force, visLevels-1)
                    else:
                        line = self.Expand(line, False, force, visLevels-1)
            else:
                line = line + 1

        return line


#----------------------------------------------------------------------
class PythonCodeEditor(PythonSTC):
    def __init__(self, parent):
        PythonSTC.__init__(self, parent, -1, style=wx.BORDER_NONE)
        self.SetUpEditor()

    # Some methods to make it compatible with how the wxTextCtrl is used
    def SetValue(self, value):
        if wx.USE_UNICODE:
            value = value.decode('utf-8')
        self.SetText(value)
        self.EmptyUndoBuffer()
        self.SetSavePoint()

    def IsModified(self):
        return self.GetModify()

    def Clear(self):
        self.ClearAll()

    def SetInsertionPoint(self, pos):
        self.SetCurrentPos(pos)
        self.SetAnchor(pos)

    def ShowPosition(self, pos):
        line = self.LineFromPosition(pos)
        #self.EnsureVisible(line)
        self.GotoLine(line)

    def GetLastPosition(self):
        return self.GetLength()

    def GetPositionFromLine(self, line):
        return self.PositionFromLine(line)

    def GetRange(self, start, end):
        return self.GetTextRange(start, end)

    def GetSelection(self):
        return self.GetAnchor(), self.GetCurrentPos()

    def SetSelection(self, start, end):
        self.SetSelectionStart(start)
        self.SetSelectionEnd(end)

    def SelectLine(self, line):
        start = self.PositionFromLine(line)
        end = self.GetLineEndPosition(line)
        self.SetSelection(start, end)
        
    def SetUpEditor(self):
        """
        This method carries out the work of setting up the demo editor.            
        It's seperate so as not to clutter up the init code.
        """
        import keyword
        
        self.SetLexer(stc.STC_LEX_PYTHON)
        self.SetKeyWords(0, " ".join(keyword.kwlist))

        # Enable folding
        self.SetProperty("fold", "1" ) 

        # Highlight tab/space mixing (shouldn't be any)
        self.SetProperty("tab.timmy.whinge.level", "1")

        # Set left and right margins
        self.SetMargins(2,2)

        # Set up the numbers in the margin for margin #1
        self.SetMarginType(1, wx.stc.STC_MARGIN_NUMBER)
        # Reasonable value for, say, 4-5 digits using a mono font (40 pix)
        self.SetMarginWidth(1, 40)

        # Indentation and tab stuff
        self.SetIndent(4)               # Proscribed indent size for wx
        self.SetIndentationGuides(True) # Show indent guides
        self.SetBackSpaceUnIndents(True)# Backspace unindents rather than delete 1 space
        self.SetTabIndents(True)        # Tab key indents
        self.SetTabWidth(4)             # Proscribed tab size for wx
        self.SetUseTabs(False)          # Use spaces rather than tabs, or
                                        # TabTimmy will complain!    
        # White space
        self.SetViewWhiteSpace(False)   # Don't view white space

        # EOL: Since we are loading/saving ourselves, and the
        # strings will always have \n's in them, set the STC to
        # edit them that way.            
        self.SetEOLMode(wx.stc.STC_EOL_LF)
        self.SetViewEOL(False)
        
        # No right-edge mode indicator
        self.SetEdgeMode(stc.STC_EDGE_NONE)

        # Setup a margin to hold fold markers
        self.SetMarginType(2, stc.STC_MARGIN_SYMBOL)
        self.SetMarginMask(2, stc.STC_MASK_FOLDERS)
        self.SetMarginSensitive(2, True)
        self.SetMarginWidth(2, 12)

        # and now set up the fold markers
        self.MarkerDefine(stc.STC_MARKNUM_FOLDEREND,     stc.STC_MARK_BOXPLUSCONNECTED,  "white", "black")
        self.MarkerDefine(stc.STC_MARKNUM_FOLDEROPENMID, stc.STC_MARK_BOXMINUSCONNECTED, "white", "black")
        self.MarkerDefine(stc.STC_MARKNUM_FOLDERMIDTAIL, stc.STC_MARK_TCORNER,  "white", "black")
        self.MarkerDefine(stc.STC_MARKNUM_FOLDERTAIL,    stc.STC_MARK_LCORNER,  "white", "black")
        self.MarkerDefine(stc.STC_MARKNUM_FOLDERSUB,     stc.STC_MARK_VLINE,    "white", "black")
        self.MarkerDefine(stc.STC_MARKNUM_FOLDER,        stc.STC_MARK_BOXPLUS,  "white", "black")
        self.MarkerDefine(stc.STC_MARKNUM_FOLDEROPEN,    stc.STC_MARK_BOXMINUS, "white", "black")

        # Global default style
        if wx.Platform == '__WXMSW__':
            self.StyleSetSpec(stc.STC_STYLE_DEFAULT, 
                              'fore:#000000,back:#FFFFFF,face:Courier New')
        elif wx.Platform == '__WXMAC__':
            # TODO: if this looks fine on Linux too, remove the Mac-specific case 
            # and use this whenever OS != MSW.
            self.StyleSetSpec(stc.STC_STYLE_DEFAULT, 
                              'fore:#000000,back:#FFFFFF,face:Monaco')
        else:
            defsize = wx.SystemSettings.GetFont(wx.SYS_ANSI_FIXED_FONT).GetPointSize()
            self.StyleSetSpec(stc.STC_STYLE_DEFAULT, 
                              'fore:#000000,back:#FFFFFF,face:Courier,size:%d'%defsize)

        # Clear styles and revert to default.
        self.StyleClearAll()

        # Following style specs only indicate differences from default.
        # The rest remains unchanged.

        # Line numbers in margin
        self.StyleSetSpec(wx.stc.STC_STYLE_LINENUMBER,'fore:#000000,back:#99A9C2')    
        # Highlighted brace
        self.StyleSetSpec(wx.stc.STC_STYLE_BRACELIGHT,'fore:#00009D,back:#FFFF00')
        # Unmatched brace
        self.StyleSetSpec(wx.stc.STC_STYLE_BRACEBAD,'fore:#00009D,back:#FF0000')
        # Indentation guide
        self.StyleSetSpec(wx.stc.STC_STYLE_INDENTGUIDE, "fore:#CDCDCD")

        # Python styles
        self.StyleSetSpec(wx.stc.STC_P_DEFAULT, 'fore:#000000')
        # Comments
        self.StyleSetSpec(wx.stc.STC_P_COMMENTLINE,  'fore:#008000,back:#F0FFF0')
        self.StyleSetSpec(wx.stc.STC_P_COMMENTBLOCK, 'fore:#008000,back:#F0FFF0')
        # Numbers
        self.StyleSetSpec(wx.stc.STC_P_NUMBER, 'fore:#008080')
        # Strings and characters
        self.StyleSetSpec(wx.stc.STC_P_STRING, 'fore:#800080')
        self.StyleSetSpec(wx.stc.STC_P_CHARACTER, 'fore:#800080')
        # Keywords
        self.StyleSetSpec(wx.stc.STC_P_WORD, 'fore:#000080,bold')
        # Triple quotes
        self.StyleSetSpec(wx.stc.STC_P_TRIPLE, 'fore:#800080,back:#FFFFEA')
        self.StyleSetSpec(wx.stc.STC_P_TRIPLEDOUBLE, 'fore:#800080,back:#FFFFEA')
        # Class names
        self.StyleSetSpec(wx.stc.STC_P_CLASSNAME, 'fore:#0000FF,bold')
        # Function names
        self.StyleSetSpec(wx.stc.STC_P_DEFNAME, 'fore:#008080,bold')
        # Operators
        self.StyleSetSpec(wx.stc.STC_P_OPERATOR, 'fore:#800000,bold')
        # Identifiers. I leave this as not bold because everything seems
        # to be an identifier if it doesn't match the above criterae
        self.StyleSetSpec(wx.stc.STC_P_IDENTIFIER, 'fore:#000000')

        # Caret color
        self.SetCaretForeground("BLUE")
        # Selection background
        self.SetSelBackground(1, '#66CCFF')

        self.SetSelBackground(True, wx.SystemSettings_GetColour(wx.SYS_COLOUR_HIGHLIGHT))
        self.SetSelForeground(True, wx.SystemSettings_GetColour(wx.SYS_COLOUR_HIGHLIGHTTEXT))

    def RegisterModifiedEvent(self, eventHandler):
        self.Bind(wx.stc.EVT_STC_CHANGE, eventHandler)


class PythonCodePanel(wx.Panel):
    """Panel for the 'Demo Code' tab"""
    def __init__(self, parent, mainFrame):
        wx.Panel.__init__(self, parent, size=(1,1))
        self.mainFrame = mainFrame
        self.editor = PythonCodeEditor(self)
        self.editor.RegisterModifiedEvent(self.OnCodeModified)

        self.btnSave = wx.Button(self, -1, "Save")
        self.btnRestore = wx.Button(self, -1, "Restore")
        self.btnSave.Enable(False)
        self.btnSave.Bind(wx.EVT_BUTTON, self.OnSave)
        self.btnRestore.Bind(wx.EVT_BUTTON, self.OnRestore)

        self.controlBox = wx.BoxSizer(wx.HORIZONTAL)
        self.controlBox.Add(self.btnSave, 0, wx.RIGHT, 5)
        self.controlBox.Add(self.btnRestore, 0)

        self.box = wx.BoxSizer(wx.VERTICAL)
        self.box.Add(self.controlBox, 0, wx.EXPAND)
        self.box.Add(wx.StaticLine(self), 0, wx.EXPAND)
        self.box.Add(self.editor, 1, wx.EXPAND)
        
        self.box.Fit(self)
        self.SetSizer(self.box)
        
        self.sourceFile = None
        
        self.Bind(wx.EVT_MENU, self.OnSave, id=wx.ID_SAVE)
        accel = wx.AcceleratorTable([wx.AcceleratorEntry(wx.ACCEL_CTRL, 83, wx.ID_SAVE)])
        self.SetAcceleratorTable(accel)

    # Loads from a file object
    def LoadSourceFile(self, filename):
        self.sourceFile = filename
        if os.path.exists(filename):
            self.LoadSource(file(filename).read())

    def LoadSource(self, source):
        self.editor.Clear()
        self.editor.SetValue(source)
        self.JumpToLine(0)
        self.btnSave.Enable(False)

    def JumpToLine(self, line, highlight=False):
        self.editor.GotoLine(line)
        self.editor.SetFocus()
        if highlight:
            self.editor.SelectLine(line)
                    
    def OnCodeModified(self, event):
        self.btnSave.Enable(self.editor.IsModified())
        # TODO : add callback
        
    def OnSave(self, event):
        overwriteMsg = "You are about to overwrite that file\n" + \
                       "Do you want to continue?"
        dlg = wx.MessageDialog(self, overwriteMsg, "wxPython Demo",
                               wx.YES_NO | wx.NO_DEFAULT| wx.ICON_EXCLAMATION)
        result = dlg.ShowModal()
        if result == wx.ID_NO:
            return
        dlg.Destroy()

        source = self.editor.GetText().encode("utf-8")

        f = file(self.sourceFile, "w")
        f.write(source)
        f.close()
         
        # TODO
        #self.mainFrame.SetTreeModified(True)


    def OnRestore(self, event):
        self.LoadSourceFile(self.sourceFile)
        self.btnSave.Enable(self.editor.IsModified())