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[wxWidgets.git] / wxPython / wx / lib / docview.py

#----------------------------------------------------------------------------
# Name:         docview.py
# Purpose:      Port of the wxWidgets docview classes
#
# Author:       Peter Yared
#
# Created:      5/15/03
# CVS-ID:       $Id$
# Copyright:    (c) 2003-2005 ActiveGrid, Inc. (Port of wxWindows classes by Julian Smart et al)
# License:      wxWindows license
#----------------------------------------------------------------------------

"""
A port of the wxWidgets doc/view classes to Python.

:see: `pydocview`
"""

import os
import os.path
import wx
import sys
_ = wx.GetTranslation


#----------------------------------------------------------------------
# docview globals
#----------------------------------------------------------------------

DOC_SDI = 1
DOC_MDI = 2
DOC_NEW = 4
DOC_SILENT = 8
DOC_OPEN_ONCE = 16
DEFAULT_DOCMAN_FLAGS = DOC_SDI & DOC_OPEN_ONCE

TEMPLATE_VISIBLE = 1
TEMPLATE_INVISIBLE = 2
DEFAULT_TEMPLATE_FLAGS = TEMPLATE_VISIBLE

MAX_FILE_HISTORY = 9


#----------------------------------------------------------------------
# Convenience functions from wxWindows used in docview
#----------------------------------------------------------------------


def FileNameFromPath(path):
    """
    Returns the filename for a full path.
    """
    return os.path.split(path)[1]

def FindExtension(path):
    """
    Returns the extension of a filename for a full path.
    """
    return os.path.splitext(path)[1].lower()

def FileExists(path):
    """
    Returns True if the path exists.
    """
    return os.path.isfile(path)

def PathOnly(path):
    """
    Returns the path of a full path without the filename.
    """
    return os.path.split(path)[0]


#----------------------------------------------------------------------
# Document/View Classes
#----------------------------------------------------------------------


class Document(wx.EvtHandler):
    """
    The document class can be used to model an application's
    file-based data. It is part of the document/view framework, and
    cooperates with the `View`, `DocTemplate` and `DocManager`
    classes.
    
    Note this wxPython version also keeps track of the modification date of the
    document and if it changes on disk outside of the application, we will warn the
    user before saving to avoid clobbering the file.
    """


    def __init__(self, parent = None):
        """
        Constructor.  Define your own default constructor to initialize
        application-specific data.
        """
        wx.EvtHandler.__init__(self)

        self._documentParent = parent
        self._documentTemplate = None
        self._commandProcessor = None
        self._savedYet = False
        self._writeable = True

        self._documentTitle = None
        self._documentFile = None
        self._documentTypeName = None
        self._documentModified = False
        self._documentModificationDate = None
        self._documentViews = []


    def ProcessEvent(self, event):
        """
        Processes an event, searching event tables and calling zero or more
        suitable event handler function(s).  Note that the ProcessEvent
        method is called from the wxPython docview framework directly since
        wxPython does not have a virtual ProcessEvent function.
        """
        return False


    def GetFilename(self):
        """
        Gets the filename associated with this document, or "" if none is
        associated.
        """
        return self._documentFile


    def GetTitle(self):
        """
        Gets the title for this document. The document title is used for an
        associated frame (if any), and is usually constructed by the framework
        from the filename.
        """
        return self._documentTitle


    def SetTitle(self, title):
        """
        Sets the title for this document. The document title is used for an
        associated frame (if any), and is usually constructed by the framework
        from the filename.
        """
        self._documentTitle = title


    def GetDocumentName(self):
        """
        The document type name given to the `DocTemplate` constructor,
        copied to this document when the document is created. If several
        document templates are created that use the same document type, this
        variable is used in `DocManager.CreateView` to collate a list of
        alternative view types that can be used on this kind of document.
        """
        return self._documentTypeName


    def SetDocumentName(self, name):
        """
        Sets the document type name given to the `DocTemplate` constructor,
        copied to this document when the document is created. If several
        document templates are created that use the same document type, this
        variable is used in `DocManager.CreateView` to collate a list of
        alternative view types that can be used on this kind of document. Do
        not change the value of this variable.
        """
        self._documentTypeName = name


    def GetDocumentSaved(self):
        """
        Returns True if the document has been saved. 
        """
        return self._savedYet


    def SetDocumentSaved(self, saved = True):
        """
        Sets whether the document has been saved.  
        """
        self._savedYet = saved


    def GetCommandProcessor(self):
        """
        Returns the command processor associated with this document.
        """
        return self._commandProcessor


    def SetCommandProcessor(self, processor):
        """
        Sets the command processor to be used for this document. The document
        will then be responsible for its deletion. Normally you should not
        call this; override `OnCreateCommandProcessor` instead.
        """
        self._commandProcessor = processor


    def IsModified(self):
        """
        Returns true if the document has been modified since the last save,
        false otherwise. You may need to override this if your document view
        maintains its own record of being modified (for example if using
        wxTextWindow to view and edit the document).
        """
        return self._documentModified


    def Modify(self, modify):
        """
        Call with true to mark the document as modified since the last save,
        false otherwise. You may need to override this if your document view
        maintains its own record of being modified (for example if using
        `wx.TextCtrl` to view and edit the document).
        """
        self._documentModified = modify


    def SetDocumentModificationDate(self):
        """
        Saves the file's last modification date.
        This is used to check if the file has been modified outside of the application.
        """
        self._documentModificationDate = os.path.getmtime(self.GetFilename())


    def GetDocumentModificationDate(self):
        """
        Returns the file's modification date when it was loaded from disk.
        This is used to check if the file has been modified outside of the application.        
        """
        return self._documentModificationDate


    def GetViews(self):
        """
        Returns the list whose elements are the views on the document.
        """
        return self._documentViews


    def GetDocumentTemplate(self):
        """
        Returns the template that created the document.
        """
        return self._documentTemplate


    def SetDocumentTemplate(self, template):
        """
        Sets the template that created the document. Should only be called by
        the framework.
        """
        self._documentTemplate = template


    def DeleteContents(self):
        """
        Deletes the contents of the document.  Override this method as
        necessary.
        """
        return True


    def Destroy(self):
        """
        Destructor. Removes itself from the document manager.
        """
        self.DeleteContents()
        if self.GetDocumentManager():
            self.GetDocumentManager().RemoveDocument(self)
        wx.EvtHandler.Destroy(self)


    def Close(self):
        """
        Closes the document, by calling `OnSaveModified` and then (if
        this returns True) `OnCloseDocument`. This does not normally
        delete the document object: use DeleteAllViews to do this
        implicitly.
        """
        if self.OnSaveModified():
            if self.OnCloseDocument():
                return True
            else:
                return False
        else:
            return False


    def OnCloseDocument(self):
        """
        The default implementation calls `DeleteContents` (an empty
        implementation) sets the modified flag to false. Override this
        to supply additional behaviour when the document is closed
        with `Close`.
        """
        self.NotifyClosing()
        self.DeleteContents()
        self.Modify(False)
        return True


    def DeleteAllViews(self):
        """
        Calls `View.Close` and deletes each view. Deleting the final view will
        implicitly delete the document itself, because the `View` destructor
        calls `RemoveView`. This in turns calls `Document.OnChangedViewList`,
        whose default implemention is to save and delete the document if no
        views exist.
        """
        manager = self.GetDocumentManager()
        for view in self._documentViews:
            if not view.Close():
                return False
        if self in manager.GetDocuments():
            self.Destroy()
        return True


    def GetFirstView(self):
        """
        A convenience function to get the first view for a document, because
        in many cases a document will only have a single view.
        """
        if len(self._documentViews) == 0:
            return None
        return self._documentViews[0]


    def GetDocumentManager(self):
        """
        Returns the associated document manager.
        """
        if self._documentTemplate:
            return self._documentTemplate.GetDocumentManager()
        return None


    def OnNewDocument(self):
        """
        The default implementation calls `OnSaveModified` and
        `DeleteContents`, makes a default title for the document, and
        notifies the views that the filename (in fact, the title) has
        changed.
        """
        if not self.OnSaveModified() or not self.OnCloseDocument():
            return False
        self.DeleteContents()
        self.Modify(False)
        self.SetDocumentSaved(False)
        name = self.GetDocumentManager().MakeDefaultName()
        self.SetTitle(name)
        self.SetFilename(name, notifyViews = True)


    def Save(self):
        """
        Saves the document by calling `OnSaveDocument` if there is an
        associated filename, or `SaveAs` if there is no filename.
        """
        if not self.IsModified():  # and self._savedYet:  This was here, but if it is not modified who cares if it hasn't been saved yet?
            return True

        """ check for file modification outside of application """
        if os.path.exists(self.GetFilename()) and os.path.getmtime(self.GetFilename()) != self.GetDocumentModificationDate():
            msgTitle = wx.GetApp().GetAppName()
            if not msgTitle:
                msgTitle = _("Application")
            res = wx.MessageBox(_("'%s' has been modified outside of %s.  Overwrite '%s' with current changes?") % (self.GetPrintableName(), msgTitle, self.GetPrintableName()),
                                msgTitle,
                                wx.YES_NO | wx.CANCEL | wx.ICON_QUESTION,
                                self.GetDocumentWindow())
    
            if res == wx.NO:
                return True
            elif res == wx.YES:
                pass
            else: # elif res == wx.CANCEL:
                return False
        
        if not self._documentFile or not self._savedYet:
            return self.SaveAs()
        return self.OnSaveDocument(self._documentFile)


    def SaveAs(self):
        """
        Prompts the user for a file to save to, and then calls `OnSaveDocument`.
        """
        docTemplate = self.GetDocumentTemplate()
        if not docTemplate:
            return False

        descr = docTemplate.GetDescription() + _(" (") + docTemplate.GetFileFilter() + _(") |") + docTemplate.GetFileFilter()  # spacing is important, make sure there is no space after the "|", it causes a bug on wx_gtk
        filename = wx.FileSelector(_("Save As"),
                                   docTemplate.GetDirectory(),
                                   FileNameFromPath(self.GetFilename()),
                                   docTemplate.GetDefaultExtension(),
                                   wildcard = descr,
                                   flags = wx.SAVE | wx.OVERWRITE_PROMPT,
                                   parent = self.GetDocumentWindow())
        if filename == "":
            return False

        name, ext = os.path.splitext(filename)
        if ext == "":
            filename += '.' + docTemplate.GetDefaultExtension()

        self.SetFilename(filename)
        self.SetTitle(FileNameFromPath(filename))

        for view in self._documentViews:
            view.OnChangeFilename()

        if not self.OnSaveDocument(filename):
            return False

        if docTemplate.FileMatchesTemplate(filename):
            self.GetDocumentManager().AddFileToHistory(filename)
            
        return True


    def OnSaveDocument(self, filename):
        """
        Constructs an output file for the given filename (which must
        not be empty), and calls `SaveObject`. If `SaveObject` returns
        true, the document is set to unmodified; otherwise, an error
        message box is displayed.
        """
        if not filename:
            return False

        msgTitle = wx.GetApp().GetAppName()
        if not msgTitle:
            msgTitle = _("File Error")

        backupFilename = None
        try:
            # if current file exists, move it to a safe place temporarily
            if os.path.exists(filename):

                # Check if read-only.
                if not os.access(filename, os.W_OK):
                    wx.MessageBox("Could not save '%s'.  No write permission to overwrite existing file." % FileNameFromPath(filename),
                                  msgTitle,
                                  wx.OK | wx.ICON_EXCLAMATION,
                                  self.GetDocumentWindow())
                    return False

                i = 1
                backupFilename = "%s.bak%s" % (filename, i)
                while os.path.exists(backupFilename):
                    i += 1
                    backupFilename = "%s.bak%s" % (filename, i)
                os.rename(filename, backupFilename)

            fileObject = file(filename, 'w')
            self.SaveObject(fileObject)

            if backupFilename:
                os.remove(backupFilename)
        except:
            # save failed, restore old file
            if backupFilename:
                os.remove(filename)
                os.rename(backupFilename, filename)
                self.SetDocumentModificationDate()

            wx.MessageBox("Could not save '%s'.  %s" % (FileNameFromPath(filename), sys.exc_value),
                          msgTitle,
                          wx.OK | wx.ICON_EXCLAMATION,
                          self.GetDocumentWindow())
            return False

        self.SetFilename(filename, True)
        self.Modify(False)
        self.SetDocumentModificationDate()
        self.SetDocumentSaved(True)
        #if wx.Platform == '__WXMAC__':  # Not yet implemented in wxPython
        #    wx.FileName(file).MacSetDefaultTypeAndCreator()
        return True


    def OnOpenDocument(self, filename):
        """
        Constructs an input file for the given filename (which must not
        be empty), and calls `LoadObject`. If `LoadObject` returns true, the
        document is set to unmodified; otherwise, an error message box is
        displayed. The document's views are notified that the filename has
        changed, to give windows an opportunity to update their titles. All of
        the document's views are then updated.
        """
        if not self.OnSaveModified():
            return False

        msgTitle = wx.GetApp().GetAppName()
        if not msgTitle:
            msgTitle = _("File Error")

        fileObject = file(filename, 'r')
        try:
            self.LoadObject(fileObject)
        except:
            wx.MessageBox("Could not open '%s'.  %s" % (FileNameFromPath(filename), sys.exc_value),
                          msgTitle,
                          wx.OK | wx.ICON_EXCLAMATION,
                          self.GetDocumentWindow())
            return False

        self.SetFilename(filename, True)
        self.Modify(False)
        self.SetDocumentModificationDate()
        self.SetDocumentSaved(True)
        self.UpdateAllViews()
        return True


    def LoadObject(self, file):
        """
        Override this function and call it from your own `LoadObject`
        before loading your own data. `LoadObject` is called by the
        framework automatically when the document contents need to be
        loaded.

        Note that the wxPython version simply sends you a Python file
        object, so you can use pickle.
        """
        return True


    def SaveObject(self, file):
        """
        Override this function and call it from your own `SaveObject`
        before saving your own data. `SaveObject` is called by the
        framework automatically when the document contents need to be
        saved.

        Note that the wxPython version simply sends you a Python file
        object, so you can use pickle.
        """
        return True


    def Revert(self):
        """
        Override this function to revert the document to its last saved state.
        """
        return False


    def GetPrintableName(self):
        """
        Copies a suitable document name into the supplied name buffer.
        The default function uses the title, or if there is no title, uses the
        filename; or if no filename, the string 'Untitled'.
        """
        if self._documentTitle:
            return self._documentTitle
        elif self._documentFile:
            return FileNameFromPath(self._documentFile)
        else:
            return _("Untitled")


    def GetDocumentWindow(self):
        """
        Intended to return a suitable window for using as a parent for
        document-related dialog boxes. By default, uses the frame associated
        with the first view.
        """
        if len(self._documentViews) > 0:
            return self._documentViews[0].GetFrame()
        else:
            return wx.GetApp().GetTopWindow()


    def OnCreateCommandProcessor(self):
        """
        Override this function if you want a different (or no) command
        processor to be created when the document is created. By
        default, it returns an instance of `CommandProcessor`.
        """
        return CommandProcessor()


    def OnSaveModified(self):
        """
        If the document has been modified, prompts the user to ask if
        the changes should be changed. If the user replies Yes, the
        `Save` function is called. If No, the document is marked as
        unmodified and the function succeeds. If Cancel, the function
        fails.
        """
        if not self.IsModified():
            return True

        """ check for file modification outside of application """
        if os.path.exists(self.GetFilename()) and os.path.getmtime(self.GetFilename()) != self.GetDocumentModificationDate():
            msgTitle = wx.GetApp().GetAppName()
            if not msgTitle:
                msgTitle = _("Warning")
            res = wx.MessageBox(_("'%s' has been modified outside of %s.  Overwrite '%s' with current changes?") % (self.GetPrintableName(), msgTitle, self.GetPrintableName()),
                                msgTitle,
                                wx.YES_NO | wx.CANCEL | wx.ICON_QUESTION,
                                self.GetDocumentWindow())
    
            if res == wx.NO:
                self.Modify(False)
                return True
            elif res == wx.YES:
                return wx.lib.docview.Document.Save(self)
            else: # elif res == wx.CANCEL:
                return False

        msgTitle = wx.GetApp().GetAppName()
        if not msgTitle:
            msgTitle = _("Warning")

        res = wx.MessageBox(_("Save changes to '%s'?") % self.GetPrintableName(),
                            msgTitle,
                            wx.YES_NO | wx.CANCEL | wx.ICON_QUESTION,
                            self.GetDocumentWindow())

        if res == wx.NO:
            self.Modify(False)
            return True
        elif res == wx.YES:
            return self.Save()
        else: # elif res == wx.CANCEL:
            return False


    def Draw(context):
        """
        Called by printing framework to draw the view.
        """
        return True


    def AddView(self, view):
        """
        If the view is not already in the list of views, adds the view and
        calls `OnChangedViewList`.
        """
        if not view in self._documentViews:
            self._documentViews.append(view)
            self.OnChangedViewList()
        return True


    def RemoveView(self, view):
        """
        Removes the view from the document's list of views, and calls
        `OnChangedViewList`.
        """
        if view in self._documentViews:
            self._documentViews.remove(view)
            self.OnChangedViewList()
        return True


    def OnCreate(self, path, flags):
        """
        The default implementation calls `DeleteContents` (an empty
        implementation) sets the modified flag to false. Override this to
        supply additional behaviour when the document is closed with Close.
        """
        return self.GetDocumentTemplate().CreateView(self, flags)


    def OnChangedViewList(self):
        """
        Called when a view is added to or deleted from this document. The
        default implementation saves and deletes the document if no views
        exist (the last one has just been removed).
        """
        if len(self._documentViews) == 0:
            if self.OnSaveModified():
                pass # C version does a delete but Python will garbage collect


    def UpdateAllViews(self, sender = None, hint = None):
        """
        Updates all views. If sender is non-None, does not update this view.
        hint represents optional information to allow a view to optimize its
        update.
        """
        for view in self._documentViews:
            if view != sender:
                view.OnUpdate(sender, hint)


    def NotifyClosing(self):
        """
        Notifies the views that the document is going to close.
        """
        for view in self._documentViews:
            view.OnClosingDocument()


    def SetFilename(self, filename, notifyViews = False):
        """
        Sets the filename for this document. Usually called by the framework.
        If notifyViews is true, `View.OnChangeFilename` is called for all
        views.
        """
        self._documentFile = filename
        if notifyViews:
            for view in self._documentViews:
                view.OnChangeFilename()


    def GetWriteable(self):
        """
        Returns true if the document can be written to its accociated file path.
        This method has been added to wxPython and is not in wxWindows.
        """
        if not self._writeable:
            return False 
        if not self._documentFile:  # Doesn't exist, do a save as
            return True
        else:
            return os.access(self._documentFile, os.W_OK)


    def SetWriteable(self, writeable):
        """
        Set to False if the document can not be saved.  This will
        disable the ID_SAVE_AS event and is useful for custom
        documents that should not be saveable.  The ID_SAVE event can
        be disabled by never modifying the document.  
        """
        self._writeable = writeable


class View(wx.EvtHandler):
    """
    The view class can be used to model the viewing and editing
    component of an application's file-based data. It cooperates
    with the `Document`, `DocTemplate` and `DocManager` classes.
    """

    def __init__(self):
        """
        Constructor. Define your own default constructor to initialize
        application-specific data.
        """
        wx.EvtHandler.__init__(self)
        self._viewDocument = None
        self._viewFrame = None


    def Destroy(self):
        """
        Destructor. Removes itself from the document's list of views.
        """
        if self._viewDocument:
            self._viewDocument.RemoveView(self)
        wx.EvtHandler.Destroy(self)


    def ProcessEvent(self, event):
        """
        Processes an event, searching event tables and calling zero or more
        suitable event handler function(s).  Note that the ProcessEvent
        method is called from the wxPython docview framework directly since
        wxPython does not have a virtual ProcessEvent function.
        """
        if not self.GetDocument() or not self.GetDocument().ProcessEvent(event):
            return False
        else:
            return True


    def ProcessUpdateUIEvent(self, event):
        """
        Processes a UI event, searching event tables and calling zero or more
        suitable event handler function(s).  Note that the ProcessEvent
        method is called from the wxPython docview framework directly since
        wxPython does not have a virtual ProcessEvent function.
        """
        return False


    def OnActivateView(self, activate, activeView, deactiveView):
        """
        Called when a view is activated by means of `View.Activate`. The
        default implementation does nothing.
        """
        pass


    def OnClosingDocument(self):
        """
        Override this to clean up the view when the document is being closed.
        The default implementation does nothing.
        """
        pass


    def OnDraw(self, dc):
        """
        Override this to draw the view for the printing framework.  The
        default implementation does nothing.
        """
        pass


    def OnPrint(self, dc, info):
        """
        Override this to print the view for the printing framework.  The
        default implementation calls `View.OnDraw`.
        """
        self.OnDraw(dc)


    def OnUpdate(self, sender, hint):
        """
        Called when the view should be updated. sender is a reference to the
        view that sent the update request, or None if no single view requested
        the update (for instance, when the document is opened). hint is as yet
        unused but may in future contain application-specific information for
        making updating more efficient.
        """
        pass


    def OnChangeFilename(self):
        """
        Called when the filename has changed. The default implementation
        constructs a suitable title and sets the title of the view frame (if
        any).
        """
        if self.GetFrame():
            appName = wx.GetApp().GetAppName()
            if not self.GetDocument():
                if appName:
                    title = appName
                else:
                    return
            else:
                if appName and isinstance(self.GetFrame(), DocChildFrame):  # Only need app name in title for SDI
                    title = appName + _(" - ")
                else:
                    title = ''
                self.GetFrame().SetTitle(title + self.GetDocument().GetPrintableName())


    def GetDocument(self):
        """
        Returns the document associated with the view.
        """
        return self._viewDocument


    def SetDocument(self, doc):
        """
        Associates the given document with the view. Normally called by the
        framework.
        """
        self._viewDocument = doc
        if doc:
            doc.AddView(self)


    def GetViewName(self):
        """
        Gets the name associated with the view (passed to the `DocTemplate`
        constructor). Not currently used by the framework.
        """
        return self._viewTypeName


    def SetViewName(self, name):
        """
        Sets the view type name. Should only be called by the framework.
        """
        self._viewTypeName = name


    def Close(self, deleteWindow = True):
        """
        Closes the view by calling `OnClose`. If deleteWindow is true, this
        function should delete the window associated with the view.
        """
        if self.OnClose(deleteWindow = deleteWindow):
            return True
        else:
            return False


    def Activate(self, activate = True):
        """
        Call this from your view frame's EVT_ACTIVATE handler to tell
        the framework which view is currently active. If your
        windowing system doesn't support EVT_ACTIVATE, you may need to
        call this function from an EVT_MENU handler, or any place
        where you know the view must be active, and the framework will
        need to get the current view.
        """
        if self.GetDocument() and self.GetDocumentManager():
            self.OnActivateView(activate,
                                self,
                                self.GetDocumentManager().GetCurrentView())
            self.GetDocumentManager().ActivateView(self, activate)


    def OnClose(self, deleteWindow = True):
        """
        Implements closing behaviour. The default implementation calls
        `Document.Close` to close the associated document. Does not delete the
        view. The application may wish to do some cleaning up operations in
        this function, if a call to `Document.Close` succeeded. For example,
        if your application's all share the same window, you need to
        disassociate the window from the view and perhaps clear the window. If
        deleteWindow is true, delete the frame associated with the view.
        """
        if self.GetDocument():
            return self.GetDocument().Close()
        else:
            return True


    def OnCreate(self, doc, flags):
        """
        `DocManager` or `Document` creates a `View` via a `DocTemplate`. Just
        after the `DocTemplate` creates the `View`, it calls `View.OnCreate`.
        In its `OnCreate` member function, the `View` can create a
        `DocChildFrame` or a derived class. This `DocChildFrame` provides user
        interface elements to view and/or edit the contents of the `Document`.

        By default, simply returns true. If the function returns false, the
        view will be deleted.
        """
        return True


    def OnCreatePrintout(self):
        """
        Returns a `wx.Printout` object for the purposes of printing. It should
        create a new object every time it is called; the framework will delete
        objects it creates.

        By default, this function returns an instance of `DocPrintout`, which
        prints and previews one page by calling `View.OnDraw`.

        Override to return an instance of a class other than `DocPrintout`.
        """
        return DocPrintout(self)


    def GetFrame(self):
        """
        Gets the frame associated with the view (if any). Note that this
        "frame" is not a `wx.Frame` at all in the generic MDI implementation
        which uses the notebook pages instead of the frames.
        """
        return self._viewFrame


    def SetFrame(self, frame):
        """
        Sets the frame associated with this view. The application should call
        this if possible, to tell the view about the frame. 
        """
        self._viewFrame = frame


    def GetDocumentManager(self):
        """
        Returns the document manager instance associated with this view.
        """
        if self._viewDocument:
            return self.GetDocument().GetDocumentManager()
        else:
            return None


class DocTemplate(wx.Object):
    """
    The `DocTemplate` class is used to model the relationship between
    a document class and a view class.
    """


    def __init__(self, manager, description, filter, dir, ext,
                 docTypeName, viewTypeName, docType, viewType,
                 flags = DEFAULT_TEMPLATE_FLAGS, icon = None):
        """
        Constructor. Create instances dynamically near the start of your
        application after creating a `DocManager` instance, and before doing
        any document or view operations.

        :param manager: the document manager object which manages this template.

        :param description: a short description of what the template
            is for. This string will be displayed in the file filter
            list of Windows file selectors.

        :param filter: an appropriate file filter such as \*.txt.

        :param dir: the default directory to use for file selectors.

        :param ext: the default file extension (such as txt).

        :param docTypeName: a name that should be unique for a given
            type of document, used for gathering a list of views
            relevant to a particular document.

        :param viewTypeName: a name that should be unique for a given view.

        :param docType: a Python class. If this is not supplied, you
            will need to derive a new `DocTemplate` class and override
            the `CreateDocument` member to return a new document
            instance on demand.

        :param viewType: a Python class. If this is not supplied, you
            will need to derive a new `DocTemplate` class and override
            the `CreateView` member to return a new view instance on
            demand.

        :param flags: a bit list of the following
        
            * TEMPLATE_VISIBLE: The template may be displayed to the
              user in dialogs.

            * TEMPLATE_INVISIBLE: The template may not be displayed
              to the user in dialogs.

            * DEFAULT_TEMPLATE_FLAGS: Defined as TEMPLATE_VISIBLE.
            
        """
        self._docManager = manager
        self._description = description
        self._fileFilter = filter
        self._directory = dir
        self._defaultExt = ext
        self._docTypeName = docTypeName
        self._viewTypeName = viewTypeName
        self._docType = docType
        self._viewType = viewType
        self._flags = flags
        self._icon = icon

        self._docManager.AssociateTemplate(self)


    def GetDefaultExtension(self):
        """
        Returns the default file extension for the document data, as
        passed to the document template constructor.
        """
        return self._defaultExt


    def SetDefaultExtension(self, defaultExt):
        """
        Sets the default file extension.
        """
        self._defaultExt = defaultExt


    def GetDescription(self):
        """
        Returns the text description of this template, as passed to
        the document template constructor.
        """
        return self._description


    def SetDescription(self, description):
        """
        Sets the template description.
        """
        self._description = description


    def GetDirectory(self):
        """
        Returns the default directory, as passed to the document
        template constructor.
        """
        return self._directory


    def SetDirectory(self, dir):
        """
        Sets the default directory.
        """
        self._directory = dir


    def GetDocumentManager(self):
        """
        Returns the document manager instance for which this template
        was created.
        """
        return self._docManager


    def SetDocumentManager(self, manager):
        """
        Sets the document manager instance for which this template was
        created. Should not be called by the application.
        """
        self._docManager = manager


    def GetFileFilter(self):
        """
        Returns the file filter, as passed to the document template
        constructor.
        """
        return self._fileFilter


    def SetFileFilter(self, filter):
        """
        Sets the file filter.
        """
        self._fileFilter = filter


    def GetFlags(self):
        """
        Returns the flags, as passed to the document template constructor.
        (see the constructor description for more details).
        """
        return self._flags


    def SetFlags(self, flags):
        """
        Sets the internal document template flags (see the constructor
        description for more details).
        """
        self._flags = flags


    def GetIcon(self):
        """
        Returns the icon, as passed to the document template
        constructor.  
        """
        return self._icon


    def SetIcon(self, flags):
        """
        Sets the icon.
        """
        self._icon = icon


    def GetDocumentType(self):
        """
        Returns the Python document class, as passed to the document template
        constructor.
        """
        return self._docType


    def GetViewType(self):
        """
        Returns the Python view class, as passed to the document template
        constructor.
        """
        return self._viewType


    def IsVisible(self):
        """
        Returns true if the document template can be shown in user dialogs,
        false otherwise.
        """
        return (self._flags & TEMPLATE_VISIBLE) == TEMPLATE_VISIBLE


    def GetDocumentName(self):
        """
        Returns the document type name, as passed to the document template
        constructor.
        """
        return self._docTypeName


    def GetViewName(self):
        """
        Returns the view type name, as passed to the document template
        constructor.
        """
        return self._viewTypeName


    def CreateDocument(self, path, flags):
        """
        Creates a new instance of the associated document class. If you have
        not supplied a class to the template constructor, you will need to
        override this function to return an appropriate document instance.
        """
        doc = self._docType()
        doc.SetFilename(path)
        doc.SetDocumentTemplate(self)
        self.GetDocumentManager().AddDocument(doc)
        doc.SetCommandProcessor(doc.OnCreateCommandProcessor())
        if doc.OnCreate(path, flags):
            return doc
        else:
            if doc in self.GetDocumentManager().GetDocuments():
                doc.DeleteAllViews()
            return None


    def CreateView(self, doc, flags):
        """
        Creates a new instance of the associated document view. If you
        have not supplied a class to the template constructor, you
        will need to override this function to return an appropriate
        view instance.
        """
        view = self._viewType()
        view.SetDocument(doc)
        if view.OnCreate(doc, flags):
            return view
        else:
            view.Destroy()
            return None


    def FileMatchesTemplate(self, path):
        """
        Returns True if the path's extension matches one of this template's
        file filter extensions.
        """
        ext = FindExtension(path)
        if not ext: return False
        return ext in self.GetFileFilter()
        # return self.GetDefaultExtension() == FindExtension(path)


class DocManager(wx.EvtHandler):
    """
    The `DocManager` class is part of the document/view framework and
    cooperates with the `View`, `Document` and `DocTemplate` classes.
    """

    def __init__(self, flags = DEFAULT_DOCMAN_FLAGS, initialize = True):
        """
        Constructor. Create a document manager instance dynamically
        near the start of your application before doing any document
        or view operations.

        :param flags: used to indicate whether the document manager is
            in DOC_SDI or DOC_MDI mode.

        :param initialize: if true, the `Initialize` function will be
            called to create a default history list object. If you
            derive from DocManager, you may wish to call the base
            constructor with false, and then call `Initialize` in your
            own constructor, to allow your own `Initialize` or
            `OnCreateFileHistory` functions to be called.
        """

        wx.EvtHandler.__init__(self)

        self._defaultDocumentNameCounter = 1
        self._flags = flags
        self._currentView = None
        self._lastActiveView = None
        self._maxDocsOpen = 10000
        self._fileHistory = None
        self._templates = []
        self._docs = []
        self._lastDirectory = ""

        if initialize:
            self.Initialize()

        wx.EVT_MENU(self, wx.ID_OPEN, self.OnFileOpen)
        wx.EVT_MENU(self, wx.ID_CLOSE, self.OnFileClose)
        wx.EVT_MENU(self, wx.ID_CLOSE_ALL, self.OnFileCloseAll)
        wx.EVT_MENU(self, wx.ID_REVERT, self.OnFileRevert)
        wx.EVT_MENU(self, wx.ID_NEW, self.OnFileNew)
        wx.EVT_MENU(self, wx.ID_SAVE, self.OnFileSave)
        wx.EVT_MENU(self, wx.ID_SAVEAS, self.OnFileSaveAs)
        wx.EVT_MENU(self, wx.ID_UNDO, self.OnUndo)
        wx.EVT_MENU(self, wx.ID_REDO, self.OnRedo)
        wx.EVT_MENU(self, wx.ID_PRINT, self.OnPrint)
        wx.EVT_MENU(self, wx.ID_PRINT_SETUP, self.OnPrintSetup)
        wx.EVT_MENU(self, wx.ID_PREVIEW, self.OnPreview)

        wx.EVT_UPDATE_UI(self, wx.ID_OPEN, self.OnUpdateFileOpen)
        wx.EVT_UPDATE_UI(self, wx.ID_CLOSE, self.OnUpdateFileClose)
        wx.EVT_UPDATE_UI(self, wx.ID_CLOSE_ALL, self.OnUpdateFileCloseAll)
        wx.EVT_UPDATE_UI(self, wx.ID_REVERT, self.OnUpdateFileRevert)
        wx.EVT_UPDATE_UI(self, wx.ID_NEW, self.OnUpdateFileNew)
        wx.EVT_UPDATE_UI(self, wx.ID_SAVE, self.OnUpdateFileSave)
        wx.EVT_UPDATE_UI(self, wx.ID_SAVEAS, self.OnUpdateFileSaveAs)
        wx.EVT_UPDATE_UI(self, wx.ID_UNDO, self.OnUpdateUndo)
        wx.EVT_UPDATE_UI(self, wx.ID_REDO, self.OnUpdateRedo)
        wx.EVT_UPDATE_UI(self, wx.ID_PRINT, self.OnUpdatePrint)
        wx.EVT_UPDATE_UI(self, wx.ID_PRINT_SETUP, self.OnUpdatePrintSetup)
        wx.EVT_UPDATE_UI(self, wx.ID_PREVIEW, self.OnUpdatePreview)


    def Destroy(self):
        """
        Destructor.
        """
        self.Clear()
        wx.EvtHandler.Destroy(self)


    def GetFlags(self):
        """
        Returns the document manager's flags. 
        """
        return self._flags


    def CloseDocument(self, doc, force = True):
        """
        Closes the specified document.
        """
        if doc.Close() or force:
            doc.DeleteAllViews()
            if doc in self._docs:
                doc.Destroy()
            return True
        return False


    def CloseDocuments(self, force = True):
        """
        Closes all currently opened documents.
        """
        for document in self._docs[::-1]:  # Close in lifo (reverse) order.  We clone the list to make sure we go through all docs even as they are deleted
            if not self.CloseDocument(document, force):
                return False
            document.DeleteAllViews() # Implicitly delete the document when the last view is removed
        return True


    def Clear(self, force = True):
        """
        Closes all currently opened document by calling `CloseDocuments` and
        clears the document manager's templates.
        """
        if not self.CloseDocuments(force):
            return False
        self._templates = []
        return True


    def Initialize(self):
        """
        Initializes data; currently just calls `OnCreateFileHistory`. Some data
        cannot always be initialized in the constructor because the programmer
        must be given the opportunity to override functionality. In fact
        Initialize is called from the `DocManager` constructor, but this can
        be prevented by passing false to the second argument, allowing the
        derived class's constructor to call Initialize, possibly calling a
        different `OnCreateFileHistory` from the default.
        """
        self.OnCreateFileHistory()
        return True


    def OnCreateFileHistory(self):
        """
        A hook to allow a derived class to create a different type of file
        history. Called from `Initialize`.
        """
        self._fileHistory = wx.FileHistory()


    def OnFileClose(self, event):
        """
        Closes and deletes the currently active document.
        """
        doc = self.GetCurrentDocument()
        if doc:
            doc.DeleteAllViews()
            if doc in self._docs:
                self._docs.remove(doc)


    def OnFileCloseAll(self, event):
        """
        Closes and deletes all the currently opened documents.
        """
        return self.CloseDocuments(force = False)


    def OnFileNew(self, event):
        """
        Creates a new document and reads in the selected file.
        """
        self.CreateDocument('', DOC_NEW)


    def OnFileOpen(self, event):
        """
        Creates a new document and reads in the selected file.
        """
        if not self.CreateDocument('', DEFAULT_DOCMAN_FLAGS):
            self.OnOpenFileFailure()


    def OnFileRevert(self, event):
        """
        Reverts the current document by calling `Document.Save` for
        the current document.
        """
        doc = self.GetCurrentDocument()
        if not doc:
            return
        doc.Revert()


    def OnFileSave(self, event):
        """
        Saves the current document by calling `Document.Save` for the
        current document.
        """
        doc = self.GetCurrentDocument()
        if not doc:
            return
        doc.Save()


    def OnFileSaveAs(self, event):
        """
        Calls `Document.SaveAs` for the current document.
        """
        doc = self.GetCurrentDocument()
        if not doc:
            return
        doc.SaveAs()


    def OnPrint(self, event):
        """
        Prints the current document by calling its
        `View.OnCreatePrintout` method.
        """
        view = self.GetCurrentView()
        if not view:
            return

        printout = view.OnCreatePrintout()
        if printout:
            pdd = wx.PrintDialogData()
            printer = wx.Printer(pdd)
            printer.Print(view.GetFrame(), printout) # , True)


    def OnPrintSetup(self, event):
        """
        Presents the print setup dialog.
        """
        view = self.GetCurrentView()
        if view:
            parentWin = view.GetFrame()
        else:
            parentWin = wx.GetApp().GetTopWindow()

        data = wx.PrintDialogData()
        printDialog = wx.PrintDialog(parentWin, data)
        printDialog.GetPrintDialogData().SetSetupDialog(True)
        printDialog.ShowModal()
        # TODO: Confirm that we don't have to remember PrintDialogData


    def OnPreview(self, event):
        """
        Previews the current document by calling its `View.OnCreatePrintout`
        method.
        """
        view = self.GetCurrentView()
        if not view:
            return

        printout = view.OnCreatePrintout()
        if printout:
            # Pass two printout objects: for preview, and possible printing.
            preview = wx.PrintPreview(printout, view.OnCreatePrintout())
            # wxWindows source doesn't use base frame's pos, size, and icon, but did it this way so it would work like MS Office etc.
            mimicFrame =  wx.GetApp().GetTopWindow()
            frame = wx.PreviewFrame(preview, mimicFrame, _("Print Preview"), mimicFrame.GetPosition(), mimicFrame.GetSize())
            frame.SetIcon(mimicFrame.GetIcon())
            frame.SetTitle(mimicFrame.GetTitle() + _(" - Preview"))
            frame.Initialize()
            frame.Show(True)


    def OnUndo(self, event):
        """
        Issues an Undo command to the current document's command processor.
        """
        doc = self.GetCurrentDocument()
        if not doc:
            return
        if doc.GetCommandProcessor():
            doc.GetCommandProcessor().Undo()


    def OnRedo(self, event):
        """
        Issues a Redo command to the current document's command processor.
        """
        doc = self.GetCurrentDocument()
        if not doc:
            return
        if doc.GetCommandProcessor():
            doc.GetCommandProcessor().Redo()


    def OnUpdateFileOpen(self, event):
        """
        Updates the user interface for the File Open command.
        """
        event.Enable(True)


    def OnUpdateFileClose(self, event):
        """
        Updates the user interface for the File Close command.
        """
        event.Enable(self.GetCurrentDocument() != None)


    def OnUpdateFileCloseAll(self, event):
        """
        Updates the user interface for the File Close All command.
        """
        event.Enable(self.GetCurrentDocument() != None)


    def OnUpdateFileRevert(self, event):
        """
        Updates the user interface for the File Revert command.
        """
        event.Enable(self.GetCurrentDocument() != None)


    def OnUpdateFileNew(self, event):
        """
        Updates the user interface for the File New command.
        """
        return True


    def OnUpdateFileSave(self, event):
        """
        Updates the user interface for the File Save command.
        """
        doc = self.GetCurrentDocument()
        event.Enable(doc != None and doc.IsModified())


    def OnUpdateFileSaveAs(self, event):
        """
        Updates the user interface for the File Save As command.
        """
        event.Enable(self.GetCurrentDocument() != None and self.GetCurrentDocument().GetWriteable())


    def OnUpdateUndo(self, event):
        """
        Updates the user interface for the Undo command.
        """
        doc = self.GetCurrentDocument()
        event.Enable(doc != None and doc.GetCommandProcessor() != None and doc.GetCommandProcessor().CanUndo())
        if doc and doc.GetCommandProcessor():
            doc.GetCommandProcessor().SetMenuStrings()
        else:
            event.SetText(_("Undo") + '\t' + _('Ctrl+Z'))


    def OnUpdateRedo(self, event):
        """
        Updates the user interface for the Redo command.
        """
        doc = self.GetCurrentDocument()
        event.Enable(doc != None and doc.GetCommandProcessor() != None and doc.GetCommandProcessor().CanRedo())
        if doc and doc.GetCommandProcessor():
            doc.GetCommandProcessor().SetMenuStrings()
        else:
            event.SetText(_("Redo") + '\t' + _('Ctrl+Y'))


    def OnUpdatePrint(self, event):
        """
        Updates the user interface for the Print command.
        """
        event.Enable(self.GetCurrentDocument() != None)


    def OnUpdatePrintSetup(self, event):
        """
        Updates the user interface for the Print Setup command.
        """
        return True


    def OnUpdatePreview(self, event):
        """
        Updates the user interface for the Print Preview command.
        """
        event.Enable(self.GetCurrentDocument() != None)


    def GetCurrentView(self):
        """
        Returns the currently active view.
        """
        if self._currentView:
            return self._currentView
        if len(self._docs) == 1:
            return self._docs[0].GetFirstView()
        return None


    def GetLastActiveView(self):
        """
        Returns the last active view.  This is used in the SDI
        framework where dialogs can be mistaken for a view and causes
        the framework to deactivete the current view.  This happens
        when something like a custom dialog box used to operate on the
        current view is shown.
        """
        if len(self._docs) >= 1:
            return self._lastActiveView
        else:
            return None


    def ProcessEvent(self, event):
        """
        Processes an event, searching event tables and calling zero or
        more suitable event handler function(s).  Note that the
        ProcessEvent method is called from the wxPython docview
        framework directly since wxPython does not have a virtual
        ProcessEvent function.
        """
        view = self.GetCurrentView()
        if view:
            if view.ProcessEvent(event):
                return True
        id = event.GetId()
        if id == wx.ID_OPEN:
            self.OnFileOpen(event)
            return True
        elif id == wx.ID_CLOSE:
            self.OnFileClose(event)
            return True
        elif id == wx.ID_CLOSE_ALL:
            self.OnFileCloseAll(event)
            return True
        elif id == wx.ID_REVERT:
            self.OnFileRevert(event)
            return True
        elif id == wx.ID_NEW:
            self.OnFileNew(event)
            return True
        elif id == wx.ID_SAVE:
            self.OnFileSave(event)
            return True
        elif id == wx.ID_SAVEAS:
            self.OnFileSaveAs(event)
            return True
        elif id == wx.ID_UNDO:
            self.OnUndo(event)
            return True
        elif id == wx.ID_REDO:
            self.OnRedo(event)
            return True
        elif id == wx.ID_PRINT:
            self.OnPrint(event)
            return True
        elif id == wx.ID_PRINT_SETUP:
            self.OnPrintSetup(event)
            return True
        elif id == wx.ID_PREVIEW:
            self.OnPreview(event)
            return True
        else:
            return False


    def ProcessUpdateUIEvent(self, event):
        """
        Processes a UI event, searching event tables and calling zero
        or more suitable event handler function(s).  Note that the
        ProcessEvent method is called from the wxPython docview
        framework directly since wxPython does not have a virtual
        ProcessEvent function.
        """
        id = event.GetId()
        view = self.GetCurrentView()
        if view:
            if view.ProcessUpdateUIEvent(event):
                return True
        if id == wx.ID_OPEN:
            self.OnUpdateFileOpen(event)
            return True
        elif id == wx.ID_CLOSE:
            self.OnUpdateFileClose(event)
            return True
        elif id == wx.ID_CLOSE_ALL:
            self.OnUpdateFileCloseAll(event)
            return True
        elif id == wx.ID_REVERT:
            self.OnUpdateFileRevert(event)
            return True
        elif id == wx.ID_NEW:
            self.OnUpdateFileNew(event)
            return True
        elif id == wx.ID_SAVE:
            self.OnUpdateFileSave(event)
            return True
        elif id == wx.ID_SAVEAS:
            self.OnUpdateFileSaveAs(event)
            return True
        elif id == wx.ID_UNDO:
            self.OnUpdateUndo(event)
            return True
        elif id == wx.ID_REDO:
            self.OnUpdateRedo(event)
            return True
        elif id == wx.ID_PRINT:
            self.OnUpdatePrint(event)
            return True
        elif id == wx.ID_PRINT_SETUP:
            self.OnUpdatePrintSetup(event)
            return True
        elif id == wx.ID_PREVIEW:
            self.OnUpdatePreview(event)
            return True
        else:
            return False


    def CreateDocument(self, path, flags = 0):
        """
        Creates a new document in a manner determined by the flags parameter,
        which can be:

            * DOC_NEW: Creates a fresh document.
            * DOC_SILENT: Silently loads the given document file.

        If DOC_NEW is present, a new document will be created and
        returned, possibly after asking the user for a template to use
        if there is more than one document template. If DOC_SILENT is
        present, a new document will be created and the given file
        loaded into it. If neither of these flags is present, the user
        will be presented with a file selector for the file to load,
        and the template to use will be determined by the extension
        (Windows) or by popping up a template choice list (other
        platforms).

        If the maximum number of documents has been reached, this
        function will delete the oldest currently loaded document
        before creating a new one.

        wxPython version supports the document manager's DOC_OPEN_ONCE
        flag.
        """
        templates = []
        for temp in self._templates:
            if temp.IsVisible():
                templates.append(temp)
        if len(templates) == 0:
            return None

        if len(self.GetDocuments()) >= self._maxDocsOpen:
           doc = self.GetDocuments()[0]
           if not self.CloseDocument(doc, False):
               return None

        if flags & DOC_NEW:
            if len(templates) == 1:
                temp = templates[0]
                newDoc = temp.CreateDocument(path, flags)
                if newDoc:
                    newDoc.SetDocumentName(temp.GetDocumentName())
                    newDoc.SetDocumentTemplate(temp)
                    newDoc.OnNewDocument()
                return newDoc

            temp = self.SelectDocumentType(templates)
            if temp:
                newDoc = temp.CreateDocument(path, flags)
                if newDoc:
                    newDoc.SetDocumentName(temp.GetDocumentName())
                    newDoc.SetDocumentTemplate(temp)
                    newDoc.OnNewDocument()
                return newDoc
            else:
                return None

        if path and flags & DOC_SILENT:
            temp = self.FindTemplateForPath(path)
        else:
            temp, path = self.SelectDocumentPath(templates, path, flags)

        # Existing document
        if self.GetFlags() & DOC_OPEN_ONCE:
            for document in self._docs:
                if document.GetFilename() == path:
                    firstView = document.GetFirstView()
                    if firstView and firstView.GetFrame():
                        firstView.GetFrame().SetFocus()  # Not in wxWindows code but useful nonetheless
                        if hasattr(firstView.GetFrame(), "IsIconized") and firstView.GetFrame().IsIconized():  # Not in wxWindows code but useful nonetheless
                            firstView.GetFrame().Iconize(False)
                    return None

        if temp:
            newDoc = temp.CreateDocument(path, flags)
            if newDoc:
                newDoc.SetDocumentName(temp.GetDocumentName())
                newDoc.SetDocumentTemplate(temp)
                if not newDoc.OnOpenDocument(path):
                    newDoc.DeleteAllViews()  # Implicitly deleted by DeleteAllViews
                    newDoc.GetFirstView().GetFrame().Destroy() # DeleteAllViews doesn't get rid of the frame, so we'll explicitly destroy it.
                    return None
                self.AddFileToHistory(path)
            return newDoc

        return None


    def CreateView(self, document, flags = 0):
        """
        Creates a new view for the given document. If more than one view is
        allowed for the document (by virtue of multiple templates mentioning
        the same document type), a choice of view is presented to the user.
        """
        templates = []
        for temp in self._templates:
            if temp.IsVisible():
                if temp.GetDocumentName() == doc.GetDocumentName():
                    templates.append(temp)
        if len(templates) == 0:
            return None

        if len(templates) == 1:
            temp = templates[0]
            view = temp.CreateView(doc, flags)
            if view:
                view.SetViewName(temp.GetViewName())
            return view

        temp = SelectViewType(templates)
        if temp:
            view = temp.CreateView(doc, flags)
            if view:
                view.SetViewName(temp.GetViewName())
            return view
        else:
            return None


    def DeleteTemplate(self, template, flags):
        """
        Placeholder, not yet implemented
        """
        pass


    def FlushDoc(self, doc):
        """
        Placeholder, not yet implemented
        """
        return False


    def MatchTemplate(self, path):
        """
        Placeholder, not yet implemented
        """
        return None


    def GetCurrentDocument(self):
        """
        Returns the document associated with the currently active view (if any).
        """
        view = self.GetCurrentView()
        if view:
            return view.GetDocument()
        else:
            return None


    def MakeDefaultName(self):
        """
        Returns a suitable default name. This is implemented by appending an
        integer counter to the string "Untitled" and incrementing the counter.
        """
        name = _("Untitled %d") % self._defaultDocumentNameCounter
        self._defaultDocumentNameCounter = self._defaultDocumentNameCounter + 1
        return name


    def MakeFrameTitle(self):
        """
        Returns a suitable title for a document frame. This is implemented by
        appending the document name to the application name.
        """
        appName = wx.GetApp().GetAppName()
        if not doc:
            title = appName
        else:
            docName = doc.GetPrintableName()
            title = docName + _(" - ") + appName
        return title


    def AddFileToHistory(self, fileName):
        """
        Adds a file to the file history list, if we have a pointer to an
        appropriate file menu.
        """
        if self._fileHistory:
            self._fileHistory.AddFileToHistory(fileName)


    def RemoveFileFromHistory(self, i):
        """
        Removes a file from the file history list, if we have a pointer to an
        appropriate file menu.
        """
        if self._fileHistory:
            self._fileHistory.RemoveFileFromHistory(i)


    def GetFileHistory(self):
        """
        Returns the file history.
        """
        return self._fileHistory


    def GetHistoryFile(self, i):
        """
        Returns the file at index i from the file history.
        """
        if self._fileHistory:
            return self._fileHistory.GetHistoryFile(i)
        else:
            return None


    def FileHistoryUseMenu(self, menu):
        """
        Use this menu for appending recently-visited document filenames, for
        convenient access. Calling this function with a valid menu enables the
        history list functionality.

        Note that you can add multiple menus using this function, to be
        managed by the file history object.
        """
        if self._fileHistory:
            self._fileHistory.UseMenu(menu)


    def FileHistoryRemoveMenu(self, menu):
        """
        Removes the given menu from the list of menus managed by the file
        history object.
        """
        if self._fileHistory:
            self._fileHistory.RemoveMenu(menu)


    def FileHistoryLoad(self, config):
        """
        Loads the file history from a config object.
        """
        if self._fileHistory:
            self._fileHistory.Load(config)


    def FileHistorySave(self, config):
        """
        Saves the file history into a config object. This must be called
        explicitly by the application.
        """
        if self._fileHistory:
            self._fileHistory.Save(config)


    def FileHistoryAddFilesToMenu(self, menu = None):
        """
        Appends the files in the history list, to all menus managed by the
        file history object.

        If menu is specified, appends the files in the history list to the
        given menu only.
        """
        if self._fileHistory:
            if menu:
                self._fileHistory.AddFilesToThisMenu(menu)
            else:
                self._fileHistory.AddFilesToMenu()


    def GetHistoryFilesCount(self):
        """
        Returns the number of files currently stored in the file history.
        """
        if self._fileHistory:
            return self._fileHistory.GetNoHistoryFiles()
        else:
            return 0


    def FindTemplateForPath(self, path):
        """
        Given a path, try to find template that matches the extension. This is
        only an approximate method of finding a template for creating a
        document.
        """
        for temp in self._templates:
            if temp.FileMatchesTemplate(path):
                return temp
        return None


    def FindSuitableParent(self):
        """
        Returns a parent frame or dialog, either the frame with the current
        focus or if there is no current focus the application's top frame.
        """
        parent = wx.GetApp().GetTopWindow()
        focusWindow = wx.Window_FindFocus()
        if focusWindow:
            while focusWindow and not isinstance(focusWindow, wx.Dialog) and not isinstance(focusWindow, wx.Frame):
                focusWindow = focusWindow.GetParent()
            if focusWindow:
                parent = focusWindow
        return parent


    def SelectDocumentPath(self, templates, flags, save):
        """
        Under Windows, pops up a file selector with a list of filters
        corresponding to document templates. The wxDocTemplate corresponding
        to the selected file's extension is returned.

        On other platforms, if there is more than one document template a
        choice list is popped up, followed by a file selector.

        This function is used in `DocManager.CreateDocument`.
        """
        if wx.Platform == "__WXMSW__" or wx.Platform == "__WXGTK__" or wx.Platform == "__WXMAC__":
            allfilter = ''
            descr = ''
            for temp in templates:
                if temp.IsVisible():
                    if len(descr) > 0:
                        descr = descr + _('|')
                        allfilter = allfilter + _(';')
                    descr = descr + temp.GetDescription() + _(" (") + temp.GetFileFilter() + _(") |") + temp.GetFileFilter()  # spacing is important, make sure there is no space after the "|", it causes a bug on wx_gtk
                    allfilter = allfilter + temp.GetFileFilter()
            descr = _("All") + _(" (") + allfilter + _(") |") + allfilter + _('|') + descr  # spacing is important, make sure there is no space after the "|", it causes a bug on wx_gtk
        else:
            descr = _("*.*")

        path = wx.FileSelector(_("Select a File"),
                               self._lastDirectory,
                               _(""),
                               wildcard = descr,
                               flags = wx.HIDE_READONLY,
                               parent = self.FindSuitableParent())
        if path:
            if not FileExists(path):
                msgTitle = wx.GetApp().GetAppName()
                if not msgTitle:
                    msgTitle = _("File Error")
                    wx.MessageBox("Could not open '%s'." % FileNameFromPath(path),
                          msgTitle,
                          wx.OK | wx.ICON_EXCLAMATION,
                          parent)
                    return (None, None)
            self._lastDirectory = PathOnly(path)

            theTemplate = self.FindTemplateForPath(path)
            return (theTemplate, path)

        return (None, None)


    def OnOpenFileFailure(self):
        """
        Called when there is an error opening a file.
        """
        pass


    def SelectDocumentType(self, temps, sort = False):
        """
        Returns a document template by asking the user (if there is more than
        one template). This function is used in `DocManager.CreateDocument`.

        :param temps: list of templates from which to choose a desired template.

        :param sort: If more than one template is passed in in
            templates, then this parameter indicates whether the list
            of templates that the user will have to choose from is
            sorted or not when shown the choice box dialog.  Default
            is false.
        """
        templates = []
        for temp in temps:
            if temp.IsVisible():
                want = True
                for temp2 in templates:
                    if temp.GetDocumentName() == temp2.GetDocumentName() and temp.GetViewName() == temp2.GetViewName():
                        want = False
                        break
                if want:
                    templates.append(temp)

        if len(templates) == 0:
            return None
        elif len(templates) == 1:
            return template[0]

        if sort:
            def tempcmp(a, b):
                return cmp(a.GetDescription(), b.GetDescription())
            templates.sort(tempcmp)

        strings = []
        for temp in templates:
            strings.append(temp.GetDescription())

        res = wx.GetSingleChoiceIndex(_("Select a document type:"),
                                      _("Documents"),
                                      strings,
                                      self.FindSuitableParent())
        if res == -1:
            return None
        return templates[res]


    def SelectViewType(self, temps, sort = False):
        """
        Returns a document template by asking the user (if there is
        more than one template), displaying a list of valid
        views. This function is used in `DocManager.CreateView`. The
        dialog normally will not appear because the array of templates
        only contains those relevant to the document in question, and
        often there will only be one such.
        """
        templates = []
        strings = []
        for temp in temps:
            if temp.IsVisible() and temp.GetViewTypeName():
                if temp.GetViewName() not in strings:
                    templates.append(temp)
                    strings.append(temp.GetViewTypeName())

        if len(templates) == 0:
            return None
        elif len(templates) == 1:
            return templates[0]

        if sort:
            def tempcmp(a, b):
                return cmp(a.GetViewTypeName(), b.GetViewTypeName())
            templates.sort(tempcmp)

        res = wx.GetSingleChoiceIndex(_("Select a document view:"),
                                      _("Views"),
                                      strings,
                                      self.FindSuitableParent())
        if res == -1:
            return None
        return templates[res]


    def GetTemplates(self):
        """
        Returns the document manager's template list.  
        """
        return self._templates


    def AssociateTemplate(self, docTemplate):
        """
        Adds the template to the document manager's template list.
        """
        if docTemplate not in self._templates:
            self._templates.append(docTemplate)


    def DisassociateTemplate(self, docTemplate):
        """
        Removes the template from the list of templates.
        """
        self._templates.remove(docTemplate)


    def AddDocument(self, document):
        """
        Adds the document to the list of documents.
        """
        if document not in self._docs:
            self._docs.append(document)


    def RemoveDocument(self, doc):
        """
        Removes the document from the list of documents.
        """
        if doc in self._docs:
            self._docs.remove(doc)


    def ActivateView(self, view, activate = True, deleting = False):
        """
        Sets the current view.
        """
        if activate:
            self._currentView = view
            self._lastActiveView = view
        else:
            self._currentView = None


    def GetMaxDocsOpen(self):
        """
        Returns the number of documents that can be open simultaneously.
        """
        return self._maxDocsOpen


    def SetMaxDocsOpen(self, maxDocsOpen):
        """
        Sets the maximum number of documents that can be open at a time. By
        default, this is 10,000. If you set it to 1, existing documents will
        be saved and deleted when the user tries to open or create a new one
        (similar to the behaviour of Windows Write, for example). Allowing
        multiple documents gives behaviour more akin to MS Word and other
        Multiple Document Interface applications.
        """
        self._maxDocsOpen = maxDocsOpen


    def GetDocuments(self):
        """
        Returns the list of documents.
        """
        return self._docs


class DocParentFrame(wx.Frame):
    """
    The DocParentFrame class provides a default top-level frame for
    applications using the document/view framework. This class can
    only be used for SDI (not MDI) parent frames.

    It cooperates with the `View`, `Document`, `DocManager` and
    `DocTemplate` classes.
    """

    def __init__(self, manager, frame, id, title,
                 pos = wx.DefaultPosition,
                 size = wx.DefaultSize,
                 style = wx.DEFAULT_FRAME_STYLE,
                 name = "frame"):
        """
        Constructor.  Note that the event table must be rebuilt for the
        frame since the EvtHandler is not virtual.
        """
        wx.Frame.__init__(self, frame, id, title, pos, size, style)
        self._docManager = manager

        wx.EVT_CLOSE(self, self.OnCloseWindow)

        wx.EVT_MENU(self, wx.ID_EXIT, self.OnExit)
        wx.EVT_MENU_RANGE(self, wx.ID_FILE1, wx.ID_FILE9, self.OnMRUFile)

        wx.EVT_MENU(self, wx.ID_NEW, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_OPEN, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_CLOSE_ALL, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_CLOSE, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_REVERT, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_SAVE, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_SAVEAS, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_UNDO, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_REDO, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_PRINT, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_PRINT_SETUP, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_PREVIEW, self.ProcessEvent)

        wx.EVT_UPDATE_UI(self, wx.ID_NEW, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_OPEN, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_CLOSE_ALL, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_CLOSE, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_REVERT, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_SAVE, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_SAVEAS, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_UNDO, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_REDO, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_PRINT, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_PRINT_SETUP, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_PREVIEW, self.ProcessUpdateUIEvent)


    def ProcessEvent(self, event):
        """
        Processes an event, searching event tables and calling zero or more
        suitable event handler function(s).  Note that the ProcessEvent
        method is called from the wxPython docview framework directly since
        wxPython does not have a virtual ProcessEvent function.
        """
        return self._docManager and self._docManager.ProcessEvent(event)


    def ProcessUpdateUIEvent(self, event):
        """
        Processes a UI event, searching event tables and calling zero or more
        suitable event handler function(s).  Note that the ProcessEvent
        method is called from the wxPython docview framework directly since
        wxPython does not have a virtual ProcessEvent function.
        """
        return self._docManager and self._docManager.ProcessUpdateUIEvent(event)


    def OnExit(self, event):
        """
        Called when File/Exit is chosen and closes the window.
        """
        self.Close()


    def OnMRUFile(self, event):
        """
        Opens the appropriate file when it is selected from the file history
        menu.
        """
        n = event.GetId() - wx.ID_FILE1
        filename = self._docManager.GetHistoryFile(n)
        if filename:
            self._docManager.CreateDocument(filename, DOC_SILENT)
        else:
            self._docManager.RemoveFileFromHistory(n)
            msgTitle = wx.GetApp().GetAppName()
            if not msgTitle:
                msgTitle = _("File Error")
            wx.MessageBox("The file '%s' doesn't exist and couldn't be opened.\nIt has been removed from the most recently used files list" % FileNameFromPath(file),
                          msgTitle,
                          wx.OK | wx.ICON_EXCLAMATION,
                          self)


    def OnCloseWindow(self, event):
        """
        Deletes all views and documents. If no user input cancelled the
        operation, the frame will be destroyed and the application will exit.
        """
        if self._docManager.Clear(not event.CanVeto()):
            self.Destroy()
        else:
            event.Veto()


class DocChildFrame(wx.Frame):
    """
    The `DocChildFrame` class provides a default frame for displaying
    documents on separate windows. This class can only be used for SDI
    (not MDI) child frames.

    The class is part of the document/view framework and cooperates
    with the `View`, `Document`, `DocManager` and `DocTemplate`
    classes.
    """


    def __init__(self, doc, view, frame, id, title, pos = wx.DefaultPosition, size = wx.DefaultSize, style = wx.DEFAULT_FRAME_STYLE, name = "frame"):
        """
        Constructor.  Note that the event table must be rebuilt for the
        frame since the EvtHandler is not virtual.
        """
        wx.Frame.__init__(self, frame, id, title, pos, size, style, name)
        wx.EVT_ACTIVATE(self, self.OnActivate)
        wx.EVT_CLOSE(self, self.OnCloseWindow)
        self._childDocument = doc
        self._childView = view
        if view:
            view.SetFrame(self)

        wx.EVT_MENU(self, wx.ID_NEW, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_OPEN, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_CLOSE_ALL, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_CLOSE, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_REVERT, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_SAVE, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_SAVEAS, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_UNDO, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_REDO, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_PRINT, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_PRINT_SETUP, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_PREVIEW, self.ProcessEvent)

        wx.EVT_UPDATE_UI(self, wx.ID_NEW, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_OPEN, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_CLOSE_ALL, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_CLOSE, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_REVERT, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_SAVE, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_SAVEAS, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_UNDO, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_REDO, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_PRINT, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_PRINT_SETUP, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_PREVIEW, self.ProcessUpdateUIEvent)


    def ProcessEvent(self, event):
        """
        Processes an event, searching event tables and calling zero or more
        suitable event handler function(s).  Note that the ProcessEvent
        method is called from the wxPython docview framework directly since
        wxPython does not have a virtual ProcessEvent function.
        """
        if self._childView:
            self._childView.Activate(True)
        if not self._childView or not self._childView.ProcessEvent(event):
            # IsInstance not working, but who cares just send all the commands up since this isn't a real ProcessEvent like wxWindows
            # if not isinstance(event, wx.CommandEvent) or not self.GetParent() or not self.GetParent().ProcessEvent(event):
            if not self.GetParent() or not self.GetParent().ProcessEvent(event):
                return False
            else:
                return True
        else:
            return True


    def ProcessUpdateUIEvent(self, event):
        """
        Processes a UI event, searching event tables and calling zero or more
        suitable event handler function(s).  Note that the ProcessEvent
        method is called from the wxPython docview framework directly since
        wxPython does not have a virtual ProcessEvent function.
        """
        if self.GetParent():
            self.GetParent().ProcessUpdateUIEvent(event)
        else:
            return False


    def OnActivate(self, event):
        """
        Activates the current view.
        """
        # wx.Frame.OnActivate(event)  This is in the wxWindows docview demo but there is no such method in wxPython, so do a Raise() instead
        if self._childView:
            self._childView.Activate(event.GetActive())


    def OnCloseWindow(self, event):
        """
        Closes and deletes the current view and document.
        """
        if self._childView:
            ans = False
            if not event.CanVeto():
                ans = True
            else:
                ans = self._childView.Close(deleteWindow = False)

            if ans:
                self._childView.Activate(False)
                self._childView.Destroy()
                self._childView = None
                if self._childDocument:
                    self._childDocument.Destroy()  # This isn't in the wxWindows codebase but the document needs to be disposed of somehow
                    self._childDocument = None
                self.Destroy()
            else:
                event.Veto()
        else:
            event.Veto()


    def GetDocument(self):
        """
        Returns the document associated with this frame.
        """
        return self._childDocument


    def SetDocument(self, document):
        """
        Sets the document for this frame.
        """
        self._childDocument = document


    def GetView(self):
        """
        Returns the view associated with this frame.
        """
        return self._childView


    def SetView(self, view):
        """
        Sets the view for this frame.
        """
        self._childView = view


class DocMDIParentFrame(wx.MDIParentFrame):
    """
    The `DocMDIParentFrame` class provides a default top-level frame
    for applications using the document/view framework. This class can
    only be used for MDI parent frames.

    It cooperates with the `View`, `Document`, `DocManager` and
    `DocTemplate` classes.
    """


    def __init__(self, manager, frame, id, title, pos = wx.DefaultPosition, size = wx.DefaultSize, style = wx.DEFAULT_FRAME_STYLE, name = "frame"):
        """
        Constructor.  Note that the event table must be rebuilt for the
        frame since the EvtHandler is not virtual.
        """
        wx.MDIParentFrame.__init__(self, frame, id, title, pos, size, style, name)
        self._docManager = manager

        wx.EVT_CLOSE(self, self.OnCloseWindow)

        wx.EVT_MENU(self, wx.ID_EXIT, self.OnExit)
        wx.EVT_MENU_RANGE(self, wx.ID_FILE1, wx.ID_FILE9, self.OnMRUFile)

        wx.EVT_MENU(self, wx.ID_NEW, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_OPEN, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_CLOSE_ALL, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_CLOSE, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_REVERT, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_SAVE, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_SAVEAS, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_UNDO, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_REDO, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_PRINT, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_PRINT_SETUP, self.ProcessEvent)
        wx.EVT_MENU(self, wx.ID_PREVIEW, self.ProcessEvent)

        wx.EVT_UPDATE_UI(self, wx.ID_NEW, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_OPEN, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_CLOSE_ALL, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_CLOSE, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_REVERT, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_SAVE, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_SAVEAS, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_UNDO, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_REDO, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_PRINT, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_PRINT_SETUP, self.ProcessUpdateUIEvent)
        wx.EVT_UPDATE_UI(self, wx.ID_PREVIEW, self.ProcessUpdateUIEvent)


    def ProcessEvent(self, event):
        """
        Processes an event, searching event tables and calling zero or more
        suitable event handler function(s).  Note that the ProcessEvent
        method is called from the wxPython docview framework directly since
        wxPython does not have a virtual ProcessEvent function.
        """
        return self._docManager and self._docManager.ProcessEvent(event)


    def ProcessUpdateUIEvent(self, event):
        """
        Processes a UI event, searching event tables and calling zero or more
        suitable event handler function(s).  Note that the ProcessEvent
        method is called from the wxPython docview framework directly since
        wxPython does not have a virtual ProcessEvent function.
        """
        return self._docManager and self._docManager.ProcessUpdateUIEvent(event)


    def OnExit(self, event):
        """
        Called when File/Exit is chosen and closes the window.
        """
        self.Close()


    def OnMRUFile(self, event):
        """
        Opens the appropriate file when it is selected from the file history
        menu.
        """
        n = event.GetId() - wx.ID_FILE1
        filename = self._docManager.GetHistoryFile(n)
        if filename:
            self._docManager.CreateDocument(filename, DOC_SILENT)
        else:
            self._docManager.RemoveFileFromHistory(n)
            msgTitle = wx.GetApp().GetAppName()
            if not msgTitle:
                msgTitle = _("File Error")
            wx.MessageBox("The file '%s' doesn't exist and couldn't be opened.\nIt has been removed from the most recently used files list" % FileNameFromPath(file),
                          msgTitle,
                          wx.OK | wx.ICON_EXCLAMATION,
                          self)


    def OnCloseWindow(self, event):
        """
        Deletes all views and documents. If no user input cancelled the
        operation, the frame will be destroyed and the application will exit.
        """
        if self._docManager.Clear(not event.CanVeto()):
            self.Destroy()
        else:
            event.Veto()


class DocMDIChildFrame(wx.MDIChildFrame):
    """
    The `DocMDIChildFrame` class provides a default frame for
    displaying documents on separate windows. This class can only be
    used for MDI child frames.

    The class is part of the document/view framework and cooperates
    with the `View`, `Document`, `DocManager` and `DocTemplate`
    classes.
    """


    def __init__(self, doc, view, frame, id, title, pos = wx.DefaultPosition, size = wx.DefaultSize, style = wx.DEFAULT_FRAME_STYLE, name = "frame"):
        """
        Constructor.  Note that the event table must be rebuilt for the
        frame since the EvtHandler is not virtual.
        """
        wx.MDIChildFrame.__init__(self, frame, id, title, pos, size, style, name)
        self._childDocument = doc
        self._childView = view
        if view:
            view.SetFrame(self)
        # self.Create(doc, view, frame, id, title, pos, size, style, name)
        self._activeEvent = None
        self._activated = 0
        wx.EVT_ACTIVATE(self, self.OnActivate)
        wx.EVT_CLOSE(self, self.OnCloseWindow)

        if frame:  # wxBug: For some reason the EVT_ACTIVATE event is not getting triggered for the first mdi client window that is opened so we have to do it manually
            mdiChildren = filter(lambda x: isinstance(x, wx.MDIChildFrame), frame.GetChildren())
            if len(mdiChildren) == 1:
                self.Activate()


##    # Couldn't get this to work, but seems to work fine with single stage construction
##    def Create(self, doc, view, frame, id, title, pos, size, style, name):
##        self._childDocument = doc
##        self._childView = view
##        if wx.MDIChildFrame.Create(self, frame, id, title, pos, size, style, name):
##            if view:
##                view.SetFrame(self)
##                return True
##        return False



    def Activate(self):  # Need this in case there are embedded sash windows and such, OnActivate is not getting called
        """
        Activates the current view.
        """
        if self._childView:
            self._childView.Activate(True)


    def ProcessEvent(event):
        """
        Processes an event, searching event tables and calling zero or more
        suitable event handler function(s).  Note that the ProcessEvent
        method is called from the wxPython docview framework directly since
        wxPython does not have a virtual ProcessEvent function.
        """
        if self._activeEvent == event:
            return False

        self._activeEvent = event  # Break recursion loops

        if self._childView:
            self._childView.Activate(True)

        if not self._childView or not self._childView.ProcessEvent(event):
            if not isinstance(event, wx.CommandEvent) or not self.GetParent() or not self.GetParent().ProcessEvent(event):
                ret = False
            else:
                ret = True
        else:
            ret = True

        self._activeEvent = None
        return ret


    def OnActivate(self, event):
        """
        Sets the currently active view to be the frame's view. You may need to
        override (but still call) this function in order to set the keyboard
        focus for your subwindow.
        """
        if self._activated != 0:
            return True
        self._activated += 1
        wx.MDIChildFrame.Activate(self)
        if event.GetActive() and self._childView:
            self._childView.Activate(event.GetActive())
        self._activated = 0

    def OnCloseWindow(self, event):
        """
        Closes and deletes the current view and document.
        """
        if self._childView:
            ans = False
            if not event.CanVeto():
                ans = True
            else:
                ans = self._childView.Close(deleteWindow = False)

            if ans:
                self._childView.Activate(False)
                self._childView.Destroy()
                self._childView = None
                if self._childDocument:
                    self._childDocument.Destroy()  # This isn't in the wxWindows codebase but the document needs to be disposed of somehow
                self._childDocument = None
                self.Destroy()
            else:
                event.Veto()
        else:
            event.Veto()


    def GetDocument(self):
        """
        Returns the document associated with this frame.
        """
        return self._childDocument


    def SetDocument(self, document):
        """
        Sets the document for this frame.
        """
        self._childDocument = document


    def GetView(self):
        """
        Returns the view associated with this frame.
        """
        return self._childView


    def SetView(self, view):
        """
        Sets the view for this frame.
        """
        self._childView = view


class DocPrintout(wx.Printout):
    """
    `DocPrintout` is a default Printout that prints the first page of
    a document view.
    """


    def __init__(self, view, title = "Printout"):
        """
        Constructor.
        """
        wx.Printout.__init__(self)
        self._printoutView = view


    def GetView(self):
        """
        Returns the DocPrintout's view.
        """
        return self._printoutView


    def OnPrintPage(self, page):
        """
        Prints the first page of the view.
        """
        dc = self.GetDC()
        ppiScreenX, ppiScreenY = self.GetPPIScreen()
        ppiPrinterX, ppiPrinterY = self.GetPPIPrinter()
        scale = ppiPrinterX/ppiScreenX
        w, h = dc.GetSize()
        pageWidth, pageHeight = self.GetPageSizePixels()
        overallScale = scale * w / pageWidth
        dc.SetUserScale(overallScale, overallScale)
        if self._printoutView:
            self._printoutView.OnDraw(dc)
        return True


    def HasPage(self, pageNum):
        """
        Indicates that the DocPrintout only has a single page.
        """
        return pageNum == 1


    def OnBeginDocument(self, startPage, endPage):
        """
        Not quite sure why this was overridden, but it was in wxWindows! :)
        """
        if not wx.Printout.base_OnBeginDocument(self, startPage, endPage):
            return False
        return True


    def GetPageInfo(self):
        """
        Indicates that the DocPrintout only has a single page.
        """
        minPage = 1
        maxPage = 1
        selPageFrom = 1
        selPageTo = 1
        return (minPage, maxPage, selPageFrom, selPageTo)


#----------------------------------------------------------------------
# Command Classes
#----------------------------------------------------------------------

class Command(wx.Object):
    """
    `Command` is a base class for modelling an application command,
    which is an action usually performed by selecting a menu item,
    pressing a toolbar button or any other means provided by the
    application to change the data or view.
    """


    def __init__(self, canUndo = False, name = None):
        """
        Constructor. Command is an abstract class, so you will need to
        derive a new class and call this constructor from your own
        constructor.

        :param canUndo: tells the command processor whether this
            command is undo-able.  You can achieve the same
            functionality by overriding the `CanUndo` member function
            (if for example the criteria for undoability is context-
            dependent).

        :param name: must be supplied for the command processor to
            display the command name in the application's edit menu.
            
        """
        self._canUndo = canUndo
        self._name = name


    def CanUndo(self):
        """
        Returns true if the command can be undone, false otherwise.
        """
        return self._canUndo


    def GetName(self):
        """
        Returns the command name.
        """
        return self._name


    def Do(self):
        """
        Override this member function to execute the appropriate
        action when called. Return true to indicate that the action
        has taken place, false otherwise. Returning false will
        indicate to the command processor that the action is not
        undoable and should not be added to the command history.
        """
        return True


    def Undo(self):
        """
        Override this member function to un-execute a previous
        `Do`. Return true to indicate that the action has taken place,
        false otherwise. Returning false will indicate to the command
        processor that the action is not redoable and no change should
        be made to the command history.

        How you implement this command is totally application
        dependent, but typical strategies include:

            * Perform an inverse operation on the last modified piece
              of data in the document. When redone, a copy of data
              stored in command is pasted back or some operation
              reapplied. This relies on the fact that you know the
              ordering of Undos; the user can never Undo at an
              arbitrary position in he command history.

            * Restore the entire document state (perhaps using
              document transactioning). Potentially very inefficient,
              but possibly easier to code if the user interface and
              data are complex, and an 'inverse execute' operation is
              hard to write.
        """
        return True


class CommandProcessor(wx.Object):
    """
    `CommandProcessor` is a class that maintains a history of
    `Command` instancess, with undo/redo functionality
    built-in. Derive a new class from this if you want different
    behaviour.
    """


    def __init__(self, maxCommands = -1):
        """
        Constructor.  maxCommands may be set to a positive integer to limit
        the number of commands stored to it, otherwise (and by default) the
        list of commands can grow arbitrarily.
        """
        self._maxCommands = maxCommands
        self._editMenu = None
        self._undoAccelerator = _("Ctrl+Z")
        self._redoAccelerator = _("Ctrl+Y")
        self.ClearCommands()


    def _GetCurrentCommand(self):
        if len(self._commands) == 0:
            return None
        else:
            return self._commands[-1]


    def _GetCurrentRedoCommand(self):
        if len(self._redoCommands) == 0:
            return None
        else:
            return self._redoCommands[-1]


    def GetMaxCommands(self):
        """
        Returns the maximum number of commands that the command processor
        stores.

        """
        return self._maxCommands


    def GetCommands(self):
        """
        Returns the list of commands.
        """
        return self._commands


    def ClearCommands(self):
        """
        Deletes all the commands in the list and sets the current command
        pointer to None.
        """
        self._commands = []
        self._redoCommands = []


    def GetEditMenu(self):
        """
        Returns the edit menu associated with the command processor.
        """
        return self._editMenu


    def SetEditMenu(self, menu):
        """
        Tells the command processor to update the Undo and Redo items
        on this menu as appropriate. Set this to None if the menu is
        about to be destroyed and command operations may still be
        performed, or the command processor may try to access an
        invalid pointer.
        """
        self._editMenu = menu


    def GetUndoAccelerator(self):
        """
        Returns the string that will be appended to the Undo menu item.
        """
        return self._undoAccelerator


    def SetUndoAccelerator(self, accel):
        """
        Sets the string that will be appended to the Redo menu item.
        """
        self._undoAccelerator = accel


    def GetRedoAccelerator(self):
        """
        Returns the string that will be appended to the Redo menu item.
        """
        return self._redoAccelerator


    def SetRedoAccelerator(self, accel):
        """
        Sets the string that will be appended to the Redo menu item.
        """
        self._redoAccelerator = accel


    def SetMenuStrings(self):
        """
        Sets the menu labels according to the currently set menu and
        the current command state.
        """
        if self.GetEditMenu() != None:
            undoCommand = self._GetCurrentCommand()
            redoCommand = self._GetCurrentRedoCommand()
            undoItem = self.GetEditMenu().FindItemById(wx.ID_UNDO)
            redoItem = self.GetEditMenu().FindItemById(wx.ID_REDO)
            if self.GetUndoAccelerator():
                undoAccel = '\t' + self.GetUndoAccelerator()
            else:
                undoAccel = ''
            if self.GetRedoAccelerator():
                redoAccel = '\t' + self.GetRedoAccelerator()
            else:
                redoAccel = ''
            if undoCommand and undoItem and undoCommand.CanUndo():
                undoItem.SetText(_("Undo ") + undoCommand.GetName() + undoAccel)
            #elif undoCommand and not undoCommand.CanUndo():
            #    undoItem.SetText(_("Can't Undo") + undoAccel)
            else:
                undoItem.SetText(_("Undo" + undoAccel))
            if redoCommand and redoItem:
                redoItem.SetText(_("Redo ") + redoCommand.GetName() + redoAccel)
            else:
                redoItem.SetText(_("Redo") + redoAccel)


    def CanUndo(self):
        """
        Returns true if the currently-active command can be undone, false
        otherwise.
        """
        if self._GetCurrentCommand() == None:
            return False
        return self._GetCurrentCommand().CanUndo()


    def CanRedo(self):
        """
        Returns true if the currently-active command can be redone, false
        otherwise.
        """
        return self._GetCurrentRedoCommand() != None


    def Submit(self, command, storeIt = True):
        """
        Submits a new command to the command processor. The command processor
        calls `Command.Do` to execute the command; if it succeeds, the
        command is stored in the history list, and the associated edit menu
        (if any) updated appropriately. If it fails, the command is deleted
        immediately. Once `Submit` has been called, the passed command should
        not be deleted directly by the application.

        storeIt indicates whether the successful command should be stored in
        the history list.
        """
        done = command.Do()
        if done and storeIt:
            self._commands.append(command)
        if self._maxCommands > -1:
            if len(self._commands) > self._maxCommands:
                del self._commands[0]
        return done


    def Redo(self):
        """
        Redoes the command just undone.
        """
        cmd = self._GetCurrentRedoCommand()
        if not cmd:
            return False
        done = cmd.Do()
        if done:
            self._commands.append(self._redoCommands.pop())
        return done


    def Undo(self):
        """
        Undoes the command just executed.
        """
        cmd = self._GetCurrentCommand()
        if not cmd:
            return False
        done = cmd.Undo()
        if done:
            self._redoCommands.append(self._commands.pop())
        return done