Source code for ImportExport

# CellTracking.py
# By MW, Jul 2013
# GPLv3+
#
# Class managing import/export routines.
#+I'm not sure that it will contain much stuff, but we'll see...

import os, logging, shutil, pickle

class ImportExport :
    def __init__(self) :
        self.VERSION = 0.4 # Version of the import/export format
        # Compatibility version: 0.4
        # Real version: 0.6
        self.movie = None
        self.filepath = None

    def set_movie(self, movie) :
        self.movie = movie

    def get_path(self) :
        return self.filepath
    def set_path(self, p) :
        if os.path.isdir(os.path.dirname(p)) :
            self.filepath = p
    def load(self) :
        """Loads the presets. The file should be provided using the function 
        self.set_path"""
        fn = self.filepath
        if fn == None :
            logging.error("Trying to save but no path has been specified")
        else :
            if not os.path.isfile(self.filepath) :
                logging.error('File does not exist')
            else :
                f = open(fn, 'r')
                dic = pickle.load(f)
                logging.info('Save data read from file %s', fn)

                # Check version
                version = dic['infos']['value']['version']['value']
                # tmp comment before stabilizing the export format
                if version != self.VERSION :
                    logging.warning('File version does not correspond with the version of the program. Beware!')
                    print "Version error"
                elif self.movie == None :
                    logging.warning('No movie has been declared (self.movie is None)')
                    print "Movie error"
                else :  # Call movie.load_save_dict
                    self.movie.load_save_dict(dic['movie'])
                    

    def save(self) :
        fn = self.filepath
        if fn == None :
            logging.error("Trying to save but no path has been specified")
        else :
            if os.path.isfile(self.filepath) :
                logging.warning("Saving but a file exist, moving previous file to a backup")
                ext = 1 # Generate filename
                while os.path.isfile(fn+'.backup.'+str(ext)) :
                    ext += 1
                shutil.move(fn, fn+'.backup.'+str(ext)) # Make backup copy
            dic = self.new_dict()
            dic['movie'] = self.movie.get_save_dict() # Get dict
            f = open(fn, 'w') # Pickle it
            pickle.dump(dic, f)
            f.close()
            logging.info('In theory (no error message displayed), the session should have been saved')

    def new_dict(self) :
        """Returns an empty dict, initialized with essential parameters"""
        version = self.VERSION
        dicinfos = {}
        dicinfos['version'] = {'descr' : 'Version of the file format. Check in the documentation if the format is backward compatible', 'value' : version}
        dic_info = {'descr' : 'Essential information about the file format', 'value' : dicinfos}
        
        return {'descr' : 'Dictionary describing a movie', 'value' : None, 'infos' : dic_info}
    def get_frames_object(self) :
        return {'type' : 'savefile', 'value' : self.filepath}