TkDND_wrapper.py

#
#    This wrapper was copied from https://mail.python.org/pipermail/tkinter-discuss/2005-July/000476.html    
#    parse_uri_list(self, uri_list) method was added by the author
#

import os
import tkinter

class TkDND(object):
    def __init__(self, tkroot):
        self._tkroot = tkroot
        # make self an attribute of the parent window for easy access in child classes
        tkroot.dnd = self
    
    def bindsource(self, widget, type=None, command=None, arguments=None, priority=None):
        '''Register widget as drag source; for details on type, command and arguments, see bindtarget().
        priority can be a value between 1 and 100, where 100 is the highest available priority (default: 50).
        If command is omitted, return the current binding for type; if both type and command are omitted,
        return a list of registered types for widget.'''
        command = self._generate_callback(command, arguments)
        tkcmd = self._generate_tkcommand('bindsource', widget, type, command, priority)
        res = self._tkroot.tk.eval(tkcmd)
        if type == None:
            res = res.split()
        return res
    
    def bindtarget(self, widget, type=None, sequence=None, command=None, arguments=None, priority=None):
        '''Register widget as drop target; type may be one of text/plain, text/uri-list, text/plain;charset=UTF-8
        (see the man page tkDND for details on other (platform specific) types);
        sequence may be one of '<Drag>', '<DragEnter>', '<DragLeave>', '<Drop>' or '<Ask>' ;
        command is the callback associated with the specified event, argument is an optional tuple of arguments
        that will be passed to the callback; possible arguments include: %A %a %b %C %c %D %d %L %m %T %t %W %X %x %Y %y
        (see the tkDND man page for details); priority may be a value in the range 1 to 100 ; if there are
        bindings for different types, the one with the priority value will be proceeded first (default: 50).
        If command is omitted, return the current binding for type, where sequence defaults to '<Drop>'.
        If both type and command are omitted, return a list of registered types for widget.'''
        command = self._generate_callback(command, arguments)
        tkcmd = self._generate_tkcommand('bindtarget', widget, type, sequence, command, priority)
        res = self._tkroot.tk.eval(tkcmd)
        if type == None:
            res = res.split()
        return res
    
    def clearsource(self, widget):
        '''Unregister widget as drag source.'''
        self._tkroot.tk.call('dnd', 'clearsource', widget)
    
    def cleartarget(self, widget):
        '''Unregister widget as drop target.'''
        self._tkroot.tk.call('dnd', 'cleartarget', widget)
    
    def drag(self, widget, actions=None, descriptions=None, cursorwindow=None, command=None, arguments=None):
        '''Initiate a drag operation with source widget.'''
        command = self._generate_callback(command, arguments)
        if actions:
            if actions[1:]:
                actions = '-actions {%s}' % ' '.join(actions)
            else:
                actions = '-actions %s' % actions[0]
        if descriptions:
            descriptions = ['{%s}'%i for i in descriptions]
            descriptions = '{%s}' % ' '.join(descriptions)
        if cursorwindow:
            cursorwindow = '-cursorwindow %s' % cursorwindow
        tkcmd = self._generate_tkcommand('drag', widget, actions, descriptions, cursorwindow, command)
        self._tkroot.tk.eval(tkcmd)
                
    def _generate_callback(self, command, arguments):
        '''Register command as tk callback with an optional list of arguments.'''
        cmd = None
        if command:
            cmd = self._tkroot._register(command)
            if arguments:
                cmd = '{%s %s}' % (cmd, ' '.join(arguments))
        return cmd
    
    def _generate_tkcommand(self, base, widget, *opts):
        '''Create the command string that will be passed to tk.'''
        tkcmd = 'dnd %s %s' % (base, widget)
        for i in opts:
            if i is not None:
                tkcmd += ' %s' % i
        return tkcmd

    def parse_uri_list(self, uri_list):
        space_in_path = False
        unprocessed_file_list = uri_list.split(' ')
        file_list = []
        processed_path = ''
        for item in unprocessed_file_list:
            if('{' in item):
                space_in_path = True
                processed_path = item.replace('{', '')
            elif('}' in item):
                space_in_path = False
                processed_path += ' ' + item.replace('}', '')
                file_list.append(processed_path)
            elif(space_in_path): 
                processed_path+= ' ' + item
            else:
                file_list.append(item)
        return file_list