"""File selection dialog classes.

Classes:

- FileDialog

- LoadFileDialog

- SaveFileDialog

"""

from Tkinter import *

from Dialog import Dialog

import os

import fnmatch

dialogstates = {}

class FileDialog:

    """Standard file selection dialog -- no checks on selected file.

    Usage:

        d = FileDialog(master)

        fname = d.go(dir_or_file, pattern, default, key)

        if fname is None: ...canceled...

        else: ...open file...

    All arguments to go() are optional.

    The 'key' argument specifies a key in the global dictionary

    'dialogstates', which keeps track of the values for the directory

    and pattern arguments, overriding the values passed in (it does

    not keep track of the default argument!).  If no key is specified,

    the dialog keeps no memory of previous state.  Note that memory is

    kept even when the dialog is canceled.  (All this emulates the

    behavior of the Macintosh file selection dialogs.)

    """

    title = "File Selection Dialog"

    def __init__(self, master, title=None):

        if title is None: title = self.title

        self.master = master

        self.directory = None

        self.top = Toplevel(master)

        self.top.title(title)

        self.top.iconname(title)

        self.botframe = Frame(self.top)

        self.botframe.pack(side=BOTTOM, fill=X)

        self.selection = Entry(self.top)

        self.selection.pack(side=BOTTOM, fill=X)

        self.selection.bind('<Return>', self.ok_event)

        self.filter = Entry(self.top)

        self.filter.pack(side=TOP, fill=X)

        self.filter.bind('<Return>', self.filter_command)

        self.midframe = Frame(self.top)

        self.midframe.pack(expand=YES, fill=BOTH)

        self.filesbar = Scrollbar(self.midframe)

        self.filesbar.pack(side=RIGHT, fill=Y)

        self.files = Listbox(self.midframe, exportselection=0,

                             yscrollcommand=(self.filesbar, 'set'))

        self.files.pack(side=RIGHT, expand=YES, fill=BOTH)

        btags = self.files.bindtags()

        self.files.bindtags(btags[1:] + btags[:1])

        self.files.bind('<ButtonRelease-1>', self.files_select_event)

        self.files.bind('<Double-ButtonRelease-1>', self.files_double_event)

        self.filesbar.config(command=(self.files, 'yview'))

        self.dirsbar = Scrollbar(self.midframe)

        self.dirsbar.pack(side=LEFT, fill=Y)

        self.dirs = Listbox(self.midframe, exportselection=0,

                            yscrollcommand=(self.dirsbar, 'set'))

        self.dirs.pack(side=LEFT, expand=YES, fill=BOTH)

        self.dirsbar.config(command=(self.dirs, 'yview'))

        btags = self.dirs.bindtags()

        self.dirs.bindtags(btags[1:] + btags[:1])

        self.dirs.bind('<ButtonRelease-1>', self.dirs_select_event)

        self.dirs.bind('<Double-ButtonRelease-1>', self.dirs_double_event)

        self.ok_button = Button(self.botframe,

                                 text="OK",

                                 command=self.ok_command)

        self.ok_button.pack(side=LEFT)

        self.filter_button = Button(self.botframe,

                                    text="Filter",

                                    command=self.filter_command)

        self.filter_button.pack(side=LEFT, expand=YES)

        self.cancel_button = Button(self.botframe,

                                    text="Cancel",

                                    command=self.cancel_command)

        self.cancel_button.pack(side=RIGHT)

        self.top.protocol('WM_DELETE_WINDOW', self.cancel_command)

        # XXX Are the following okay for a general audience?

        self.top.bind('<Alt-w>', self.cancel_command)

        self.top.bind('<Alt-W>', self.cancel_command)

    def go(self, dir_or_file=os.curdir, pattern="*", default="", key=None):

        if key and dialogstates.has_key(key):

            self.directory, pattern = dialogstates[key]

        else:

            dir_or_file = os.path.expanduser(dir_or_file)

            if os.path.isdir(dir_or_file):

                self.directory = dir_or_file

            else:

                self.directory, default = os.path.split(dir_or_file)

        self.set_filter(self.directory, pattern)

        self.set_selection(default)

        self.filter_command()

        self.selection.focus_set()

        self.top.wait_visibility() # window needs to be visible for the grab

        self.top.grab_set()

        self.how = None

        self.master.mainloop()          # Exited by self.quit(how)

        if key:

            directory, pattern = self.get_filter()

            if self.how:

                directory = os.path.dirname(self.how)

            dialogstates[key] = directory, pattern

        self.top.destroy()

        return self.how

    def quit(self, how=None):

        self.how = how

        self.master.quit()              # Exit mainloop()

    def dirs_double_event(self, event):

        self.filter_command()

    def dirs_select_event(self, event):

        dir, pat = self.get_filter()

        subdir = self.dirs.get('active')

        dir = os.path.normpath(os.path.join(self.directory, subdir))

        self.set_filter(dir, pat)

    def files_double_event(self, event):

        self.ok_command()

    def files_select_event(self, event):

        file = self.files.get('active')

        self.set_selection(file)

    def ok_event(self, event):

        self.ok_command()

    def ok_command(self):

        self.quit(self.get_selection())

    def filter_command(self, event=None):

        dir, pat = self.get_filter()

        try:

            names = os.listdir(dir)

        except os.error:

            self.master.bell()

            return

        self.directory = dir

        self.set_filter(dir, pat)

        names.sort()

        subdirs = [os.pardir]

        matchingfiles = []

        for name in names:

            fullname = os.path.join(dir, name)

            if os.path.isdir(fullname):

                subdirs.append(name)

            elif fnmatch.fnmatch(name, pat):

                matchingfiles.append(name)

        self.dirs.delete(0, END)

        for name in subdirs:

            self.dirs.insert(END, name)

        self.files.delete(0, END)

        for name in matchingfiles:

            self.files.insert(END, name)

        head, tail = os.path.split(self.get_selection())

        if tail == os.curdir: tail = ''

        self.set_selection(tail)

    def get_filter(self):

        filter = self.filter.get()

        filter = os.path.expanduser(filter)

        if filter[-1:] == os.sep or os.path.isdir(filter):

            filter = os.path.join(filter, "*")

        return os.path.split(filter)

    def get_selection(self):

        file = self.selection.get()

        file = os.path.expanduser(file)

        return file

    def cancel_command(self, event=None):

        self.quit()

    def set_filter(self, dir, pat):

        if not os.path.isabs(dir):

            try:

                pwd = os.getcwd()

            except os.error:

                pwd = None

            if pwd:

                dir = os.path.join(pwd, dir)

                dir = os.path.normpath(dir)

        self.filter.delete(0, END)

        self.filter.insert(END, os.path.join(dir or os.curdir, pat or "*"))

    def set_selection(self, file):

        self.selection.delete(0, END)

        self.selection.insert(END, os.path.join(self.directory, file))

class LoadFileDialog(FileDialog):

    """File selection dialog which checks that the file exists."""

    title = "Load File Selection Dialog"

    def ok_command(self):

        file = self.get_selection()

        if not os.path.isfile(file):

            self.master.bell()

        else:

            self.quit(file)

class SaveFileDialog(FileDialog):

    """File selection dialog which checks that the file may be created."""

    title = "Save File Selection Dialog"

    def ok_command(self):

        file = self.get_selection()

        if os.path.exists(file):

            if os.path.isdir(file):

                self.master.bell()

                return

            d = Dialog(self.top,

                       title="Overwrite Existing File Question",

                       text="Overwrite existing file %r?" % (file,),

                       bitmap='questhead',

                       default=1,

                       strings=("Yes", "Cancel"))

            if d.num != 0:

                return

        else:

            head, tail = os.path.split(file)

            if not os.path.isdir(head):

                self.master.bell()

                return

        self.quit(file)

def test():

    """Simple test program."""

    root = Tk()

    root.withdraw()

    fd = LoadFileDialog(root)

    loadfile = fd.go(key="test")

    fd = SaveFileDialog(root)

    savefile = fd.go(key="test")

    print loadfile, savefile

if __name__ == '__main__':

    test()