Lib/idlelib/config_key.py

"""
Dialog for building Tkinter accelerator key bindings
"""
from tkinter import *
from tkinter.ttk import Scrollbar
from tkinter import messagebox
import string
import sys


class GetKeysDialog(Toplevel):

    # Dialog title for invalid key sequence
    keyerror_title = 'Key Sequence Error'

    def __init__(self, parent, title, action, current_key_sequences,
                 *, _htest=False, _utest=False):
        """
        parent - parent of this dialog
        title - string which is the title of the popup dialog
        action - string, the name of the virtual event these keys will be
                 mapped to
        current_key_sequences - list, a list of all key sequence lists
                 currently mapped to virtual events, for overlap checking
        _htest - bool, change box location when running htest
        _utest - bool, do not wait when running unittest
        """
        Toplevel.__init__(self, parent)
        self.withdraw()  # Hide while setting geometry.
        self.configure(borderwidth=5)
        self.resizable(height=False, width=False)
        self.title(title)
        self.transient(parent)
        self.grab_set()
        self.protocol("WM_DELETE_WINDOW", self.cancel)
        self.parent = parent
        self.action = action
        self.current_key_sequences = current_key_sequences
        self.result = ''
        self.key_string = StringVar(self)
        self.key_string.set('')
        # Set self.modifiers, self.modifier_label.
        self.set_modifiers_for_platform()
        self.modifier_vars = []
        for modifier in self.modifiers:
            variable = StringVar(self)
            variable.set('')
            self.modifier_vars.append(variable)
        self.advanced = False
        self.create_widgets()
        self.load_final_key_list()
        self.update_idletasks()
        self.geometry(
                "+%d+%d" % (
                    parent.winfo_rootx() +
                    (parent.winfo_width()/2 - self.winfo_reqwidth()/2),
                    parent.winfo_rooty() +
                    ((parent.winfo_height()/2 - self.winfo_reqheight()/2)
                    if not _htest else 150)
                ) )  # Center dialog over parent (or below htest box).
        if not _utest:
            self.deiconify()  # Geometry set, unhide.
            self.wait_window()

    def showerror(self, *args, **kwargs):
        # Make testing easier.  Replace in #30751.
        messagebox.showerror(*args, **kwargs)

    def create_widgets(self):
        frame = Frame(self, borderwidth=2, relief=SUNKEN)
        frame.pack(side=TOP, expand=True, fill=BOTH)

        frame_buttons = Frame(self)
        frame_buttons.pack(side=BOTTOM, fill=X)

        self.button_ok = Button(frame_buttons, text='OK',
                                width=8, command=self.ok)
        self.button_ok.grid(row=0, column=0, padx=5, pady=5)
        self.button_cancel = Button(frame_buttons, text='Cancel',
                                   width=8, command=self.cancel)
        self.button_cancel.grid(row=0, column=1, padx=5, pady=5)

        # Basic entry key sequence.
        self.frame_keyseq_basic = Frame(frame)
        self.frame_keyseq_basic.grid(row=0, column=0, sticky=NSEW,
                                      padx=5, pady=5)
        basic_title = Label(self.frame_keyseq_basic,
                            text=f"New keys for '{self.action}' :")
        basic_title.pack(anchor=W)

        basic_keys = Label(self.frame_keyseq_basic, justify=LEFT,
                           textvariable=self.key_string, relief=GROOVE,
                           borderwidth=2)
        basic_keys.pack(ipadx=5, ipady=5, fill=X)

        # Basic entry controls.
        self.frame_controls_basic = Frame(frame)
        self.frame_controls_basic.grid(row=1, column=0, sticky=NSEW, padx=5)

        # Basic entry modifiers.
        self.modifier_checkbuttons = {}
        column = 0
        for modifier, variable in zip(self.modifiers, self.modifier_vars):
            label = self.modifier_label.get(modifier, modifier)
            check = Checkbutton(self.frame_controls_basic,
                                command=self.build_key_string, text=label,
                                variable=variable, onvalue=modifier, offvalue='')
            check.grid(row=0, column=column, padx=2, sticky=W)
            self.modifier_checkbuttons[modifier] = check
            column += 1

        # Basic entry help text.
        help_basic = Label(self.frame_controls_basic, justify=LEFT,
                           text="Select the desired modifier keys\n"+
                                "above, and the final key from the\n"+
                                "list on the right.\n\n" +
                                "Use upper case Symbols when using\n" +
                                "the Shift modifier.  (Letters will be\n" +
                                "converted automatically.)")
        help_basic.grid(row=1, column=0, columnspan=4, padx=2, sticky=W)

        # Basic entry key list.
        self.list_keys_final = Listbox(self.frame_controls_basic, width=15,
                                       height=10, selectmode=SINGLE)
        self.list_keys_final.bind('<ButtonRelease-1>', self.final_key_selected)
        self.list_keys_final.grid(row=0, column=4, rowspan=4, sticky=NS)
        scroll_keys_final = Scrollbar(self.frame_controls_basic,
                                      orient=VERTICAL,
                                      command=self.list_keys_final.yview)
        self.list_keys_final.config(yscrollcommand=scroll_keys_final.set)
        scroll_keys_final.grid(row=0, column=5, rowspan=4, sticky=NS)
        self.button_clear = Button(self.frame_controls_basic,
                                   text='Clear Keys',
                                   command=self.clear_key_seq)
        self.button_clear.grid(row=2, column=0, columnspan=4)

        # Advanced entry key sequence.
        self.frame_keyseq_advanced = Frame(frame)
        self.frame_keyseq_advanced.grid(row=0, column=0, sticky=NSEW,
                                         padx=5, pady=5)
        advanced_title = Label(self.frame_keyseq_advanced, justify=LEFT,
                               text=f"Enter new binding(s) for '{self.action}' :\n" +
                                     "(These bindings will not be checked for validity!)")
        advanced_title.pack(anchor=W)
        self.advanced_keys = Entry(self.frame_keyseq_advanced,
                                   textvariable=self.key_string)
        self.advanced_keys.pack(fill=X)

        # Advanced entry help text.
        self.frame_help_advanced = Frame(frame)
        self.frame_help_advanced.grid(row=1, column=0, sticky=NSEW, padx=5)
        help_advanced = Label(self.frame_help_advanced, justify=LEFT,
            text="Key bindings are specified using Tkinter keysyms as\n"+
                 "in these samples: <Control-f>, <Shift-F2>, <F12>,\n"
                 "<Control-space>, <Meta-less>, <Control-Alt-Shift-X>.\n"
                 "Upper case is used when the Shift modifier is present!\n\n" +
                 "'Emacs style' multi-keystroke bindings are specified as\n" +
                 "follows: <Control-x><Control-y>, where the first key\n" +
                 "is the 'do-nothing' keybinding.\n\n" +
                 "Multiple separate bindings for one action should be\n"+
                 "separated by a space, eg., <Alt-v> <Meta-v>." )
        help_advanced.grid(row=0, column=0, sticky=NSEW)

        # Switch between basic and advanced.
        self.button_level = Button(frame, command=self.toggle_level,
                                  text='<< Basic Key Binding Entry')
        self.button_level.grid(row=2, column=0, stick=EW, padx=5, pady=5)
        self.toggle_level()

    def set_modifiers_for_platform(self):
        """Determine list of names of key modifiers for this platform.

        The names are used to build Tk bindings -- it doesn't matter if the
        keyboard has these keys; it matters if Tk understands them.  The
        order is also important: key binding equality depends on it, so
        config-keys.def must use the same ordering.
        """
        if sys.platform == "darwin":
            self.modifiers = ['Shift', 'Control', 'Option', 'Command']
        else:
            self.modifiers = ['Control', 'Alt', 'Shift']
        self.modifier_label = {'Control': 'Ctrl'}  # Short name.

    def toggle_level(self):
        "Toggle between basic and advanced keys."
        if  self.button_level.cget('text').startswith('Advanced'):
            self.clear_key_seq()
            self.button_level.config(text='<< Basic Key Binding Entry')
            self.frame_keyseq_advanced.lift()
            self.frame_help_advanced.lift()
            self.advanced_keys.focus_set()
            self.advanced = True
        else:
            self.clear_key_seq()
            self.button_level.config(text='Advanced Key Binding Entry >>')
            self.frame_keyseq_basic.lift()
            self.frame_controls_basic.lift()
            self.advanced = False

    def final_key_selected(self, event):
        "Handler for clicking on key in basic settings list."
        self.build_key_string()

    def build_key_string(self):
        "Create formatted string of modifiers plus the key."
        keylist = modifiers = self.get_modifiers()
        final_key = self.list_keys_final.get(ANCHOR)
        if final_key:
            final_key = self.translate_key(final_key, modifiers)
            keylist.append(final_key)
        self.key_string.set(f"<{'-'.join(keylist)}>")

    def get_modifiers(self):
        "Return ordered list of modifiers that have been selected."
        mod_list = [variable.get() for variable in self.modifier_vars]
        return [mod for mod in mod_list if mod]

    def clear_key_seq(self):
        "Clear modifiers and keys selection."
        self.list_keys_final.select_clear(0, END)
        self.list_keys_final.yview(MOVETO, '0.0')
        for variable in self.modifier_vars:
            variable.set('')
        self.key_string.set('')

    def load_final_key_list(self):
        "Populate listbox of available keys."
        # These tuples are also available for use in validity checks.
        self.function_keys = ('F1', 'F2' ,'F3' ,'F4' ,'F5' ,'F6',
                              'F7', 'F8' ,'F9' ,'F10' ,'F11' ,'F12')
        self.alphanum_keys = tuple(string.ascii_lowercase + string.digits)
        self.punctuation_keys = tuple('~!@#%^&*()_-+={}[]|;:,.<>/?')
        self.whitespace_keys = ('Tab', 'Space', 'Return')
        self.edit_keys = ('BackSpace', 'Delete', 'Insert')
        self.move_keys = ('Home', 'End', 'Page Up', 'Page Down', 'Left Arrow',
                          'Right Arrow', 'Up Arrow', 'Down Arrow')
        # Make a tuple of most of the useful common 'final' keys.
        keys = (self.alphanum_keys + self.punctuation_keys + self.function_keys +
                self.whitespace_keys + self.edit_keys + self.move_keys)
        self.list_keys_final.insert(END, *keys)

    @staticmethod
    def translate_key(key, modifiers):
        "Translate from keycap symbol to the Tkinter keysym."
        translate_dict = {'Space':'space',
                '~':'asciitilde', '!':'exclam', '@':'at', '#':'numbersign',
                '%':'percent', '^':'asciicircum', '&':'ampersand',
                '*':'asterisk', '(':'parenleft', ')':'parenright',
                '_':'underscore', '-':'minus', '+':'plus', '=':'equal',
                '{':'braceleft', '}':'braceright',
                '[':'bracketleft', ']':'bracketright', '|':'bar',
                ';':'semicolon', ':':'colon', ',':'comma', '.':'period',
                '<':'less', '>':'greater', '/':'slash', '?':'question',
                'Page Up':'Prior', 'Page Down':'Next',
                'Left Arrow':'Left', 'Right Arrow':'Right',
                'Up Arrow':'Up', 'Down Arrow': 'Down', 'Tab':'Tab'}
        if key in translate_dict:
            key = translate_dict[key]
        if 'Shift' in modifiers and key in string.ascii_lowercase:
            key = key.upper()
        return f'Key-{key}'

    def ok(self, event=None):
        keys = self.key_string.get().strip()
        if not keys:
            self.showerror(title=self.keyerror_title, parent=self,
                           message="No key specified.")
            return
        if (self.advanced or self.keys_ok(keys)) and self.bind_ok(keys):
            self.result = keys
        self.grab_release()
        self.destroy()

    def cancel(self, event=None):
        self.result = ''
        self.grab_release()
        self.destroy()

    def keys_ok(self, keys):
        """Validity check on user's 'basic' keybinding selection.

        Doesn't check the string produced by the advanced dialog because
        'modifiers' isn't set.
        """
        final_key = self.list_keys_final.get(ANCHOR)
        modifiers = self.get_modifiers()
        title = self.keyerror_title
        key_sequences = [key for keylist in self.current_key_sequences
                             for key in keylist]
        if not keys.endswith('>'):
            self.showerror(title, parent=self,
                           message='Missing the final Key')
        elif (not modifiers
              and final_key not in self.function_keys + self.move_keys):
            self.showerror(title=title, parent=self,
                           message='No modifier key(s) specified.')
        elif (modifiers == ['Shift']) \
                 and (final_key not in
                      self.function_keys + self.move_keys + ('Tab', 'Space')):
            msg = 'The shift modifier by itself may not be used with'\
                  ' this key symbol.'
            self.showerror(title=title, parent=self, message=msg)
        elif keys in key_sequences:
            msg = 'This key combination is already in use.'
            self.showerror(title=title, parent=self, message=msg)
        else:
            return True
        return False

    def bind_ok(self, keys):
        "Return True if Tcl accepts the new keys else show message."
        try:
            binding = self.bind(keys, lambda: None)
        except TclError as err:
            self.showerror(
                    title=self.keyerror_title, parent=self,
                    message=(f'The entered key sequence is not accepted.\n\n'
                             f'Error: {err}'))
            return False
        else:
            self.unbind(keys, binding)
            return True


if __name__ == '__main__':
    from unittest import main
    main('idlelib.idle_test.test_config_key', verbosity=2, exit=False)

    from idlelib.idle_test.htest import run
    run(GetKeysDialog)