diff urwid_satext/keys.py @ 84:9f683df69a4c

shortcut keys are now managed in separate module, with a class checking for conflicts
author Goffi <goffi@goffi.org>
date Thu, 04 Sep 2014 16:50:12 +0200
parents
children e0c8274f9b1c
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line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/urwid_satext/keys.py	Thu Sep 04 16:50:12 2014 +0200
@@ -0,0 +1,149 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+
+# Urwid SàT extensions
+# Copyright (C) 2009, 2010, 2011, 2012, 2013, 2014 Jérôme Poisson (goffi@goffi.org)
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""This module manage action <==> key mapping and can be extended to add new actions"""
+
+
+class ConflictError(Exception):
+    pass
+
+
+class ActionMap(dict):
+    """Object which manage mapping betwwen actions and keys"""
+
+    def __init__(self, source_dict=None):
+        """ Initialise the map
+
+        @param source_dict: dictionary-like object with actions to import
+        """
+        self._namespaces_actions = {} # key = namespace, values (set) = actions
+        self._close_namespaces = tuple()
+        self._alway_check_namespaces = None
+        if source_dict is not None:
+            self.update(source_dict)
+
+    def __setitem__(self, action, shortcut):
+        """set an action avoiding conflicts
+
+        @param action (str,tuple): either an action (str) or a (namespace, action) tuple. action without namespace will not be checked by cbeck_namespaces(). namespace can also be a tuple itself, the action will the be assigned to several namespaces.
+        @param shortcut (str): key shortcut for this action
+        @raise: ConflictError if the action already exists
+        """
+        if isinstance(action, tuple):
+            namespaces, action = action
+            if not isinstance(namespaces, tuple):
+                namespaces = (namespaces,)
+            for namespace in namespaces:
+                namespace_map = self._namespaces_actions.setdefault(namespace.lower(), set())
+                namespace_map.add(action)
+
+        if action in self:
+            raise ConflictError("The action [{}] already exists".format(action))
+        return super(ActionMap, self).__setitem__(action, shortcut.lower())
+
+    def __delitem__(self, action):
+        # we don't want to delete actions
+        raise NotImplementedError
+
+    def update(self, dict_like):
+        """Update actions with an other dictionary
+
+        @param dict_like: dictionary like object to update actions
+        @raise: ConflictError if at least one of the new actions already exists
+        """
+        if not isinstance(dict_like, dict):
+            raise ValueError("only dictionary subclasses are accepted for update")
+        conflict = dict_like.viewkeys() & self.viewkeys()
+        if conflict:
+            raise ConflictError("The actions [{}] already exists".format(','.join(conflict)))
+        for action, shortcut in dict_like.iteritems():
+            self[action] = shortcut
+
+    def set_close_namespaces(self, close_namespaces, always_check=None):
+        """Set namespaces where conflicting shortcut should not happen
+
+        used by check_namespaces to see if the same shortcut is not used in two close namespaces (e.g. 'tab' used in edit_bar and globally)
+        @param close_namespaces (tuple of tuples): tuple indicating namespace where shortcut should not conflict. e.g.: (('global', 'edit'), ('confirm', 'popup', 'global')) indicate that shortcut in 'global' and 'edit' should not be the same, nor the ones between 'confirm', 'popup' and 'global'.
+        @param always_check (tuple): if not None, these namespaces will be close to every other ones (useful for global namespace)
+        """
+        assert isinstance(close_namespaces, tuple)
+        if always_check is not None:
+            assert isinstance(always_check, tuple)
+        self._close_namespaces = close_namespaces
+        self._alway_check_namespaces = always_check
+
+    def check_namespaces(self):
+        """Check that shortcuts are not conflicting in close namespaces"""
+        # we first check each namespace individually
+        checked = set()
+
+        def check_namespaces(namespaces):
+            # for each namespace which save keys used
+            # if 1 key is used several times, we raise
+            # a ConflictError
+            set_shortcuts = {}
+
+            to_check = set(namespaces + self._alway_check_namespaces)
+
+            for namespace in to_check:
+                checked.add(namespace)
+                for action in self._namespaces_actions[namespace]:
+                    shortcut = self[action]
+                    if shortcut in set_shortcuts:
+                        set_namespace = set_shortcuts[shortcut]
+                        if set_namespace == namespace:
+                            msg = 'shortcut [{}] is not unique in namespace "{}"'.format(shortcut, namespace)
+                        else:
+                            msg = 'shortcut [{}] is used both in namespaces "{}" and "{}"'.format(shortcut, set_namespace, namespace)
+                        raise ConflictError(msg)
+                    set_shortcuts[shortcut] = namespace
+
+        # we first check close namespaces
+        for close_namespaces in self._close_namespaces:
+            check_namespaces(close_namespaces)
+
+        # then the remaining ones
+        for namespace in set(self._namespaces_actions.keys()).difference(checked):
+            check_namespaces((namespace,))
+
+
+keys = {
+        ("edit", "EDIT_HOME"): 'ctrl a',
+        ("edit", "EDIT_END"): 'ctrl e',
+        ("edit", "EDIT_DELETE_TO_END"): 'ctrl k',
+        ("edit", "EDIT_DELETE_LAST_WORD"): 'ctrl w',
+        ("edit", "EDIT_ENTER"): 'enter',
+        ("edit", "EDIT_COMPLETE"): 'shift tab',
+        (("edit", "modal"), "MODAL_ESCAPE"): 'esc',
+        ("selectable", "TEXT_SELECT"): ' ',
+        ("selectable", "TEXT_SELECT2"): 'enter',
+        ("menu_box", "MENU_BOX_UP"): 'up',
+        ("menu_box", "MENU_BOX_LEFT"): 'left',
+        ("menu_box", "MENU_BOX_RIGHT"): 'right',
+        ("menu", "MENU_DOWN"): 'down',
+        ("menu", "MENU_UP"): 'up',
+        ("menu_roller", "MENU_ROLLER_UP"): 'up',
+        ("menu_roller", "MENU_ROLLER_DOWN"): 'down',
+        ("menu_roller", "MENU_ROLLER_RIGHT"): 'right',
+        ("columns_roller", "COLUMNS_ROLLER_LEFT"): 'left',
+        ("columns_roller", "COLUMNS_ROLLER_RIGHT"): 'right',
+        ("focus", "FOCUS_SWITCH"): 'tab',
+       }
+
+action_key_map = ActionMap(keys)