--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libervia/frontends/tools/misc.py	Fri Jun 02 14:12:38 2023 +0200
@@ -0,0 +1,96 @@
+#!/usr/bin/env python3
+
+
+# SAT helpers methods for plugins
+# Copyright (C) 2013-2016 Adrien Cossa (souliane@mailoo.org)
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero 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 Affero General Public License for more details.
+
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+
+class InputHistory(object):
+    def _update_input_history(self, text=None, step=None, callback=None, mode=""):
+        """Update the lists of previously sent messages. Several lists can be
+        handled as they are stored in a dictionary, the argument "mode" being
+        used as the entry key. There's also a temporary list to allow you play
+        with previous entries before sending a new message. Parameters values
+        can be combined: text is None and step is None to initialize a main
+        list and the temporary one, step is None to update a list and
+        reinitialize the temporary one, step is not None to update
+        the temporary list between two messages.
+        @param text: text to be saved.
+        @param step: step to move the temporary index.
+        @param callback: method to display temporary entries.
+        @param mode: the dictionary key for main lists.
+        """
+        if not hasattr(self, "input_histories"):
+            self.input_histories = {}
+        history = self.input_histories.setdefault(mode, [])
+        if step is None and text is not None:
+            # update the main list
+            if text in history:
+                history.remove(text)
+            history.append(text)
+        length = len(history)
+        if step is None or length == 0:
+            # prepare the temporary list and index
+            self.input_history_tmp = history[:]
+            self.input_history_tmp.append("")
+            self.input_history_index = length
+        if step is None:
+            return
+        # update the temporary list
+        if text is not None:
+            # save the current entry
+            self.input_history_tmp[self.input_history_index] = text
+        # move to another entry if possible
+        index_tmp = self.input_history_index + step
+        if index_tmp >= 0 and index_tmp < len(self.input_history_tmp):
+            if callback is not None:
+                callback(self.input_history_tmp[index_tmp])
+            self.input_history_index = index_tmp
+
+
+class FlagsHandler(object):
+    """Small class to handle easily option flags
+
+    the instance is initialized with an iterable
+    then attribute return True if flag is set, False else.
+    """
+
+    def __init__(self, flags):
+        self.flags = set(flags or [])
+        self._used_flags = set()
+
+    def __getattr__(self, flag):
+        self._used_flags.add(flag)
+        return flag in self.flags
+
+    def __getitem__(self, flag):
+        return getattr(self, flag)
+
+    def __len__(self):
+        return len(self.flags)
+
+    def __iter__(self):
+        return self.flags.__iter__()
+
+    @property
+    def all_used(self):
+        """Return True if all flags have been used"""
+        return self._used_flags.issuperset(self.flags)
+
+    @property
+    def unused(self):
+        """Return flags which has not been used yet"""
+        return self.flags.difference(self._used_flags)