2025-07-01

2026-03-17 14:30:01 -06:00
parent f9a22056dd
commit 62b5978595
4579 changed files with 1257472 additions and 0 deletions
@@ -0,0 +1,108 @@
+'''
+Copyright (C) 2023 CG Cookie
+http://cgcookie.com
+hello@cgcookie.com
+
+Created by Jonathan Denning, Jonathan Williamson, and Patrick Moore
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU 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 General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+'''
+
+from collections import namedtuple
+
+
+class UndoStack:
+    def __init__(self, fn_create_state, fn_restore_state, *, max_size=100):
+        self._fn_step = namedtuple('UndoStep', 'key repeatable state')
+        self._fn_create = fn_create_state
+        self._fn_restore = fn_restore_state
+        self._max_size = max_size
+        self.clear()
+
+    def _pop(self, *, undo=True):
+        stack = (self._undo if undo else self._redo)
+        return stack.pop()
+
+    def _restore(self, step, *args, **kwargs):
+        self._fn_restore(step.state, *args, **kwargs)
+
+    def _push_step(self, key, *, repeatable=False, undo=True, clear=True):
+        step = self._fn_step(key, repeatable, self._fn_create(key))
+        if undo:
+            self._undo.append(step)
+            if clear:
+                self._redo.clear()
+            # limit stack size
+            while len(self._undo) > self._max_size:
+                self._undo.pop(0)
+        else:
+            self._redo.append(step)
+
+    def _is_empty(self, *, undo=True):
+        return not bool(self._undo if undo else self._redo)
+
+    def keys(self, *, undo=True):
+        stack = reversed(self._undo if undo else self._redo)
+        return [step.key for step in stack]
+
+    def _top(self, *, undo=True):
+        stack = (self._undo if undo else self._redo)
+        return stack[-1] if stack else None
+
+    def top_key(self, *, undo=True):
+        top = self._top(undo=undo)
+        return top.key if top else None
+
+    def clear(self):
+        self._undo = []
+        self._redo = []
+        self._changes = 0
+
+    @property
+    def changes(self):
+        return self._changes
+
+    def push(self, key, *, repeatable=False):
+        # skip pushing to undo if action is repeatable and we are repeating actions
+        top = self._top()
+        if repeatable and top and top.repeatable and top.key == key: return
+        self._push_step(key, repeatable=repeatable)
+        self._changes += 1
+
+    def pop(self, *args, undo=True, **kwargs):
+        if self._is_empty(undo=undo): return
+        key = 'undo' if undo else 'redo'
+        self._push_step(key, undo=not undo, clear=undo)
+        step = self._pop(undo=undo)
+        self._restore(step, *args, **kwargs)
+        self._changes += 1
+
+    #### the following code is not working??
+    # def restore(self, *args, **kwargs):
+    #     if self._is_empty(): return
+    #     step = self._top()
+    #     self._restore(step, *args, **kwargs)
+    #     self._redo.clear()
+    #     self._changes += 1
+
+    def cancel(self, *args, **kwargs):
+        if self._is_empty(): return
+        step = self._pop()
+        self._restore(step, *args, **kwargs)
+        self._changes += 1
+
+    def break_repeatable(self):
+        if self._is_empty(): return
+        self._top().repeatable = False
+