(Init): Added shit

nirimod/undo.py

@@ -0,0 +1,61 @@
+
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+
+
+@dataclass
+class UndoEntry:
+    description: str
+    snapshot_before: str
+    snapshot_after: str
+
+
+class UndoManager:
+    def __init__(self, max_depth: int = 100):
+        self._stack: list[UndoEntry] = []
+        self._redo_stack: list[UndoEntry] = []
+        self._max = max_depth
+
+    def push(self, entry: UndoEntry) -> None:
+        self._stack.append(entry)
+        if len(self._stack) > self._max:
+            self._stack.pop(0)
+        self._redo_stack.clear()
+
+    @property
+    def last_snapshot(self) -> str | None:
+        if self._stack:
+            return self._stack[-1].snapshot_after
+        return None
+
+    @property
+    def last_description(self) -> str | None:
+        if self._stack:
+            return self._stack[-1].description
+        return None
+
+    def pop_undo(self) -> UndoEntry | None:
+        if not self._stack:
+            return None
+        entry = self._stack.pop()
+        self._redo_stack.append(entry)
+        return entry
+
+    def pop_redo(self) -> UndoEntry | None:
+        if not self._redo_stack:
+            return None
+        entry = self._redo_stack.pop()
+        self._stack.append(entry)
+        return entry
+
+    def can_undo(self) -> bool:
+        return bool(self._stack)
+
+    def can_redo(self) -> bool:
+        return bool(self._redo_stack)
+
+    def clear(self) -> None:
+        self._stack.clear()
+        self._redo_stack.clear()