1 files changed, 104 insertions, 0 deletions
diff --git a/src/avp/libcomponent/actions.py b/src/avp/libcomponent/actions.py
new file mode 100644
index 0000000..f534685
--- /dev/null
+++ b/src/avp/libcomponent/actions.py
@@ -0,0 +1,104 @@
+"""
+QUndoCommand class for generic undoable user actions performed to a BaseComponent
+
+See `../life.py` for an example of a component that uses a custom QUndoCommand
+"""
+
+from PyQt6.QtGui import QUndoCommand
+from copy import copy
+import logging
+
+log = logging.getLogger("AVP.ComponentHandler")
+
+
+class ComponentUpdate(QUndoCommand):
+    """Command object for making a component action undoable"""
+
+    def __init__(self, parent, oldWidgetVals, modifiedVals):
+        super().__init__("change %s component #%s" % (parent.name, parent.compPos))
+        self.undone = False
+        self.res = (int(parent.width), int(parent.height))
+        self.parent = parent
+        self.oldWidgetVals = {
+            attr: (
+                copy(val)
+                if attr not in self.parent._relativeWidgets
+                else self.parent.floatValForAttr(attr, val, axis=self.res)
+            )
+            for attr, val in oldWidgetVals.items()
+            if attr in modifiedVals
+        }
+        self.modifiedVals = {
+            attr: (
+                val
+                if attr not in self.parent._relativeWidgets
+                else self.parent.floatValForAttr(attr, val, axis=self.res)
+            )
+            for attr, val in modifiedVals.items()
+        }
+
+        # Because relative widgets change themselves every update based on
+        # their previous value, we must store ALL their values in case of undo
+        self.relativeWidgetValsAfterUndo = {
+            attr: copy(getattr(self.parent, attr))
+            for attr in self.parent._relativeWidgets
+        }
+
+        # Determine if this update is mergeable
+        self.id_ = -1
+        if self.parent.mergeUndo:
+            if len(self.modifiedVals) == 1:
+                attr, val = self.modifiedVals.popitem()
+                self.id_ = sum([ord(letter) for letter in attr[-14:]])
+                self.modifiedVals[attr] = val
+                return
+            log.warning(
+                "%s component settings changed at once. (%s)",
+                len(self.modifiedVals),
+                repr(self.modifiedVals),
+            )
+
+    def id(self):
+        """If 2 consecutive updates have same id, Qt will call mergeWith()"""
+        return self.id_
+
+    def mergeWith(self, other):
+        self.modifiedVals.update(other.modifiedVals)
+        return True
+
+    def setWidgetValues(self, attrDict):
+        """
+        Mask the component's usual method to handle our
+        relative widgets in case the resolution has changed.
+        """
+        newAttrDict = {
+            attr: (
+                val
+                if attr not in self.parent._relativeWidgets
+                else self.parent.pixelValForAttr(attr, val)
+            )
+            for attr, val in attrDict.items()
+        }
+        self.parent.setWidgetValues(newAttrDict)
+
+    def redo(self):
+        if self.undone:
+            log.info("Redoing component update")
+        self.parent.oldAttrs = self.relativeWidgetValsAfterUndo
+        self.setWidgetValues(self.modifiedVals)
+        self.parent.update(auto=True)
+        self.parent.oldAttrs = None
+        if not self.undone:
+            self.relativeWidgetValsAfterRedo = {
+                attr: copy(getattr(self.parent, attr))
+                for attr in self.parent._relativeWidgets
+            }
+            self.parent._sendUpdateSignal()
+
+    def undo(self):
+        log.info("Undoing component update")
+        self.undone = True
+        self.parent.oldAttrs = self.relativeWidgetValsAfterRedo
+        self.setWidgetValues(self.oldWidgetVals)
+        self.parent.update(auto=True)
+        self.parent.oldAttrs = None