Ctrl+V pasted in place, which put the copy exactly on top of the original.
Nothing appeared to happen: the only clue was a doubled outline, and the
copy had to be dragged off the original to be seen at all. The cursor was
ignored entirely.
Ctrl+V now starts a placement. The items appear under the cursor and follow
it until a left click or Return drops them; Escape or a right click takes
them away again. That is the same interaction as placing a new element, so
paste behaves like every other way of putting something on a folio, and the
copy lands where the user is looking.
Implemented as a DiagramEventInterface beside the existing add-element and
add-macro tools. The pasted items are the real ones from the start rather
than a preview: Diagram::fromXml creates them exactly as before, this class
moves them, and PasteDiagramCommand is pushed only once they are dropped.
PasteDiagramCommand's first redo() deliberately does not add items to the
scene -- it assumes fromXml already did -- so pushing it on commit adopts
them rather than duplicating them. One copy of the paste logic, and a
cancelled paste leaves nothing on the undo stack.
Conductors are not moved directly; they are drawn from their terminals and
follow the elements they attach to. On cancel they are removed before the
elements, so none is left in the scene holding a pointer to a freed
terminal.
Verified by counting elements in the saved file rather than by eye:
56 to start, 56 after paste-then-Escape, 57 after paste-then-drop, and 56
again after undo. Save determinism run against this build: pass, no
regressions against baseline. Tests 5/5 on Qt 6.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
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