Method ClearUndoStack

src/board/UBBoardController.cpp:1835–1887

}

void UBBoardController::ClearUndoStack()
{
    QSet<QGraphicsItem*> uniqueItems;
    // go through all stack command
    for (int i = 0; i < UBApplication::undoStack->count(); i++) {
        findUniquesItems(UBApplication::undoStack->command(i), uniqueItems);
    }

    // Get items from clipboard in order not to delete an item that was cut
    // (using source URL of graphics items as a surrogate for equality testing)
    // This ensures that we can cut and paste a media item, widget, etc. from one page to the next.
    QClipboard *clipboard = QApplication::clipboard();
    const QMimeData* data = clipboard->mimeData();
    QList<QUrl> sourceURLs;

    if (data && data->hasFormat(UBApplication::mimeTypeUniboardPageItem)) {
        const UBMimeDataGraphicsItem* mimeDataGI = qobject_cast <const UBMimeDataGraphicsItem*>(data);

        if (mimeDataGI) {
            foreach (UBItem* sourceItem, mimeDataGI->items()) {
                sourceURLs << sourceItem->sourceUrl();
            }
        }
    }

    // go through all unique items, and check, if they are on scene, or not.
    // if not on scene, than item can be deleted
    QSetIterator<QGraphicsItem*> itUniq(uniqueItems);
    while (itUniq.hasNext())
    {
        QGraphicsItem* item = itUniq.next();
        UBGraphicsScene* scene = nullptr;
        if (item->scene()) {
            scene = dynamic_cast<UBGraphicsScene*>(item->scene());
        }

        bool inClipboard = false;
        UBItem* ubi = dynamic_cast<UBItem*>(item);
        if (ubi && sourceURLs.contains(ubi->sourceUrl()))
            inClipboard = true;

        if(!scene && !inClipboard)
        {
            if (!mActiveScene->deleteItem(item)){
                delete item;
                item = 0;
            }
        }
    }

    // clear stack, and command list
    UBApplication::undoStack->clear();
}

void UBBoardController::adjustDisplayViews()
{