Adjust ContainerStore / InventoryStore to allow partial unequip of items.

apps/openmw/mwworld/containerstore.cpp

@@ -136,16 +136,18 @@ int MWWorld::ContainerStore::count(const std::string &id)
     return total;
 }
 
-void MWWorld::ContainerStore::unstack(const Ptr &ptr, const Ptr& container)
+MWWorld::ContainerStoreIterator MWWorld::ContainerStore::unstack(const Ptr &ptr, const Ptr& container, int count)
 {
-    if (ptr.getRefData().getCount() <= 1)
-        return;
-    MWWorld::ContainerStoreIterator it = addNewStack(ptr, ptr.getRefData().getCount()-1);
+    if (ptr.getRefData().getCount() <= count)
+        return end();
+    MWWorld::ContainerStoreIterator it = addNewStack(ptr, ptr.getRefData().getCount()-count);
     const std::string script = it->getClass().getScript(*it);
     if (!script.empty())
         MWBase::Environment::get().getWorld()->getLocalScripts().add(script, *it);
 
-    remove(ptr, ptr.getRefData().getCount()-1, container);
+    remove(ptr, ptr.getRefData().getCount()-count, container);
+
+    return it;
 }
 
 MWWorld::ContainerStoreIterator MWWorld::ContainerStore::restack(const MWWorld::Ptr& item)

apps/openmw/mwworld/containerstore.hpp

@@ -130,8 +130,10 @@ namespace MWWorld
             ///
             /// @return the number of items actually removed
 
-            void unstack (const Ptr& ptr, const Ptr& container);
-            ///< Unstack an item in this container. The item's count will be set to 1, then a new stack will be added with (origCount-1).
+            ContainerStoreIterator unstack (const Ptr& ptr, const Ptr& container, int count = 1);
+            ///< Unstack an item in this container. The item's count will be set to count, then a new stack will be added with (origCount-count).
+            ///
+            /// @return an iterator to the new stack, or end() if no new stack was created.
 
             MWWorld::ContainerStoreIterator restack (const MWWorld::Ptr& item);
             ///< Attempt to re-stack an item in this container.

apps/openmw/mwworld/inventorystore.cpp

@@ -574,6 +574,33 @@ MWWorld::ContainerStoreIterator MWWorld::InventoryStore::unequipItem(const MWWor
     throw std::runtime_error ("attempt to unequip an item that is not currently equipped");
 }
 
+MWWorld::ContainerStoreIterator MWWorld::InventoryStore::unequipItemQuantity(const Ptr& item, const Ptr& actor, int count)
+{
+    if (!isEquipped(item))
+        throw std::runtime_error ("attempt to unequip an item that is not currently equipped");
+    if (count <= 0)
+        throw std::runtime_error ("attempt to unequip nothing (count <= 0)");
+    if (count > item.getRefData().getCount())
+        throw std::runtime_error ("attempt to unequip more items than equipped");
+
+    if (count == item.getRefData().getCount())
+        return unequipItem(item, actor);
+
+    // Move items to an existing stack if possible, otherwise split count items out into a new stack.
+    // Moving counts manually here, since ContainerStore's restack can't target unequipped stacks.
+    for (MWWorld::ContainerStoreIterator iter (begin()); iter != end(); ++iter)
+    {
+        if (stacks(*iter, item) && !isEquipped(*iter))
+        {
+            iter->getRefData().setCount(iter->getRefData().getCount() + count);
+            item.getRefData().setCount(item.getRefData().getCount() - count);
+            return iter;
+        }
+    }
+
+    return unstack(item, actor, item.getRefData().getCount() - count);
+}
+
 MWWorld::InventoryStoreListener* MWWorld::InventoryStore::getListener()
 {
     return mListener;

apps/openmw/mwworld/inventorystore.hpp

@@ -188,6 +188,15 @@ namespace MWWorld
             /// (it can be re-stacked so its count may be different than when it
             /// was equipped).
 
+            ContainerStoreIterator unequipItemQuantity(const Ptr& item, const Ptr& actor, int count);
+            ///< Unequip a specific quantity of an item identified by its Ptr.
+            /// An exception is thrown if the item is not currently equipped,
+            /// if count <= 0, or if count > the item stack size.
+            ///
+            /// @return an iterator to the unequipped items that were previously
+            /// in the slot (they can be re-stacked so its count may be different
+            /// than the requested count).
+
             void setListener (InventoryStoreListener* listener, const Ptr& actor);
             ///< Set a listener for various events, see \a InventoryStoreListener