@5929 Add drag-n-drop reordering for clothing layers (#5918)

- Drag-and-drop reordering for clothing layers with visual insertion indicator
- Includes new `keep_scroll_pos` param to preserve and restore scroll positions during layout and resize

8 files changed, 213 insertions, 50 deletions

diff --git a/indra/newview/llagentwearables.cpp b/indra/newview/llagentwearables.cpp
index a075b6f004..edd08c19e5 100644
--- a/indra/newview/llagentwearables.cpp
+++ b/indra/newview/llagentwearables.cpp
@@ -547,14 +547,23 @@ const S32 LLAgentWearables::getWearableIdxFromItem(const LLViewerInventoryItem*
     U32 wearable_count = getWearableCount(type);
     if (0 == wearable_count) return -1;
 
-    const LLUUID& asset_id = item->getAssetUUID();
+    // Match by linked inventory item id so the correct copy is found when several
+    // worn wearables of this type share the same asset.
+    const LLUUID item_id = gInventory.getLinkedItemID(item->getUUID());
+    for (U32 i = 0; i < wearable_count; ++i)
+    {
+        const LLViewerWearable* wearable = getViewerWearable(type, i);
+        if (!wearable) continue;
+        if (wearable->getItemID() == item_id) return i;
+    }
 
+    // Fall back to asset id for items whose inventory id can't be resolved.
+    const LLUUID& asset_id = item->getAssetUUID();
     for (U32 i = 0; i < wearable_count; ++i)
     {
         const LLViewerWearable* wearable = getViewerWearable(type, i);
         if (!wearable) continue;
-        if (wearable->getAssetID() != asset_id) continue;
-        return i;
+        if (wearable->getAssetID() == asset_id) return i;
     }
 
     return -1;
@@ -1529,6 +1538,37 @@ bool LLAgentWearables::moveWearable(const LLViewerInventoryItem* item, bool clos
     return false;
 }
 
+bool LLAgentWearables::moveWearableToIndex(const LLViewerInventoryItem* item, U32 new_index)
+{
+    if (!item) return false;
+    if (!item->isWearableType()) return false;
+
+    LLWearableType::EType type = item->getWearableType();
+    U32 wearable_count = getWearableCount(type);
+    if (wearable_count < 2) return false;
+
+    if (new_index >= wearable_count) new_index = wearable_count - 1;
+
+    S32 cur = getWearableIdxFromItem(item);
+    if (cur < 0) return false;
+    if ((U32)cur == new_index) return true; // already in place
+
+    // step the wearable to its new slot one swap at a time
+    U32 pos = (U32)cur;
+    while (pos < new_index)
+    {
+        if (!swapWearables(type, pos, pos + 1)) return false;
+        ++pos;
+    }
+    while (pos > new_index)
+    {
+        if (!swapWearables(type, pos, pos - 1)) return false;
+        --pos;
+    }
+
+    return true;
+}
+
 // static
 void LLAgentWearables::createWearable(LLWearableType::EType type, bool wear, const LLUUID& parent_id, std::function<void(const LLUUID&)> created_cb)
 {
diff --git a/indra/newview/llagentwearables.h b/indra/newview/llagentwearables.h
index 70da86805c..3c9ffa7443 100644
--- a/indra/newview/llagentwearables.h
+++ b/indra/newview/llagentwearables.h
@@ -129,6 +129,7 @@ public:
     static void     createWearable(LLWearableType::EType type, bool wear = false, const LLUUID& parent_id = LLUUID::null, std::function<void(const LLUUID&)> created_cb = nullptr);
     static void     editWearable(const LLUUID& item_id);
     bool            moveWearable(const LLViewerInventoryItem* item, bool closer_to_body);
+    bool            moveWearableToIndex(const LLViewerInventoryItem* item, U32 new_index);
 
     void            requestEditingWearable(const LLUUID& item_id);
     void            editWearableIfRequested(const LLUUID& item_id);
diff --git a/indra/newview/llappearancemgr.cpp b/indra/newview/llappearancemgr.cpp
index 4f549314af..80a3344979 100644
--- a/indra/newview/llappearancemgr.cpp
+++ b/indra/newview/llappearancemgr.cpp
@@ -4269,77 +4269,110 @@ bool LLAppearanceMgr::moveWearable(LLViewerInventoryItem* item, bool closer_to_b
 {
     if (!item || !item->isWearableType()) return false;
     if (item->getType() != LLAssetType::AT_CLOTHING) return false;
-    if (!gInventory.isObjectDescendentOf(item->getUUID(), getCOF())) return false;
 
     S32 pos = gAgentWearables.getWearableIdxFromItem(item);
     if (pos < 0) return false; // Not found
+    if (closer_to_body && pos == 0) return false; // already closest to the body
+
+    return reorderWearable(item, closer_to_body ? (U32)(pos - 1) : (U32)(pos + 1));
+}
+
+bool LLAppearanceMgr::reorderWearable(LLViewerInventoryItem* item, U32 new_index)
+{
+    if (!item || !item->isWearableType()) return false;
+    if (item->getType() != LLAssetType::AT_CLOTHING) return false;
+    if (!gInventory.isObjectDescendentOf(item->getUUID(), getCOF())) return false;
+
+    LLWearableType::EType type = item->getWearableType();
+    U32 count = gAgentWearables.getWearableCount(type);
+    if (count < 2) return false; // nothing to reorder against
+
+    if (new_index >= count) new_index = count - 1;
 
-    U32 count = gAgentWearables.getWearableCount(item->getWearableType());
-    if (count < 2) return false; // Nothing to swap with
-    if (closer_to_body)
+    S32 cur = gAgentWearables.getWearableIdxFromItem(item);
+    if (cur < 0) return false;
+    if ((U32)cur == new_index) return false; // already in place
+
+    // Update the live layer order first; bail before touching inventory if it fails.
+    if (!gAgentWearables.moveWearableToIndex(item, new_index)) return false;
+
+    persistWearableOrder(type);
+    return true;
+}
+
+bool LLAppearanceMgr::reorderWearableGroup(LLWearableType::EType type, const uuid_vec_t& ordered_link_ids)
+{
+    U32 count = gAgentWearables.getWearableCount(type);
+    if (count < 2) return false;
+    if (ordered_link_ids.size() != count) return false; // order must cover the whole group
+
+    // Validate everything before mutating, so a bad link can't leave it half-reordered.
+    for (const LLUUID& link_id : ordered_link_ids)
     {
-        if (pos == 0) return false; // already first
+        LLViewerInventoryItem* link = gInventory.getItem(link_id);
+        if (!link || link->getWearableType() != type) return false;
     }
-    else
+
+    // ordered_link_ids runs furthest-to-closest; body index 0 is closest to the body.
+    // Place each target at its body index, leaving already-placed lower indices untouched.
+    for (U32 body_index = 0; body_index < count; ++body_index)
     {
-        if (pos == count - 1)  return false; // already last
+        const LLUUID& link_id = ordered_link_ids[count - 1 - body_index];
+        LLViewerInventoryItem* link = gInventory.getItem(link_id);
+        if (!link || link->getWearableType() != type) return false;
+        if (!gAgentWearables.moveWearableToIndex(link, body_index)) return false;
     }
 
-    U32 old_pos = (U32)pos;
-    U32 swap_with = closer_to_body ? old_pos - 1 : old_pos + 1;
-    LLUUID swap_item_id = gAgentWearables.getWearableItemID(item->getWearableType(), swap_with);
+    persistWearableOrder(type);
+    return true;
+}
+
+void LLAppearanceMgr::persistWearableOrder(LLWearableType::EType type)
+{
+    U32 count = gAgentWearables.getWearableCount(type);
 
-    // Find link item from item id.
+    // Rewrite the sort-index descriptions for the whole type group in one pass so
+    // the order survives relog, trusting gAgentWearables over existing descriptions.
     LLInventoryModel::cat_array_t cats;
     LLInventoryModel::item_array_t items;
-    LLFindWearablesOfType filter_wearables_of_type(item->getWearableType());
+    LLFindWearablesOfType filter_wearables_of_type(type);
     gInventory.collectDescendentsIf(getCOF(), cats, items, true, filter_wearables_of_type);
-    if (items.empty()) return false;
 
-    LLViewerInventoryItem* swap_item = nullptr;
-    for (auto iter : items)
+    for (U32 i = 0; i < count; ++i)
     {
-        if (iter->getLinkedUUID() == swap_item_id)
+        LLUUID linked_id = gAgentWearables.getWearableItemID(type, i);
+        if (linked_id.isNull()) continue;
+
+        LLViewerInventoryItem* link = nullptr;
+        for (auto iter : items)
         {
-            swap_item = iter.get();
-            break;
+            if (iter->getLinkedUUID() == linked_id)
+            {
+                link = iter.get();
+                break;
+            }
         }
-    }
-    if (!swap_item)
-    {
-        return false;
-    }
+        if (!link) continue;
 
-    // Description is supposed to hold sort index, but user could have changed
-    // order rapidly and there might be a state mismatch between description
-    // and gAgentWearables, trust gAgentWearables over description.
-    // Generate new description.
-    std::string new_desc = build_order_string(item->getWearableType(), old_pos);
-    swap_item->setDescription(new_desc);
-    new_desc = build_order_string(item->getWearableType(), swap_with);
-    item->setDescription(new_desc);
+        std::string new_desc = build_order_string(type, i);
+        if (new_desc == link->getActualDescription()) continue;
 
-    item->setComplete(true);
-    item->updateServer(false);
-    gInventory.updateItem(item);
-
-    swap_item->setComplete(true);
-    swap_item->updateServer(false);
-    gInventory.updateItem(swap_item);
+        // Keep the local cache consistent immediately (so the COF list does not
+        // flicker back on a refresh), and persist durably via AISv3, matching
+        // updateClothingOrderingInfo() rather than the legacy UDP updateServer().
+        link->setDescription(new_desc);
+        LLSD updates;
+        updates["desc"] = new_desc;
+        update_inventory_item(link->getUUID(), updates, NULL);
+    }
 
-    //to cause appearance of the agent to be updated
-    bool result = false;
-    if ((result = gAgentWearables.moveWearable(item, closer_to_body)))
+    if (isAgentAvatarValid())
     {
-        gAgentAvatarp->wearableUpdated(item->getWearableType());
+        gAgentAvatarp->wearableUpdated(type);
     }
 
     setOutfitDirty(true);
-
-    //*TODO do we need to notify observers here in such a way?
     gInventory.notifyObservers();
-
-    return result;
 }
 
 //static
diff --git a/indra/newview/llappearancemgr.h b/indra/newview/llappearancemgr.h
index 9d90be0004..77146ba0be 100644
--- a/indra/newview/llappearancemgr.h
+++ b/indra/newview/llappearancemgr.h
@@ -210,6 +210,15 @@ public:
 
     bool moveWearable(LLViewerInventoryItem* item, bool closer_to_body);
 
+    // Move a clothing item to an absolute layer index within its wearable type
+    // (0 == closest to the body). Persists the new order to the COF link descriptions.
+    bool reorderWearable(LLViewerInventoryItem* item, U32 new_index);
+
+    // Apply a complete layer order for one wearable type, persisting it to the
+    // COF link descriptions. ordered_link_ids lists the type's COF link items
+    // furthest-to-closest.
+    bool reorderWearableGroup(LLWearableType::EType type, const uuid_vec_t& ordered_link_ids);
+
     static void sortItemsByActualDescription(LLInventoryModel::item_array_t& items);
 
     //Divvy items into arrays by wearable type
@@ -250,6 +259,10 @@ private:
 
 private:
 
+    // Rewrite COF sort-index descriptions for one wearable type to match the
+    // current in-memory layer order, then trigger a single appearance update.
+    void persistWearableOrder(LLWearableType::EType type);
+
     void filterWearableItems(LLInventoryModel::item_array_t& items, S32 max_per_type, S32 max_total, bool skip_bodyparts = false);
 
     void getDescendentsOfAssetType(const LLUUID& category,
diff --git a/indra/newview/llcofwearables.cpp b/indra/newview/llcofwearables.cpp
index 6bd15d4b61..f5d144dcc6 100644
--- a/indra/newview/llcofwearables.cpp
+++ b/indra/newview/llcofwearables.cpp
@@ -292,7 +292,8 @@ LLCOFWearables::LLCOFWearables() : LLPanel(),
     mBodyPartsTab(NULL),
     mLastSelectedTab(NULL),
     mAccordionCtrl(NULL),
-    mCOFVersion(-1)
+    mCOFVersion(-1),
+    mRefreshPending(false)
 {
     mClothingMenu = new CofClothingContextMenu(this);
     mAttachmentMenu = new CofAttachmentContextMenu(this);
@@ -326,6 +327,10 @@ bool LLCOFWearables::postBuild()
     mClothing->setCommitOnSelectionChange(true);
     mBodyParts->setCommitOnSelectionChange(true);
 
+    mClothing->setReorderValidateCallback(boost::bind(&LLCOFWearables::canReorderClothing, this, _1, _2));
+    mClothing->setReorderCallback(boost::bind(&LLCOFWearables::onClothingReordered, this, _1, _2));
+    mClothing->setReorderEndedCallback(boost::bind(&LLCOFWearables::onReorderEnded, this));
+
     //clothing is sorted according to its position relatively to the body
     mAttachments->setComparator(&WEARABLE_NAME_COMPARATOR);
     mBodyParts->setComparator(&WEARABLE_NAME_COMPARATOR);
@@ -377,6 +382,50 @@ void LLCOFWearables::onSelectionChange(LLFlatListView* selected_list)
     onCommit();
 }
 
+bool LLCOFWearables::canReorderClothing(const LLSD& dragged_value, const LLSD& neighbour_value)
+{
+    LLViewerInventoryItem* dragged = gInventory.getItem(dragged_value.asUUID());
+    LLViewerInventoryItem* neighbour = gInventory.getItem(neighbour_value.asUUID());
+    if (!dragged || !neighbour) return false; // reject placeholder/dummy rows
+    if (!dragged->isWearableType() || !neighbour->isWearableType()) return false;
+
+    return dragged->getWearableType() == neighbour->getWearableType();
+}
+
+void LLCOFWearables::onClothingReordered(const LLSD& dragged_value, S32 /*new_index*/)
+{
+    LLViewerInventoryItem* item = gInventory.getItem(dragged_value.asUUID());
+    if (!item || !item->isWearableType()) return;
+
+    LLWearableType::EType type = item->getWearableType();
+
+    // Persist the affected type group's full order from the list's current order
+    // (furthest-to-closest), which covers both single- and multi-row drags.
+    uuid_vec_t ordered_link_ids;
+    std::vector<LLSD> values;
+    mClothing->getValues(values);
+    for (const LLSD& value : values)
+    {
+        LLViewerInventoryItem* other = gInventory.getItem(value.asUUID());
+        if (!other || !other->isWearableType() || other->getWearableType() != type) continue;
+
+        ordered_link_ids.push_back(value.asUUID());
+    }
+
+    if (ordered_link_ids.size() < 2) return;
+
+    LLAppearanceMgr::getInstance()->reorderWearableGroup(type, ordered_link_ids);
+}
+
+void LLCOFWearables::onReorderEnded()
+{
+    // Run a refresh that arrived (and was skipped) while the drag was active.
+    if (mRefreshPending)
+    {
+        refresh();
+    }
+}
+
 void LLCOFWearables::onAccordionTabStateChanged(LLUICtrl* ctrl, const LLSD& expanded)
 {
     bool had_selected_items = mClothing->numSelected() || mAttachments->numSelected() || mBodyParts->numSelected();
@@ -401,6 +450,15 @@ void LLCOFWearables::onAccordionTabStateChanged(LLUICtrl* ctrl, const LLSD& expa
 
 void LLCOFWearables::refresh()
 {
+    // Don't rebuild mid-drag, clearing the list would cancel the active reorder.
+    // Remember it so onReorderEnded() can re-run the skipped refresh on release.
+    if (mClothing && mClothing->isReorderActive())
+    {
+        mRefreshPending = true;
+        return;
+    }
+    mRefreshPending = false;
+
     const LLUUID cof_id = LLAppearanceMgr::instance().getCOF();
     if (cof_id.isNull())
     {
@@ -560,6 +618,12 @@ LLPanelClothingListItem* LLCOFWearables::buildClothingListItem(LLViewerInventory
     item_panel->setShowMoveUpButton(!first);
     item_panel->setShowMoveDownButton(!last);
 
+    // hint that rows in a multi-layer group can be dragged to reorder
+    if (!(first && last))
+    {
+        item_panel->setToolTip(LLTrans::getString("ReorderClothingTooltip"));
+    }
+
     //setting callbacks
     //*TODO move that item panel's inner structure disclosing stuff into the panels
     item_panel->childSetAction("btn_delete", boost::bind(mCOFCallbacks.mDeleteWearable));
diff --git a/indra/newview/llcofwearables.h b/indra/newview/llcofwearables.h
index b349f35921..7d4d8917b4 100644
--- a/indra/newview/llcofwearables.h
+++ b/indra/newview/llcofwearables.h
@@ -102,6 +102,12 @@ protected:
     void onSelectionChange(LLFlatListView* selected_list);
     void onAccordionTabStateChanged(LLUICtrl* ctrl, const LLSD& expanded);
 
+    // Clothing drag-to-reorder: only allow moves within the same wearable type,
+    // and translate a drop into a layer-order change.
+    bool canReorderClothing(const LLSD& dragged_value, const LLSD& neighbour_value);
+    void onClothingReordered(const LLSD& dragged_value, S32 new_index);
+    void onReorderEnded();
+
     LLPanelClothingListItem* buildClothingListItem(LLViewerInventoryItem* item, bool first, bool last);
     LLPanelBodyPartsListItem* buildBodypartListItem(LLViewerInventoryItem* item);
     LLPanelDeletableWearableListItem* buildAttachemntListItem(LLViewerInventoryItem* item);
@@ -132,6 +138,9 @@ protected:
 
     /* COF category version since last refresh */
     S32 mCOFVersion;
+
+    /* a refresh arrived mid-drag and was skipped; re-run it when the drag ends */
+    bool mRefreshPending;
 };
 
 
diff --git a/indra/newview/skins/default/xui/en/panel_cof_wearables.xml b/indra/newview/skins/default/xui/en/panel_cof_wearables.xml
index 9544042e94..37867b4a0e 100644
--- a/indra/newview/skins/default/xui/en/panel_cof_wearables.xml
+++ b/indra/newview/skins/default/xui/en/panel_cof_wearables.xml
@@ -26,10 +26,12 @@
          title="Clothing">
             <flat_list_view
              allow_select="true"
+             allow_reorder="true"
              follows="all"
              height="10"
              item_pad="3"
              keep_selection_visible_on_reshape="true"
+             keep_scroll_pos="true"
              layout="topleft"
              left="0"
              multi_select="true"
diff --git a/indra/newview/skins/default/xui/en/strings.xml b/indra/newview/skins/default/xui/en/strings.xml
index a8fa4b735a..e44a18ae79 100644
--- a/indra/newview/skins/default/xui/en/strings.xml
+++ b/indra/newview/skins/default/xui/en/strings.xml
@@ -225,6 +225,7 @@ If you feel this is an error, please contact support@secondlife.com</string>
     <string name="Toycamera">Toy Camera</string>
 	
     <!-- Tooltip -->
+	<string name="ReorderClothingTooltip">Drag to reorder layers, or use the arrows</string> <!-- Hint shown on clothing rows that can be dragged to reorder -->
 	<string name="TooltipPerson">Person</string><!-- Object under mouse pointer is an avatar -->
 	<string name="TooltipNoName">(no name)</string> <!-- No name on an object -->
 	<string name="TooltipOwner">Owner:</string> <!-- Owner name follows -->