Drag-n-drop for tattoo layers

- Drag-and-drop reordering for clothing layers with visual insertion indicator
- Scroll containers should also better preserve and restore scroll positions during layout and resize

Author: gwigz

indra/llui/llflatlistview.cpp

@@ -30,6 +30,7 @@
 #include "llpanel.h"
 #include "llscrollcontainer.h"
 #include "lltextbox.h"
+#include "lluicolor.h"
 
 
 /**
@@ -106,12 +107,28 @@ class LLFlatListView : public LLScrollContainer, public LLEditMenuHandler
         /** padding between items */
         Optional<U32> item_pad;
 
+        /** allow items to be reordered by dragging them with the mouse */
+        Optional<bool> allow_reorder;
+
+        /** colour of the insertion indicator drawn while reordering */
+        Optional<LLUIColor> drag_indicator_color;
+
         /** textbox with info message when list is empty*/
         Optional<LLTextBox::Params> no_items_text;
 
         Params();
     };
 
+    /** Fired after the user drags an item to a new position: (moved value, new visible index). */
+    typedef boost::function<void(const LLSD& value, S32 new_index)> reorder_signal_t;
+
+    /**
+     * Returns true if the dragged item is allowed to move past the given neighbour.
+     * Lets owners constrain reordering (e.g. keep items within a group). Optional;
+     * when unset any reorder is permitted.
+     */
+    typedef boost::function<bool(const LLSD& dragged, const LLSD& neighbour)> reorder_validate_signal_t;
+
     // disable traversal when finding widget to hand focus off to
     /*virtual*/ bool canFocusChildren() const override { return false; }
 
@@ -265,6 +282,12 @@ class LLFlatListView : public LLScrollContainer, public LLEditMenuHandler
     /** Turn on/off selection support */
     void setAllowSelection(bool can_select) { mAllowSelection = can_select; }
 
+    /** Turn on/off drag-to-reorder support */
+    void setAllowReorder(bool allow) { mAllowReorder = allow; }
+
+    void setReorderCallback(reorder_signal_t cb) { mReorderCallback = cb; }
+    void setReorderValidateCallback(reorder_validate_signal_t cb) { mReorderValidateCallback = cb; }
+
     /** Sets flag whether onCommit should be fired if selection was changed */
     // FIXME: this should really be a separate signal, since "Commit" implies explicit user action, and selection changes can happen more indirectly.
     void setCommitOnSelectionChange(bool b)     { mCommitOnSelectionChange = b; }
@@ -374,6 +397,12 @@ class LLFlatListView : public LLScrollContainer, public LLEditMenuHandler
 
     virtual bool handleKeyHere(KEY key, MASK mask) override;
 
+    virtual bool handleHover(S32 x, S32 y, MASK mask) override;
+
+    virtual bool handleMouseUp(S32 x, S32 y, MASK mask) override;
+
+    virtual void onMouseCaptureLost() override;
+
     virtual bool postBuild() override;
 
     virtual void onFocusReceived() override;
@@ -390,6 +419,26 @@ class LLFlatListView : public LLScrollContainer, public LLEditMenuHandler
 
 private:
 
+    // Drag-to-reorder helpers.
+    void armReorderDrag(item_pair_t* item_pair);
+    void updateReorderDrag(S32 x, S32 y);
+    void finishReorderDrag();
+    void cancelReorderDrag();
+    void clearReorderDragState();
+
+    // Builds the set of pairs being dragged (the whole selection when the grabbed
+    // row is part of a multi-selection, constrained to the validator's group).
+    void buildReorderGroup();
+    bool isInReorderGroup(item_pair_t* item_pair) const;
+
+    // The remaining visible pairs (those not being dragged), in visual order.
+    void getReorderRemaining(pairs_list_t& remaining) const;
+    // Number of leading non-dragged items whose centre sits above (x, y).
+    S32 getInsertIndexAt(S32 x, S32 y) const;
+    // Clamps an insertion boundary to the validator's contiguous group.
+    S32 constrainInsertIndex(S32 dest_index) const;
+    void drawReorderIndicator();
+
     void setItemsNoScrollWidth(S32 new_width) {mItemsNoScrollWidth = new_width - 2 * mBorderThickness;}
 
     void setNoItemsCommentVisible(bool visible) const;
@@ -433,6 +482,20 @@ class LLFlatListView : public LLScrollContainer, public LLEditMenuHandler
 
     bool mFocusOnItemClicked;
 
+    /** Drag-to-reorder state */
+    bool mAllowReorder;
+    bool mIsReordering;             // a drag is currently in progress
+    bool mProcessingRightClick;     // suppress drag arming during right-click handling
+    item_pair_t* mReorderDragPair;  // the grabbed pair (drag anchor)
+    pairs_list_t mReorderDragGroup; // all pairs being dragged, in visual order
+    item_pair_t* mDeferredSelectPair; // collapse selection to this on mouse-up if no drag
+    S32 mReorderMouseDownX;
+    S32 mReorderMouseDownY;
+    S32 mReorderInsertIndex;        // current drop boundary among the remaining (non-dragged) items
+    LLUIColor mDragIndicatorColor;
+    reorder_signal_t mReorderCallback;
+    reorder_validate_signal_t mReorderValidateCallback;
+
     /** All pairs of the list */
     pairs_list_t mItemPairs;
 

indra/llui/llflatlistview.h

@@ -95,6 +95,9 @@ LLScrollContainer::LLScrollContainer(const LLScrollContainer::Params& p)
     mScrolledView(NULL),
     mSize(p.size)
 {
+    mStoredDocPos[VERTICAL] = 0;
+    mStoredDocPos[HORIZONTAL] = 0;
+
     static LLUICachedControl<S32> scrollbar_size_control ("UIScrollbarSize", 0);
     S32 scrollbar_size = (mSize == -1 ? scrollbar_size_control : mSize);
 
@@ -197,11 +200,8 @@ void LLScrollContainer::reshape(S32 width, S32 height,
         bool show_h_scrollbar = false;
         calcVisibleSize( &visible_width, &visible_height, &show_h_scrollbar, &show_v_scrollbar );
 
-        mScrollbar[VERTICAL]->setDocSize( scrolled_rect.getHeight() );
-        mScrollbar[VERTICAL]->setPageSize( visible_height );
-
-        mScrollbar[HORIZONTAL]->setDocSize( scrolled_rect.getWidth() );
-        mScrollbar[HORIZONTAL]->setPageSize( visible_width );
+        preserveScrollbarMetrics(VERTICAL, show_v_scrollbar, scrolled_rect.getHeight(), visible_height);
+        preserveScrollbarMetrics(HORIZONTAL, show_h_scrollbar, scrolled_rect.getWidth(), visible_width);
         updateScroll();
     }
 }
@@ -586,6 +586,24 @@ bool LLScrollContainer::addChild(LLView* view, S32 tab_group)
     return ret_val;
 }
 
+void LLScrollContainer::preserveScrollbarMetrics(EOrientation axis, bool show, S32 doc_size, S32 page_size)
+{
+    // Snapshot the position before the resize, but only while the scrollbar is
+    // visible: during a transient full-content pass it hides and its position is
+    // forced to 0, which would otherwise clobber the remembered position.
+    if (show && mScrollbar[axis]->getVisible())
+    {
+        mStoredDocPos[axis] = mScrollbar[axis]->getDocPos();
+    }
+    mScrollbar[axis]->setDocSize(doc_size);
+    mScrollbar[axis]->setPageSize(page_size);
+    if (show)
+    {
+        mScrollbar[axis]->setDocPos(mStoredDocPos[axis]);
+        mStoredDocPos[axis] = mScrollbar[axis]->getDocPos();
+    }
+}
+
 void LLScrollContainer::updateScroll()
 {
     if (!getVisible() || !mScrolledView)
@@ -605,6 +623,9 @@ void LLScrollContainer::updateScroll()
     calcVisibleSize( &visible_width, &visible_height, &show_h_scrollbar, &show_v_scrollbar );
 
     S32 border_width = getBorderWidth();
+    preserveScrollbarMetrics(VERTICAL, show_v_scrollbar, doc_height, visible_height);
+    preserveScrollbarMetrics(HORIZONTAL, show_h_scrollbar, doc_width, visible_width);
+
     if( show_v_scrollbar )
     {
         if( doc_rect.mTop < getRect().getHeight() - border_width )
@@ -667,12 +688,6 @@ void LLScrollContainer::updateScroll()
         mScrollbar[HORIZONTAL]->setVisible( false );
         mScrollbar[HORIZONTAL]->setDocPos( 0 );
     }
-
-    mScrollbar[HORIZONTAL]->setDocSize( doc_width );
-    mScrollbar[HORIZONTAL]->setPageSize( visible_width );
-
-    mScrollbar[VERTICAL]->setDocSize( doc_height );
-    mScrollbar[VERTICAL]->setPageSize( visible_height );
 } // end updateScroll
 
 void LLScrollContainer::setBorderVisible(bool b)

indra/llui/llscrollcontainer.cpp

@@ -136,8 +136,10 @@ class LLScrollContainer : public LLUICtrl
     void updateScroll();
     bool autoScroll(S32 x, S32 y, bool do_scroll);
     void calcVisibleSize( S32 *visible_width, S32 *visible_height, bool* show_h_scrollbar, bool* show_v_scrollbar ) const;
+    void preserveScrollbarMetrics(EOrientation axis, bool show, S32 doc_size, S32 page_size);
 
     LLScrollbar* mScrollbar[ORIENTATION_COUNT];
+    S32         mStoredDocPos[ORIENTATION_COUNT];
     S32         mSize;
     bool        mIsOpaque;
     LLUIColor   mBackgroundColor;

indra/llui/llscrollcontainer.h

@@ -557,14 +557,23 @@ 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;
@@ -1604,6 +1613,37 @@ 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)
 {

indra/newview/llagentwearables.cpp

@@ -139,6 +139,7 @@ class LLAgentWearables : public LLInitClass<LLAgentWearables>, public LLWearable
     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);